Angiotensin Converting Enzyme (ACE) Inhibitors from Jasminum azoricum and Jasminum grandiflorum

Abstract

Bioactivity-guided fractionation of extracts of the aerial parts of Jasminum azoricum var. travancorense, using an in vitro ACE inhibition assay, led to isolation of three oligomeric, iridoid-type compounds, which were named sambacein I-III. Their structures are based on spectroscopic and chemical evidence. Similarly, fractionation of extracts of aerial parts of J. grandiflorum resulted in the isolation of the previously reported ACE inhibitor, oleacein. The IC₅₀ values of purified ACE inhibitors were 26-36 µM. Moreover, 2-(3,4-dihydroxyphenyl)-ethanol, isoquercitrin and ursolic acid were isolated from J. grandiflorum. Sambaceins and oleacein are formed from genuine iridoid glucosides during processing of the plant material. NMR spectroscopy was used to measure the level of the ACE inhibitors in the traditional medicines prepared in Kerala from these Jasminum species.

Key words

Jasminum azoricum var. travancorense - J. grandiflorum - Oleaceae - Indian traditional medicine - iridoids - 2-(3,4-dihydroxyphenyl)ethanol - isoquercitrin - molihuaside - oleacein - oleuropein - sambacein - sambacoside - ursolic acid - NMR spectroscopy - ¹³C-NMR esterification shifts