Studies Of Chemical Constituents And Pharmacological Activities Of The Leaves Of Melaleuca Leucadendron

Objective:The Melaleuca leucadendron belongs to Melaleuca genus of Myrtaceae. As a medicinal plant, its essential oil has pharmacological activities such as disinfection,sterilization,antivirus,mould proof,anti-inflammatory pain and cough expectorant.The domestic and overseas scholars have researched the chemical constituents and pharmacological activities of Melaleuca genus,essential oil,triterpenes,flavonoids and steroids have been obtained,but chemical constitutes and pharmacological activities of the leaves of Melaleuca leucadendron in Hainan have never been reported previously.To determine the structure of main chemical constituents,active constituents and the total content of active constituents,we study the active ingredients through the methods of extraction, separation, purification, characterization,etc.It is very useful for developing and using resources, searching the new active ingredients and accumulating information of natural medicinal chemistry.Method:The75%EtOH extraction of Melaleuca leucadendron was re-extracted with petroleum ether,chloroform,ethyl acetate,and n-butanol successively to get four fractions.The chemical constituents were isolated by means of silica gel column chromatography (CC),Sephadex LH-20,preparative thin layer chromatography (PTLC) and high performance liquid chromatography (HPLC),etc.Then various spectrum methods including NMR,UV,IR,MS were used to elucidate the structures combining with their physical and chemical properties.The total content of terpene acid,flavonoids,polysaccharide in stems and leaves of Melaleuca leucadendron were determined by UV spectrophotometry.The antioxidant activity of essential oil in leaves of Melaleuca leucadendron and the antitumor activity of extraction parts and some of the compounds were researched too.Result:Eighteen compounds were identified and fifteen compounds were identified by the modern spectrum technology, unifies physicochemical method and literature comparison as trans-cinnamaldehyde(1), vanillin(2), rutin(3), ursolic acid(4), betulinic acid(5), β-sitosterol(6),oxalic acid(7), genistein(8), luteolin(9), vanillic acid(10),β-daucosterol(11), citric acid(12), benzoic acid(13), salicylic acid(14), trans-cinnamic acid(15).All the compounds were isolated from the plant for the first time, and all of them were isolated from Melaleuca spach first except compounds (5) and (6).The total content of essential oil in stems and leaves of Melaleuca leucadendron in Hainan were19.72%and64.46%.The total content of terpene acid,flavonoids,polysaccharide in leaves were1.017%,0.627%and14.46%,the total content of terpene acid and flavonoids in stems were1.096%and0.689%.Compound (3) had an inhibition rate of76.98%to SPCA-1,had an inhibition rate of72.21%to SGC-7901.Compound (9) had an inhibition rate of77.97%to SGC-7901.