Hinokitiol


Hinokitiol is a natural monoterpenoid found in the wood of trees in the family Cupressaceae. It is a tropolone derivative and one of the thujaplicins. Hinokitiol is widely used in oral care and treatment products.
Hinolitiol was originally isolated in Taiwanese hinoki in 1936. It is almost absent in Japanese hinoki while it is contained in high concentration in Juniperus cedrus, hiba cedar wood and western red cedar. It can be readily extracted from the cedarwood with solvent and ultrasonication.
Hinokitiol is structurally related to tropolone, which lacks the isopropyl substituent. Tropolones are well-known chelating agents.

Antimicrobial activity

Hinokitiol has been shown to possess inhibitory effects on Chlamydia trachomatis and may be clinically useful as a topical drug.

Products containing hinokitiol

Hinokitiol is used in a range of consumer products including cosmetics, toothpastes, oral sprays, sunscreens And hair-growth. In 2006, hinokitiol was categorised under the Domestic Substances List in Canada as non-persistent, non-bioaccumulative and non-toxic to aquatic organisms.
In April 2020, Advance Nanotek, an Australian producer of zinc oxide, filed a joint patent application with AstiVita Limited, for an anti-viral composition that included oral care products.

History

Hinokitiol was discovered in 1936 by Tetsuo Nozoe from the essential oil component of Taiwan cypress. The compound has a heptagonal molecular structure.

Research directions

In animals

Researchers screening a library of small biomolecules for signs of iron transport found that hinokitiol restored cell functionality. Further work by the team suggested a mechanism by which hinokitiol restores or reduces cell iron. In mammals, they found that when rodents that had been engineered to lack "iron proteins" were fed hinokitiol, they regained iron uptake in the gut. In a similar study on zebrafish, the molecule restored hemoglobin production.