Studies On Alkaloids Constituents From The Twigs And Leaves Of Alstonia Yunnanensis

The plant of Alstonia yunnanensis Diels?Apocynaceae?,which is endemic to China,is mainly distributed in Yunnan,Guizhou and Guangxi province of China.The the roots of A.yunnanensis are used as folk medicine to treat headaches,fever,tumidness and hypertension.The twigs and leaves of A.yunnanensis are used for the treatment of inflammatory,hemostatic and pain.Forty alkaloids were isolated bIn order to search for bioactive and novel monoterpenoid indole alkaloids,we had systematically investigated the total alkaloids of A.yunnanensis.By the using of silica gel,ODS,Sephadex LH-20 and HPLC chromatographies,Forty alkaloids were isolated from the crude alkaloids of the aerial parts of A.yunnanensis.By physical,chemical and spectroscopic methods,their structures were identified as:N₄-methylpseudoakuammigine?A-1?,pseudoakuammigine?A-2?,pseudoakuammigine N₄-oxide?A-3?,akuammiline?A-4?,picraline?A-5?,nareline?A-6?,deacetylpicraline?A-7?,picralinal?A-8?,picrinine?A-9?,cathufiline N?4?_-oxide?A-10?,alstoyunine B?A-11?,vellosiminol?A-12?,sarpagine?A-13?,akuammidine?A-14?,panarine?A-15?,17-O-acetyl derivative?A-16?,vinorine?A-17?,?-yohimbine?A-18?,pseudoyohimbine?A-19?,isorayohimbine?A-20?,yohimbine?A-21?,?-yohimbine?A-22?,ajmalicine?A-23?,tetrahydroalstonine N₄-oxide?A-24?,dihydrositsirikine?A-25?,sitsirikin?A-26?,16R-E-isositsirikine,A-27),?Z?-epiisositsirikine?A-28?,dihydrocorynantheol?A-29?,alstoyunine A?A-30?,norfluorocurarine?A-31?,norfluorocurarine N-oxide?A-32?,tubotaiwine?A-33?,tubotaiwine N₄-oxide?A-34?,lanceomigine N-oxide?A-35?,19R-hydroxytabersonine?A-36?,vandrikidine?A-37?,normavacurine-21-one?A-38?,melosline B?A-39?,pyridinium?A-40?.Among of them,compounds A-1,A-11,A-30 are new compounds,And compound A-11 is the first example of akuammidine-type alkaloid with a reduction of one carbonyl and one hydroxymethyl at C-16.Compounds A-3,A-4,A-6,A-7,A-14?A-16,A-18?A-20,A-22?A-29,A-31?A-35,A-38?A-40 are obtained from this plant for the first time.This study enriches the chemical composition of genus Alstonia and provides a material basis and scientific basis for the study of Apocynaceae in the direction of pharmacological activity.