Isolation and structure determination of acetylated triterpenoid saponins from the seeds ofCentratherum anthelminticum

Abstract

Phytochemical investigation of Centratherum anthelminticum seeds resulted in the isolation of two novel glycosides. The pentacyclic triterpenoid saponins were shown to contain hederagenin and sugar residues forming two glycosyl chains. The structural analysis of its acetylated derivative was determined using a combination of homo- (1D 1H NMR, 13C NMR and 13C NMR-DEPT) and heteronuclear 2D NMR techniques (1H-1H-COSY, total correlated spectroscopy (TOCSY), heteronuclear multiple quantum coherence (HMQC)), heteronuclear multiple bond correlation (HMBC) and chemical methods. The structure of the saponins were established to be 3-O-[beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranosyl]-23-hydroxyolean-12-en-28-oic acid and 3-O-[beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-glucoyranosyl-(1 --> 3)-beta-D-glucopyranosyl]-23-hydroxyolean-12-en-28-oic acid. Different extracts and compounds were also tested for antifilarial and antimicrobial activities. Methanolic, acetone and aqueous extracts of seeds exhibited some pronounced pharmacological activity under study.

Baccharoides anthelmintica (L.) Moench: A Review on Ethnomedicinal, Phytochemical, Pharmacological and Toxicological Profile

“…The solvents ratio (C 6 H 6 : EtOAc) was used in a gradient manner with the ratio of benzene: EtOAc (3 : 1) to benzene: methanol (1 : 1). Acetylated saponin 1 (170 mg) was prepared using benzene: methanol (1 : 1), fractions 40–50 (2500 ml) [68] . Arya et al.…”

“…Various solutions of B. anthelmintica powder were tested for fluorescence and general behavior using ultraviolet and visible light (254 and 365 nm) [74] . FT‐IR (Fourier Transform Infrared) spectroscopy technique was used to record the spectra in the KBr in the range between 4000–400 cm −1 (Perkin‐Elmer 377) [68,75] . This technique was used to identify various functional groups present in the powder of B. anthelmintica as well as different crude extracts like‐ n‐hexane, chloroform, ethyl acetate, n‐butanol, methanol, ethanol, and aqueous fractions [76] .…”

“…The types of carbon like primary (−CH 3 ), secondary (−CH 2 ), and tertiary (−CH) were analyzed by DEPT tests. Standard techniques were used for the TOCSY, DQF‐COSY, HMBC, and HMQC pulse sequences [68] …”

“…Mehta et al. (2010) studied the in‐vitro anti‐filarial activity against Setaria cervi of methanol and aqueous seed extracts of B. anthelmintica and observed the activities (LC 90 : 33 and LC 50 : 75 μg/ml, respectively) [68] . In addition, petroleum ether and chloroform extracts of B. anthelmintica seeds exhibited in‐vitro activity against filaria ( Culex quinquefasciatus ) and observed the activities (LC 50 : 143 ppm and 64–71 ppm, respectively) [141] .…”

“…Acetylated saponin 1 (170 mg) was prepared using benzene: methanol (1 : 1), fractions 40-50 (2500 ml). [68] Arya et al (2012), extracted coarsely powdered seeds (2 kg) with a Soxhlet extractor using n-hexane (100 % ) solvent for 24 hours. After defatting, the residue was further extracted with chloroform (100 %) and then absolute methanol (100 %).…”