Why cannabis smells skunky

Date:
December 1, 2021
Source:
American Chemical Society
Summary:
As cannabis is legalized in more areas, it has become increasingly
popular as a medicinal and recreational drug. This plant
produces a pungent, skunk-like odor that is pleasing to some
but repulsive to others. Now, researchers have discovered a new
family of prenylated volatile sulfur compounds (VSCs) that give
cannabis its characteristic skunky aroma. The findings open up
opportunities to investigate the molecules for medicinal benefits,
the researchers say.



FULL STORY ==========================================================================
As cannabis is legalized in more areas, it has become increasingly
popular as a medicinal and recreational drug. This plant produces a
pungent, skunk-like odor that is pleasing to some but repulsive to
others. Now, researchers reporting in ACS Omega have discovered a new
family of prenylated volatile sulfur compounds (VSCs) that give cannabis
its characteristic skunky aroma. The findings open up opportunities to investigate the molecules for medicinal benefits, the researchers say.


========================================================================== Cannabis sativa L. produces more than 200 known aroma compounds. Prior
studies have focused mainly on terpenoids -- molecules that range in
odor from fuel- like to woody, citrusy or floral. Different cannabis
cultivars have diverse mixtures of these compounds that contribute to
their unique aromas. However, although terpenoids are the most abundant
aroma compounds in cannabis, there is little evidence that they provide
the underlying skunk-like smell of many cultivars. Skunks use several VSCs
in their smelly defense sprays, so Iain Oswald and colleagues suspected
that there could be similar molecules in cannabis. The team decided to
use sensitive analytical techniques to find out.

The researchers analyzed flowers from 13 cannabis cultivars using a
custom- built 2D gas chromatography system with three different types
of detectors.

Then, a four-person panel ranked the pungency of the cultivars on a
scale from 0 to 10. The most pungent one, called Bacio Gelato, had the
highest concentration of VSCs. The team identified seven VSCs in this
cultivar, some of which were also present in other cultivars. Five of
the VSCs contained the prenyl functional group and had skunk-like or
sulfuric aromas. One compound in particular, 3-methyl-2-butene-1-thiol, referred to as VSC3, was the most abundant VSC in the cultivars that
the panel reported to be most pungent. This compound has previously been implicated in the flavor and aroma of "skunked beer" -- beer that goes
bad after being exposed to UV light.

To confirm that VSC3 was the main source of the skunk-like aroma,
the team added it to a mixture of 10 other major aroma compounds from
cannabis, producing a combined odor very similar to the characteristic
scent of cannabis.

They also detected VSC3 in cannabis concentrates, such as those used for vaping. Finally, in greenhouse experiments, the researchers determined
that the prenylated VSCs increased significantly toward the end of the flowering stage of cannabis growth, reached a maximum during curing
and then dropped substantially after 10 days of storage. Because the
molecular structures of the VSCs resemble compounds from garlic that have anti-cancer and cardioprotective effects, the new family of prenylated
odor molecules should be investigated for medicinal properties, the
researchers say.

The authors do not acknowledge any external funding sources for this
study.

Three of the authors have filed a patent related to the findings.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Iain W. H. Oswald, Marcos A. Ojeda, Ryan J. Pobanz, Kevin A. Koby,
Anthony J. Buchanan, Josh Del Rosso, Mario A. Guzman, Thomas
J. Martin.

Identification of a New Family of Prenylated Volatile Sulfur
Compounds in Cannabis Revealed by Comprehensive Two-Dimensional
Gas Chromatography.

ACS Omega, 2021; 6 (47): 31667 DOI: 10.1021/acsomega.1c04196 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/12/211201085147.htm

--- up 2 weeks, 6 days, 2 hours, 55 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)