Studies On Chemical Constituents,Structural Modification And Antitumor Activities Of Cycas Revoluta Thunb

Cycas revoluta Thunb belongs to one of the most widely distributed species in Cycadaceae.Many studies have shown that Cycas has pharmacological activities such as antiinflammatory and bacteriostasis,anti-tumor,diuretic,hemostasis and anti-oxidation effects.It has a long history of drug use,its roots,stems and leaves can be used as medicine,and also has edible value because of cyca’s stemes and seeds contain a lot of starch,which after processing can become one of people’s daily consumption-sago.At present,the compounds isolated from cycas are mainly flavonoids,terpenoids,steroids and lignin.Some studies have shown that the cycads contained in cycas revoluta Thunb have cytotoxicities,but which can be easily removed by simple methods such as high temperature and water washing,so the research values of cycas will not be reduced.Apigenin is widely existing in fruits and vegetables,studies have shown that the presence of large amounts of apigenin in leaves of cycas,many modern pharmacological experiments had proved that apigenin has good antitumor activity,antioxidant,antibacterial and antiviral and other pharmacological activities,but because of its poor watersoluble and fat-soluble,to some extent,limits its application.Therefore,in this study,cycas leaves were selected as the research object to study the chemical components in the extraction layer of dichloromethane,and apigenin was modified to obtain compounds with higher antitumor activity,which laid a relevant foundation for the further development of cycas and the study of new drugs in this study.This research group determined the extraction and separation route of Cycas by consulting a large number of literatures and aslo according to the experiences of our laboratory.The dichloromethane layer of cycads was separated and purified by silica gel column,ODS column,Sephadex LH-20 column and semi-preparative HPLC.All the compounds were characterized by 1H-NMR and 13C-NMR,and were confirmed by reference literature.Finally,10 compounds were extracted and isolated from the dichloromethane layer of the crushed leaves of cycas,respectively are N,N-bis(2-hydroxyethyl)tetradecanamide(1)、N,N-bis(2hydroxyethyl)dodecanamide(2)、N,N-bis(2-hydroxyethyl)octanamide(3)、cinnamic acid(4)、3-(sec-butyl)-6-isobutylpiperazine-2,5-dione(5)、3-benzyl-6-isobutylpiperazine-2,5dione(6)、Kaempferol(7)、Quercetin(8)、Gallic acid(9)、Dipentyl phthalate(10).These compounds were isolated from the Cycadaceae for the first time except compound 10.Through a large number of literature review,three structural modification routes of apigenin were determined from two aspects of increasing water solubility and fat solubility of apigenin,in which ethylenediamine could increase the water solubility of apigenin,and 3,3dimethylallyl and 4-fluorobromobenzyl could increase the lipid solubility of apigenin and its antitumor activity.A new target product was designed in each route,but due to the time and condition restrictions,the new compounds could not be completely separated into pure.All the target compounds were characterized and confirmed by 1H-NMR and 13C-NMR combined with literatures.Among them,3,3-dimethylallyl trisubstituted apigenin(13*)is a new compound that has not been reported in literatures.Finally,4 compunds was determined by MTT method to evaluate the antitumor activity,the results showed that 3,3-dimethyl allyl replace apigenin element derivatives(12,13*),and 4-fluorine benzyl bromide(14)to replace the apigenin,derivatives of SGC-7901 human gastric cancer cells,human liver HepG2 cells,HT-29 human colon cancer cells in vitro antitumor activity.The results have showed that 12 and 13*have good inhibitory activitives,which provided a theoretical basis for future researches.