Cannabis and hemp flowers are known for their strong and diverse aromas, which range from earthy to sweet to "skunk-like". This study published in November 2021 in the American Chemical Society's journal, ACS Omega was looking to isolate the source of this skunky aroma, since terpenoids and terpenes are not usually associated with this scent.
The aromatic properties of cannabis flowers and concentrated extracts were analyzed using comprehensive 2D gas chromatography equipped with time-of-flight mass spectrometry, flame ionization detection, and sulfur chemiluminescence.
"We discovered a new family of volatile sulfur compounds (VSCs) containing the prenyl (3-methylbut-2-en-1-yl) functional group that is responsible for this scent. In particular, the compound 3-methyl-2-butene-1-thiol was identified as the primary odorant."
They also monitored an indoor greenhouse and found that these VSCs increase dramatically during the final weeks of flowering, reach their maximum concentration during curing, then start dropping after just one week in storage. They noted the similarity of these VSCs with those in garlic, a food that is known to have health benefits.
The original full-text paper is here at ACS Publications.