Abstract
This paper describes the anti-nociceptive activity of isolated di-naphthodiospyrols fromDiospyros lotusL., Ebenaceae. The roots ofD.lotuswere collected from the surroundings of Razagram, Pakistan. Six dimeric di-naphthodiospyrols were isolated by column chromatography and identified as follows: 5,4-dihydroxy-1-methoxy-6,6-dimethyl-7,3-binaphthyl-1,4,5,8-tetraone (1), 5,8-dihydroxy-5-methoxy-6,6-dimethyl-7,3-binaphthyl-1,4,1,4-tetraone (2), 8,5,8-trihydroxy-6,6-dimethyl-7,3-binaphthyl1,4,1,4-tetraone (3), 5 ',8 '-dihydroxy-6,6 '-dimethyl-7,3 '-binaphthyl-1,4,1 ',4 '-tetraone (4), 5 ',8 '-dihydroxy-5,8-dimethoxy-6,6 '-dimethyl-7,3 '-binaphthyl-1,4,1 ',4 '-tetraone (5), and 5,8,5-trihydroxy-8-methoxy-6,6-dimethyl-7,3-binaphthyl-1,4,1,4-tetraone (6). They were subjected to anti-nociceptive assay by the hot plate test. Results revealed that compounds3and4significantly increased the latency time and can be considered an evidence for the anti-nociceptive effect of the studied plant material. Molecular docking study was also performed against cyclooxygenase (COX) isomers (type 1 and 2) in order to assess the possible binding mechanism of compounds3and4, which established various significant electrostatic interactions with critical residues in both enzymatic targets. These results suggest that di-naphthodiospyrols are natural products that could be considered to have a good anti-nociceptive potential.