Methane thiol, from oxidation

Alkyl sulfides and thiols. Some alkyl thiols and sulfides, notably those from commonly ingested Allium sativum (garlic) and Allium cepa (onion) (Alliaceae), are variously bioactive as odorants and antimicrobials. Propanethial S-oxide (CH3-CH2-CH=S=0) is a lachrymatory irritant principle of onion. Allicin (S-oxodiallydisulfide CH2=CH—CH2-SO-S-CH2— CH=CH2), diallyldisulfide (CH2=CH-CH2-S-S-CH2-CH=CH2) and diallylsulfide (CH2=CH—CH2—S—CH2-CH=CH2) are major odorants of garlic that are reactive and irritant because of the allyl groups. Dimethyl disulfide (CH3—S—S-CH3), dipropyl disulfide (CH3-CH2-CH2-S-S-CH2-CH2-CH3), methyl allyl disulfide (CH3-S-S-CH2-CH=CH2) and propane-1-thiol (CH3-CH2—CH2—SH) are further Allium odorants. Methane thiol (methyl mercaptan CH3—SH) is a widespread plant volatile and notably derives from anaerobic bacterial degradation of cysteine as in human flatus and bad mouth odour. The aliphatic disulfides allicin and ajoene inhibit proinflammatory expression of iNOS. 

As we have seen, the likely first metabolic pathway driven by the disequilibrium between carbon oxides and hydrothermal hydrogen is toward the synthesis of acetate. In a notable experiment Huber and Wachtershauser 60) generated high yields of activated acetate from CO and CH3SH (methane thiol) in hydrothermal conditions previously synthesized from CO2 and H2S by Heinen and Lauwers 61). Yields were generally greatest in alkaline conditions. Nickel was the most effective catalyst, whether as (Fe,Ni)S, NiS or NiS04. In further experiments... 

Co-oxidation of thiols with 1,3-butadiene, the simplest conjugated diolefin, has been studied in the presence of r-butylamine . Products derived from 1,2- and 1,4-addition were observed in the reaction with methane- and ethane-thiols, predominant 1,2-co-oxidation products were formed when benzene or p-toluenethiol were used (equation 104). 

---