GARLIC CHEMISTRY - STABILITY OF S-(2-PROPENYL) 2-PROPENE-1-SULFINOTHIOATE (ALLICIN) IN BLOOD, SOLVENTS, AND SIMULATED PHYSIOLOGICAL FLUIDS

S-(2-Propenyl) 2-propene-1-sulfinothioate (allicin), which is one of t he constituents of freshly crushed garlic (garlic homogenate), was syn thesized, and its stability in blood, ethyl acetate, methanol, simulat ed gastric fluid (SGF, pH 1.2), simulated intestinal fluid (STF, pH 7. 5), and water (pH 1.2 and 7.5) and under simulated digestive condition s (sequential combination of SGF and SIF) was investigated by HPLC. Al though neat allicin decomposes rapidly at 37 degrees C, it is more sta ble in protic polar methanol than in aprotic polar ethyl acetate. Appr oximately 90% of the allicin remained after incubation at 37 degrees C for 5 h in water at pH 1.2 and 7.5, Only traces of allicin could be d etected after it was incubated in blood for 5 min. The allicin content and allicin-producing potential of commercial garlic preparations wer e also analyzed. The allicin contents in these garlic preparations wer e less than 1 ppm, and the allicin-producing potential was severely su ppressed under simulated digestive conditions (sequential combination of SGF and SIE). The transformation products of allicin. [(E)-ajoene, 2-ethenyl-4H-1,3-dithiin, diallyl disulfide] were identified.