A recent Scientific Reports study has discovered two new phytocannabinoids: cannabidihexol (CBDH) and tetrahydrocannabihexol (THCH). 
CBDH and THCH fill the gap between the pentyl (C5H11) and heptyl (C7H15) homologs of cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), marking the first discovery of hexyl (C6H13) derivatives in cannabis. The molecules bear an “n-hexyl side chain on the resorcinyl moiety,” and are unique in that “[u]p to now, only cannabinoids with an odd number of carbon atoms on the side chain have been reported…”
The study utilized a medical cannabis variety known as FM2. The authors isolated the newly discovered phytocannabinoids from FM2 using ultra high performance liquid chromatography (UHPLC) with heated electrospray ionization (HESI) and an Orbitrap (high resolution mass spectrometry)—collectively, UHPLC-HESI-Orbitrap. The researchers noted unique retention times in both raw and decarboxylated extracts. To confirm the identity of the compounds, they re-created them synthetically in the lab.
When identifying the cannabinoids, the researchers explained that “negative ionization mode helped us to distinguish between CBDH and Δ9-THCH, which were identical in positive ionization mode…”
They also quantified the unique cannabinoids. Key cannabinoids CBD and THC were present at 56 mg/g and 39 mg/g, respectively. CBDH and THCH were present in much lower quantities, 27μg/g and 7μg/g, respectively. Thus, these values did not reflect on the CBD:THC ratio.
Although there are no studies on CBDH and THCH’s efficacy in treating pain and other conditions in humans, this study explored an in vivo model and yielded interesting findings in formalin-induced mice.
Researchers found that CBDH has crucial mechanisms needed for pharmacological effects. Doses of 1-2 mg/kg CBDH in formalin-induced mice “significantly reduced” late-phase pain, while higher doses were largely ineffective. The researchers hypothesized that the low doses activate pain receptors such as TRPV1 while the higher doses block receptors including endocannabinoid type 1 and type 2 (CB1 and CB2). 
In all, the study is a leap forward in the discovery of new phytocannabinoids and their possible implementation in medicine. It paves the way for future findings on the medicinal efficacy of CBDH and THCH down the road. It also highlights the power of technologies like Orbitrap mass spectrometry to identify compounds hitherto unknown.
- Linciano P,et al. Identification of a new cannabidiol n-hexyl homolog in a medicinal cannabis variety with an antinociceptive activity in mice: cannabidihexol. Sci Rep. 2020;10(22019). Impact Factor: 3.998; Times Cited: 1 (Semantic Scholar)
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