Study On Chemical Compositions Of The Leaves Of Dendrocalamus

The chemical utilization of plant resources has been a hot area of research currently.Bamboo is an important part of the forest resources and widely distributed in China. Bamboohas a wealth of secondary metabolites. It has great significance to research and utilize thechemical compositions of bamboo resources. Dendrocalamus is the important sympodialbamboo in our country. In order to comprehensive study the chemical composition ofDendrocalamus, reveal biological activity of the chemical composition of bamboo leaves, thechemical compositions of the leaves of Dendrocalamus latiflorus Munro were isolated,purified and identified. The HPLC method for determination coumarins of bamboo wasestablished. Ten kinds of Dendrocalamus bamboo leaves were analysed so as to explore thedifferences of the chemical compositions of the same genus. The research could provide thetheoretical guidance for utilization of bamboo resources of Dendrocalamus. The researchresults were as follows:(1) The leaves of Dendrocalamus latiflorus Munro were collected, extracted by95%ethanol and leached by petroleum ether, ethyl acetate and n-butyl alcohol respectively. Theextractions were isolated by column chromatography on silica gel, Sephadex LH-20, PrepHPLC and recrystallization. Seventeen compounds were obtained. Their structures wereelucidated on the basis of physicochemical constants and spectral analysis. They wereidentified as vitexin, isovitexin, luteolin, tricin,7-methoxy-tricin, tricin-4’-O-glucopyranoside,tricin-7-O-glucopyranoside, apigenin, apigenin-7-O-glucopyranoside, apigenin-6-C-arabinfuranoside, apigenin-7-O-glucopyranoside-6’’-O-rhamnoside, p-hydroxybenzaldehyde,5-hydroxy-2-methoxy-benzaldehyde, loliolide, dehydrovomifoliol, vomifoliol-9-O-glucopyranoside,4,4’,9,9’-tetrahydroxy-3,3’,5,5’-tetramethoxy-7,7’-monoepoxy lignan. Therewere11flavonoids,2phenolic acids,3terpenes and1lignans. Sixteen compounds were firstlyisolated from Dendrocalamus latiflorus Munro except vitexin. Meanwhile, the anti-tumor cellactivity of4,4’,9,9’-tetrahydroxy-3,3’,5,5’-tetramethoxy-7,7’-monoepoxy lignan the quality of which was relatively large was determinated and the results showed that it had no inhibitoryeffect on the proliferation of HeLa cells.(2) A HPLC method was developed for simultaneous analysis of thirteen flavonoidscompounds in bamboo leaves. The method was simple, rapid and accurate. The result showedthat The standard curves of isoorientin, orientin, vitexin, isovitexin, luteolin,apigenin-7-O-glucopyranoside-6’’-O-rhamnoside, apigenin-7-O-glucopyranoside, tricin-7-O-glucopyranoside,6-trans-(2’’-O-α-rhamnopyranosyl)ethenyl-5,7,3’,4’-tetrahydroxyflavone,apigenin, tricin, demethyltorosaflavone and7-methoxy-tricin in the corresponding ranges hadgood linear relation. LOD of them were at the range of0.01mg/kg to0.03mg/kg and LOQ ofthem were at the range of0.02mg/kg to0.34mg/kg. The instrument of the test was fine and thestandards were stable.Ten bamboo leaves of Dendrocalamus (Dendrocalamus latiflorus, D. giganteus, D.strictus, D. membranceus, D. farinosus, D.minor var. amoenus, D. yunnanicus, D. fugongensis,D. brandisii and D. hamiltonii) were detected using this method. The results showed that theflavonoids contents in different bamboo leaves exist differences. The contents of isoorientin,orientin, vitexin, isovitexin and apigenin-7-O-glucopyranoside-6’’-O-rhamnoside were high inthe ten bamboo leaves. Next were the contents of apigenin-7-O-glucopyranoside andtricin-7-O-glucopyranoside. The contents of luteolin,6-trans-(2’’-O-α-rhamnopyranosyl)ethenyl-5,7,3’,4’-tetrahydroxyflavone, apigenin, tricin, demethyltorosaflavone and7-methoxy-tricin were less.(3) A HPLC method was firstly developed for simultaneous analysis of twelve coumarincompounds in bamboo leaves. The samples were extracted with ethanol/water (70/30, v/v)under ultrasonic and purified through Florisil SPE. The result showed that LOD of skimin,scopolin, scopoletin, umbelliferone,6,7-dimethoxycoumarin, coumarin, psoralen, xanthotoxin,5,7-dimethoxycoumarin, pimpinellin, imperatorin and osthole were at the range of0.19mg/kgto0.85mg/kg and LOQ of them were at the range of0.64mg/kg to2.82mg/kg. The recoveryrates were at the range of47.41%to112.25%with addition quantities of5mg/kg to45mg/kg.The values of RSDs were less than19.69%. Ten bamboo leaves of Dendrocalamus were detected using this method. The resultshowed that five coumarins, namely scopolin, scopoletin, umbelliferone, coumarin andpimpinellin were found in the extracts of ten bamboo leaves. Scopoletin was the commoncomposition of the leaves and the contents were at the range of5.26mg/kg to37.84mg/kg. Theconcentrations of total coumarins were at the range of20.39mg/kg to152.96mg/kg. Themaximum concentration of total coumarins was found in D. fugongensis and the minimum wasin D. farinosus.(4) The chemical compositions of essential oils of the ten bamboo leaves ofDendrocalamus were analysised and compared. In the ten bamboo essential oils, the relativecontents of aldehydes, ketones alcohols were more larger, the relative contents of alkanesolefins, phenols, esters were second and the relative contents of ethers, acids, naphthalenes,furans and the others were low. There were eighteen common compounds in the ten bambooessential oils and (E)-2-Hexenal was the important composition of them.(5) The contents of major chemical compositions (protein, polysaccharides, chlorophylland mineral elements) of the ten bamboo leaves of Dendrocalamus were analysised andcompared. The result showed that contents of protein were at the range of12.90%to22.12%.The maximum content of protein was found in D. farinosus and the minimum content ofprotein was found in D. latiflorus. Protein contents of D. membranceus and D. yunnanicus hadlittle difference, the same as D.minor var. amoenus and D. hamiltonii. Protein contents of theother bamboo leaves had significant differences. Polysaccharides contents of ten bambooleaves were at the range of0.38mg/g to0.82mg/g. The maximum content of polysaccharideswas found in D. giganteus and the minimum content of polysaccharides was found in D.strictus. The contents of chlorophyll a of ten bamboo leaves were at the range of1.69mg/g to3.82mg/g, the contents of chlorophyll b were at the range of0.79mg/g to1.60mg/g and thecontents of total chlorophyll were at the range of2.48mg/g to5.37mg/g. Chlorophyll contentsof D. brandisii were more larger. Ten kinds of bamboo leaves were rich in mineral elements.The contents of K, Ca,mg were more larger, the contents of Mn, Fe, Al, Na, Zn were secondand the contents of Co, As, Se, Mo, Hg, Pb were very low. The results of the research established the foundation for clarification pharmacologicalactivity of the leaves of Dendrocalamus latiflorus Munro, provided scientific basis fordevelopment and utilization of coumarins of bamboo leaves. It had important theoreticalsignificance on the chemical utilization of bamboo leaves resources of Dendrocalamus.