Phytochemical Profiling of Echinacea Genus: A mini Review of Chemical Constituents of Selected Species

Abstract

The Echinacea genus is known for its medicinal properties, particularly its immune-stimulating effects. Thus, it makes a significant focus of phytochemical research. This literature review provides a short overview of the chemical constituents found within the Echinacea genus, with a primary emphasis on E. purpurea, E. angustifolia, and E. pallida, the three most extensively studied species. The constituents discussed include alkamides, polysaccharides, glycoproteins, phenolic compounds, and flavonoids, which are derived from various plant parts, such as roots, stems, leaves, and flowers. Detailed insights into the structural diversity, distribution, and biological significance of these compounds are presented. Additionally, key differentiating markers for species identification are highlighted, aiding researchers and herbal practitioners in understanding the chemical complexities of Echinacea species. This review offers information for the development of herbal medicines and supplements, shedding light on the potential therapeutic benefits of chemical constituents of these species.

Full text

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Phytochemical profiling of Echinacea Genus: A mini review of
chemical constituents of selected species
Đặc điểm hóa thực vật của chi Echinacea: tổng quan ngắn về thành phần hóa học
của một số loài
Truong Thi Diem Quynha, Tran Thi Diem Thuyb, Pham Vu Khiemc,
Nguyen Viet Thiend,e, Ha Hai Anhb,f,*
Trương Thị Diễm Quỳnha, Trần Thị Diễm Thùyb, Phạm Vũ Khiêmc,
Nguyễn Việt Thiênd,e, Hà Hải Anhb,f,*
aK24YDH5, College of Medicine and Pharmacy, Duy Tan University, Da Nang, 550000, Vietnam
aK24YDH5, Trường Y Dược, Đại học Duy Tân, Đà Nẵng, Việt Nam
bFaculty of Pharmacy, College of Medicine and Pharmacy, Duy Tan University, Da Nang, 550000, Vietnam
bKhoa Dược, Trường Y Dược, Đại học Duy Tân, Đà Nẵng, Việt Nam
cHerbitech technology Co., Ltd, Ha Noi, 100000, Vietnam
cCông ty TNHH Công nghệ Herbitech, Hà Nội, Việt Nam
dQuang Nam Department of Health, Quang Nam, 560000, Vietnam
dSở Y tế Quảng Nam, Quảng Nam, Việt Nam
eViet Institute of Medicine and Pharmacy, Ho Chi Minh City, 700000, Vietnam
eViện Y Dược Việt, TP. Hồ Chí Minh, Việt Nam
fDa Nang Pharmaceutical Association, Da Nang, 550000, Vietnam
fHội Dược học Đà Nẵng, Đà Nẵng, Việt Nam
(Ngày nhận bài: 18/9/2023, ngày phản biện xong: 10/10/2023, ngày chấp nhận đăng: 18/10/2023)
Abstract
The Echinacea genus is known for its medicinal properties, particularly its immune-stimulating effects. Thus, it makes a
significant focus of phytochemical research. This literature review provides a short overview of the chemical
constituents found within the Echinacea genus, with a primary emphasis on E. purpurea, E. angustifolia, and E. pallida,
the three most extensively studied species. The constituents discussed include alkamides, polysaccharides,
glycoproteins, phenolic compounds, and flavonoids, which are derived from various plant parts, such as roots, stems,
leaves, and flowers. Detailed insights into the structural diversity, distribution, and biological significance of these
compounds are presented. Additionally, key differentiating markers for species identification are highlighted, aiding
researchers and herbal practitioners in understanding the chemical complexities of Echinacea species. This review
offers information for the development of herbal medicines and supplements, shedding light on the potential therapeutic
benefits of chemical constituents of these species.
Keywords: Echinacea; E. purpurea; E. angustifolia; E. pallida; chemical constituents.
*Corresponding Author: Ha Hai Anh
Email: hahaianh@dtu.edu.vn
5(60) (2023) 123-131

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Tóm tắt
Chi Echinacea được biết đến với khả năng sử dụng làm thuốc, đặc biệt là khả năng kích thích hệ miễn dịch. Vì vậy, chi
này là một trọng điểm quan trọng trong nghiên cứu về hóa học cây cỏ. Bài tổng quan này cung cấp một cái nhìn tổng
thể về các thành phần hóa học được tìm thấy trong chi Echinacea, tập trung chủ yếu vào E. purpurea, E. angustifolia và
E. pallida, ba loài phổ biến nhất, đã có nhiều nghiên cứu được triển khai. Các thành phần được thảo luận bao gồm
alkamid, polysaccharid, glycoprotein, các hợp chất phenolic và flavonoid, có thể chiết xuất từ nhiều bộ phận dùng khác
nhau, chẳng hạn như rễ, thân, lá và hoa. Bài viết cũng cung cấp thông tin chi tiết về sự đa dạng về cấu trúc, phân bố và
ý nghĩa sinh học của những hợp chất này. Ngoài ra, những dấu hiệu khác biệt quan trọng để nhận biết các loài thông
qua thành phần hóa học cũng được nêu đề cập, giúp các nhà nghiên cứu và các chuyên gia về thảo dược hiểu sâu về sự
phức tạp về hóa học của các loài Echinacea. Bài tổng quan này cung cấp thông tin nhằm thúc đẩy phát triển các loại
thuốc thảo dược và thực phẩm bổ sung, đồng thời làm sáng tỏ về tiềm năng lợi ích trong trị liệu từ những thành phần
hóa học trong nhóm cây thuốc này.
Từ khóa: Echinacea; E. purpurea; E. angustifolia; E. pallida; thành phần hóa học.
1. Introduction
The genus Echinacea, comprising several
species commonly known as coneflowers, has
garnered substantial attention in both botanical
and pharmaceutical research due to its immune-
stimulating properties and diverse
pharmacological effects [9,12]. Among the
Echinacea species, E. purpurea, E.
angustifolia, and E. pallida have emerged as
focal points of investigation, predominantly for
their roles in traditional herbal medicine
(Figure 1) [4,9,16]. These species exhibit a
remarkable versatility in terms of their
medicinal applications, with various plant parts,
including roots, stems, leaves, and flowers,
being employed to harness their therapeutic
potential.
Figure 1: Flowers of E. purpurea, E. angustifolia and E. pallida
With the valuable characteristics mentioned
above, the Echinacea genus is in high demand
globally, resulting in substantial import and
export volumes [25]. Vietnam boasts a diverse
ecosystem that is well-suited for the cultivation
and development of medicinal plants,
characterized by a rich biodiversity [3,13].
However, Vietnam has not yet engaged in the
promising Echinacea medicinal herb market.
Researching the phytochemical characteristics
of Echinacea species holds the potential to
enhance our knowledge base and provide a
foundation for subsequent experimental studies
aimed at identifying the most suitable species
for cultivating medicinal herbs within local
regions.
Reports on the phytochemistry of Echinacea
are primarily limited to three important species:
E. purpurea, E. angustifolia, and E. pallida,
which are utilized in medicine due to their
immune-stimulating properties and various
pharmacological effects. Plant parts used
include the roots, stems, leaves, and flowers,
with E. purpurea being more commonly used
than E. angustifolia and E. pallida [2]. From
the extracted Echinacea species, several groups

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of important compounds have been identified,
including alkamides, polysaccharides,
glycoproteins, flavonoids, and phenolic
compounds [7].
Alkamides
Alkamides, also known as alkylamides, are
amides of fatty acids isolated from the Echinacea
genus. They possess a distinctive structure,
comprising an amide head and a hydrocarbon tail
derived from various fatty acids with differing
chain lengths and numbers of double and triple
bonds [6]. Structurally, alkamides are naturally
occurring compounds formed by linking straight-
chain aliphatic acids, primarily unsaturated, to
various amines through amide bonds. Apart from
a few saturated derivatives, alkamides include
pure olefinic compounds and compounds with
both olefinic and acetylenic bonds. Originating
from oleic acid (C18), the acid portions are
modified by extending the chain to C28 or
shortening through oxidative cleavage to C4. The
presence of 2-methylbutylamine, a cyclic amine,
is characteristic of the Asteraceae family.
Alkamides reported from E. angustifolia and E.
purpurea are mainly acetylenic, with a few pure
olefinic structures. Alkamides are characteristic
chemical constituents in the roots of E.
angustifolia and the whole plant of E. purpurea.
However, E. pallida roots lack alkamide
compounds but contain polyacetylenes [15]. In
the n-hexane extract of E. purpurea roots, 10
alkamides have been isolated, with majority
containing isobutylamide and 2-
methylbutylamide. Chloroform extraction of E.
purpurea roots resulted in the purification and
isolation of alkamides, with the majority of these
compounds containing 2,4-dienoic structures
[4-6,21].
Polysaccharides
Two polysaccharides (PS I and PS II) have
been isolated from the aerial parts of E.
purpurea. Their structures were identified as 4-
O-methyl-glucuronoarabinoxylan (average MW
35,000) and acidic arabinorhamnogalactan
(MW 50,000). Polysaccharides isolated from E.
purpurea roots exhibit a similar composition to
those from its aerial parts. Leaves and stems of
E. purpurea contain a polysaccharide
resembling pectin, while E. angustifolia roots
are reported to contain 5.9% inulin [4,9,21].
Glycoproteins
Three glycoproteins with molecular weights
of 17,000, 21,000, and 30,000, containing
approximately 3% protein, have been isolated
from the roots of E. angustifolia and E.
purpurea. ELISA assays revealed that the main
protein components in the roots of E.
angustifolia and E. purpurea are aspartate,
glycine, glutamate, and alanine, while the major
sugars identified are arabinose (64% to 84%),
galactose (1.9% to 5.3%), and glucosamine
(6%). However, E. pallida roots contain fewer
glycoproteins compared to the roots or any
other part of E. purpurea and E. angustifolia
[2,4,21].
Phenolic compounds
Derivatives of caffeic acid represent a major
group of phenolic constituents found in all
Echinacea species. Among the two main
derivatives of caffeic acid, chicoric acid
exhibits greater pharmacological effects
compared to echinacoside. Additionally, small
amounts of chlorogenic acid and isochlorogenic
acid have been identified in both the leaves and
roots of E. angustifolia and E. pallida. Some
representative structures of phenolic
compounds found in the Echinacea genus are
chicoric acid, echinacoside, chlorogenic acid
and isochlorogenic acid [17,21-22].
Caffeoylquinic and caffeoyltartaric esters
constitute characteristic phenolic components
of E. angustifolia, E. purpurea, and E. pallida.

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Each species exhibits distinct features, with
varying caffeoyl conjugation patterns in
different plant parts.
Chicoric acid is ubiquitously distributed
throughout the entire Echinacea plant, while
echinacoside is primarily concentrated in the
roots, with smaller amounts found in the
flowers and leaves of species within the
Echinacea genus. The content of chicoric acid
is notably higher in E. purpurea compared to E.
angustifolia and E. pallida.
The roots of E. angustifolia primarily
contain echinacoside as the major caffeoyl
component, lacking chicoric acid. This species
is further characterized by the presence of
cynarin (1,3-dicaffeoylcaffeoyl quinic acid) and
1,5-dicaffeoylquinic acid in its roots,
distinguishing it from both E. purpurea and E.
pallida. Similarly, the absence of echinacoside
in the rootstocks of E. purpurea and E. pallida
serves as a distinguishing feature from E.
angustifolia [11,23,26].
Moreover, it has been demonstrated that E.
purpurea leaves contain methyl esters of
chicoric acid, namely, 2-caffeoyl-3-
feruloyltartaric acid, 2,3-diferuloyltartaric acid,
2-feruloyltartaric acid, and 2-caffeoyl-3-p-
coumaroyltartaric acid. Notably, E. purpurea
lacks echinacoside [17,21].
Flavonoids
The concentration of flavonoids in the three
Echinacea species is relatively low. Common
flavonoids found in Echinacea leaves include
luteolin, kaempferol, quercetin, quercetin-7-
galactoside, luteolin-7-glucoside, kaempferol-
3-glucoside, quercetin-3-arabinoside, quercetin-
3-galactoside, quercetin-3-xyloside, quercetin-
3-glucoside, kaempferol-3-rutinoside, rutin, and
isorhamnetin-3-rutinoside. Rutin is a major
flavonoid present in the leaves of E.
angustifolia, E. purpurea, and E. pallida. The
typical structures of some flavonoids can be
found as phenonic compounds, such as luteolin,
rutosid, kaempferol, quercetin, isorhamnetin
and its derivatives [21].
Anthocyanins contribute predominantly to
the plant pigmentation found in the flowers of
Echinacea species. The main anthocyanins
identified are cyanidin-3-O-β-glucopyranoside
and cyanidin-3-O-6-malonyl-β-D-
glucopyranoside [16,21]. The absence of
polyacetylenes from the roots of E. angustifolia
and E. purpurea serves to distinguish products
derived from E. pallida from those of the two
aforementioned species. In comparison to
echinacoside and chicoric acid, both
chlorogenic and isochlorogenic acids are
relatively minor constituents in the Echinacea
genus.
Furthermore, E. purpurea leaves contain
methyl esters of chicoric acid, such as 2-
caffeoyl-3-feruloyltartaric acid, 2,3-
diferuloyltartaric acid, 2-feruloyltartaric acid,
and 2-caffeoyl-3-p-coumaroyltartaric acid,
whereas echinacoside is not present in E.
purpurea. Conversely, E. angustifolia roots are
characterized by echinacoside without chicoric
acid, while the presence of cynarin (1,3-
dicaffeoylcaffeoyl quinic acid) and 1,5-
dicaffeoylquinic acid in its roots distinguishes it
from both E. purpurea and E. pallida. These
differences serve as key markers for species
differentiation [11,23,26].
2. The distribution of chemical compounds
within different parts of Echinacea
The distribution of chemical compounds
within different parts of Echinacea plants
reveals interesting variations and potential
implications for their medicinal properties. The
distribution of chemical compounds within
different parts of Echinacea plants highlights
the complexity of its phytochemical profile
[5,21]. This complexity may have implications
for the overall therapeutic potential of the herb,

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and suggests that different parts of the plant
could be utilized for specific medicinal
purposes. Further research is needed to explore
the specific health benefits associated with each
compound and plant part.
The main chemical composition of
Echinacea purpurea, as reported by previous
studies [4-5,8,21], outlined in Table 1. These
chemical constituents are of significant
importance in both botanical and
pharmaceutical research, as they underlie the
potential therapeutic properties associated with
E. purpurea. The chemical composition of E.
purpurea is characterized by a wide range of
bioactive compounds distributed across
different plant parts. The root, with its
alkamides and glycoproteins, appears to be a
particularly valuable source of bioactive
compounds. Additionally, the presence of
polysaccharides, caffeic acid derivatives, and
volatile oils in various plant parts underscores
the complexity of the chemical profile of E.
purpurea.
Table 1. Summary of chemical components found in some parts of E. purpurea
No.
Compound/group
Part(s)
1
Alkamide
Root, aerial part
2
Glycoprotein
Root
3
Polysaccharides, including PSI and PSII
Aerial part
Pectin-like polysaccharide
Leaves and stems
4
* Derivatives of caffeic acid:
- Chicoric acid (acid 2,3-dicaffeoyl tartaric)
- Caftaric acid (acid 2-caffeoyltartaric),
chlorogenic acid.
Root, aerial part
- Chicoric acid is more abundant in
the flowers compared to the leaves
and stems
- Leaf: methyl esters of chicoric acid
5
- Volatile oils: ~ 0,2%
- Caryophyllene (2,1%), Humulene (0,6%) and
Caryophyllene epoxide (1,3%).
- α-pinene, α-phellandrene, β-farnesene, myrcene,
limonene, carvomenthene, caryophyllene.
Root
The chemical composition of Echinacea
angustifolia, as summarized from earlier
studies [14,21], presented in Table 2. The
chemical composition of E. angustifolia
demonstrates a diverse array of bioactive
compounds distributed across various plant
parts. This distribution underscores the
importance of selecting the appropriate plant
part for medicinal or research purposes. The
root, with its high content of alkamides,
glycoproteins, and phenolic compounds, is a
valuable source of bioactive compounds and is
commonly utilized in traditional herbal
medicine. The presence of inulin in the root and
additional phenolic compounds in the leaves
further adds to the potential therapeutic value of
the plants. Comprehensive research is needed to
investigate the synergistic interactions among
these compounds and their specific health
benefits. This detailed knowledge of chemical
composition of E. angustifolia is essential for
harnessing its full potential in herbal medicine
and pharmaceutical applications.

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Table 2. Summary of chemical components found in some parts of E. angustifolia
No.
Compound/group
Part(s)
1
Alkamide
Root
2
Glycoprotein
Root
3
Polysaccharid (inulin 5%)
Root
4
*Phenolic:
- Echinacoside (caffeoyl derivative)
- Phenylethanoid glycosid
Root
*Other phenolic:
- Chlorogenic acid
- Isochlorogenic acid
Leave and root
5
- Volatile oils: α-phellandrene.
Root
The chemical composition of E. pallida, as
summarized from previous studies [21,24], to
be outlined in Table 3. The chemical
composition of E. pallida is characterized by a
variety of bioactive compounds distributed
across different plant parts. The root, in
particular, appears to be rich in polyacetylenes,
hydrocarbons, chicoric acid, and
phenylethanoid glycosides, all of which may
play essential roles in the defense mechanisms
and other potential medicinal properties of the
herbs. Additionally, the presence of phenolic
compounds such as chlorogenic acid and
isochlorogenic acid in both leaves and roots
highlights the complexity of chemical profile of
E. pallida.
Table 3. Summary of chemical components found in some parts of E. pallida
No.
Compound/group
Part(s)
1
- Major hydrocacbons:
+ Ketoankene
+ Ketoalkyne
+ Other polyacetylenes
Root
2
Chicoric acid (Acid 2,3-dicaffeoyl tartaric).
Root
3
- Phenolic: Phenylethanoid glycoside.
Root
4
*Phenolic
- Chlorogenic acid
- Isochlorogenic acid
Leave and root
3. Chemical compositions of three common
Echinacea species and its potential
bioactivities
The sharing chemical composition of all
three Echinacea species (E. purpurea, E.
angustifolia, and E. pallida) [4,8,10,19-21], as
summarized in Table 4, reveals a complex array
of bioactive compounds, and they underpin the
therapeutic potential and biological activity
associated with Echinacea.

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Table 4. Chemical components of the genus Echinacea and potential bioactivities
No.
Compound/group
Potential bioactivities
1
Alkamide
Immunomodulation and anti-
inflammatory effects
2
Volatile oils
Terpenoid: α-pinene, β-pinene, β-myrcene, ocimene,
limonene, camphene, terpinene
Terpenoids have diverse
pharmacological properties, including
antimicrobial and anti-inflammatory
effects
3
Phenolic compounds, such as chicoric acid and
echinacoside
known for antioxidant properties and
may contribute to the overall
medicinal effects of the plants.
4
Flavonoids (luteolin, kaempferol, quercetin,
quercetin-7-galactoside, luteolin-7-glucoside,
kaempferol-3-glucoside, quercetin-3-arabinoside,
quercetin-3-galactoside, quercetin-3-xyloside,
quercetin-3-glucoside, kaempferol-3-rutinoside,
rutoside and isorahmnetin-3-rutinoside).
Known for their antioxidant and anti-
inflammatory properties
Although their concentration is
relatively low, they may still
contribute to the overall health
benefits of Echinacea
5
Anthocyanins: (responsible for the vibrant
pigmentation of Echinacea flowers):
cyanidin-3-O-β-glucopyanoside and cyanidin-3-
O-6-malonyl-β-D-glucopyranoside.
These compounds are of particular
interest for their potential antioxidant
and anti-inflammatory properties
Due to the important role of Echinacea and
the significance of its chemical constituents,
various studies have employed biotechnological
methods to enhance the yield of certain
bioactive compounds, with a particular focus on
the caffeic derivatives group[1,18-19,22,24].
The Figure 2 illustrates the molecular structures
of compounds derived from Echinacea,
demonstrating their potential production
through biotechnological methods [22]. In
particular, the compounds echinacoside,
cynarin, and chlorogenic acid are highlighted as
important chemical components with
substantial potential for further growth in the
pharmaceutical and cosmetics industries
[8,18,22]. Biotechnological approaches offer a
promising avenue for the sustainable and
controlled synthesis of these bioactive
compounds, ensuring a reliable source for
pharmaceutical and nutraceutical industries.

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Figure 2: Chemical structures of echinacea-derived compounds biosynthesized for use in pharmaceutical
and cosmetics industries
4. Conclusion
Overall, the distribution of these chemical
compounds across different plant parts of
Echinacea species highlights the importance of
considering the specific plant part used for
medicinal or research purposes. The roots, with
their high concentration of phenolic compounds
and terpenoids, may be particularly valuable for
traditional medicinal applications. Conversely,
the leaves and flowers, with their flavonoid and
anthocyanin content, may also contribute to the
overall therapeutic potential of Echinacea.
Further research is needed to explore the
synergistic interactions of these compounds and
their specific health benefits. This detailed
understanding of chemical composition of
Echinacea may aid in harnessing its full
potential in herbal medicine and
pharmaceuticals.
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