Identification of a thiamin odor compound from photolysis of thiamin

Identification and synthesis of new odor compounds from photolysis of thiamin

“…The first compound was the title compound (4); spectral data were identical with those reported by Seifert et al (1978). The second compound proved to be 1-methylbicyclo[3.3.0]-thia-2,8-dioxaoctane (5), an oxygen analogue.…”

“…Irradiation of Thiamin. The formation of the new compound (5) as a byproduct of 4 prompted us to repeat the photolysis experiment of Seifert et al (1978) to see whether or not the new compound is also formed as a photodegradation product of thiamin. The results are given in Scheme I: a number of new compounds, among which is the new aroma compound, were isolated and identified (MS, NMR, IR).…”

Odor threshold of thiamin odor compound 1-methylbicyclo[3.3.0]-2,4-dithia-8-oxaoctane

“…Possible Mechanism of Formation of I. In the earlier paper (Seifert et al, 1978) no suggestion was given on a possible mechanism of how I might be derived from thiamin. On looking at the structure of thiamine, it is not obvious at first how it can be converted to I.…”

“…A possible mechanism pathway for the formation of the thiamin odor compound from thiamin is proposed. Some of the authors (Seifert et al, 1978) had already reported on the determination of the structure of the thiamin odor compound as l-methylbicyclo[3.3.0]-2,4dithia-8-oxaoctane (I, Figure 1) which they had found from the photolysis of thiamin hydrochloride (vitamin Bx). This compound appeared to be responsible for the characteristic aroma of commercial thiamin and multivitamin preparations.…”

“…EXPERIMENTAL SECTION Materials. The thiamin odor compound (I) was prepared by the ultraviolet light (UV) irradiation of thiamin hydrochloride and purified by gas-liquid chromatography separation as described previously (Seifert et al, 1978).…”