Syntheses of carnosic acid and carnosol, anti-oxidants in Rosemary, from pisiferic acid, the major constituent of Sawara.

Masahiro Tada, Tomoyuki Ohkanda, Jun Kurabe

Index: Chem. Pharm. Bull. 58(1) , 27-9, (2010)

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Abstract

Carnosic acid (2), a major anti-oxidant in rosemary (Rosmarinus officinalis), was synthesized from pisiferic acid (1), the major constituent of Sawara (Chamaecyparis pisifera), via ortho-oxidation of the phenol using meta-chlorobenzoyl peroxide (mCBPO), chloroacetyl meta-chlorobenzoyl peroxide (CAMCBPO) or 2-iodoxybenzoic acid (IBX). Carnosol (3), another anti-oxidant in rosemary, was synthesized from carnosic acid by oxidation with silver oxide. Potent antibacterial activities against Propionibacterium acnes (ATCC 6919) (minimum inhibitory concentration (MIC) mug/ml) and Staphylococcus aureus ME/GM/TC Resistant (ATCC 33592) (MIC mug/ml) of carnosic acid and carnosol were reported.