Characterization of some compounds isolated from Sweet Basil (Ocimum basilicum L.) leaf extract

Abstract

Background: For thousands of years, several people depend on traditional medicines from flowers, bark, leaves and fruits of plants. Sweet Basil ( Ocimum basilicum L.) is a medicinal herb which belongs to the family of Labiatae and it is the most abundant of the genus Ocimum. The present study aimed to isolate pure compounds from chloroform/methanol (1:1) crude extract of the leaves of O. basilicum herb and characterize them using infra-red (IR) and nuclear magnetic resonance (NMR) spectroscopic techniques. Methods: The sample of powdered leaves of O. basilicum was extracted using a mixture of chloroform and methanol (1:1) and the crude extract was investigated for its chemical composition using spectroscopic techniques. Results: Only one fraction designated as O. basilicum -14 (OB-14) displayed a single spot on TLC plate. Results showed that two isomeric compounds named (1-(2-vinylcyclohexa-1,4-dienyl) propan-2-ol and 2-(2-vinylcyclohexa-1,5-dienyl) propan-1-ol) were isolated as a mixtures using column chromatography over silica gel. The structures of these compounds were identified using IR and one dimensional NMR spectroscopic techniques such as proton NMR ( 1 H NMR), carbon-13 NMR ( 13 C NMR) and distortionless enhancement by polarization transfer (DEPT). Conclusions: So, more compounds can be isolated from the plant using different chromatographic techniques.