Smallanthus sonchifolius and Lepidium meyenii – Prospective Andean crops for the prevention of chronic diseases

Abstract

Smallanthus sonchifolius (yacon) and Lepidium meyenii (maca) were the traditional crops of the original population of Peru where they are also still used in folk medicine. These plants are little known in Europe and Northern America although at least yacon can be cultivated in the climatic conditions of these regions. This article deals with the botany and the composition, the structure of main constituents, biological activity of these plants and the cultivation of yacon in the Czech Republic. The potential of yacon tubers to treat hyperglycemia, kidney problems and for skin rejuvenation and the antihyperglycemic and cytoprotective activity of its leaves seems to be related mostly to its oligofructan and phenolic content, respectively. Maca alkaloids, steroids, glucosinolates, isothicyanates and macamides are probably responsible for its aptitude to act as a fertility enhancer, aphrodisiac, adaptogen, immunostimulant, anabolic and to influence hormonal balance. Yacon and maca are already on the European market as prospective functional foods and dietary supplements, mainly for use in certain risk groups of the population, e.g. seniors, diabetics, postmenopausal women etc.

Full text

119
SMALLANTHUS SONCHIFOLIUS AND LEPIDIUM MEYENII –
PROSPECTIVE ANDEAN CROPS FOR THE PREVENTION OF CHRONIC DISEASES
Kateřina Valentová, Jitka Ulrichová
Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacký University, Hněvotínská 3,
775 15 Olomouc, Czech Republic
Received: September 10, 2003; Accepted: October 15, 2003
Key words: Yacon / Maca / Phytochemistry / Biological activity
Smallanthus sonchifolius (yacon) and Lepidium meyenii (maca) were the traditional crops of the original population
of Peru where they are also still used in folk medicine. These plants are little known in Europe and Northern America
although at least yacon can be cultivated in the climatic conditions of these regions. This article deals with the botany
and the composition, the structure of main constituents, biological activity of these plants and the cultivation of yacon
in the Czech Republic. The potential of yacon tubers to treat hyperglycemia, kidney problems and for skin rejuvenation
and the antihyperglycemic and cytoprotective activity of its leaves seems to be related mostly to its oligofructan and
phenolic content, respectively. Maca alkaloids, steroids, glucosinolates, isothicyanates and macamides are probably
responsible for its aptitude to act as a fertility enhancer, aphrodisiac, adaptogen, immunostimulant, anabolic and to
inuence hormonal balance. Yacon and maca are already on the European market as prospective functional foods and
dietary supplements, mainly for use in certain risk groups of the population, e.g. seniors, diabetics, postmenopausal
women etc.
Biomed. Papers 147(2), 119–130 (2003)
© K. Valentová, J. Ulrichová
INTRODUCTION
An optimal diet is frequently a good preventive mea-
sure against chronic diseases. Classic examples abound in
the use of diet in the control of blood cholesterol levels,
blood glucose level regulation and control, arteriosclerosis
and diabetes risk factor lowering, dietary substitution of
estrogenic hormones in menopause, inuence on osteo-
arthritis development, osteoporosis and digestive tract
cancer, amelioration of some neurological illnesses, im-
provement of impaired immunity and lowering of food
contaminant toxic eects. Plant products that have posi-
tive physiological eects on the human organism can be
classied as follows: (i) functional foods and (ii) dietary
supplements (nutraceuticals), that is, concentrated, che-
mically characterised and standardised mixtures of com-
pounds originating from plants, e.g. plant extracts. In all
food products with demonstrable physiological eects,
there is a specic group of compounds responsible, these
include biogenic elements, avonoids, phytosterols, poly-
saccharides including ber, β-D-glucans, polyunsaturated
fatty acids and other components with positive physiologi-
cal activity.
The health status of people in developed countries is
becoming so alarming, that market expansion in preven-
tive, inexpensive, physiologically eective and safe func-
tional foods and dietary supplements for risk groups of
the population including the elderly is desirable. Of these
foods, most traditional Andean crops, apart from potatoes
and maize are practically unknown in Europe despite the
fact that they served for centuries to enable native popu-
lations to survive severe climatic conditions
1
. Tuber and
root crops are predominantly cultivated in the Andes:
these include several potato varieties, Solanum tuberosum,
S. andigenum, S. ajanhuiri, S. stenotomum, S. goniocalyx,
S. phureja
2
(Solanaceae), also ahipa (Pachyrhizus ahipa,
Leguminosae), arracacha (Arracacia xanthorrhiza, Apia-
ceae), mashua or añu (Tropaeolum tuberosum, Tropaeo-
laceae), sweet potato (Ipomoea batata, Convolvulaceae),
mauka (Mirabilis expansa, Nyctaginaceae)
3
yacon (Small-
anthus sonchifolius)
4
and maca (Lepidium meyenii)
5, 6
. This
review focuses on the two last crops, yacon and maca. The
former can be successfully cultivated in the European cli-
mate. Yacon (S. sonchifolius, Asteraceae (Compositae)) is
a Jerusalem artichoke (Helianthus tuberosus) related plant.
Maca (L. meyenii, Brassicaceae (Cruciferae)) is related to
watercress (L. sativum) and among ethnopharmacologists
known as Peruvian ginseng.
BOTANY AND HISTORY
Yacon and related plants were originally classied
under the genus Polymnia (Asteraceae, Heliantheae, Me-
lampodinae)
4, 7–9
, although the genus Smallanthus (Astera-
ceae, Heliantheae), rediscovered by Robinson
10
in 1978
along with 21 other species, had already been proposed
in 1933. The new classication, Smallanthus sonchifolius
(Poepp. & Endl.), is currently preferred while the old
name Polymnia sonchifolia Poepp. & Endl. is considered
as synonymous
4, 11
. The name Polymnia edulis also appears
in the literature
11
. Yacon is a perennial plant forming

120
121
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
a clump of more then twenty
12, 13
big underground tubers
weighing from 100–500 g, exceptionally more than one
kilogram. These resemble dahlia tubers
9
. Their shape and
size depend on the particular clone, but in most cases the
tubers are irregularly spindle-shaped, sometimes almost
round-shaped. They are edible and colourless if freshly
harvested. The epidermis becomes rapidly dark after
exposure to air. Under the epidermis, cortex tissue with
a slightly resinous taste is found and under this, mild yel-
lowish esh with a fruit taste
6
. The whole plant is much
less resistant to frost than the Dahlia which is why its cul-
tivation is limited to a much shorter period in European
climates compared to its country of origin
6
. Apart from
tuberous roots, yacon also forms short caudices, growing
directly on the basal part of the main stem. These are usu-
ally used for the vegetative propagation of yacon (genera-
tive reproduction capability was lost during evolution
4
).
Yacon propagation through tissue leaf culture is currently
studied
14
. The stem can reach 2 m in height; it is densely
foliaged with dark green leaves and covered by violet-co-
loured trichomes. The inorescence is small, about 30 mm
in diameter, with a yellow or orange colour. It grows at
the top of the main stem and also on other stems growing
from lower nodal buds. Flower production is quite limited
in yacon, more so than in barren Smallanthus species. The
fruits are black, about 2 mm small achenes. The somatic
chromosome number has been found
15
to be 2n = 60 and
this is in accordance with the cytological analysis of our
clone material. In early evolutionary periods, Andean
farmers had already recognized the properties of yacon
and had transformed the plant into a cultivated crop. Ya-
con is found in burial grounds from centuries before the
Incas
2
. The oldest yacon representation on textile and ce-
ramics has been found in a littoral archaeological deposit
Nazca (500–1200 A.C.)
4
. The rst written allusion on
yacon comes from the chronicler Padre Bernabé Cobo
12
(1653). In the Andes, yacon is cultivated at altitudes of
880 to 3500 m. Its cultivation extends from Venezuela to
northwestern Argentina
12
. In most cases, just a few plants
are cultivated for family consumption
4
. From the Andes,
yacon was transferred in the 80’ies of the 20
th
century
through the New Zealand to Japan
6
. Its cultivation was
successfully introduced into Italy, Germany, France
and USA though yacon is still not remarkably diused
there. In Italy, yacon tubers are used to produce alcohol
and inulin
12
. In 1993, it was introduced into the Czech
Republic in the form of caudices originating from New
Zealand
6
. More recently, it has also been introduced into
Russia
16, 17
.
The genus Lepidium belongs to the family Brassicaceae
(Cruciferae) like other important crops such as, e.g. rape,
cabbage, head cabbage, radish, garden cress or mustard;
members of this genus are distributed throughout all con-
tinents
5
. The genus probably originates in the Mediterra-
nean basin; long-distance dispersal during the late Tertiary
and Quaternary period was probably responsible for the
colonization of these species to the Americas and Aus-
tralia. The genus consists of approximately 175 species;
some of them are cultivated, e.g. garden cress (L. sativum).
Maca (L. meyenii Walp. syn. L. peruvianum Chacón, re-
views
6, 18, 19
) is cultivated over the whole of South America
as a starch crop. L. peruvianum Chacón is found exclusive-
ly in Peru
20, 21
. The aerial part of L. meyenii forms a rosette
of 12–20 leaves like in radish, but the foliage forms a mat,
growing in close contact with the soil. The main stem is
reduced while the underground part is a storage organ re-
sembling turnip
1, 20
. For simplicity, we will call this organ,
formed by the taproot and the lower part of the hypocotyl,
just “hypocotyl”. This is the economic product of maca.
The hypocotyls display a variety of colours from purple to
cream and yellow (the Peruvians distinguish 4 cultivars,
cream, purple, red and black
1, 22
). They are about 10–14 cm
in length and 3–5 cm in width, with a solid consistency
20
.
Maca is an annual crop completing its life cycle within
a year when climatic conditions are favourable. The seeds,
its only means of propagation, have no dormancy, germi-
nating in 5–7 days at 25 °C under good moisture condi-
tions. A single plant of maca produces approximately 14 g
of seeds
5
. It is probably an autogamous species. The basic
genomic chromosome number in Lepidium is x = 8. Maca
is an octoploid with 2n = 8x = 64 chromosomes
21
. The
direct ancestor of L. meyenii are unknown, but they are
none of the three main wild Lepidum species from the An-
des i.e. L. bipinnatidum, L. kalenbornii nor L. chichicara.
Cultivated maca (L. meyenii) is also the only species in
the entire genus that produces eshy roots
23
. The rst far-
mers and herdsmen lived in the Andes before 2000 B.C.
and maca was probably domesticated between 1300 and
2000 years ago. Primitive maca cultivars have been found
in archaeological sites from about 1600 B.C. (ref.
2
). Inter-
estingly, maca is not depicted on old Peruvian ceramics,
so rich in agricultural crop pictures
1
. Knowledge of this
plant and its activities was transferred from generation to
generation. During Spanish colonization, the native peo-
ple used maca as currency
20
. Although maca is adapted
to high altitudes and extremely low temperatures (it even
grows more quickly at lower temperatures
21
), it can be
successfully transplanted to the Peruvian seacoast
20
. It
is a plant with a neutral reaction to day length
5, 21
and it
can be successfully cultivated outside its natural locali-
ties
5
. We have obtained maca hypocotyls in the Czech
Republic, but these are smaller than the Peruvian ones.
More recently, maca has been introduced into Russia
24
.
It is not yet entirely known, how the climate changes
inuence its spectrum of components. According to so-
me researchers
25
, particularly harsh conditions give to
maca its strength and potency. In lower altitudes, such
as in Germany, maca does not form hypocotyls
25
. In the
Czech Republic, hypocotyls are formed only in elds, not
in greenhouses and dierences in chemical composition
(higher content of proteins and nitrates and lower content
of saccharides) compared to commercial maca powder
were observed
26
. It seems that for hypocotyl formation
a cold climate is important.

120
121
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
CHEMISTRY
The chemical composition of aerial and underground
parts of yacon and of dried maca
27
hypocotyls (fresh ma-
ca contains up to 80 % of water and its composition was
not found in the literature) is shown in Table 1. Yacon
composition diers according to author
4, 9, 28
. For compari-
son, composition of the Jerusalem artichoke (Helianthus
tuberosus)
29
and of radish (Raphanus sativus)
30
is also
presented in Table 1.
Table 1. Composition of yacon tubers, leaves and stems
4, 9, 28
, Jerusalem artichoke tubers
29
,
of dried maca
27
and radish
30
hypocotyls.
Yacon
Jerusalem
artichoke
Maca Radish
Stem Leaf Tuber Tuber Hypocotyl Hypocotyl
Water
%
10.47 93–70 80 10.4
c
88.8
Proteins 9.73
a
21.48
a
0.4–2.0 10–15
b
10.2
c
1.9
Saccharides 12.5 60–76
b
59.0
c
6.6
Lipids 1.98 4.2 0.1–0.3 1
b
2.2
c
Ash 9.60 12.52 0.3–2.0 5
b
4.9
c
1.2
Fibre 23.82 11.63 0.3–1.7 4–6
b
8.5
c
Calcium
mg/100 g
967 1805 23 23 150
c
1.2
Phosphorus 415 543 21 99 0.7
Iron 7.29 10.82 0.3 3.4 16.6
c
0.02
Copper <0.5 <0.5 0.963 5.9
c
Manganese <0.5 3.067 0.541 0.8
c
Zinc 2.93 6.20 0.674 traces 3.8
c
Retinol 10
Thiamine 0.01 0.28
c
0.05
Ascorbate 13.10 traces 8.00
c
20.0
Carotene 0.02
Riboavin 0.11 traces 0.65
c
0.05
Niacin 0.34 traces 0.30
a
Content of N-substances;
b
Content in solid matter;
c
Content in dried hypocotyl
Saccharides
Yacon tubers contain as storage compounds mainly
fructans with low glucose content. Their structure is of
the inulin type, i.e. β(2→1)fructofuranosylsaccharose (see
Table 2), of the same type as in other Asteraceae species,
e.g. Jerusalem artichoke
31
. Similar low DP fructans have
been used as sucrose substitutes; they are considered
dietetic. They have a favourable inuence on the human
intestinal ora and can modify some hyperlipidemias.
Humans have no enzyme capable of hydrolysing the
β(2→1)bond
2
. β(2→1)fructans of the inulin type are thus
dietary bre or the indigestible residues of plant origin in
human diet
32
.
Recently, oligofructans have been classied as prebio-
tics
33
. These are not digested in the human gastrointestinal
tract and they are transported to the colon where they are
fermented by selected species of gut micro-ora, espe-
cially Bidobacterium and Lactobacillus, both indicators
of a balanced gut ora. Studies in voluntary subjects have
demonstrated that prebiotic consumption modies gut
ora composition and its metabolic activities. Probably
through this action they also modulate lipid metabolism,
calcium absorption, childhood immune systems and gut
function. The prebiotic eect of yacon tuber extracts has
been demonstrated by their fermentation by several com-
mon gut bacteria Lactobacillus plantarum, L. acidophilus
and Bidobacterium bidum
34
. β(2→1)fructans are related
to β-glucans, native polysaccharides from yeast and fungi,
which act as non-specic immunostimulators. They bind
specically to macrophages, activate them and initiate
the immunity cascade. β-Glucans are recommended for
the treatment of immunity defects, infections, allergies,
chronic fatigue syndrome, high cholesterol levels, stomach
problems and as an adjuvant in carcinoma therapy
35
.
Yacon tubers are also rich in free fructose, glucose
and sucrose
8
. Saccharide and the related enzyme content

122
123
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
in tubers uctuates during cultivation and storage; during
cultivation, the degree of polymerisation in the fructans
increases while it declines during storage, increasing in
content of fructose, glucose and sucrose
34, 36, 37
. Similar
changes in composition occur also in the Jerusalem arti-
choke, so far the greatest source of inulin and fructose
38
.
The enzymes involved in oligofructans metabolism and
also the oligosaccharides themselves have been recently
isolated and identied from yacon tubers and caudices
in dierent stages of growth. According to one study
39
,
eight months after planting is the best yacon harvest time
in tropical regions.
Hydrolysable saccharides constitute 59.0 % of dried
maca hypocotyls
27
. In our hands
26
, maca dehydrated pow-
der contained 29.56 % of saccharides (1.55 % fructose,
23.4 % sucrose and 4.56 % oligosaccharides, HPLC) and
89 % sucrose (HPLC) representing about 50 % of dry
weight was precipitated from maca methanol extract
40
.
Table 2. Content of saccharides in yacon tubers
(according to ref.
8
).
Component Content (mg/g DW)
Fructose
350.1 ± 42.0
Glucose
158.3 ± 28.6
Sucrose
74.5 ± 19.0
GF
2
60.1 ± 12.6
GF
3
47.4 ± 8.2
GF
4
33.6 ± 9.3
GF
5
20.6 ± 5.2
GF
6
15.8 ± 4.0
GF
7
12.7 ± 4.0
GF
8
9.6 ± 7.2
GF
9
6.6 ± 2.3
inulin 13.5 ± 0.4
G = glucose. F = fructose. GF
n
= glukosylfructose
Phenolics
Phenolics (203 mg/100g, ref.
41
), tryptophane
(14.6 ± 7.1 μg/g) and chlorogenic acid
11
(48.5 ± 12.9 μg/g)
in particular have been identied in yacon tubers. Re-
cently, ve caeic acid derivatives as main water-soluble
phenolics have been isolated
42
. These were identied as
chlorogenic (3-caeoylquinic, I) and 3,5-dicaeoylquinic
(II) acids and three caeic and altraric acids esters
(2,4 or 3,5-dicaeoylaltraric (III and IV), 2,5-dicaeoyl-
altraric (V) and 2,3,5 or 2,4,5-tricaeoylaltraric acids
VI and VII). The same researchers also isolated from
yacon tubers derivatives of octulosonic acid (VIII and
IX, ref.
43
, Fig. 1). Chlorogenic, ferulic and caeic acids
have also been found in yacon tubers in our laboratory.
After hydrolysis, we have also identied quercetin and
2 other avonoids
44
. Yacon tubers have been identied as
a good source of phenol oxidase, the enzyme catalysing
oxygenation of phenolic compounds to quinones that after
polymerisation, give the typical brown to black pigments
known from enzymatic browning of fruits and vegetables
and observed also in yacon
45
.
We have already described the presence of caeic,
chlorogenic and ferulic acids in yacon leaves detected
using HPLC/DAD-MS in ethyl acetate extract from the
leaves of yacon
46
. The presence of the phenolic acids was
then conrmed by HPLC coupled with electrochemical
detection (HPLC-ECD)
47
together with identication
of gallic and gentisic acid. Recently, we have described
a detailed analysis of phenolic compounds from three
extracts of S. sonchifolius leaves
44
. We conrmed chloro-
genic, caeic and ferulic acid, three isomers of dicae-
oylquinic acids (M
r
= 516), an additional still unknown
derivative of chlorogenic acid (M
r
= 562) and an equally
unknown avonoid by HPTLC and HPLC/MS. These
compounds were then also conrmed in yacon leaves,
stems, caudices and tubers
48
. Flavonoid compounds
with antimitotic activity have been isolated from related
S. fruticosus, particularly centaureidin (X) (4,5,7-trihy-
droxy-3,6-dimethoxy-avone)
49
(Fig. 2).
Fig. 1. Caeic acid derivatives found in yacon tubers
6
5
4
3
2
1
OH
R
2
O
OH
OR
1
OH
O
I  R
1
=caffeoyl, R
2
=H
II
 R
1
=R
2
=caffeoyl
2
3
4
5
H
R
1
O
OR
2
OR
3
OR
4
H
H
H
1
OH
O
6
OH
O
III  R
1
=R
3
=caffeoyl, R
2
=R
4
=H
IV
 R
2
=R
4
=caffeoyl, R
1
=R
3
=H
V  R
1
=R
4
=caffeoyl, R
2
=R
3
=H
VI
 R
1
=R
2
=R
4
=caffeoyl, R
3
=H
VII
 R
1
=R
3
=R
4
=caffeoyl, R
2
=H
O
OH
OH
Caffeo
y
l =
5
O
1
7
O
OR
2
R
1
O
OH
OH
COOH
H
H
H
H
H
VIII  R
1
= H, R
2
= caffeoyl
IX R
1
= R
2
= caffeoyl

122
123
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
Catechins (2.5 mg/g of hypocotyls DW) have also
been identied in maca hypocotyl aqueous extract. This
displayed antioxidant activity. From comparison with
green tea the authors concluded that this activity is due
to maca isothiocyanates rather than to the catechins
50
.
O
O
OH
OH
OH
OMe
OMe
MeO
X
Fig. 2. Centaureidin
Terpenes
A methanol extract of yacon leaves contained ent-
kaurenoic acid (XI) and related diterpenoid substances
(ent-kaur-16-en-19-oic acid 15-angeloyloxy ester (XII),
18-angeloyloxy-ent-kaur-16-en-19-oic acid (XIII) and
15-angeloyloxy-ent-kauren-19-oic acid 16-epoxide (XIV)
(Fig. 3). These compounds probably play a certain physio-
logical role in the defense mechanisms of this plant and
it is highly pest-resistant
51
. Its antifungal activity has also
been attributed to 4-hydroxystyrene and 3,4-dihydroxysty-
rene that are formed in yacon damaged leaves by oxida-
tive decarboxylation of p-coumaric and caeic acids by
enzymatic systems of epiphytic bacteria
52, 53
. Ent-kaurenoic
acid is one of the terpenoid phytohormone gibberellins
biosynthesis intermediates in Gibberella fujikuroi
54
. Ent-
kaurene is responsible for the antibacterial activity of
Brazilian propolis from native stingless bees Melipona
quadrifasciata anthidioides
55
. Antifungal sesquiterpene
lactones of the melampolide type sonchifolin (XV) (8-an-
geloyl-1(10),4,11(13)-germacratrien-12,6-olid-14-oic acid
methyl ester), polymatin B (XVI) (acetoxy derivative at
C-9 of sonchifolin), uvedalin (XVII) (polymatin derivative
with epoxidised angeloyloxy group) and enhydrin (XVIII)
(epoxy derivative of uvedalin)
56
have been isolated from
70 % methanolic extract from the leaves (Fig. 4). Son-
chifolin, uvedalin, enhydrin, and related compounds
uctuanin XIX, 8β-tigloyloxymelampolid-14-oic acid
methyl ester XX and 8β-methacryloyloxymelampolid-
4-oic acid methyl ester XXI (Fig. 4) from yacon leaves
exhibited also antimicrobial activity
58
. These substances
are also contained in other Smallanthus species, e.g.
S. uvedalia
57
(which contain ceteri paribus enhydrin
59
),
S. fruticosus
60
and S. maculatus, as well as species from
the genus Melampodium (Asteraceae)
61
, which has given
the name to these compounds. Sesquiterpene lactones
from S. maculatus displayed anti-inammatory activity
62
.
Sesquiterpene lactones seem to be a chemotaxonomic
Asteraceae sign. They are regularly present in plants
from this family and they display strong biological ac-
tivity, e.g. artemisin and related sesquiterpene lactones
from Artemisia annua display antimalaric
63
and cytotoxic
activities against bone narrow and tumour cells
64
, repin
from Acroptilon repens is toxic against embryonic sensory
neurones
65
. Hypocretenolides from Leotodon hispidus
are cytotoxic against cancer cells
66
. Germacran type ses-
quiterpene lactones have been among other compounds
(avonoids, coumarins, phenolic acids, triterpenoids,
steroids and gaian type sesquiterpene lactones) isolated
from dandelion (Taraxacum ocinale Web.), which is
used in traditional medicine for its choleretic, diuretic
and anti-inammatory activities
67
.
R
1
R
2
R
3
XI
-H -CH
3
-H
XII
-CH
3
-H
XIII
-H -H
R
2
H
H
COOR
3
H
R
1
H
H
H
O
COOH
O
O
C O
O
XIV
CO
CH
2
O
Fig. 3. Ent-kaurenoic acid and its derivatives from yacon leaves

124
125
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
Alkaloids
Already in 1961, alkaloids named macaine 1, 2, 3 and
4 (ref.
20, 27
) were found in maca hypocotyls. These com-
pounds, not structurally characterized, were found in ac-
etone, ether and ethanolic extracts. Chacón de Popovici
20
deduced from her experiments (see below) that the maca
active constituents are precisely these alkaloids. Recently,
four alkaloids have been identied as (1R,3S)-1-methyl-
tetrahydro-β-carboline-3-oic acid
68
XXII, a benzylated
1,2-dihydro-N-hydroxypyridine derivative named macari-
dine
69
XXIII and two imidazole alkaloids
70
1,3-dibenzyl-
4,5-dimethylimidazolium chloride XXIV named lepidilin
A and 1,3-dibenzyl-2,4,5-trimethylimidazolium chloride
XXV named lepidilin B (Fig. 5). An alkaloid named lepi-
dine XXVI (Fig. 6) is present in the related garden cress
(L. sativum).
R
1
R
2
XV
O
-H
XVI
O
-OAc
XVII
O
O
-OAc
XX
O
-H
XXI
O
-H
R
XVIII
O
O
XIX
O
O
OR
OAc
O
COOMe
O
O
O R
1
R
2
O
C O O M e
Fig. 4. Sonchifolin and its derivatives
N
OH
H
O
XXIII
N
H
NH
COOH
CH
3
XXII
N
N
CH
3
CH
3
R
Cl
+
XXIV  R=H
XXV  R=CH
3
Fig. 5. Maca alkaloids
N
N
O
CH
2
CH
2
N
N
XXVI
Fig. 6. Lepidine
Glucosinolates and isothiocyanates
Some authors
5
believe, that active maca constituents
are aromatic isothiocyanates, i.e. benzylisothiocyanate
XXVII and 4-methoxybenzylisothiocyanate XXVIII or
prostaglandins and sterols. Aromatic isothiocyanates
are present in mashua (Tropaeolum tuberosum), known
for its aphrodisiac and contraceptive activity in men and
increasing female fertility
71
.
Isothiocyanates, capable of reducing the risk of breast,
stomach and liver cancer, arise in plants from glucosi-
nolates hydrolysis by myrosinase
72
. The glucosinolate con-
tent in maca seeds, sprouts and mature plants as well as
in commercial maca products was recently investigated
73
.
Benzyl glucosinolate XXIX (glucotropaeolin), 4-meth-
oxybenzyl glucosinolate XXX, 5-methyl-sulnylpentyl
glucosinolate XXXI (glucoalyssin), 4-hydroxybenzyl glu-
cosinolate XXXII, pent-4-enyl glucosinolate XXXIII (glu-
cobrassicanapin), indolyl-3-methyl glucosinolate XXXIV
(glucobrassicin) and 4-methoxyindolyl-3-methyl glucosi-
nolate XXXV were found in all samples in dierent ratios.
Maca hypocotyls and also the aerial parts display a strong
disagreeable aroma owing to these compounds
5
. Glucosi-
nolates glucotropaeolin XXIX, 3-methoxyglucotropaeolin

124
125
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
XXXVI, as well as isothiocyanates benzylisothiocyanate
XXVII, 3-methoxybenzylisothiocyanate XXXVII (Fig. 7)
and other compounds (uridine, malate, benzoylmalate
and the alkaloid XXII) were conrmed in maca hypocotyl
methanolic extract by Piacente et al.
68
.
Other components
4’-Hydroxyacetophenone related antifungal fytoalexins
4’-hydroxy-3’-(3-methylbutanoyl) acetophenone (XXXVIII),
4’-hydroxy-3’-(3-methylbutenyl) acetophenone (XXXIX)
and 5-acetyl-2-(1-hydroxy-1-methylethyl) benzofurane
(XXXX) (Fig. 8) have been isolated by combination of
chromatographic methods from yacon tuber acetone ex-
tract. Identical compounds also exist in other Asteraceae
species
74
.
Maca hypocotyls contain linoleic, palmitic and oleic
acids, aminoacids lysine and arginine
75
, many trace ele-
ments including Mn, Cu, Sn, Al, Zn, Bi; tannins and
saponins. Maca steroid fraction contained brassicasterol
(9.1 %), ergosterol (13.6 %), campesterol (27.3 %), ergos-
tadienol (4.15 %) and sitosterol (45.5 %)
27
. Estrogenicity
of β-sitosterol was demonstrated in the MCF-7 cell line
and in vivo in trout
76
. Benzylated amides (macamides),
N-benzyl-5-oxo-6E,8E-octadecadienamide XXXXI, N-ben-
zylhexadecanamid XXXXII and an acyclic polyunsaturated
5-oxo-6E,8E-octadecadienoic acid macaene XXXXIII were
also found in maca hypocotyls
69
(Fig. 9). The macaenes
and macamides XXXXI–XXXXIII have been utilized
together with the linoleic and linolic acids for maca
commercial products characterization and standardiza-
tion
77
. Macamides may display similar biological eects
as anandamide and anandamide-type compounds, which
were isolated from porcine brain. These compounds have
been found to inhibit specic binding of cannabinoids and
act as competitive ligands
78
.
The essential oil from maca aerial part was analysed in
detail using GC/MS
79
. Up to 53 components were identi-
ed, mainly phenylacetonitrile (85.9 %), benzaldehyde
(3.1 %), 3-methoxyphenylacetonitrile (2.1 %) and benzyli-
sothiocyanate (0.6 %). Ascorbic acid (7.0 % of extract
DW), carotenoids (0.85 %) and avonoids (0.55 %) have
been identied in aqueous-ethanolic maca leaves extract
that displayed antioxidant activity in the system gly-trp +
+ riboavine
24
.
The above-mentioned maca relative garden cress
(L. sativum) is an interesting vitamin C (52 mg in 100 g),
B
1
, K and β-carotene source. Its typical spicy avour is due
to its content of glucosinolates and isothiocyanates, espe-
cially glycotropaeolin and benzylisothiocyanate. Garden
cress improves digestion. Another European maca relative,
radish (Raphanus sativus var. nigra), contains ceteri pari-
bus glucobrassicin XXX (3-indoyl-methylglucosinolate),
isothiocyanates and it is traditionally used as choleretic,
cholagogue, to treat bronchitis and burns
80, 81
.
(a) R1 R2
XXVII
H H
XXVIII
CH
3
O- H
XXXVII
H CH
3
O-
(b) R R
XXIX
CH
2
XXXIII
CH
2
CH
CH
2
CH
2
CH
2
XXX
CH
2
CH
3
O
XXXIV
N
CH
2
XXXI
CH
3
SO
CH
2
CH
2
CH
2
CH
2
CH
2
XXXV
N
CH
2
CH
3
O
XXXII
CH
2
OH
XXXVI
CH
3
O
CH
2
C
H
2
N
C
S
R1
R2
OH
OH
OH
OH
S
N
R
O
S
O
O
O
Fig. 7. Benzylisothiocyanates (a) and glucosinolates (b) present in maca

126
127
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
BIOLOGICAL AND PHARMACEUTICAL
ACTIVITIES, USES
In local Andean markets yacon is classied as a fruit
and sold together with apples, avocados and pineapples
and not together with potatoes or tuber crops as one
could expect. Its tubers have a delicious sweet avour,
they are crispy and native people commonly expose
them to sunlight to increase their sweetness. They are
consumed, peeled, usually in fruit salads together with e.g.
bananas or oranges. They can also be eaten steamed when
they conserve their crispiness to a certain extent and it
is possible to cook or fry them in many dierent ways
6
.
Refreshing juices or concentrates suitable as sweetener
for diabetics can be made from the tubers
4
. Also young
stems can be used as vegetable; the main stem is used as
celeri
2
. In Japan, yacon tubers are processed into juices,
bakery products, fermented beverages, lyophilized powder
or pulp
82
. The suitability of yacon foodstus for diabetic
dishes, diets for weight reduction and for patients with
chronic liver diseases has been shown in a clinical study
performed at Olomouc Faculty Hospital
6
. Yacon tubers
were used for centuries by original Peruvian populations
as a traditional folk medicament to treat hyperglycemia,
kidney problems and for skin rejuvenation. In Brazil, me-
dicinal properties have been ascribed to yacon leaves that
are used to prepare a medicinal tea. In Japan, yacon leaves
and stems are mixed with tea leaves
83
. Yacon aerial parts,
containing large amounts of proteins, can be also used as
green stu for livestock
4
.
Hypoglycemic eects of yacon leaf aqueous extracts
have been demonstrated in normal and diabetic rats
4, 83
.
We have described the antioxidant activity of two extracts
in relation to the content of phenolics
46
. Moreover, we
have shown that extracts exhibited cytoprotective eects
against tert-butyl hydroperoxide and allyl alcohol induced
oxidative damage of rat hepatocytes in primary cultures.
We have also demonstrated that yacon leaf extracts reduce
glucose production in hepatocytes via both gluconeoge-
nesis and glycogenolysis pathway, and their insulin-like
eect was demonstrated on CYP2B and 2E mRNA ex-
pression in Fao cells
84
.
O
O
OH
O
O
OH
O
OH
XXXVII
XXXIX XXXX
Fig. 8. Antifungal phytoalexins from yacon tubers
N
H
O
O
N
H
O
O
OH
O
XXXXI
XXXXIII
XXXXII
Fig. 9. Macaenes and macamides

126
127
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
Maca is eaten raw or cooked in pachamancas (un-
derground ovens lined with hot stones) or stored dried
for later consumption. Dried maca hypocotyls conserve
their properties for years
5
. The dried roots are eaten after
boiling in water or milk, and are sometimes mixed with
honey and fruits for the preparation of juices, gelatines
or jams, and addition of sugarcane rum for cocktails
and other alcoholic beverages. Native herbalists recom-
mend maca decoction in reconvalescence
20
. Flour is also
prepared from the dried roots for making bread and coo-
kies. Toasted and ground hypocotyls are used to prepare
“maca coee”
5
. Maca is fermented to prepare a beer in
several Peruvian areas
75
. Maca leaves, like garden cress
(L. sativum), are consumed in salads
2
. Complementary
and alternative medicine recommend ground maca hy-
pocotyls as fertility enhancers and aphrodisiacs for men
and livestock. Indian women eat it when they want to get
pregnant
1
. In South America maca is called Peruvian or
Andean Ginseng
1, 5, 85
. Maca is also recommended as an
adaptogen, immunostimulant, anabolic, in menopause
and for inuence on hormonal balance. Maca hypocotyls
are ground and sold as a nutracetical
1
. In Peru, maca is
oered in the form of powder, chips, liqueurs
75
etc., on the
world market it is distributed under the commercial names
Royal Maca™ (ref.
86
), Maca750™ (ref.
87
), MacaMagic™
(ref.
88
), “Maca Andina”
89
, Vimaca®, Eregma power
90
and
MACA
91
. Aphrodisiac eects of maca hypocotyls have
been ascribed especially to its alkaloids, which according
to Natural Health Consultants
86
aect the pituitary-hy-
pothalamus axis. In contrast, MacaMagic™ producer
HERBS AMERICA NETWORK
88
declare that unique
maca properties are due exclusively to its composition of
essential amino acids, fatty acids, vitamins and minerals.
Chacón de Popovici
20
recommends maca use for treating
malabsorption syndrome, protein deciency disease, du-
ring chemotherapy for leukaemia, AIDS treatment, alco-
holism and menopausal anaemia. Others mention its use
to treat chronic polyarthritis, during allergy attacks and
as laxative
71
. Traditional maca uses are also related to re-
ligious ceremonies; it was mixed with hallucinogens used
in sacricial ceremonies
71
.
Reliable pharmacological conrmation of all cited
eects was missing until very recently. Chacón de Popo-
vici
20
concluded that maca stimulates Graaan follicle
maturation after an experiment on female rats fed maca,
or maca alkaloid extracts for 6 months. In males she ob-
served a clear stimulation of spermatogenesis.
A number of studies showing the aphrodisiac eects
of maca have appeared over the last few years. Positive
eects of a lipidic extract, containing mainly macaenes
and macamides, on mice and rats were described in
2000 (ref.
92
). The extract not only increased the number
of complete intromissions and sperm-positive females
in normal animals, but also decreased latent period of
erection in rats with erectile dysfunction. Application of
maca hypocotyl aqueous extract to male rats induced an
increase in testis size and stimulation of spermatogenesis
in its initial stages
93
. Enhanced sexual behaviour was also
observed when Maca pulverized root was administered
to sexually inexperienced rat males by a gastric tube. The
eect on the parameters tested was already observable
after acute administration and was independent of maca
action on spontaneous locomotor activity
94
. In the same
test, using maca successive hexanic, chloroformic and
methanolic extracts, the hexanic extract was the most
ecient
95
. In adult men, after 4 months maca treatment,
signicant sperm volume, total sperm count and sperm
motility increase was observed. In contrast, serum sexual
hormone level was not aected by the treatment
96–98
.
Progesterone and testosterone levels were increased in
maca treated mice but there were no marked changes in
estradiol levels or in the rate of embryo implantation
99
.
Some compounds with testosterone-like activity, probably
phytosterols, are responsible for maca biological activity.
We have also recently proved estrogenic activity of maca
extracts on MCF-7 estrogen positive cell line
40
.
Maca nutritional properties were evaluated in white
mice
100
. The growth curves in all groups fed maca were
signicantly better than in those of a control group. This
study demonstrates, according to the authors, one of the
traditionally attributed properties of maca, its nutritional
capability.
CONCLUSION
Trends in nutraceuticals and functional foods con-
taining biologically active natural substances are orien-
ted towards intact plants or plant extract utilization in
this millennium. Nutraceuticals are coming to be indis-
pensable diet constituents for all population groups in
the prevention or remedial treatment of many chronic
diseases. Considering the fact that yacon and maca can
be cultivated in the European climatic conditions we
assume that nutraceuticals based on these plants could
be a contribution to the prevention and remediation of
diseases such as diabetes mellitus, cardiovascular disease,
fatigue syndrome etc. Promising seem to be the combina-
tion of yacon with silymarin which has been shown to
improve the metabolism of triacylglycerols and glucose
in both humans and rats
101
. The preparations should be
economically accessible to wide public, without adverse
side eects and according to valid legislation
102
. Compre-
hensive yacon and maca investigation is related to low
economic risk and ready application of results.
ACKNOWLEDGEMENTS
Supported by grants GACR 303/01/0171, MPO FD-K/096
and MSM 151100003.
REFERENCES
1. León J. (1964) The “maca” (Lepidium meyenii), a little-known
food plant of Peru. Econ Bot 18, 122–7.
2. National Research Council. Lost Crops of the Incas: Little-
Known Plants of the Andes with promise for Worldwide Culti-
vation. Washington, D. C.: National Academy Press, 1989.

128
129
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
3. Flores HE, Flores T. Biology and biochemistry of underground
plant storage organs. In: Johns T, Romeo JT, editors. Function-
nality of food phytochemicals. New York: Plenum Press, 1997.
p. 113–32.
4. Grau A, Rea J. Yacon. Smallanthus sonchifolius (Poep. & Endl.)
H. Robinson. In: Hermann M, Heller J, editors. Andean roots
and tubers: Ahipa, arracacha, maca and yacon. Rome: IPGRI,
1997. p. 199–242.
5. Quirós CF, Aliaga RC. Maca. Lepidium meyenii Walp. In:
Hermann M, Heller J, editors. Andean roots and tubers: Ahipa,
arracacha, maca and yacon. Rome: IPGRI, 1997. p. 173–97.
6. Valentová K, Frček J, Ulrichová J. (2001) Yacon (Smallanthus
sonchifolius) and Maca (Lepidium meyenii), Traditional Andean
Crops as New Functional Foods on the European Market. Chem
Listy 95, 594–601.
7. Wells JR. (1965) A taxonomic study of Polymnia (Compositae).
Brittonia 17, 144–59.
8. Ohyama T, Ito O, Yasuyoshi S, Ikarashi T., Minamisawa K,
Kubota M, Tsukihashi T, Asami T. (1990) Composition of sto-
rage carbohydrates in tubers of yacon (Polymnia sonchifolia).
Soil Sci Plant Nutr 36, 167–71.
9. Asami T, Kubota M, Minamisawa K, Tsukihashi T. (1989)
Chemical composition of yacon, a new crop from the Andean
Highlands. Japan J. Soil Sci Plant Nutr 60, 122–6.
10. Robinson H. (1978) Studies in the Heliantheae (Asteraceae).
XII. Re-establishment of the genus Smallanthus. Phytologia 39,
47–53.
11. Yan X, Suzuki M, Ahnishi-Kameyama M, Sada Y, Nakanishi T,
Nagata T. (1999) Extraction and identication of antioxidants
in the roots of yacon (Smallanthus sonchifolius). J Agric Food
Chem 47, 4711–3.
12. Lachman J, Fernández EC, Orsák M. (2003) Yacon [Smallanthus
sonchifolia (Poepp. Et Endl.) H. Robinson] chemical composi-
tion and use – a review. Plant Soil Environ 49, 283–90.
13. Zardini E. (1991) Ethnobotanical notes on “yacon”, Polymnia
sonchifolia (Asteraceae). Econ Bot 45, 72–85.
14. Niwa M, Arai T, Fujita K, Marubachi W, Inoue E, Tsukihashi T.
(2002) Plant regeneration through leaf culture of yacon. J Jap
Soc Hortic Sci 71, 561–7.
15. Talledo D, Escobar C. Genética de las Células Somáticas de
Raíces y Tuberosas Andinas.Raíces Andinas, Manual de Ca-
pacitación, Lima: CIP 2000, Fascículo 7, p. 1–20.
16. Tyukavin GB. (2001) Introdukcia jakona v Rossii. Moskva: Vym-
pel.
17. Tyukavin GB. (2002) Productivity and morphological determi-
nants of yacon under the inuence of growing conditions and
in connection with date of harvesting. Selskochozyaystvennaya
biologia 3, 81–7.
18. Maca (Lepidium meyenii). http://herb.nu/maca.html
19. Balick MJ, Lee R. Maca: From traditional food crop to energy
and libido stimulant. Altern Ther Health Med 8, 96–98 (2002).
20. Chacón de Popovici G. La importancia de Lepidium peruvianum
(“Maca”) en la alimentacion y salud del ser humano y animal
2,000 anos antes y desputes del Cristo y en el siglo XXI. Lima:
Servicios Grácos “ROMERO”, 1997.
21. Quirós CF, Epperson A, Hu JH, Holle M. (1996) Physiological
studies and determination of chromosome number in Maca,
Lepidium meyenii (Brassicaceae). Econ Bot 50, 216–23.
22. Ochoa C. (2001) Maca (Lepidium meyenii Walp.; Brassicaceae):
A nutritious root crop of the central Andes. Econ Bot 55, 344–5.
23. Toledo J, Dehal P, Jarrin F, Hu J, Hermann M, Al-Shehbaz I,
Quiros CF. (1998) Genetic variability of Lepidium meyenii and
other Andean Lepidium species (Brassicaceae) assessed by mo-
lecular markers. Ann Bot 82, 525–30.
24. Gins MS, Lozovskaya EL, Gins VK, Kononkov PF, Tkacheva
TV. (2000) Vitamin content and antioxidant activity of extracts
of introduced vegetable plants. Doklady Rosselchozakademii 3,
14–5.
25. Anonymous. Http://www.frozensh.com/maca.htm
26. Lebeda A, Doležalová I, Valentová K, Dziechciarková M, Gre-
plová M, Opatová H, Ulrichová J. (2003) Biological and chemical
variability of maca and yacon. Chem. Listy 97, 548–56.
27. Dini A, Migliuolo G, Rastrelli L, Saturnino P, Schettino O.
(1994) Chemical composition of Lepidium meyenii. Food Chem
49, 347–9.
28. Nieto C. (1991) Agronomical and bromatological studies in ji-
cama. Arch Latinoam Nutr 41, 213–21.
29. Anonymous. http://www.hort.purdue.edu/newcrop/duke_energy/
Helianthus_tuberosus.html#Chemistry
30. Toul V. Zelenina ve výživě lidí. In: Mareček F. et al. Tržní
zelinářství, Praha: SZN, 1976, p. 291–303.
31. Goto K, Fukai K, Hikida J, Nanjo F, Hara Y. (1995) Isolation
and structural analysis of oligosaccharides from yacon (Polymnia
sonchifolia). Biosci Biotech Biochem 59, 2346–7.
32. Zadák Z. Význam dietní vlákniny ve výživě.
http://www.mednet.cz/odbornici/index.php?rubrika=14&clanek-
602
33. Andrieux C. (2002) Prebiotics and health. Eltville June 14.
34. Pedreschi R, Campos D, Noratto G, Chirinos G, Cisneros-Zeval-
los L. Andea yacon root (Smallanthus sonchifolius Poepp. Endl).
Fructooligosaccharides as a potential novel source of prebiotics.
(2003) J Agric Food Chem 51, 5278–84.
35. Mertens G. From Quackery to Credibility. Finacial Times Busi-
ness, London 2000.
36. Asami T, Minasawa K, Tsuchiya T, Kano K, Hori I, Ohyama T,
Kubota M, Tzukihashi T. (1991) Fluctuation of oligofructan con-
tents in tubers of yacon (Polymnia sonchifolia) during growth and
storage. Jpn J Soil Sci Plant Nutr 62, 621–7.
37. Fukai K, Ohno S, Goto K, Nanjo F, Hara Y. (1997) Seasonal
uctuations in fructan content and related enzyme activities in
yacon (Polymnia sonchifolia). Soil Sci. Plant Nutr 43, 171–7.
38. Benchekroun M, Amzile J, El Yachioui M, El Haloui NE,
Prevost J. (1995) Utilisation du topinambour pour la produc-
tion de fructose et teneurs en fonction de la taille des tubercules.
Belg Journ Bot 128, 90–4.
39. Itaya NM, de Carvakho MAM, Figueiredo-Ribeiro RDL. (2002)
Fructosyl transferase and hydrolase activities in rhizophores and
tuberous roots upon growth of Polymnia sonchifolia. Physiol
Plant 116, 451–9.
40. Valentová K, Buckiová D, Ulrichová J. In-vitro biological activity
of Lepidium meyenii extracts. Manuscript for Fitoterapia.
41. Tzukihashi T. Kiseki no kenkô jasai jâkon. Tokio: Kosaido Books,
1999.
42. Takenaka M, Yan X, Ono H, Mitsuru Y, Nagata T, Nakanishi T.
(2003) Caeic acid derivatives in the roots of Yacon (Smallan-
thus sonchifolius). J Agric Food Chem 51, 793–6.
43. Takenaka M, Ono H. (2003) Novel octulosonic acid derivatives
in the composite Smallanthus sonchifolius. Tetrahedron Lett 44,
999–1002.
44. Simonovska B, Vovk I, Andrenšek S, Valentová K, Ulrichová J.
(2003) Investigation of phenolic acids in yacon (Smallanthus
sonchifolius) leaves and tubers. J Chromatogr A 1016, 89–98.
45. Yoshida M, Ono H, Mori Y, Chuda Y, Mori M. (2002) Oxy-
genation of bisphenol A to quinones by polyphenol oxidase in
vegetables. J Agric Food Chem 50, 4377–81.
46. Valentová K, Cvak L, Muck A, Ulrichová J, Šimánek V. (2003)
Eur J Nutr 42, 61–6.
47. Jirovský D, Horáková D, Kotouček M, Valentová K, Ulrichová J.
(2003) J Sep Sci 26, 739–42.
48. Lachman J, Hejtmánková A, Dudjak J, Fernández EC, Pivec V:
Content of polyphenolic antioxidants and phenolcarboxylic acids
in selected organs of yacon [Smallanthus sonchifolius (Poepp.
et Endl.) H. Robinson]. In: Blatná J, Horna A, editors. Vitamins
2003, Proceeding of Conf. Pardubice, Czech Republic, 15–17.Sep-
tember 2003. Pardubice: Univerzita Pardubice, 2003. p. 89–97.
49. Beutler JA, Cardellina JH II, Lin CM, Hamel E, Cragg G M,
Boyd MR. (1993) Centaureidin, a cytotoxic avone from Polym-
nia fruticosa, inhibits tubulin polymerization. BioMed Chem Lett
3, 581–4.
50. Sandoval M, Okuhama NN, Angeles FM, Melchor VV, Condenzo
LA, Lao J, Miller MJS. (2002) Antioxidant activity of the cru-
ciferous vegetable Maca (Lepidium meyenii). Food Chem 79,
207–13.

128
129
K. Valentová, J. Ulrichová
Smallanthus sonchifolius and Lepidium meyenii –
prospective Andean crops for the prevention of chronic diseases
51. Kakuta H, Seki T, Hashidoko Y, Mizutani J. (1992) Ent-kaurenoic
acid and its related compounds from glandular trichome exudate
and leaf extract of Polymnia sonchifolia. Biosci Biotech Biochem
56, 1562–4.
52. Hashidoko Y, Urashima T, Yoshida T, Mizutani J. (1993) De-
carboxylative conversion of hydroxycinnamic acids by Klebsiella
oxytoca and Erwinia uredovora, epiphytic bacteria of Polymnia
sonchifolia leaf, possibly associated with formation of microora
on the damaged leaves. Biosci Biotech Biochem 57, 215–9.
53. Hashidoko Y, Urashima M, Yoshida T. (1994) Predominant
epiphytic bacteria on damaged Polymnia sonchifolia leaves and
their metabolic properties on phenolics of plant origin. Biosci
Biotech Biochem 58, 1894–6.
54. Barrero AF, Oltra JE, Cerdá-Olmedo E, Ávalos J, Justicia J.
(2001) Microbial Transformation of ent-Kaurenoic Acid and
Its 15-Hydroxy derivatives by the SG138 Mutant od Gibberella
fujikuroi. J Nat Prod 64, 222–5.
55. Velikova, M., Bankova, V., Tsvetkova, I., Kujumgiev, A., Marcucci,
M. C. (2001) Antibacterial ent-kaurene from Brazilian propolis
of native stingless bees. Fitoterapia 71, 693–6.
56. Inoue A, Tamogami S, Kato H, Nakazato Y, Akiyama M, Koda-
ma O, Akatsuka T, Hashidoko Y. (1995) Antifungal melapolides
from leaf extract of Smallanthus sonchifolius. Phytochemistry 39,
845–8.
57. Bohlmann F, Knoll KH, Robinson H, Kong RM. (1980)
Naturally-occurring derivatives. 237. New kaurene derivatives
melapolides from Smallantus uvedalia. Phytochemistry 19,
107–10.
58. Lin F, Hasegawa M, Kodama O. (2003) Purication and iden-
tication of antimicrobial sesquiterpene lactones from yacon
(Smallanthus sonchifolius) leaves. Biosci Biotechnol Biochem
67, 2154–9.
59. Tak HY, Fronczek FR, Vargas D, Fischer NH. (1994) Assignment
of the C-13 NMR spectra of enhydrin and 2’,3’-dehydromelnerin-
A and the molecular structure of enhydrin. Spectrosc Lett 27,
1481–8.
60. Bohlmann F, Knoll KH, Robinson H, Kong RM. (1980) Natural-
ly-occurring derivatives. 260. New melapolides from Smallantus
fruticosus. Phytochemistry 19, 973–4.
61. Castro V, Jakupovic J, Dominiguez XA. (1989) Melampolides
from Melampodium and Smallanthus species. Phytochemistry
28, 2727–9.
62. Bork PM, Schmitz ML, Kuhnt M, Esher C, Heindrich M. (1997)
Sesquiterpene lactone containing Mexican Indian medicinal
plants and pure seskviterpene lactones as potent inhibitors of
transcription factor NF-kappa B. Febs Lett. 402, 85–90.
63. Bhakuni RS, Jain DC, Sharma RP, Kumar S. (2001) Secondary
metabolites of Artemisia annua and their biological activity. Curr
Sci 80, 35–48.
64. Beekman AC, Wierenga PK, Woerdenbag HJ, Van Uden W,
Pras N, Konings AWT, El-Feraly FS, Galal AM, Wikström HV.
(1998) Artemisin-Derived Sesquiterpene Lactones as a Potential
Antitumour Compounds: Cytotoxic Action against Bone Marrow
and Tumour Cells. Planta Med 64, 615–9.
65. Stevens KL, Riopelle RJ, Wong RY. (1990) Repin, a sesquiterpene
lactone from Acroptylon repens possessing exceptional biological
activity. J Nat Prod 53, 218–21.
66. Zidorn C, Stuppner H, Tienfenthaler M, Konwalinka G. (1999)
Cytotoxic Activities of Hypocretenolides from Leontodon
hispidus. J Nat Prod 62, 984–7.
67. Kisiel W, Barszcz B. (2000) Further sesquiterpenoids and phe-
nolics from Taraxacum ocinale. Fitoterapia 71, 269–73.
68. Piacente S, Carbone V, Plaza A, Zampelli A, Pizza C. (2002) In-
vestigation of the tuber constituents of maca (Lepidium meyenii
Walp.). J Agric Food Chem 50, 5621–5.
69. Muhammad I, Zhao J, Dunbar DC, Khan IA. (2002) Consti-
tuents of Lepidium meyenii ‘maca’. Phytochemistry 59, 105–10.
70. Cui B, Zheng BL, He K, Zheng QY. (2003) Imidazole Alkaloids
from Lepidium meyenii. J Nat Prod 66, 1101–3.
71. Aliaga EC, Aliaga RC. Guia para el cultivo, aprovechamiento
y conservacion de la maca, Lepidium meyenii Walpers. Santafé
de Bogotá: Convenio Andres Bello, 1998.
72. Johns T. (1981) The anu and the maca. J Ethnobiol 1, 208–12.
73. Li G, Ammermann U, Quirós CF. (2001) Glucosinolate contents
in Maca (Lepidium peruvianum Chacón) seeds, sprouts, mature
plants and several derived commercial products. Econ Bot 55,
255–62.
74. Takasugi M, Masuda T. (1996) Three 4’-hydroxyacetophenone-
related phytoalexins from Polymnia sonchifolia. Phytochemistry
43, 1019–21.
75. Anonymous. Http://www.ssc.upemm.edu/~roberto3
76. Rosenblum ER, Stauber RE, Van Thiel DH, Campbell IM,
Gavaler JS. (1993) Assessment of the estrogenic acitivity of phy-
toestrogens isolated from bourbon and beer. Alcohol Clin Exp
Res 17, 1207–9.
77. Ganzera M, Zhao J, Muhammad I, Khan IA. (2002) Chemical
Proling and Standardization of Lepidium meyenii (maca) by
Reversed Phase High Performance Liquid Chromatography.
Chem Pharm Bull 50, 988–91.
78. Mechoulam R. (2002) Discovery of endocannabinoids and
some random thoughts on their possible roles in neuroprotec-
tion and aggression. Prostaglandins Leukot Essent Fatty Acids
66, 93–99.
79. Tellez MR, Khan IA, Kobaisy M, Schrader KK, Dayan FE, Os-
brink W. (2002) Composition of the essential oil of Lepidium
meyenii (Walp.). Phytochemistry 61, 149–55.
80. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants.
Hampshire: Intercept Ltd., 1995.
81. Kresánek J, Krejča J. Atlas liečivých rastlín a lesných plodov.
Martin: Vydavateľstvo Osveta, 1977.
82. Anonymous. Http://www.yaconcha.com
83. Aybar MJ, Sánchez Riera AN, Grau A, Sánchez SS. (2001) Hy-
poglycemic eect of the water extract of Smallanthus sonchifolius
(yacon) leaves in normal and diabetic rats. J Ethnopharmacol 74,
125–32.
84. Valentová K, Moncion A., de Waziers I, Ulrichová J. The eect of
Smallanthus sonchifolius leaf extracts on rat hepatic metabolism.
Cell Biol Toxicol, In press.
85. Gutierrez, C. Maca, the gin-seng of the Andes.
http:/www.peruonline.net./el_dorado/Jul-Se97/Maca/
/Macap1-1.htm
86. Anonymous. The Royal Maca Pages. Information on Royal Maca
Peruvian Maca herb.
http://naturalhealthconsult.com/Monographs/maca.html
87. Anonymous. http://www.maca750.com
88. Anonymous. MacaMagic-(Maca roots)-HERBS AMERIKA
NETWORK. http://www.macaroot.com
89. Anonymous. http://ethnohealth.com.
90. Anonymous. http://www.eregma.cz
91. Anonymous. http://www.prozdravi.cz
92. Zheng BL, He K, Kim CH, Rogers L, Shao Y, Huang ZY,
Qien LC, Zheng QY. (2000) Eect of a lipidic extract from
Lepidium meyenii on sexual behavior in mice and rats. Urology
55, 598–602.
93. Gonzales GF, Ruiz A, Gonzales C, Villegas L, Cordova A. (2001)
Eect of Lepidium meyenii (maca) roots on spermatogenesis of
male rats. Asian J Androl 3, 231–3.
94. Cicero AFG, Bandieri E, Arletti R. (2001) Lepidium meyenii
Walp. improves sexual behavior in male rats independently from
its action on spontaneous locomotor activity. J Ethnopharmacol
75, 225–9.
95. Cicero AFG, Piacente S, Plasa A, Sala E, Arletti R, Pizza C.
(2002) Hexanic Maca extract improves rat sexual performance
more eectively than methanolic and chloroformic Maca extracts.
Andrologia 34, 177–9.
96. Gonzales GF, Córdova A, Gonzales C, Chung A, Vega K. (2001)
Lepidium meyenii (Maca) improved semen parameters in adult
men. Asian. J Androl 3, 301–3.
97. Gonzales GF, Córdova A, Vega K, Chung A, Villena A, Gónez C,
Castillo S. (2002) Eect of Lepidium meyenii (Maca) on sexual
desire and its absent relationship with serum testosteron levels
in adult healthy men. Andrologia 34, 367–72.
98. Gonzales GF, Córdova A, Vega K, Chung A, Villena A, Gónez C.
(2003) Eect of Lepidium meyenii (Maca), a root with aphro-

130
131
disiac and fertility-enhancing properties, on serum reproductive
hormone levels in adult healthy men. J. Endocrinol 176, 163–8.
99. Oshima M, Gu Y, Tsukada S. (2003) Eects of Lepidium meyenii
Walp. and Jatropha macrantha on blood estradiol-17β, progeste-
rone, testosterone and the rate of embryo implantation in mice.
J Vet Med Sci 65, 1145–6.
100. Canales M, Aguilar J, Prada A, Marcelo A, Huaman C,
Carbajal L. (2000) Nutritional evaluation of Lepidium meyenii
(MACA) in albino mice and their descendant. Arch Latinoam
Nutr 50, 126–33.
101. Steskal D, Dvořáčková S, Volný T, Bartek J, Večeřa R, Škottová N,
Šimánek V. Combination of silymarin with yacon (Smallanthus
sonchifolius) as a prospective nutraceutical. In: Eklund T, De
Brabander H, Daeseleire E, Dirinck I, Ooghe W, editors. Euro
Food Chem XII Strategies for Safe Food. Proceedings Volume
2, Brugge, Belgium, 24–26 September 2003. Heverlee: KVCV
Centraal, 2003. p.741–4.
102. Directive 96/84/EC of the European Parliament and of the
Council of 19 December 1996 amending Council Directive
89/398/EEC of 3 May 1989 on the approximation of the laws of
the Member States relating to foodstus intended for particular
nutritional uses.
K. Valentová, J. Ulrichová