January 2006

Methyl Mercaptan

Methyl mercaptan (CH3SH) was first identified in Sgr B2 in 1979 by Linke et al. via six rotational lines. It was detected toward the hot core G327.3-0.6 by Gibb et al.. Torsionally excited methyl mercaptan was observed in Sgr B2 by Müller et al. and reported in 2016. Methyl mercaptan was searched for but not detected in the dark clouds TMC-1 and L134N. While methyl mercaptan has not been observed to date on any of the other Solar System planets, it could be used as a biomaker for detecting evidence of Martian life.

Methyl mercaptan is a close cousin of methanol (CH3OH), with the O atom replaced by S. While the odors of methanol and similar alcohols are distinctive, they are nothing in constrast to mercaptans, also known as thiols. Methyl mercaptan is used as an odorant in natural gas. As Wikipedia notes, methyl mercaptan

... is a colorless gas with a distinctive putrid smell. It is a natural substance found in the blood and brain of humans and other animals as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main compounds responsible for bad breath and the smell of flatus.

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Links verified / updated 13 October 2016