ANGIOTENSIN-CONVERTING ENZYME (ACE) INHIBITORS FROM JASMINUM-AZORICUMAND JASMINUM-GRANDIFLORUM

Bioactivity-guided fractionation of extracts of the aerial parts of Ja sminum azoricum var. travancorense, using an in vitro ACE inhibition a ssay, led to isolation of three oligomeric, iridoid-type compounds, wh ich were named sambacein I-III. Their structures are based on spectros copic and chemical evidence. Similarly, fractionation of extracts of a erial parts of J. grandiflorum resulted in the isolation of the previo usly reported ACE inhibitor, oleacein. The IC50 values of purified ACE inhibitors were 26-36 mu M. Moreover, 2-(3,4-dihydroxyphenyl)ethanol, isoquercitrin and ursolic acid were isolated from J. grandiflorum. Sa mbaceins and oleacein are formed from genuine iridoid glucosides durin g processing of the plant material. NMR spectroscopy was used to measu re the level of the ACE inhibitors in the traditional medicines prepar ed in Kerala from these Jasminum species.