Chemical constituents from the branches and leaves of Alchornea annamica

Phytochemical investigation of the branches and leaves of Alchornea annamica led to isolation of ten secondary metabolites, including two new megastigmane glucosides alnamicosides A (1) and B (2). The structure elucidation was confirmed by 1 D and 2 D NMR, ECD as well as HR-QTOF-MS experiments. The megastigmane derivatives 1 - 3 exhibited inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC₅₀ values of 78.72 ± 1.90, 77.40 ± 9.40 and 82.16 ± 4.56 µM, respectively. This is the first report on chemical constituents and biological activity of the plant A. annamica.

Polyacetylene and phenolic constituents from the roots of Codonopsis javanica

Chemical investigation of the roots of Codonopsis javanica resulted in isolation of 12 compounds, including one new polyacetylene, codojavanyol (1), one new phenolic glycoside, codobenzyloside (7), and 10 known compounds, (2E,8E)-9-(tetrahydro-2H-pyran-2-yl)nona-2,8-diene-4,6-diyl-1-ol (2), lobetyol (3), lobetyolin (4), lobetyolinin (5), cordifolioidyne B (6), benzyl-α-L-arabinopyranosyl (1-6)-β-D-glucopyranoside (8), (Z)-8-β-D-glucopyranosyloxycinnamic acid (9), syringin (10), syringaresinol (11), and tryptophan (12). Their structures were elucidated by 1 D and 2 D NMR and MS spectroscopic analyses in comparison with the data reported in the literature. The stereochemistry of the C-2' position of 1 was identified based on time-dependent density functional theory (TDDFT) electronic circular dichroism (ECD) calculation. Among the isolates, compounds 3-5 were shown to have weak cytotoxicity toward three human carcinoma cell lines, including lung (A549), liver (HepG2), and breast (MCF7), with the induction of 41.4 to 55.6% cell death at the concentration of 100 µM.

Chemical Constituents from the Branches and Leaves of Alchornea trewioides

Two new megastigmane glucosides namely trewiosides A (1) and B (2), along with 20α-hydroxypregn-4-en-3-one β-D-glucopyranoside (3), sugeroside (4), and schizandriside (5) were isolated from the branches and leaves of Alchornea trewioides. The structure elucidation was confirmed by extensive analysis of the one and two dimensional (1 and 2D) NMR, electronic circular dichroism (ECD) as well as high resolution electrospray ionization quadrupole time-of-flight (HR-ESI-QTOF) mass spectra. Noteworthily, the isolation of compounds 1 and 2 represents the second finding of megastigmane derivatives with a methoxycarbonyl group at C-5 to date. In addition, compound 3 showed weak cytotoxicity against three human cancer cell lines as A549 (lung carcinoma), HepG2 (hepatocarcinoma), and MCF7 (breast carcinoma). Besides, compounds 2 and 3 exhibited moderate inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells. Whereas, the remaining compounds 1, 4 and 5 showed weak inhibitory activity.

Limonoids From Choerospondias axillaris

Eight limonoids (1-8), including 1 new compound named as axillariol A (1), were isolated from the dichloromethane extract of Choerospondias axillaris branches and leaves using various chromatographic separations. Their structures were confirmed by detailed analysis of the 1-dimensional (1D), 2D nuclear magnetic resonance, and high-resolution electrospray ionization quadrupole time-of-flight mass spectra. In addition, toonaciliatins N (6) and toonaciliatins O (7) showed selective and significant cytotoxicity on the rhabdomyosarcoma human cancer cell line with half-maximal inhibitory concentration values of 9.12 and 7.79 µM, respectively.