Separation and purification of cannabinoid from hemp leaves

Separation and purification of cannabinoid from hemp leaves

Hemp, also known as hemp, hemp and cold hemp, belongs to the dicotyledonous class of urticaria. It originated in Central Asia and is a dioecious plant. It is known as "the source of national textile and the ancestor of thousands of years". It has many functions, such as moisture absorption, heat dissipation, bacteriostasis, ventilation and so on. With the scientific and technological progress of hemp company, more than 120 kinds of active ingredients, called cannabinoids, have been found in hemp, of which tetrahydrocannabinol (THC) and cannabinoid diphenol (CBD) are the main active ingredients.

THC has hallucinogenic and addictive effects, which is the only reason for banning cannabis cultivation in many countries. Cannabis diphenol is a non-toxic and non addictive hallucinogenic active substance in industrial cannabis, known as "anti drug compound". China's industrial cannabis industry has gradually moved from the initial food production and processing to the comprehensive development and utilization of CBD and other effective ingredients extracted from the leaves of industrial fried dough twist.

At present, the common methods of cannabinoid extraction include organic solvent extraction, supercritical CO2 extraction, membrane separation technology and so on. Haohongjiang et al. Extracted hemp leaves with 7 times volume fraction 60% ethanol for 3 times, 2h/ time, and obtained a good CBD process. At this time, the yield of cannabinoid extract was 0.134%, and CBD accounted for 2.89% of the extract content; Moreno et al. Obtained the extract with high CBD content of 449mg/g from the flower buds of New Zealand Industrial cannabis by supercritical CO2 technology, extraction pressure of 130Mpa and ethanol as cosolvent; Zhengling et al. Used membrane separation technology to optimize CBD industrial extraction. Through methanol extraction, water precipitation and 50 ℃ hot reflux extraction of alcohol water system for 5h, CBD crude products with purity higher than 60% can be obtained after water precipitation crystallization.

Although there are many ways to obtain cannabinoids, the purity of CBD is about 60%. At present, there is little research on CBD extraction and function in China. Resin adsorption method is often used, and then crude CBD products are obtained through vacuum concentration, with the content of less than 60%. There are also crude cannabinoid products with the content of more than 60% CBD obtained by membrane separation technology.

Clinical studies have shown that CBD can quickly penetrate the blood-brain barrier and can be used as a drug for the treatment of nervous system diseases caused by stress. It can effectively treat arthritis, multiple sclerosis, chronic pain, schizophrenia and epilepsy. Sartim et al. Showed through the forced swimming experiment of mice that CBD can reduce the time of mice at rest, thus proving that CBD may have antidepressant effect. Linge et al. Explored the effect of CBD on different kinds of mouse depression models, and explored the signal pathway that may activate BDNF TrkB to cause synaptic plasticity. With the gradual emergence of various biological activities and medical values of CBD, obtaining high-purity CBD has become a research hotspot.