Alstonia scholaris: Struktur des Indolalkaloides Narelin

Abstract

60. Gebul-t\lng gcwidmet Q3.III. 77)AIstoniu scholaris: The structure of the indole alkaloid nareline SummaryBesides the known akuammidine, picralinal, picrinine and pseudoakuammigine a new indole alkaloid called nareline ( M = 352) was isolated from A lstonia scholaris R. BR., which belongs to the plant family of Apocynaceae. Its structure 2 was deduced by single crystal X-ray diffraction. 2 represents the absolute configuration. The spectroscopic data of 2 and its derivatives (Scheme 1) as well as their chemical behavior support this structure. In biogenetic sense nareline is related to the bases akuammiline (4) and picraline (5) (Scheme 2). In contrast to those the C-atom 5 is exocyclic and represents an aldehyde group which forms together with the oxygen atom of the N(4)-hydroxylamine group a cyclic half acetale. -By oxidation (CrO,/ CH,COOH) of 2 the oxindol derivative 19 (oxonareline) is formed which contains a cyclic acetal as a partial structure element (Scheme 4). Alstonia scholaris R. BR. ist eine in Indien beheimatete

A Review of the Ethnobotany and Pharmacological Importance ofAlstonia booneiDe Wild (Apocynaceae)

“…Alkaloids and related compounds isolated from other Alstonia species include the glycosides of venoterpene [24], nareline [25, 26], lagunamine [27], 19-epischolaricine [28], butamine, dobutamine [29, 30], alschomine [31], N α -methylbutylamine, isoaslchomine[32], picrinine [33], strictamine [34, 35], rhazimanine [36], vallesamine [37], (20S)-19,20 dihydrocondylocarpine [38], scholarine[39], pseudoakuammigine[40], tetrahydroalstonine[41], akuammicine[42], picralinal[43], rhazine[44], scorlarine-N(4)- oxide, scholaricine [45, 46], and flavone glycosides [47, 48]. …”

Three New Indole Alkaloids from the Leaves of Alstonia scholaris

“…ROESY cross-peaks were observed between HÀC(3) and H a ÀC(14), between HÀC(3) and Me(24), between H b ÀC(14) and HÀC(15), and between HÀC(5) and Me(18). On the basis of the above discussion, and by comparison with the literature data of pseudoakuammigine [9], the structure of compound 3 could be fully identified.…”

Access to the Akuammiline Family of Alkaloids: Total Synthesis of (+)-Scholarisine A

“…9 Akuammiline ( 7 ) could also give rise to picraline ( 3 ) 10 upon oxidation at C-5, while additional loss of the acetoxymethyl moiety from C-16 would lead to picrinine ( 4 ). 11 Further functionalization of the picrinine core would result in formation of lanciferine ( 10 ) 12 , nareline ( 11 ) 13 , and arbophylline ( 12 ), 14 while vincorine ( 13 ) 15 and echitamine ( 14 ) 16 consist of a scaffold containing a nitrogen shift. 17 A racemic synthesis of vincorine ( 13 ) was reported by Qin in 2009, 18 while a more recently (2012) Ma reported an asymmetric total synthesis.…”