Silke Hilmer of Symrise , proves the reliability of a nature-identical GMP-certified CBD
As a major flavour and fragrance ( F & F ) expert and a specialist in terpene chemistry , Symrise has developed a straightforward synthesis of cannabidiol ( CBD ), using the renewable terpene D-limonene as the starting material . D-Limonene is produced from orange peel during the manufacturing of orange juice . Terpenes in general are one of the most widely occurring molecules in plants and are present in larger quantities in conifers and citrus fruits . They are aromatic secondary ingredients in nature , having protective roles in the plant , for example antibacterial or anti-fungal effects . Terpenes and terpene-based products are widely used in F & F applications , for example in essential oils for their aromatherapy properties . Natural remedies very often contain terpene-rich extracts , such as sage , thyme , eucalyptus or ribwort , for their commonly known healing effects . There are multiple other applications .
Limonene is one of the most relevant terpenes and is predominantly used as a F & F material , as well as for technical applications . However , it is also playing an increasingly important role in R & D into cannabinoids , especially CBD and its derivatives . ( Symrise also uses D-limonene to manufacture L-carvone , an ingredient that provides the typical spearmint character for oral care products , chewing gum and candy . The other antipode , L-limonene , can be obtained from mint species or conifers and has a herbal , spicy scent .) D-Limonene is transformed into to ( - ) -CBD and later on into ( - ) -Δ9- tetrahydrocannabinol (( - ) -Δ9-THC ), which is also known as Dronabinol ( Figure 1 ). The manufacturing process for Symrise ’ s Canapure * nature-identical ( - ) -CBD is based on extensive R & D work and secured in an appropriate patent landscape . Two raw materials are used as starting materials : limonene , which is converted into menthadienol , and olivetol methyl ester . The main coupling reaction and two subsequent steps yield crude CBD . Final purification yields 99.8 % pure Canapure . Tetrahydro cannabidol derivatives are not detectable in it . Both Canapure and the starting materials are produced in compliance with GMP regulations . However , that still leaves questions to answer , notably ‘ Does the nature-identical quality of Canapure exhibit the same biological value as natural ( - ) -CBD from hemp ?’ A joint comparison study carried out by the universities of Madrid and Córdoba , together with specialised institutes in Spain and Germany , tested multiple parameters . The first two columns in Figure 2 show the binding affinity of both on CB1- and CB2-receptors . These are on the same level for both qualities and with a slightly higher selectivity for CB2 ( column 3 ). The
Figure 1 – Limonene - origin for the development of Cannabinoids
20 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981