Cycloartane-type glycosides from thalictri herba

Ethnobotany, botany, phytochemistry and ethnopharmacology of the genus Thalictrum L. (Ranunculaceae): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Thalictrum (Ranunculaceae) is known for its important alkaloids which have been reported to exhibit various pharmacological activities, viz. antitumor, antimicrobial, antitussive, antiamebic, hypotensive effects, HIV antiviral, etc. Throughout the world, the plant has been used as a tonic, purgative, stimulant, aperient and is utilized in various systems of medicine in the treatment of various ailments like snake bite, jaundice, rheumatism, stomachache, wounds, swellings, uterine tumors, paralysis, joints pain, nervous disorders, toothache, diarrhea, piles, fever, peptic ulcer, ophthalmic, headache, diuretic, dyspepsia, convalescence, etc. AIMS OF THIS REVIEW: To bring together all the information regarding the botany, phytochemistry, ethnobotany and ethnopharmacology of Thalictrum and identify the gaps in the existing studies so that full medicinal potential of the genus can be realized.

METHODS

Available literature on botany, geography, traditional uses, phytochemicals, and pharmacology was gathered by referring to library and electronic searches in PubMed, Science Direct, Google Scholar, relevant journals and books.

RESULTS

A variety of phytochemicals like alkaloids, essential oils, glycosides, phenols and terpenoids have been reported from Thalictrum species. Alkaloids are the most dominant diverse group with 178 different types. The crude extracts and isolates exhibit a gamut of pharmacological activities, namely anticancer, antimalarial, antioxidant, antipyretic, anti-tumor, ant-influenza virus, contraceptive and immunosuppressive. Northalrugosidine, an alkaloid from T. alpinum shows in vivo antileishmanial activity. So far, cytotoxic effects of only three Thalictrum species, viz. T. dasycarpum, T. foliolosum and T. simplex have been reported. Thl isolated from T. simplex is found to be 50% toxic (CC50%) at the concentration ranging from 53 to 95 μM.

CONCLUSIONS

Thalictrum has tremendous medicinal values used in many traditional systems of medicine. It has multiple chemical components and still there is scope to explore more. Multiple chemical constituents and its utilization signify its high demand in the drug markets or pharmaceutical companies. In depth phytochemical studies along with in vitro studies with respect to their active principles can help in tapping the full medicinal potential of the genus.

Cytotoxic triterpenoid saponins from Thalictrum atriplex

Two new cycloartane glycosides, cycloatriosides A and B (1-2), and a new oleanolic acid glycoside, thaliatrioside A (3), along with 7 known triterpenoids (4-10) were isolated from Thalictrum atriplex. The structures of the new compounds were established as 3-O-β-D-galactopyranosyl (20S, 24 R)-3β,16β,25,29-tetrahydroxy-20,24-epoxycycloartane-29-O-β-D-glucopyranoside (1), 3-O-β-D-glucopyranosyl-(1→2)-α-arabinopyranosyl-3β,22ξ,30-trihydroxycycloart-24-en-21-oic acid α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (2) and 3-O-[α-L-rhamnopyranosyl-(1→3)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl]-oleanolic acid 28-O-β-D-glucopyranosyl ester (3) on the basis of extensive NMR and HR-ESI-MS analyses, along with acid hydrolysis. Their cytotoxic activities against human lung cancer cells A549 and human breast cancer cells MDA-MB-231 were evaluated using MTT method. Compound 9 showed cytotoxicity against MDA-MB-231 cell line with the IC₅₀ value of 72.53 ± 1.08 μM.

Terpenoids from the tuber of Cremastra appendiculata

Two new terpenoids including a cadinane sesquiterpene (1), and an ent-kaurane diterpene diglycoside (2), together with a known triterpene containing 32 carbons (3), have been isolated from the ethanolic extract of Cremastra appendiculata. Their structures were established by the spectroscopic methods including the IR, MS, 1D-, and 2D-NMR experiments as ( - )-cadin-4,10(15)-dien-11-oic acid (1), ( - )-ent-12beta-hydroxykaur-16-en-19-oic acid, 19-O-beta-D-xylopyranosyl-(1 --> 6)-O-beta-D-glucopyranoside (2), and (+)-24,24-dimethyl-25,32-cyclo-5alpha-lanosta-9(11)-en-3beta-ol (3). Compounds 1-3 were evaluated against several human cancer cell lines. Compound 3 showed in vitro-selective cytotoxicity against human breast cancer cell lines (MCF-7) with an IC50 of 3.18 microM, but 1 and 2 were inactive (IC50>10 microg/ml).

Natural products from medicinal plants: non-alkaloidal natural constituents of the Thalictrum species

Thalictrum is an important plant genus that is widely used in traditional medicine. In this review considerable attention has been given to triterpenoid saponins in connection with their specific distribution in the Thalictrum genus and with their biological activity. All other non-alkaloid compounds isolated from the Thalictrum genus are also reviewed; these metabolites are discussed in relation to their structural features and to their role in the plants.

Thirteen novel cycloartane-type triterpenes from Combretum quadrangulare

Thirteen novel cycloartane-type triterpenes were isolated from Combretum quadrangulare, a Vietnamese medicinal plant. The structures of the novel triterpenes were determined by spectroscopic methods as well as by chemical transformations. Among those compounds, quadrangularic acids F (1), G (2), and H (4) and 24-epiquadrangularic acid G (3) are the first examples of cycloartane-type triterpenes bearing carboxylic acid groups at both C-4 and C-20. Furthermore, norquadrangularic acid A (13) is the first example of a trinorcycloartane-type triterpene isolated from the genus Combretum.

Cycloartane-type glycosides from Aquilegia flabellata

Two new cycloartane-type glycosides, named aquilegiosides A and B, were isolated from the dried aerial parts of Aquilegia flabellata Sieb.et Zucc.var flabellata (Ranunculaceae). Their chemical structures have been characterized as 22S-3beta,16alpha,29-trihydroxy-cycloart-24-en-26,22-olid e 3-O-beta-D-glucopyranosyl-(1--->6)-beta-D-glucopyranosyl-(1--->2)-alpha- L-arabinopyranoside and 3-O-beta-D-glucopyranosyl-(1--->2)-alpha-L-arabinopyranoside, by chemical and spectroscopic evidence.