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Sterols and triterpenes from the fruit of Annona muricata Linn.

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Annona muricata Linn., commonly known as guyabano, is a well-known medicinal tree. The bioactivities of A. muricata are varied, but the commonly isolated compounds are acetogenins which exhibit anticancer properties. This study reports on the isolation of the sterols: β-sitosterone (1), β-sitosteryl fatty acid ester (2) and β-sitosterol (3); and the triterpenes: α-amyrin (4), β-amyrin (5) and squalene (6) from the dichloromethane extract of the freeze-dried fruit of Annona muricata Linn. Compounds 1-6 were isolated by silica gel chromatography and identified by NMR spectroscopy. These compounds were reported to possess diverse bioactivities.
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Sterols and Triterpenes From the Fruit of Annona muricata Linn.
Consolacion Y. Ragasa, Oscar B. Torres, Geneveve Soriano
Chemistry Department and Center for Natural Sciences and Ecological Research, De La Salle University
Manila, Philippines
Chien-Chang Shen
National Research Institute of Chinese Medicine Taipei, Taiwan
Annona muricata Linn., commonly known as guyabano, is a well-known medicinal tree. The bioactivities
of A. muricata are varied, but the commonly isolated compounds are acetogenins which exhibit
anticancer properties. This study reports on the isolation of the sterols:
β
-sitosterone (1),
β
-sitosteryl
fatty acid ester (2) and
β
-sitosterol (3); and the triterpenes:
α
-amyrin (4),
β
-amyrin (5) and squalene (6)
from the dichloromethane extract of the freeze-dried fruit of Annona muricata Linn. Compounds 1-6 were
isolated by silica gel chromatography and identified by NMR spectroscopy. These compounds were
reported to possess diverse bioactivities.
Keywords: Annona muricata, Annonaceae, sitosterone,
β
-sitosteryl fatty acid ester,
β
-sitosterol,
α
-
amyrin,
β
-amyrin, squalene
INTRODUCTION
A
nnona muricata Linn. of the family Annonaceae, commonly known as guyabano, is a well-
known medicinal tree with anti-bacterial (Oberlies et al., 1997), antiviral (Padma et
al., 1998; Betancur-Galvis et al., 1999), molluscicidal (Dos Santos & Sant’Ana,
2001), anti-oxidative stress (Adewole & Caxton-Martins,2006) and diuretic properties
(Quisumbing, 1951). The bioactivities of A. muricata are varied, but the commonly
isolated compounds are acetogenins which are known for their anticancer
properties.Annohexocin, a mono-THF annonaceous acetogenin from the leaves of A.
muricata, showed significant inhibitory effect against six human cancer cell lines:
lung, breast, colon, pancreatic, kidney carcinoma and prostate adenocarcinoma (Zeng
et al., 1995). Muricoreacin and murihexocin C, acetogenins from the leaves of A.
muricata, exhibited significant cytotoxicities against six human tumor cell lines
with selectivities to the prostate adenocarcinoma (PC-3) and pancreatic carcinoma
(PACA-2) cell lines (Kim et al, 1998a). Annomuricine and muricapentocin showed
significant cytotoxicities against six types of human tumors, with selectivity to
pancreatic carcinoma (PACA-2)and colon adenocarcinoma (HT-29) cell lines (Kim et
al.,1998b).In our earlier study, we reported the isolation of three acetogenins: cis-
annoreticuin and sabadelin from the fruit; and annoreticuin-9-one from the seeds of
A. muricata (Ragasa et al., 2012). Annoreticuin-9-one was earlier reported to exhibit
cytotoxic activities against the human pancreatic tumor cell line (PACA-2), human
prostate adenocarcinoma (PC-3) and human lung carcinoma (A-549) (Craig Hopp et
al.,1997), while cis-annoreticuin exhibited cytotoxicity against human hepatoma
carcinoma cell line (Hep G2) (Liaw et al., 2004). This article reports on the
VOL. 54 NO. 1 JANUARY TO JUNE 2013 SILLIMAN JOURNAL
108 STEROLS AND TRITERPENES FROM ANNONA MURICATA
isolation of the sterols: β-sitosterone (
1
),β-sitosteryl fatty acid ester (
2
) and
β-sitosterol (
3
); and the triterpenes:α-amyrin (
4
), β-amyrin (
5
), and squalene (
6
)
from the fruit of Annona muricata (Fig. 1). To the best of our knowledge, this is the
first report on the isolation of 1-6 from A. muricata.
1
O
R
2 R = CH
3
(CH
2
)nCOO
3 R = OH
HO
5
HO
4
6
H
H
H
H
H
H
Figure 1. The sterols: β-sitosterone (1), β-sitosteryl fatty acid ester (2) and β-sitosterol (3), and triterpenes: α-
amyrin (4), β-amyrin (5), and squalene (6) from the freeze-dried fruit of Annona muricata.
MATERIALS AND METHODS
General Experimental Procedures
NMR spectra were recorded on a Varian VNMRS spectrometer in CDCl
3
at 600 MHz for
1
H
NMR and 150 MHz for
13
C NMR spectra.Column chromatography was performed with silica
gel 60 (70-230 mesh). Thin layer chromatography was performed with plastic backed
plates coated with silica gel F
254
and the plates were visualized by spraying with
vanillin/H
2
SO
4
followed by warming.
Plant Material
The Annona muricata Linn. fruits were collected from Painaan, Rizal,Philippines in
September 2012. The specimens of the plant were authenticated at the Bureau of Plant
industry, Quirino Avenue,Manila, Philippines.
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C.Y. RAGASA, ET AL. 109
Extraction and Isolation
The flesh of the A. muricata fruit (3 kg) was separated from the seeds and fruit
peel,and then freeze-dried. The freeze-dried flesh of the fruit (550 g) was ground in
a blender, soaked in CH
2
Cl
2
for three days and then filtered. The filtrate was
concentrated under vacuum to afford a crude extract (5 g). The crude extract was
fractionated by silica gel chromatography using increasing proportions of acetone in
CH2Cl2 (10% increment)as eluents. A glass column 18 inches in height and 1.0 inch
internal diameter was used for the fractionation of the crude extract. Five
milliliter fractions were collected. Fractions with spots of the same Rf values were
combined and rechromatographed in appropriate solvent systems until TLC pure isolates
were obtained. A glass column of 30.5 cm height and 1.3 cm internal diameter was used
for the rechromatography. Two milliliter fractions were collected. Final
purifications were conducted using Pasteur pipettes as columns. One milliliter
fractions were collected. The CH
2
Cl
2
fraction from the chromatography of the crude
extract was rechromatographed using petroleum ether as eluent. The less polar
fractions were rechromatographed (3x) in petroleum ether to afford 6 (6 mg). The more
polar fractions were rechromatographed (2x) in petroleum ether to afford 1 (4 mg).
The 10% and 20% acetone in CH
2
Cl
2
fractions were combined and rechromatographed (2x)
using 1% EtOAc in petroleum ether, followed by 2.5% EtOAc in petroleum ether and
finally, 5% EtOAc in petroleum ether to afford 2 (9 mg).The 30% and 40% acetone in
CH
2
Cl
2
fraction was rechromatographed using 5% EtOAc in petroleum ether, followed by
7.5% EtOAc in petroleum ether and finally, 10% EtOAc in petroleum ether to afford 3
(12 mg) and a mixture of 4 and 5 (8 mg) after washing with petroleum ether.
RESULT S AND DISCUSSION
The dichloromethane extract of the freeze-dried fruit of Annona muricata afforded the
sterols: β-sitosterone (1), β-sitosteryl fatty acid ester (2) and β-sitosterol
(3); and the triterpenes: α-amyrin (4), β-amyrin (5), and squalene (6) by silica
gel chromatography. The structures of
1
and
2
were elucidated by extensive 1D and 2D
NMR spectroscopy and confirmed by comparison of their
13
C NMR data with those reported
in the literature for β-sitosterone (Prachayasittikul et al., 2009) andβ-sitosteryl
fatty acid ester (Julien-David et al., 2008), respectively. The structures of
3
-
6
were identified by comparison of their
13
C NMR data with those reported in the
literature for β-sitosterol (Kojima et al., 1990), α-amyrin (Mahato & Kundo, 1994),
β-amyrin (Mahato & Kundo, 1994), and squalene (Brown & Martens, 1977), respectively.
Literature search revealed that the compounds isolated from Annona muricata were
reported to possess diverse bioactivities.β-Sitosterone exhibited significant
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110 STEROLS AND TRITERPENES FROM ANNONA MURICATA
hypoglycemic (Alexander-Lindo et al., 2007), antiarrhythmic (Hotta et al., 2003) and
pronounced antitubercular (Saludes et al., 2002) activities. β-Sitosterol had been
shown to inhibit proliferation and induce apoptosis in human solid tumors such as
colon and breast cancers (Park et al., 2007). α-Amyrin and β-amyrin were reported
to possess anti-inflammatory (Recio et al., 1995; Madeiros et al., 2007) and
analgesic properties (Otuki et al., 2005; Soldi et al., 2008). Squalene had shown
cardioprotective effect which is related to inhibition of lipid accumulation by its
hypolipidemic properties and/or its antioxidant properties (Farvin et al., 2006).
Furthermore, this triterpene significantly suppresses colonic ACF formation and crypt
multiplicity which strengthens the hypothesis that it possesses chemopreventive
activity against colon carcinogenesis (Rao et al., 1998).
CONCLUSION
Compounds 1-6 which were isolated for the first time from A. muricata were reported to
possess diverse biological activities. β-Sitosterone exhibited significant
hypoglycemic, antiarrhythmic and antitubercular activities, while β-sitosterol
inhibited proliferation and induced apoptosis in human solid tumors. α-Amyrin and
β-amyrin were reported to possess anti-inflammatory and analgesic properties,while
squalene showed cardioprotective effect and significantly suppressed colonic ACF
formation and crypt multiplicity.
REFERENCES
Adewole, S.O., & Caxton-Martins, E.A. (2006). Morphological changes and hypoglycemic effects of Annona
muricata Linn. (Annonaceae) leaf aqueous extract on pancreatic B-cells of streptozotocin-treated diabetic
rats. African Journal of Biomedical Research, 9, 173–87.
Alexander-Lindo, R.L., Morrison, E.Y.S.A., Nair. M.G., & McGrowder, D.A. (2007). Effect of the fractions
of the hexane bark extract and stigmast-4-en-3-one isolated from Anacardium occidentale on blood glucose
tolerance test in an animal model. International Journal of Pharmacollogy, 3, 41-47.
Betancur-Galvis, L., Saez, J., Granados, H., Salazar, A., & Ossa, J. (1999). Antitumor and antiviral
activity of Colombian medicinal plant extracts. Mem Inst Oswaldo Cruz, 94, 531–535.
Brown, J.A., & Martens, D.R.M. (1977). An assessment of the mobility of squalene in part-aqueous
solutions from carbon magnetic resonance spin-lattice relaxation times. Comparison of squalene and 2,3-
dihydroxy-2,3-dihydrosqualene. Tetrahedron, 33, 931-935.
Craig Hopp, D., Zeng, L., Gu, Z.-M., Kozlowski, J.F., & McLaughlin, J.L. (1997). Novel mono-
tetrahydrofuran ring acetogenins, from the bark of Annona squamosa, showing cytotoxic selectivities for
the human pancreatic carcinoma cell line, PACA-2. Journal of Natural Products, 60, 581–586.
SILLIMAN JOURNAL JANUARY TO JUNE 2013 VOL. 54 NO. 1
C.Y. RAGASA, ET AL. 111
Dos Santos, A.F., & Sant’Ana, A.E.G. (2001). Molluscicidal properties of some species of Annona.
Phytomedicine, 82, 115–20.
Farvin, K.H.S., Anandan, R., Hari, S., Kumar, S., Shing, K.S., Mathew, S., Sankar, T.V., & Nai, P.G.V.
(2006). Cardioprotective effect of squalene on lipid profile in isoprenaline-induced myocardial
infarction in rats. Journal of Medicinal Food, 9, 531-536.
Hotta, K., Noguchi, Y., Matsunaga, M., Nishibe, K., Uchida, K., Shimizu, K., Kono, T., & Sumio, K.
(2003). Leonurus heterophyllus extracts and β-sitostenone as antiarrhythmics. JP Pat. 2003113107, 2003;
[Chem. Abstr. 2003, 138: 297657].
Julien-David, D., Geoffroya, P., Marchionib, E., Raulc, F., Aoud´e-Wernerd, D., & Miescha, M. (2008).
Synthesis of highly pure oxyphytosterols and (oxy) phytosterol esters Part II. (Oxy)-sitosterol esters
derived from oleic acid and from 9,10-dihydroxystearic acid. Steroids, 73, 1098–1109.
Kim, G.-S., Lu, Z., Feras, A.L.L., Rogers, L.L., Wu, F-E., Sastrodihardjio, S., & Mclaughlin, J.L.
(1998a). Muricoreacin and murihexocin C, monotetrahydrofuran acetogenins from the leaves of Annona
muricata. Phytochemistry, 49, 565-571.
Kim, G.-S., Zeng, L., Alali, F., Rogers, L.L., Wu, F.-E., McLaughlin, J.L., & Sastrodihardjo, S.
(1998b). Two new mono-tetrahydrofuran ring acetogenins, annomuricin E and muricapentocin, from the
leaves of Annona muricata. Journal of Natural Products, 61, 432-6.
Kojima, H., Sato, N., Hatano, A., Ogura, H. (1990). Sterol glucosides from Prunella vulgaris. Phytochemistry,
29, 2351-2355.
Liaw, C.-C., Chang, F.-R., Wu, C.-C., Chen, S.-L., Bastow, K.F., Hayashi, K.-I., Nozaki, H., Lee, K.-H.,
& Wu, Y.-C.. (2004). Nine new cytotoxic monotetrahydrofuranic annonaceous acetogenins from Annona
montana. Planta Medica, 70, 948–59.
Madeiros, R., Otuki, M.F., Avellar, M.C., & Calixto, J.B.. (2007). Mechanisms underlying the inhibitory
actions of the pentacyclic triterpene α-amyrin in the mouse skin inflammation induced by phorbol ester
12-O-tetradecanoylphorbol-13-acetate. European Journal of Pharmacology, 55, 227-235.
Mahato, S.B., & Kundo, A.P. (1994).
13
C NMR spectra of pentacyclic triterpenoids A compilation of some
salient features. Phytochemistry, 37, 1517-1575.
Oberlies, N.H., Croy, V.L., Harrison, M.L., & McLaughlin, J.L. (1997). The Annonaceous acetogenin
bullatacin is cytotoxic against multidrug-resistant human mammary adenocarcinoma cells. Cancer Letters,
115, 73–9.
Otuki, C., Ferreira, J., Lima, F., Meyre-Silva, C., Madeiros, A., Muller, L., Can, G., Santos, A.,
Yunes, R., & Calixto, J. (2005). Antinociceptive properties of a mixture of α-amyrin and β-amyrin
triterpenes: evidence for participation of protein kinase C and protein kinase A pathways. Journal of
Pharmacology and Experimental Therapeutics, 31, 310-318.
Padma, P., Pramod, N.P., Thyagarajan, S.P., Khosa, R.L. (1998). Effect of the extract of Annona muricata
and Petunia nyctaginiflora on herpes simplex virus. Journal of Ethnopharmacology, 61, 81–3.
VOL. 54 NO. 1 JANUARY TO JUNE 2013 SILLIMAN JOURNAL
112 STEROLS AND TRITERPENES FROM ANNONA MURICATA
Park, C., Moon, D., Choi, B.T., Lee, W.H., Kim, G., & Choi, Y.H. (2007). β-Sitosterol induces anti-
proliferation and apoptosis in human leukemic U937 cells through activation of caspase-3 and induction
of Bax/Bcl-2 ratio. Biological & Pharmaceutical Bulletin, 30, 1317-1323.
Prachayasittikul, S., Suphapong, S., Worachartcheewan, A., Lawung, R., Ruchirawat, S., &
Prachayasittikul, V. (2009). Bioactive Metabolites from Spilanthes acmella Murr. Molecules, 14, 850-867.
Quisumbing, E. (1951). Medicinal plants of the Philippines. Manila: Katha Publishing.
Ragasa, C.Y., Soriano, G., Torres, O.B., & Shen, C.-C. (2012). Acetogenins from Annona muricata.
Pharmacognosy Journal, 4, 32-37.
Rao, C.V., Mark, H.L.N., & Reddy, B.S. (1998). Chemopreventive effect of squalene on colon cancer.
Carcinogenesis, 19, 287-290.
Recio, M.C., Giner, R.M., Manez, S., & Rios, J.L. (1995). Structural requirements for the anti-
inflammatory activity of natural triterpenoids. Planta Medica, 61, 181-185.
Saludes, J.P., Garson, M.J., Franzblau, S.G., & Aguinaldo, A.M. (2002). Antitubercular constituents from
the hexane fraction of Morinda citrifolia Linn. (Rubiaceae). Phytotherapy Resesearch, 16, 683-685.
Soldi, C., Pizzolatti, G., Luiz, A., Marcon, R., Meotti, F., Miobtob, L., & Santos, A. (2008). Synthetic
derivatives of the α- and β-amyrin triterpenes and their antinociceptive properties. Bioorganic
Medicinal Chemistry, 16, 3377-3386.
Zeng, L., Wu, F.-E., McLaughlin, J.L. (1995). Annohexocin, a novel mono-THF acetogenin with six
hydroxyl, from Annona muricata (Annonaceae). Bioorganic Medicinal Chemistry Letters, 5, 1865-1868.
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... The results were supported the previous study that indicated the presence of secondary metabolites like tannins, steroids, cardiac glycosides in Annona muricata L. leaf extract [3]. Sterols that have been isolated from Annona muricata are β sitosterone, β sitosteryl fatty acid ester, and β sitosterole, whereas hypoglycemic effect caused by β sitosterone activities [17]. ...
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The 1H and 13C NMR spectra of sitosterol, stigmasterol, stigmast-7-en-3β-ol and spinasterol have been unambiguously assigned by use of HOMCOR and HETCOR techniqeus. The extensive application of these results leads to the direct identification of a mixture of the four β-d-glucopyranosides of the sterols, which were obtained from Prunelia vulgaris.
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The study was undertaken to investigate the possible effect(s) of the hexane extract of the bark of Anacardium occidentale (cashew) and the fractions collected at different stages of the purification process on glucose tolerance in normoglycaemic dogs. The possible hypoglycaemic effect of stigmast-4-en-3-one isolated from the hexane extract of the bark of Anacardium occidentale and cholest-4-en-3-one was also investigated. The hexane extract of the bark of Anacardium occidentale was administered at 300 mg kg<sup>-1</sup> Body Weight (BW) to normoglycaemic dogs followed by an oral glucose tolerance test. There was significant reduction in the fasting and postprandial blood glucose concentrations especially at the 1.0 and 2.0 h time points (p<0.05). Subsequent fractions of the hexane extract of the bark of Anacardium occidentale showed a hypoglycaemic effect on fasting and postprandial blood glucose concentrations. A hypoglycaemic assay guided extraction, isolation and structure elucidation produced stigmast-4-en-3-one. Stigmast-4-en-3-one administered at 3 mg kg<sup>-1</sup> BW produced significant reductions in the postprandial blood glucose concentrations especially at the 1.5 h time point (p<0.05). Cholest-4-en-3-one at 3 mg kg<sup>-1</sup> BW (i.v.) was found to be more potent than stigmast-4-en-3-one at the 1.5 h time point (p<0.05). The results indicate that stigmast-4-en-3-one isolated from hexane extract of the bark of Anacardium occidentale possesses hypoglycaemic activity and this lends credence to the suggested use of this herb in the control and/or management of type 2 diabetes mellitus in Jamaica and other Caribbean islands.