Study On Chemical Constituents Of Caesalpinia Sappan L.

Caesalpinia sappan L., a species in Caesalpinia, belongs to the family Leguminosae. The dried heartwood of Caesalpinia sappan L. was extracted with95%ethylalcohol. It was verified that the petroleum ether, ethyl acetate and n-butanol extract fraction of the95%ethanol extracts showed good antitumor activities based on in vitro antitumor activity screening experiment. Chemical constituents of petroleum ether fraction have not been reported yet. Diterpenoids, homoisoflavonoids are characteristic components of the genus Caesalpinia. The pharmacological activities covered various aspects. Constituents of the petroleum ether fraction are likely efficacy components to cure diseases. In addition, Caesalpinia is a very complicated group, up to now, researches to this genus were limited to morphological classification, lack of chemical and cytological evidences. Flavonoids, which are rarely disjunctively distributed and raletivey common existed or lacked, provide a valuable evidence for plant classification. Homoisoflavonoids are rarely found in nature, only existing in a few plants, which are meaningful in taxonomy and pharmacophylogenetics.The present paper selected chooses diterpenoids and homoiso-flavonoids as targets, under the guidance of the pharmacological activity screening results and the distribution of diterpenoids. We mainly focused on the chemical components of petroleum ether extraction layer and ethyl acetate extraction extract fraction from95%ethanol extracts of Caesalpinia sappan L., in order to explore the chemical composition of Caesalpinia sappan L., and make use of existing chemical materials to support or revise plant taxonomic treatment., This study would also pursue to enrich natural products, obtain more efficacy substances, provide leading compounds for innovative natural medicine if possible.The major results are as follows:1. Fourty-three compounds have been isolated from the dried heartwood of Caesalpinia sappan L.. On the basis of their physiochemical and spectroscopic evidences, the structures of twenty-eight compounds were elucidated as follows:homoisoflavonoids:7,4'-dimethoxyhomoisoflavanone (CS-PE-13), brazilin (CS-EA-14), sappanone A (CS-EA-15), caesalpin J (CS-EA-16,28),3,7,3',4'-tetrahydroxy-4-dimethoxy-homoisoflavans (CS-EA-17), brazilide A (CS-EA-18), protosappanin A (CS-EA-19); xanthones:1-hydroxy-7-methoxyxanthone (CS-PE-1),2-hydroxyxanthone (CS-PE-2),1,5-dihydroxyxanthone (CS-PE-3),1,7-dihydroxyxanthone (CS-PE-4); chromones:3,7-dihydroxy-4H-chromen-4-one (CS-EA-20); chalcones:3-deoxysappan chalcone (CS-EA-22), sappanchalcon (CS-EA-21),3,4,2',4'-tetrahydroxy chalcone (CS-EA-23); flavanone:7,3',5'-trihydroxy flavanone (CS-EA-24); flavonoid:rhamnetin(CS-EA-25); anthraquinones: chrysophanol (CS-PE-5); triterpenes:friedelin (CS-PE-6), ursolic acid (CS-PE-7); steroids:β-sitosterol palmitate (CS-PE-8), ergosta-4,6,8(14),22(23)-tetraen-3-one (CS-PE-9), stigmasterol (CS-PE-11),β-sitosterol (CS-PE-12); lactone:diisooctane-phthalate (CS-PE-10); aldehyde:2,4,5-trihydroxy benzaldehyde (CS-EA-26); xylogen:(±)-lyoniresinol (CS-EA-27).Compounds CS-EA-28is new compound. Compound CS-EA-13is isolated from natural products for the first time. Compounds CS-PE-1-CS-PE-10,CS-EA-17,CS-EA-24are isolated from this plant for the first time. Compound CS-PE-1-CS-PE-5, CS-EA-17. CS-EA-24are isolated from the genus Caesalpinia for the first time, moreover, compounds CS-PE-1-CS-PE-5with xanthone and anthraquinone skeletons are also firstly isolated from the genus Caesalpinia.2. After a general literature investigation, we found that: homoisoflavonoids are rarely found in nature, only exist in a few plants, up to the family Leguminosae, homoisoflavonoids obviously are confined to the genus Caesalpinia, which can be the chemical classification feature of it.3. It has been thought that anthraquinones are only distributed in the genus Chamaecrista of Leguminosae family. We isolated anthraquinones from Caesalpinia sappan L. for the first time, moreover, they are also firstly isolated from the genus Caesalpinia, if this is not an isolated phenomenon, anthraquinones may also exist in other plants of Caesalpinia, on the chemical gradients aspect, it can provide evidence on the evolvement study of Caesalpinioideae taub and other subfamily.4. Homoisoflavonoids either isolated from Caesalpinia sappan L mainly exist in the form of aglycones. Analyses show that Caesalpinia sappan L. is subjected to dungarunga, medicinal part is the heartwood, the main function of this part is supporting, it is not the organization for nutrients'synthesis or storage, so the secondary metabolites primarily exist in the form of aglycones.