Compounds from the insect Blaps japanensis with COX-1 and COX-2 inhibitory activities

Blapsols A-D (1-4), four new compounds possessing a 2,3-dihydrobenzo[b][1,4]dioxin group, together with five known N-acetyldopamine dimers (5-9), were isolated from Blaps japanensis. Their structures including the absolute configuration of (+)-1 were determined by means of spectroscopic and X-ray crystallographic methods. Chiral HPLC was used to separate (-)- and (+)-enantiomers of compounds 1-4, which were isolated from this insect as racemic mixtures. All the compounds were found to have inhibitory effects towards COX-2 with IC50 values in the range of 1.3-17.8μM.