Humans have been using cannabis for thousands of years for medical treatments, spiritual purposes, textile manufacturing, and other reasons. In recent history, chemists have isolated many cannabinoids, the metabolites in cannabis sativa, and have described some of their biological activities. For example, some cannabinoids have potent effects on multidrug resistant bacteria and others are effective against pain. The structures of known cannabinoids also inspire chemists to create synthetic chemicals to mimic certain aspects of their function, like pain reduction, while providing a powerful medical effect and avoiding negative side effects.

Although a lot of work that has been done on cannabis, scientists have not identified every cannabinoid, so many research groups are continuing to identify and categorize the chemicals in cannabis. Samir Ross from the University of Mississippi led one such group in the discovery of nine new cannabinoids, and they published the structures and biological activities of these chemicals in an advanced article in the Journal of Natural Products.

The researchers grew plants from high-potency Mexican C. sativa seeds and harvested the whole buds of mature female plants. They performed chemical extraction and purification procedures on the plant material to isolate the nine cannabinoids. They then determined the molecular structures of these new chemicals using a variety of techniques, including 1D and 2D NMR, UV, and HRESIMS (high resolution electron spray ionization mass spectra).

After figuring out the chemical structures, it was crucial to know how useful these molecules might be in terms of medicinal properties. The first good news was that none of the cannabinoids were toxic to cells extracted from African green monkey kidneys, which meant that they have potential as drugs. Upon closer inspection, several of the compounds had respectable biological activities, as well.

Compound 5 had potent antileishmanial activity, which makes it a possible candidate against leishmaniasis, a parasitic disease that is spread by the bite of the sandfly. Compound 8 was effective at killing Staphylococcus aureus, a frequent cause of staph infections, and compound 7 had good activity against Candida albicans, a fungus that gives people oral and genital infections. The other cannabinoids weren’t as biologically active, but they all had some drug potential. For insistence, compounds 2 and 6 were mildly affective against MRSA, and compound 1 had some antimalarial activity.

The identification of these biologically relevant cannabinoids will give natural product chemists new ideas for future drugs. Even the less active ones can turn out to be useful, as chemists can make modifications of the structures that are more potent.

Journal of Natural Products, 2009. DOI: 10.1021/np900067k

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