Sulfur dioxide, addition compound

Four hundred milliliters of petroleum ether (dried-over sodium) is poured into a dry three-necked flask fitted with an inlet tube, a mechanical stirrer, and a barium oxide drying tube. The flask is cooled by an ice-salt mixture. Then 46 g. of gaseous amine is slowly added. Next 50 g. of dry sulfur dioxide is added, with continuous stirring and at such a rate that the temperature of the reaction mixture remains at about 0°. The solid sulfur dioxide addition compound is filtered quickly in a Buchner funnel. The product is then left in vacuo over phosphorus (V) oxide for several hours. Yield 90 to 96 g. (94 to 100 per cent). Anal. Calcd. for (CH3)3 N SO2 N, 11.4. Found N, 11.4 11.5. 

Lysozyme s application is directed primarily toward white wines for the control of LAB. Unlike compounds previously discussed, lysozyme exhibits activity toward all species and strains of LAB studied. At its suggested use level of 250-500 mg/L, the enzyme preparation may be added before alcoholic fermentation to prevent MLF, at some time during MLF, or upon completion to prevent subsequent activity of unwanted LAB. Its activity is not affected by ethanol, although upon reaction with tannin and pigment complexes, activity decreases (Villa, 1996). Similarly, bentonite dramatically decreases activity. In white juice, this ranged from 37% reduction after bentonite additions of 0.25 g/L to complete inactivation with additions of 1 g/L. In white wines, the impact of bentonite was less, ranging from 10% reduction with 0.25 g/L to 75% reduction at 1.0 g/L. The effect of sulfur dioxide additions in white wine was also investigated. In this case. Villa reports that SO2 at 80 mg/L had an indirect effect on lysozyme activity... 

Most winemakers prefer limiting air contact with crushed grapes and white juice as much as possible. An adapted sulfur dioxide addition to juice blocks the enzymatic oxidation of phenolic compounds. This philosophy is based on empirical observation juices of many grape varieties must conserve a green color dming the pre-fermentation phase to be transformed into fruity white wines. Oxidation phenomena must consequently be avoided as much as possible. 

Sodium suifite, acid (saturated) dissolve 600 g of NaHS03 in water and dilute to 1 liter for the preparation of addition compounds with aldehydes and ketones prepare a saturated solution of sodium carbonate in water and saturate with sulfur dioxide. 

SuWta.tlon. Sulfur dioxide is added to a level of about 150 ppm on juice to discourage further color-forming Malliard reactions by tying up the small amount of invert sugars as bisulfite addition compounds. 

The first synthesis of thiepin 1,1-dioxide (131) was performed by Mock in 1967 75>. With exess bromine in chloroform 2,7-dihydrothiepin 1,1-dioxide (129), prepared by 1,6-addition of sulfur dioxide to m-hexatriene, gave a dibromide 130 which, on treatment with two equivalents of triethylamine, afforded 131. Upon catalytic reduction, 131 rapidly absorbed three molar equivalents of hydrogen to yield hexahydrothiepin 1,1-dioxide (132). The 1,1-dioxide 131 is a fairly stable compound ... 

Heating pure TBMS, TBS and TBSS films at 130 C gave no volatile products. Pyrolysis at 725°C gave rise to both deprotection (as determined by the evolution of isobutene and carbon dioxide), and depolymerization to afford the respective monomers, sulfur dioxide, 4-hydroxystyrene, or 4-hydroxy-a-methylstyrene. The compounds, 4-hydroxystyrene and 4-hydroxy-a-methylstyrene, were identified on the basis of their mass spectra, which were consistent with those reported in the literature for these materials (22,23). Additionally, TGA analysis confirmed that all three polymers undergo complete volatilization upon heating to >400 C. 

Wilson et alP measured irradiated automobile exhaust and pure organic compounds and found that the addition of sulfur dioxide, although it increased aerosol formation, decreased eye irritation in many of the hydrocarbon-NO, systems studied. 

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