Three new quassinoids isolated from the wood of Picrasma javanica and their anti-Vpr activities.

Three new quassinoids, javanicinols A and B (1 and 2) and 4-keto-(16S)-methoxyjavanicin B (3), together with three known quassinoids (4-6) were isolated from the chloroform-soluble fraction of the methanol extract of the Picrasma javanica wood. The structures of 1-3 were determined by spectroscopic analyses, including 1D and 2D NMR, HRESIMS, and CD. The anti-HIV-1 viral protein R (Vpr) assay revealed that 1 and 2 exhibited potent anti-Vpr activities at 1.25 µM. Furthermore, the assay also revealed the potent anti-Vpr activities of (16R)-methoxyjavanicin B (7) and (16S)-methoxyjavanicin B (8), which were previously isolated from the Picrasma javanica wood.

Bis-iridoid and iridoid glycosides: Viral protein R inhibitors from Picrorhiza kurroa collected in Myanmar.

Four new bis-iridoid glycosides, saungmaygaosides A-D (1-4), and six known iridoid glycosides (5-10) were isolated from the n-butanol extract of the stems of Picrorhiza kurroa collected in Myanmar. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were assayed for anti-Vpr activity, using TREx-HeLa-Vpr cells. Among the isolates, saungmaygaoside D (4), sylvestroside IV dimethyl acetal (7), and sweroside (8) were the most potent inhibitors with effective doses of 5 and 10 µM, respectively, without showing any notable cytotoxicities.

Two new quassinoids and other constituents from Picrasma javanica wood, and their biological activities.

Picrasma javanica Blume (Simaroubaceae) is a medium-sized tree that is distributed widely in tropical Asia. In our previous study, we isolated quassinoids from P. javanica bark collected in Myanmar, and reported their antiproliferative activities. In our ongoing research for the discovery of bioactive compounds from Myanmar medicinal plants, two new quassinoids, (16R)-methoxyjavanicin B (1) and (16S)-methoxyjavanicin B (2), along with seven known compounds (3-9), were isolated during the phytochemical investigation of the CHCl3 soluble portion of the MeOH extract of P. javanica wood. The structures of the new compounds were elucidated by analyses of their spectroscopic data (1D- and 2D-NMR, HRESIMS, and CD). A cytotoxicity assay revealed that compound 8 showed moderate activities against all tested cancer cell lines, the human lung (A549), breast (MCF7), and cervical (HeLa), and the normal fibroblast cell line, with IC50 values ranging from 48.6 to 65.9 µM. Furthermore, the antibacterial assay demonstrated that 1 and 2 had the highest activities (MIC value of 1.6 µM each), followed by 5 and 3 (MIC values of 3.1 and 6.3 µM, respectively) against the Gram-positive bacterium B. subtilis.

Labdane diterpenoids from Curcuma amada rhizomes collected in Myanmar and their antiproliferative activities.

Four new labdane diterpenoids, 12ß-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (1), (E)-15-ethoxy-15-methoxylabda-8(17),12-dien-16-al (2), (E)-15α-ethoxy-14α-hydroxylabda-8(17),12-dien-16-olide (3), and 15-ethoxy-12ß-hydroxylabda-8(17),13(14)-dien-16,15-olide (4) were isolated from the methanol extract of Curcuma amada rhizomes collected in Myanmar, together with 13 known analogs. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were evaluated for their antiproliferative activities against a small panel of five different human cancer cell lines (A549, human lung cancer; HeLa, human cervical cancer; MCF7, human breast cancer; PANC-1 and PSN-1, human pancreatic cancer). Among the isolates, compounds 2-4, 7, 8, 12, and 17 showed mild antiproliferative activities with IC50 values ranging from 19.7 to 96.1µM. (E)-14-Hydroxy-15-norlabda-8(17),12-dien-16-al (11) exhibited strong antiproliferative activities selectively against HeLa, PANC-1, and PSN-1 cells, with IC50 values of 5.88, 1.00, and 3.98µM, respectively. These potencies were comparable to those of the positive control, 5-fluorouracil.