Synthesis of some o-substituted derivatives of natural 6-hydroxymethyl-4- methoxy-2H-pyran-2-one (opuntiol)

This manuscript reports the synthesis of a series of new o-substituted derivatives of opuntiol (1) which is a naturally occurring compound isolated from a plant opuntia dillenii haw belonging to family cactaceae. these derivatives 3a-t,were characterized by fab-ms,ir,and 1hnmr and then screened against acetylcholinesterase,butyrylcholinesterase,lipoxygenase and - chymotrypsin enzymes. the screening results revealed that 6-(acetyloxy) methyl- 4-methoxy-2hpyran- 2-one (3b) and n-(2,5-dimethylphenyl)-2-[(4-methoxy- 6-oxo-2h-pyran-2-yl) methoxy]acetamide (3p) were found to be the inhibitor of butyrylcholinesterase while 6-(acetyloxy) methyl- 4-methoxy-2h-pyran-2-one (3b),6-(ethoxymethyl)-4-methoxy-2h-pyran-2-one (3c),4- methoxy-6-[(phenylmethoxy) methyl]-2h-pyran-2-one (3g),6-[(2-bromoethyloxy)methyl]-4- methoxy-2h-pyran-2- one (3j),n-(5-chloro-2-ethoxyphenyl)-2-[(4-methoxy-6-oxo-2h-pyran-2- yl)methoxy]acetamide (3r),n-(3,4-dimethylphenyl)-2-[(4-methoxy-6-oxo-2h-pyran- 2- yl)methoxy]acetamide (3s) n-(3,5-dimethylphenyl)-2-[(4-methoxy-6-oxo-2h- pyran-2- yl)methoxy]acetamide (3t) were found to be active against α-chymotrypsin and among these 3s was the good inhibitor of this enzyme having ic50 value of 142.71 ± 0.22 μmoles/l.