Background

Cannabis sativa L. is an annual dicotyledonous herbaceous plant of the Cannabaceae family [1]. Nowadays, the female plant is mainly used in the medical, cosmetic, and pharmaceutical industries. The development of new products in these health-related fields is mainly due to the therapeutic effects associated with various cannabinoids [2]. These compounds are present in trichomes, glandular structures located mainly in female inflorescences [3,4]. Currently, several subclasses of cannabinoids have been identified and categorized into 11 families, each containing a variable number of compounds. The best-known cannabinoids include tetrahydrocannabinol, cannabidiol, cannabinol, cannabichromene, cannabicyclol, and cannabigerol. In addition, there is a wide variety of terpenes, sugars, steroids, flavonoids, and nitrogenous compounds that give flavor and aroma to different strains and have synergistic effects with cannabinoids [5]. The ratios of active compounds in flowers are influenced by a number of factors, including plant genetics, growing and storage conditions, maturity at harvest, and the methods used to process and formulate the material [6].

To maintain the genetic stability of a plant with a specific chemical profile, asexual propagation by vegetative stem cutting is a very suitable method [7]. In this technique, a section of the plant is taken to create a clone that is genetically identical to the parent plant. It is then placed on a moist substrate to allow the roots to develop. When the root system is thriving, it is transplanted to its final location where the plant will grow vegetatively until it reaches flowering and subsequent cannabinoid production. Although this technique is simple, the success of this method depends on many variables such as plant genetics, explant characteristics, hormones, and growing conditions such as light, humidity, and temperature [8].

Once harvested, flowers should be trimmed and then dried (in the absence of sunlight to prevent photochemical transformation) before beginning extraction of the active compounds. Cannabinoids are located in the trichomes on the surface of the bud, where the concentration gradient between the solvent and the trichome surface acts as the primary barrier to chemical transfer. Ethanol is the solvent of choice because of its solubility, relatively low price, and more importantly, its boiling point (for recovery purposes). For medical or dietary applications, ethanol is preferred due to its lower toxicity [9]. After extraction, the solvent is removed to yield a resin consisting of cannabinoids, terpenes, and other accompanying compounds. Depending on the final use of the resin, additional steps for purification and/or isolation are required. In this paper, we specifically detail the procedure to effectively generate cuttings and then list the steps to achieve an efficient resin yield from an alcoholic extraction of cannabinoids.