Testusterol, a new sterol of the sponge species Xestospongia testudinaria from Phu Quoc island, Vietnam.

A new sterol, named testusterol (1), and five known compounds (2-6) were isolated from the n-hexane and dichloromethane extracts of the sponge species Xestospongia testudinaria. Their chemical structures were elucidated based on extensive spectroscopic analyses (1D, 2D NMR, ESIMS and HRESIMS) and comparison with published data. The results of in vitro test (utilizing brine shrimp Artemia salina LEACH) showed that three extracts ethanol, dichloromethane, and ethanol/water, significantly inhibited Artemia salina with LC50 values ranging from 6.09 to 16.83 µg/mL. Remarkably, the new compound 1 exhibited potent inhibition against both Gram-positive (Staphyloccocus aureus, Bacillus subtilis, Lactobacillus fermentum), and Gram-negative (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa) bacteria species, with IC50 values of less than 12.0 nM and MIC ranging from 4.70 to 75.23 nM as determined by the broth-microdilution assay.

Aspidiatas C and D, two new spirostanol saponins from Aspidistra triradiata and their cytotoxic activities.

Aspidiatas C and D (1 and 2), two new spirostanol saponins, were isolated along with two known compounds, (25 R*)-spirost-5-en-3ß-yl α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (3), (25 R*)-spirost-5-en-3ß-yl α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranoside (4) from the whole plant of Aspidistra triradiata collected in Vietnam. The chemical structures were determined by HRESIMS, 1D- and 2D-NMR analysis, and comparison with published data. Compound 3 exhibited potent cytotoxicity against MCF7, HepG2, SK-LU-1, and HT-29 human cancer cell lines with IC50 values ranging from 0.19 to 0.65 µM. Compounds 1, 2, and 4 displayed moderate cytotoxic effects with IC50 values ranging from 12.32 to 82.27 µM. Compounds 1-4 were isolated from the genus Aspidistra for the first time.

Antioxidant, Anti-Skin-Aging, Anti-Inflammatory, and Anti-Acetylcholinesterase Activities of Rourea oligophlebia Extracts.

The objective of this study was to evaluate the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the hexane (n-hex), AcOEt, BuOH, MeOH, and aqueous extracts from R. oligophlebia roots. The total phenolic and flavonoid contents (TPC and TFC) were determined using Folin-Ciocalteu and AlCl3 colorimetric assays. The antioxidant capacity was examined by reducing power (RP), ferric reducing antioxidant power (FRAP), ABTS⋅+ , and DPPH⋅+ radical cation assays. All extracts potentially exhibited antioxidant activity with IC50 values ranging from 2.93 to 5.73 µg/mL for ABTS⋅+ and from 5.69 to 7.65 µg/mL for DPPH⋅+ except the n-hex extract. The BuOH, MeOH, and aqueous extract possess promising anti-skin-aging activities, as observed by an attenuation of UV-A toxicity on human keratinocytes. We proposed that these anti-skin-aging properties are possibly due to direct scavenging activity against reactive oxygen species and upregulate cellular antioxidant machinery. Moreover, we found that the antioxidant capacity was well correlated with anti-inflammatory capacity against nitric oxide (NO) production in terms of the n-hex, AcOEt, and BuOH extracts with IC50 values from 23.21 to 47.1 µg/mL. In contrast, these activities were found to be poorly correlated with AchE activity. To the best of our knowledge, this is the first report of the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the extracts of R. oligophlebia roots. These findings indicated that this species could be a potential source of natural antioxidant, anti-aging, and anti-inflammatory agents. Consequently, it may be suggested as a medicinal plant that prevents diseases related to oxidative stress and inflammatory responses.

Structure revision and absolute configuration of 5,7-diepi-2α-hydroxyoplopanone and anti-osteoporotic activities of sesquiterpenoids from the rhizomes of Homalomena pendula.

Five sesquiterpenoids including 2α-hydroxyoplopanone (1), oplopanone (2), 1ß,4ß,6α-trihydroxy-eudesmane (3), 1ß,4ß,7α-trihydroxy-eudesmane (4) and bullatantriol (5) were isolated from Homalomena pendula. The structure of the previously reported compound, 5,7-diepi-2α-hydroxyoplopanone (1a), has been revised to 1 by the spectroscopic evidences (1D-/2D-NMR, IR, UV and HRESIMS) and by comparison between experimental and theoretical NMR data using DP4+ protocol. Furthermore, the absolute configuration of 1 was unambiguously assigned by ECD experiments. Compounds 2 and 4 displayed a potent ability to stimulate osteogenic differentiation of MC3T3-E1 cells at 4 µg/mL (by 123.74% and 131.07%, respectively) and 20 µg/mL (by 112.45% and 126.41%, respectively) whilst 3 and 5 did not show any activities. At 20 µg/mL, 4 and 5 significantly promoted the mineralization of MC3T3-E1 cells with values of 112.95% and 116.37%, respectively, whereas 2 and 3 were inactive. The results indicated that 4 could be an excellent component for anti-osteoporosis studies from the rhizomes of H. pendula.

A new spirostanol steroid and a new spirostanol steroidal saponin from Aspidistra triradiata and their cytotoxic activities.

A new spirostanol steroid, aspidiata A (1), and a new spirostanol steroidal saponin, aspidiata B (2), along with three known compounds, paris saponin VII (3), daucosterol (4), and (25R)-spirostane-1ß,2ß,3ß,4ß,5ß,6ß-hexol (5), were isolated from whole plants of Aspidistra triradiata collected in Vietnam. Their chemical structures were established by spectroscopic analysis and comparison with previously published data. Compound 3 showed strong cytotoxicity against LU-1, Hep-G2, MCF-7, and KB human cancer cell lines with half maximal inhibitory concentration (IC50) values ranging from 0.57 to 1.23 µM. Compound 5 exhibited weak cytotoxic activity against the LU-1 cell line, with an IC50 value of 95.81 µM.

Antimelanogenic Activity of Ocotillol-Type Saponins from Panax vietnamensis.

The ocotillol (OCT)-type saponins have been known as a tetracyclic triterpenoid, possessing five- or six-membered epoxy ring in the side chain. Interestingly, this type saponin was mostly found in Panax vietnamensis Ha et Grushv., Araliaceae (VG), hence making VG unique from the other Panax spp. Five OCT-type saponins, majonoside R2, vina-ginsenoside R2, majonoside R1, pseudoginsenoside RT4, vina-ginsenoside R11, together with three protopanaxadiol (PPD)-type saponins and four protopanaxatriol (PPT)-type saponins from VG were evaluated for their antimelanogenic activity. All of isolates were found to be active. More importantly, the five OCT-type saponins inhibited melanin production in B16-F10 mouse melanoma cells, without showing any cytotoxicity. Besides ginsenoside Rd and ginsenoside Rg3 in PPD and notoginsenoside R1 in PPT-type saponins, majonoside R2 was the most potent melanogenesis inhibitory activity in OCT-type saponins. In this article, we highlighted antimelanogenic activity of OCT-type saponins and potential structure-activity relationship (SAR) of ginsenosides. Our results suggested that OCT-type saponins could be used as a depigmentation agent.

A new triterpene ester and other chemical constituents from the aerial parts of Anodendron paniculatum and their cytotoxic activity.

The aim of the research was to study the active constituents of Anodendron paniculatum Roxb. (Apocynaceae). A new triterpene ester, named anopaniester (1), and cycloartenol (2), ursolic acid (3), esculenic acid (4), bis-(2-ethylhexyl) phthalate (5), desmosterol (6), stigmasterol (7), vaniline (8), and (E)-phytol (9), were isolated from the aerial parts of A. paniculatum. Compounds 3 and 6 showed the significant inhibitory effect (IC50 values ranging from 30.89 ± 3.60 to 44.37 ± 5.40 µg/ml) against tested human cancer cell lines LU-1 and MKN-7. The compounds 1-4, and 6 were isolated from this genus Anodendron for the first time.