Cycloastragenol glycosides from Astragalus illyricus (original) (raw)

Secondary metabolites from the roots of Astragalus maximus

2017

Background and objectives: Astragalus is one of the most abundant genera of flowering plants in Iran. There are a few reports on phytochemical investigation of this valuable genus. Saponins, flavonoids and polysaccharides have been reported as the most important metabolites in Astragalus species. In the present research, we aimed to identify the foremost constituents of Astragalus maximus. Method: Phytochemical analysis of the ethyl acetate (EtOAc) fraction of Astragalus maximus roots was performed using different methods of chromatography such as HPLC, SPE and preparative TLC. The structures of the isolated compounds were elucidated on the basis of extensive spectral evidence from 1D and 2D NMR including DQF-COSY, HSQC, HMBC, and DEPT, in comparison with reported values in the literature. Results: Analysis of the extract yielded three flavonoids namely liquiritigenin, formononetin, isoquercitrin and one acylated cycloartane-type saponin, astragaloside I. Conclusion: According to th...

Secondary metabolites of genus Astragalus: Structure and biological activity

Studies in Natural Products Chemistry, 2002

Astragalus L. is the largest genus in the family Leguminosae (subfamily Papilionideae, tribe Galegeae). Widely distributed throughout the temperate region of the world, is principally located in Europe, Asia and North America, but also on mountains in Africa and South America. They are annual and perennial herbs or small shrubs. Astragalus species are divided in two main groups: the medicinal plants and the poisonous species. "Astragali radix" (dried roots of ^4. membranaceous Bunge and other Astragalus spp.) represents a very old and well known drug in traditional Chinese medicine. They are officially listed in the Chinese Pharmacopoeia and prescribed mainly as an antiperspirant, a diuretic and a tonic, but also for their hepatoprotective, antioxidative, immunostimulant and antiviral properties. The other most common use of Astragalus is as forage for liverstock and wild animals; however a number of species are toxic for cattle and in many cases this toxicity could be transferred to humans through meat and milk. From a chemical point of view the biologically active principles of Astragalus species consist of saponins, polysaccharides and phenolics, while the toxic compounds include imidazoline alkaloids, nitro toxins and selenium derivatives. This review deals with the chemistry, purification procedures, structure elucidation methods and biological activity of triterpenoidic sapogenins and saponins, the most widely studied secondary metabolites from Astragalus. However the other important metabolites, such as phenolics, polysaccharides, alkaloids, nitro compounds and seleniferous derivatives, have been considered and a brief summary of their important biological properties has also been included. BNTRODUCnON Astragalus L. is the largest genxis in the Leguminosae (Fabaceae) family and one of the largest genera of vascular plants on Earth, comprising ca. 2500 species of herbs or shrubs, mostly perennial, grouped into more than 100 subdivisions [51]. Astragalus is cosmopolitan, distributed in cool, temperate, arid and semiarid continental region of SouthWestern Asia (the largest centre of distribution with 1000-1500 spp.), Sino-03 !2 *o c a u H CD 60 c c lit s so

Secondary Metabolites from the Roots of Astragalus zahlbruckneri

Journal of Natural Products, 2001

Four new phenolic glycosides, -apiofuranosyl-(1f2)--glucopyranosides (1-4), along with the cycloartane triterpenes 20(R),25-epoxy-3 ,6R,16 ,24R-tetrahydroxycycloartane (5) and 20(R),24(S)-epoxy-3 ,6R,25trihydroxycycloartan-16-one (6) were isolated from roots of Astragalus zahlbruckneri. The structure elucidation of all compounds was based on their 1 H and 13 C NMR spectral data including 1D-TOCSY, DQF-COSY, HSQC, and HMBC experiments.

Secondary Metabolites from the Roots of Astragalus trojanus

Journal of Natural Products, 1999

Six novel cycloartane-type glycosides were isolated from the roots of Astragalus trojanus. Two of these, compounds 1 and 2, have (20R, 24S)-epoxy-3beta,6alpha,16beta,25-tetrahydroxycycloartane as the aglycon, while compounds 3-6 possess 3beta,6alpha,16beta,(24S), 25-pentahydroxycycloartane as the aglycon. The saccharide moieties linked to the C-3, C-6, and C-24 or C-25 positions of the aglycons in 1-6 contained either xylopyranose, glucopyranose, rhamnopyranose, or arabinopyranose units. Structure elucidation of compounds 1-6 was accomplished through the extensive use of 1D and 2D NMR techniques. In addition, a new oleanene glycoside (7) and a new tryptophan derivative (8) were also isolated and characterized.

Triterpenoid saponins from Astragalus wiedemannianus Fischer

Phytochemistry, 2010

Three cycloartane-type triterpene glycosides were isolated from Astragalus wiedemannianus together with eight known secondary metabolites namely cycloastragenol, cycloascauloside B, astragaloside IV, astragaloside VIII, brachyoside B, astragaloside II, astrachrysoside A, and astrasieversianin X. The structures were established mainly by a combination of 1D and 2D-NMR techniques as 3

Cycloartane triterpene glycosides from Astragalus trigonus

Phytochemistry, 1995

Key Word Index--Astragalus sieberi; Leguminosae; structural elucidation; 1D-and 2D-gradient enhanced NMR techniques; 20(S),24(R)-epoxy-9fl, 19-cyclolanostan-3fl,&t,16fl,25-tetrol glycosides; sieberoside I and II.

Further Saponins and Flavonoids from Astragalus verrucosus Moris

Pharmaceutical Biology, 2003

From the aerial parts of Astragalus verrucosus Moris, a novel cycloartane-type triterpene glycoside, named astraverrucin VII, was isolated along with cycloaraloside D (peregrinoside II) and cycloaraloside C (astrailienin A). The flavonoid composition was investigated for the first time, and fifteen known flavonoids were isolated and identified. All structural elucidation were performed by spectral means. The chemiotaxonomic importance of these findings is discussed.