Thiols can have a strong unpleasant odour and occur naturally in cannabis. Thiols are the sulfur analogue of alcohols, and they are often referred to as mercaptans.
Read more about thiols <a href="https://www.sciencedirect.com/topics/chemistry/thiol">here</a>.

Thiol 

A thiol is an alcohol group with a sulphur atom in place of an oxygen atom. 

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