Formulasi Sediaan Masker Gel Peel-Off dari Ekstrak Buah Tomat (Solanum Lycopersicum L.) Beserta Uji Aktivitas Antioksidan

Tomatoes are well-known as the source of antioxidants due to the content of lycopene, i.e., a potential free radical inhibitor. Gel peel-off masks are among the chemical products containing antioxidants. The first step of the study was extracting tomato fruits by macerating the fruits using alcohol solvents 96%. The obtained thick extract was used as the material of the gel mask; the percentage of the extract comprised 3% (F1), 5% (F2), and 7% (F3), and it used PVA basis 11% and viscolam 3%. According to the result, the gel peel-off masks meet the requirements of physical and storage stability evaluation. The result of the antioxidant test reveals that the IC50 value of the three masks is F1 189.22 µg/mL, F2 89.34 µg/mL, and F3 36.77 µg/mL. Further, the result of T-Test reveals that P-value = 0.019 (α = 0.05), indicating a difference in the result of the antioxidant test of the three formulae in day one (t0) and day 28 (t28).

Oxidation of organic sulphides - VI. Interaction of hydroperoxides with unsaturated sulphides

Previous investigations on the reaction of hydroperoxides with a saturated sulphide (parts I and II) have been extended to two unsaturated sulphides. In alcohol solvents the reactions of the latter show all the features previously observed for the saturated sulphide. In benzene, however, the reaction with t -butyl hydroperoxide leads to a non-quantitative yield of sulphoxide. Kinetic and product investigations indicate that the reaction occurs in two successive steps; the first leads to a quantitative yield of sulphoxide; the second, an interaction between the sulphide and the hydrogen bonded complex of the hydroperoxide and sulphoxide produces disulphide, water and an unidentified peroxide. The principle of hydroperoxide-sulphide interaction according to this two-step mechanism is applied to the autoxidation of unsaturated sulphides and to the sulphide inhibition of olefin autoxidation. The oxygen-catalyzed reaction between t -butyl hydroperoxide and a saturated sulphide in benzene (part II) does not occur with cyclohexenyl methyl sulphide. It is inferred that the unsaturated sulphide is a free radical inhibitor and the relevance of this to its autoxidation characteristics is discussed.