Gymnema sylvestre, a medicinal plant, has been used in Indian ayurvedic traditional medicine for the treatment of diabetes. Phytochemical investigation of Gymnema sylvestre led to the isolation of five new pregnane glycosides, gymsylosides A–E (1–5) and four known oleanane saponins, 3β-O-β-D-glucopyranosyl (1→6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester (6), gymnemoside-W1 (7), 3β-O-β-D-xylopyranosyl-(1→6)-β-D- glucopyranosyl-(1→6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester (8), and alternoside XIX (9). Their structures were identified based on spectroscopic evidence and comparison with those reported in the literature. All compounds were evaluated for their α-glucosidase and α-amylase inhibitory activities. Compounds 2–4 showed significant α-amylase inhibitory activity, with IC50 values ranging from 113.0 to 176.2 µM.
Anoctamin1 (ANO1), a calcium-activated chloride channel, is frequently overexpressed in several cancers, including human prostate cancer and oral squamous cell carcinomas. ANO1 plays a critical role in tumor growth and maintenance of these cancers. In this study, we have isolated two new compounds (1 and 2) and four known compounds (3–6) from Mallotus apelta. These compounds were evaluated for their inhibitory effects on ANO1 channel activity and their cytotoxic effects on PC-3 prostate cancer cells. Interestingly, compounds 1 and 2 significantly reduced both ANO1 channel activity and cell viability. Electrophysiological study revealed that compound 2 (Ani-D2) is a potent and selective ANO1 inhibitor, with an IC50 value of 2.64 μM. Ani-D2 had minimal effect on cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel activity and intracellular calcium signaling. Notably, Ani-D2 significantly reduced ANO1 protein expression levels and cell viability in an ANO1-dependent manner in PC-3 and oral squamous cell carcinoma CAL-27 cells. In addition, Ani-D2 strongly reduced cell migration and induced activation of caspase-3 and cleavage of PARP in PC-3 and CAL-27 cells. This study revealed that a novel ANO1 inhibitor, Ani-D2, has therapeutic potential for the treatment of several cancers that overexpress ANO1, such as prostate cancer and oral squamous cell carcinoma.
Using chromatographic methods, three new dihydrostilbene glycosides, sasastilbosides A-C (1-3) and four known compounds, catechin (4), rutin (5), nicotiflorin (6), and rehmaionoside A (7) have been isolated from Camellia sasanqua Thunb. Their chemical structures were elucidated by spectroscopic methods (1 D-, 2 D-NMR) and mass spectra. Compounds 1-7 were evaluated for α-glucosidase and α-amylase inhibitory effects. Compounds 3 and 4 showed α-glucosidase inhibitory activity with IC50 values of 77.6 ± 1.6 and 72.4 ± 1.3 μM, respectively. Compound 1 showed α-amylase inhibitory activity with IC50 value of 53.7 ± 1.6 μM.
Three undescribed dihydrostilbene glycosides, 3,5-dihydroxyldihydrostilbene 4′-O-[6′′-O-(4′′′-hydroxylbenzoyl)]-β-D-glucopyranoside (1), 3,5-dihydroxyldihydrostilbene 4′-O-(6′′-O-galloyl)-β-D-glucopyranoside (2), and 3,5-dihydroxyldihydrostilbene 4′-O-[6′′-O-(3′′′,4′′′-dimethoxyl)galloyl]-β-D-glucopyranoside (3), and seven known compounds, kaempferol 3-O-β-D-glucopyranoside (4), isoquercitrin (5), kaempferol 3-O-α-L-rhamnoside (6), quercitrin (7), (6S,9R)-roseoside (8), (-)-epicatechin 3-O-gallate (9), and (-)-epigallocatechin 3-O-gallate (10) have been isolated from the methanol extract of the leaves of Camellia sinensis var. assamica (J.W.Mast.) Kitam. (synnonym of Camellia assamica (Mast.) H.T.Chang) (Theaceae). Their structures were elucidated by spectroscopic methods (1 D-, 2 D-NMR) and mass spectra. All compounds were evaluated for cytotoxic activity against human oral cancer (CAL27) and human breast cancer (MDAMB231) cell lines. Compound 10 showed significant cytotoxic activity against CAL27 and MDAMB231 cell lines with IC50 values of 9.78 ± 0.25 and 3.27 ± 0.18 μM, respectively, compared to those of positive control, capecitabine (IC50 values of 8.20 ± 0.75 and 5.20 ± 0.89 μM). Graphical Abstract
The methanolic extract of Mussaenda pubescens Dryand leaves exhibited significant anti-osteoclastogenic activity. Chemical investigation of M. pubescens led to the isolation of one new cycloartane saponin, mussaendoside X (1) along with eight known compounds: heinsiagenin A 3-O-[α-L-rhamnopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→2)]-O-β-D-glucopyranoside (2), mussaendoside O (3), heinsiagenin A 3-O-[α-L-rhamnopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→2)]-O-β-D-glucopyranosyl-(1→4)-O-β-D-glucopyranoside (4), mussaendoside G (5), mussaendoside U (6), shanzhiside methyl ester (7), barlerin (8) and musaenoside (9). Their structures were elucidated by extensive spectroscopic methods including 1D- and 2D-NMR as well as MS analysis and comparison with the literature. Cycloartane saponins 1–6 positively suppressed osteoclast formation in an anti-osteoclastogenic screening assay. Consequently, treatment of RANKL-stimulated RAW 264.7 cells with compounds 1–4 significantly decreased the number of osteoclasts in a concentration-dependent manner. Six compounds from M. pubescens, with the new cycloartane, mussaendoside X, were shown for the first time as potential effective inhibitors of osteoclastogenesis. Graphical Abstract