Triterpenoids of the cycloartane series

Исаев, М. И.; Gorovits, M. B.; Abubakirov, N. K.

doi:10.1007/bf00579134

Cited by 24 publications

(32 citation statements)

References 124 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The S-configuration of C-22 was determined [36] using the Moscher method [37] after acetylation of the primary alcohol on C-26. In this instance, 13 C chemical shifts (CSs) of 11 [35] and the corresponding values for 22S-and 22R-hydroxycholestanols [38] were compared.…”

Section: Cycloartane Compoundsmentioning

confidence: 99%

“…The S-configuration of chiral center C-22 in both genins (53 and 54, respectively) was determined using the literature method [28]. The configuration of the C-24 hydroxyl was determined as S in 57 and R in 58 using the NOE in 13 Acid hydrolysis of the methanol extract of the aerial part of T. squarrosum produced squarrofuric acid (59) [49], which contains a CH 3 -19, a 9(11)-double bond, a sidechain with a disubstituted THF ring, which is analogous to the same ring in the genins mentioned above, and a C-21 carboxyl. Apparently this compound is an artifact formed during hydrolysis by the action of mineral acid on squarrogenins 1-4.…”

Section: Cycloartane Compoundsmentioning

confidence: 99%

“…Individual representatives of these compounds were included in reviews on triterpenoids [11,12] and cycloartanes [13,14]. However, the complete picture will be given for the first time.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Structural Studies and Biological Activity of Plant Triterpenoids from the Thalictrum Genus

et al. 2005

View full text Add to dashboard Cite

Structures and chemical and spectral properties of triterpenoids isolated from plants of the Thalictrum genus were systematized for the first time. Features of 13 C NMR spectra of cycloartane triterpenoids were discussed. Data for the biological activities of certain cycloartane and oleanane triterpenoids were given.Triterpenoids are natural isoprenoids, the skeleton of which is constructed of 30 C atoms. They are widely distributed in both terrestrial plants and marine flora and fauna. They occur in the free state and as esters and glycosides called saponins. Triterpenoids are usually classified by the number of rings in the C skeleton. Tetra-and pentacyclic compounds are most widely distributed in nature. This review covers representatives of them.Plants of the Thalictrum (Ranunculaceae) genus produce a large quantity of triterpenoids and other secondary metabolites. The former are interesting because of their chemical structures and practical uses. It should be noted that investigations of secondary metabolites from these plants focused rather successfully and until recently on the alkaloids [1-5]. The first publications devoted to the study of triterpene saponins from plants of the Thalictrum genus appeared at the start of the 1981s [6].There is a reason for the interest in representatives of the broad Thalictrum genus. Plants of this genus have been used since long ago by peoples of many nations for medicinal purposes to treat gastrointestinal and gynecological illnesses, various neoplasms, and tuberculosis [7-10]. This, in turn, stimulated studies of the chemical composition of the plants, the isolation of biologically active compounds, and investigations of their pharmacologic activity.We have for the first time systematized and generalized information on triterpenoids from plants of the Thalictrum genus (from 1981 to 2003), features of their spectral and chemical properties, and their biological activity. Individual representatives of these compounds were included in reviews on triterpenoids [11,12] and cycloartanes [13,14]. However, the complete picture will be given for the first time. TRITERPENOID GENINS AND THEIR GLYCOSIDESTriterpenoid saponins from plants of the Thalictrum genus were first isolated and characterized in 1981-1983 from T. minus and T. foetidum collected in eastern Siberia [6,15,16]. Compounds of this type were not observed in the same species from Middle Asia and Europe. Based on this, which indicates that the chemical composition of a species is dependent on the ecological and geographical habitat, it was proposed [17,18] to separate the species growing in eastern Siberia into a Siberian chemorace. Then, the triterpenoid compounds were isolated only from species growing in the east (Japan, China, Korea). Now it is probably possible to generalize and view the Siberian chemorace as the "eastern Asian" one.

show abstract

Section: Cycloartane Compoundsmentioning

confidence: 99%

Section: Cycloartane Compoundsmentioning

confidence: 99%

See 1 more Smart Citation

Structural Studies and Biological Activity of Plant Triterpenoids from the Thalictrum Genus

et al. 2005

View full text Add to dashboard Cite

show abstract

“…As expected, the 13 C NMR spectrum of this same glycoside showed resonances at G 21.12, 29.03, and 30.23 for quaternary C-9 and C-10 and methylene C-19 composing the three-membered ring, indicating that the studied glycoside was a cycloartane triterpenoid [2][3][4][5]. 1 2 -4, 6 5 OH OH OH OH O O HO OH OH O HO HO O OH OH O CH 2 OH OH O CH 3 OOC 2 -5 6 Enzyme Í + OH OH OH OH RO R 1 O OH OH OH OH O O HO O OH OH OH O O HO HO HO O OH OH O CH 2 OH OH O HOOC 2: R = R 1 = H; 3: R = E-D-Xylp, R 1 = H 4: R = H, R 1 = E-D-GlcUA(1o2)-E-D-Glcp 6: R = D-L-Arap(1o2)-E-D-Xylp, R 1 = E-D-Glcp…”

mentioning

confidence: 54%

Triterpene glycosides from Astragalus and their genins. XC. Askendoside K from Astragalus taschkendicus

Isaev

Исаев

2011

Chem Nat Compd

Self Cite

View full text Add to dashboard Cite

A new triterpene cycloartane glycoside called askendoside K was isolated from roots of Astragalus taschkendicus Bunge (Leguminosae). The structure of this glycoside was established using chemical and biochemical transformations and spectral data.In continuation of research on polar triterpene glycosides from Astragalus taschkendicus Bunge (Leguminosae) [1], we isolated one more new glycoside from roots of this plant and called it askendoside K (1). Herein we report the structure determination of this glycoside.The PMR spectrum of 1 (Table 1) exhibited at strong field 1H doublets for an AX system at G 0.06 and 0.35 that belonged to the isopropane methylene of a cyclopropane ring in addition to resonances for seven methyls. As expected, the 13 C NMR spectrum of this same glycoside showed resonances at G 21.12, 29.03, and 30.23 for quaternary C-9 and C-10 and methylene C-19 composing the three-membered ring, indicating that the studied glycoside was a cycloartane triterpenoid [2][3][4][5]. 1 2 -4, 6 5 OH OH OH OH O O HO OH OH O HO HO O OH OH O CH 2 OH OH O CH 3 OOC 2 -5 6 Enzyme Í + OH OH OH OH RO R 1 O OH OH OH OH O O HO O OH OH OH O O HO HO HO O OH OH O CH 2 OH OH O HOOC 2: R = R 1 = H; 3: R = E-D-Xylp, R 1 = H 4: R = H, R 1 = E-D-GlcUA(1o2)-E-D-Glcp 6: R = D-L-Arap(1o2)-E-D-Xylp, R 1 = E-D-Glcp

show abstract

“…Also, it is noted that all the calculated distances between the protons in this preferred conformation that show NOE correlations listed in Table 2 are less than 2.6 Å. To our knowledge, this is the most comprehensive NOE analysis of cycloartan-3-one derivatives, [8][9][10][11][12][13][14][15][16][17][18][19] and thus leading to the assignment of a preferred conformation of compound 2 in solution with the aid of advanced computational methods (B3LYP/6-31G*). This information indeed furnished the foundation for the theoretical calculation of its ECD spectrum.…”

mentioning

confidence: 88%

Capisterones A and B, which Enhance Fluconazole Activity in Saccharomyces cerevisiae, from the Marine Green Alga Penicillus capitatus

Jacob

Ding

et al. 2006

J. Nat. Prod.

View full text Add to dashboard Cite

A whole cell-based assay using Saccharomyces cerevisiae strains that overexpress Candida albicans CDR1 and MDR1 efflux pumps has been employed to screen natural product extracts for reversal of fluconazole resistance. The tropical green alga Penicillus capitatus was selected for bioassay-guided isolation, leading to the identification of capisterones A and B (1 and 2), which were recently isolated from this alga and shown to possess antifungal activity against the marine pathogen Lindra thallasiae. Current work has assigned their absolute configurations using electronic circular dichroism and determined their preferred conformations in solution based on detailed NOE analysis. Compounds 1 and 2 significantly enhanced fluconazole activity in S. cerevisiae, but did not show inherent antifungal activity when tested against several opportunistic pathogens, or cytotoxicity to several human cancer and non-cancerous cell lines (up to 35 μM). These compounds may have a potential for combination therapy of fungal infections caused by clinically relevant azole-resistant strains.The molecular mechanisms of antifungal drug resistance may involve a variety of factors such as mutation of target genes and decreased drug concentrations in the cells due to overexpression of efflux pumps. 1,2 In recent years, the rapid development of such drug resistance, particularly for azole antifungals, has highlighted the need for new strategies in antimycotic therapies. 1-5 Efflux pump inhibition has been considered as a promising approach in this regard. Two families of efflux pumps found in Candida albicans include the major facilitators (multidrug resistance, MDR) that are fueled by a proton gradient and the P-glycoprotein ABC transporters (Candida drug resistance, CDR) that require ATP hydrolysis for energy. Within each family, several subtypes have been discovered (i.e., CDR1, CDR2, MDR1). 1,2 We have established a whole cell-based assay using Saccharomyces cerevisiae strains that overexpress C. albicans CDR1 and MDR1 efflux pumps to screen for natural products that can reverse fluconazole resistance and may not be necessarily antifungal. 6In a continuing effort to search for new efflux inhibitors from natural sources, we have screened over 5000 marine extracts from the National Cancer Institute Open Repository. In the presence of a subinhibitory concentration of fluconazole, an extract of the tropical green alga Penicillus capitatus (Halimedaceae) that had an IC 50 value of 55 μg/mL against S. cerevisiae DSY 415 strain (overexpressing the CDR1 efflux pump) and an IC 50 value of < 6 μg/mL against S.

show abstract

Triterpenoids of the cycloartane series

Cited by 24 publications

References 124 publications

Structural Studies and Biological Activity of Plant Triterpenoids from the Thalictrum Genus

Structural Studies and Biological Activity of Plant Triterpenoids from the Thalictrum Genus

Triterpene glycosides from Astragalus and their genins. XC. Askendoside K from Astragalus taschkendicus

Capisterones A and B, which Enhance Fluconazole Activity in Saccharomyces cerevisiae, from the Marine Green Alga Penicillus capitatus

Contact Info

Product

Resources

About