Two New Enantiomers of Phenylethanoid and Their Anti-Inflammatory Activities

In this phytochemical investigation, two pairs of new phenylethanoid derivative enantiomers (1a/1b and 2a/2b), a new phenylethanoid derivative 3b, and seven known compounds (3a, 4-9) were isolated from the leaves of Picrasma quassioides. Spectroscopic techniques were used for the elucidation of their chemical structures, and the absolute configurations were determined by a comparison between the experimental and calculated ECD data, as well as the application of Snatzke's method. Compounds (1a/1b-3a/3b) were measured for their production of NO levels in LPS-induced BV-2 microglial cells. The results showed that all compounds exhibited potential inhibitory effects, and compound 1a showed stronger activity than the positive control.

Trimeric chalchonoids from the total phenolic extract of Chinese dragon's blood (the red resin of Dracaena cochinchinensis)

Four new chalchonoid trimers, named cochinchinenins N-Q (1-4), along with a pair of known enantiomers (5-6), were isolated from the total phenolic extract of Chinese dragon's blood (the red resin of Dracaena cochinchinensis). The planar structures of 1-4 were elucidated by extensive spectroscopic analysis including HRESIMS and 1D/2D NMR. The absolute configurations of new compounds were established by ECD data. Compound 1 exhibited significant inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC₅₀ value of 11.5 ± 1.7 μM.