Table 1.

Inhibitory potential of protocatechuic acid (1), geniposide (2), 6'-O-trans-p-coumaroylgeniposide (3), 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl) heptanes (4) and ursolic acid (5)

Compound	Yield (%)	IC50 valueb			Specific activityd
		MAO-A μM	MAO-B μM	DBH μM	MAO-A	MAO-B Unitc/g	DBH
1	0.01	2,411	300	334	2,695	21,739	19,608
2	0.16	>12,887	223	>12,887	<200	11,628	<200
3	0.0003	>9,363	127	>9,363	<200	14,706	<200
4	0.0009	400	196	941	7,937	16,129	3,367
5	0.007	>10,965	780	214	<200	2,809	10,204
Iproniazida	-	40	60	-
Deprenyla	-	3.3	0.05	-

^aPositive control for MAO. ^bInhibitory potency is obtained by Logic-log graph paper. ^cOne unit is defined as a sample amount to give 50% inhibition against the enzymes. ^dSpecific activity means the amount of unit in 1 g of a test sample.