Racemic norneolignans from the resin of Ferula sinkiangensis and their COX-2 inhibitory activity.

Five new norneolignans sinkianlignans G-K (1-5), one phenolic compound ferulagenol A (6) and seven known compounds (7-13) were isolated from Ferula sinkiangensis. All the norneolignans were racemic mixtures, and chiral HPLC was used to further separate them. Their structures were assigned, including absolute configurations, using spectroscopic and computational methods. Biological evaluation showed that compounds 1-9 had significant COX-2 inhibitory activity with IC50 values ranging from 3.00 µM to 23.19 µM.

Periplanetols A-F, phenolic compounds from Periplaneta americana with potent COX-2 inhibitory activity.

Six new compounds, periplanetols A - F (1-4, 6 and 7), a compound isolated from natural origin for the first time (5), and nine known ones (8-16) were isolated from the 70% ethanol extract of the whole bodies of Periplaneta americana. Their structures including absolute configurations were unambiguously identified by comprehensive spectroscopic analyses and computational methods. Biological evaluation toward COX-2 inhibition revealed that compounds 1, 2, and 10 could inhibit COX-2 activity with the IC50 values of 768.0 nM, 617.7 nM, and 599.5 nM respectively, indicating their potential in developping novel agents against inflammation related disorders.

Racemic xanthine and dihydroxydopamine conjugates from Cyclopelta parva and their COX-2 inhibitory activity.

Seven new compounds including three pairs of enantiomeric xanthine analogues (1-3), a pair of enantiomeric hypoxanthine analogue (4), and three pairs of enantiomeric N-acetyldopamine dimers (6-8), together with a known one (5) were isolated from the insect Cyclopelta parva. Their structures including absolute configurations were assigned by using spectroscopic and computational methods. Chiral HPLC was used to separate racemic 1-8. Biological evaluation found that 6b and 7a are potent COX-2 inhibitory agents with IC50 values at 385.2 nM and 868.8 nM respectively.