Study On The Chemical Constituents And Biological Activity Of Cannabis Sativa Roots

Cannabis sativa L.,the sole species of Cannabis,is an annual herbage belonging to family Maraceae.This species is grown native to China,India and other Asian countries and now extensively cultured all over the world.In traditional Chinese medicines,the flower,fruit,xylem and leaf of C.sativa have long been used to cure or prevent various disorders,such as tinnitus,arthritic pain,and febrile convulsion.Now C.sativa is used as an effevtive remedy in some cancer treatments.In addition to the medicinal value,C.sativa has been widely employed in modern chemical engineering industry as raw material for furniture,clothing,rope,and paper.In this paper,chemical compositions of C.sativa roots were investigated.Dried and powdered root of C.sativa was extracted by 95%ethanol at room temperature.After combination,filtration and concentration in vacuo,the aqueous residue(crude extract)was yieled.The crude extract was suspended in water and then successfully fractionated by n-hexane,CH2Cl2,EtOAc and n-BuOH on separation funnels.After concentration and freeze-drying,the resulted soluble fractions were obtained as fine powders(n-hexane soluble fraction,yield 1.28%;CH2Cl2 soluble fraction,yield 0.08%;EtOAc soluble fraction,yield 0.06%;n-BuOH soluble fraction,yield 0.09%;H2O soluble fraction,yield 0.35%).Repeated sephadex LH-20 Column Chromatography(CC)and Thin Layer Chromatography(TLC)over the n-hexane soluble fraction led to the isolation and purification of one secondary metabolite,which was identified as Friedelin.The structure of the compound was mainly elucidated on the basis of Nuclear Magnetic Resonance(NMR)and Mass Spectrometry(MS)techniques.Gas Chromatographic and Mass Spectrometric(GC-MS)was used to analyze the volatile components,and area normalization method was utilized to determine the relative content,27 volatile components including terpenes and sterols were acquired.Friedelin and friedelanol were most abundant and they accounted for 54.62%of the volatiles.The contents of the total polysaccharides,total tannins,total flavonoids and total polyphenols from the crude extracts were also determined,and results exhibited that they represented 7.51%,20.10%,16.47%and 26.53%,respectively.Antioxidant activity was evaluated by two in vitro antioxidant methods,including DPPH and hydroxyl free radical scavenging protocols.As a whole,EtOAc soluble fraction showed significant scavenging activity to both radicals.Meanwhile,CH2Cl2 and n-BuOH soluble fractions demonstrated potent hydroxyl free radical scavenging activities and the rest soluble fractions exhibited weak properties to both radicals.And the isolated compound friedelin revealed relative strong potency to DPPH free radical.Antibacterial activity was investigated using cylinder-plate method against Gram-positive bacteria(Staphylococous aureus and Bacillus subtilis)and Gram-negative bacteria(Escherichia coli and Salmonella enteric).Results suggested that the EtOAc soluble fraction and the isolated compound friedelin exhibited strong antibacterial activity,and the n-hexane and n-BuOH soluble fractions,and the crude extract showed moderate antibacterial effect.While,the CH2Cl2 and H2O soluble fractions presented weaker antibacterial activity in general.