Saiphon SongarsaShuleewan RajviroongitDarinee Sae-TangSupa HannongbuaKanyawim KirtikaraPrasat KittakoopMahidol UniversityKasetsart UniversityThailand National Center for Genetic Engineering and Biotechnology2018-06-212018-06-212005-12-01Chemistry and Biodiversity. Vol.2, No.12 (2005), 1635-164716121880161218722-s2.0-30344455603https://repository.li.mahidol.ac.th/handle/20.500.14594/16263Racemosol (1) and 10-O-demethylracemosol (2), natural products from Bauhinia malabarica Roxb., exhibit potent in vitro anti-inflammatory activities against cyclooxygenase-1 and -2 (COX-1 and -2) enzymes. To investigate the structure - activity relationship (SAR) of these molecules, we prepared and fully characterized 17 derivatives by functionalizing one, two, or all three OH group(s) of 2 (Scheme). Both the size and polarity of the substituents as well as the substitution pattern in compounds 3a-q were found to be critical for anti-inflammatory activity. The orientation of the drugs and their mode of binding were studied by molecular docking based on the known 3D structure of the complex between COX-2 and the drug SC-558. Whereas the monoacetoxy derivative 3h exhibited an equally potent inhibitory activity towards both COX-1 and -2 (Table 1), its diacetoxy congener 3i was slightly more selective toward COX-2. In vivo anti-inflammatory tests showed that 3i and 2 are slightly more active than the reference compound phenylbutazone (Table 2). © 2005 Verlag Helvetica Chimica Acta AG, Zürich.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1002/cbdv.200590133