The structure of an alkaloid, picrinine, from Alstonia scholaris

Indole type akuammiline from Vinca erecta: Crystal structure of 10-OAc-Akuammine

“…Alkaloid 2 differs from compound 1 by the presence of the 10-exo OCH3-group in the position, and in compound 3 the aldehyde CHO-group is added to the position C16. The spatial structure of compound 1 was previously defined by the single crystal X-ray diffraction analysis [16]. The CCDC base contains its 3D structure, where all sixmembered boat-shaped cycles, ring C (C2-C3-N4-C5-C6-C7) is divided by the ether bridge into two five-membered cycles, the C/D-cis junction (C3-C14-C15-C20-C21-N4).…”

“…In indolines of V. erecta, the skeletons of the akuammiline type are observed in the Z-states of the exomethylene group (fragment C18-C19=C20-C15). However, in the CCDC database there are examples of indolines (the same types of skeletons) isolated from other plants with E-states of the exomethyl fragment [16]. In the crystal structure of compound 6, the molecules are connected via weak non classic hydrogen bonds (Table 3).…”

Alstonia scholaris: It′s Phytochemistry and pharmacology

“…5-methoxystrictamine (=methyl (5β,16R,19E)-5methoxyakuaramilan-17-oate, methyl (16R,19E)-1,2-dihydro-16-(hydroxymethyl)-5-oxoakuammilan-17-oate, and methyl (2β,16R,19E)-4,5-didehydro-1,2-dihydro-2-hydroxy-16-(hydroxymethyl) akuammilan-4-ium-17-oate chloride [39] Methanolic extract The first seco-uleine alkaloids, manilamine (18-hydroxy-19,20-dehydro-7,21-seco-uleine) and N4methyl angustilobine B, together with the known indole alkaloids, (E)-vallesamine, angustilobine B N4 oxide, (S)-tubotaiwine, and 6,7-seco-angustilobine B [40] Leaves extract Three new indole alkaloids, nareline ethyl ether, 5-epi-nareline ethyl ether and scholarine-N(4)oxide, in addition to nareline methyl ether, picrinine and scholaricine [41] Leaves extract Picrinine and akuammidine [42] Alcoholic extract Picralinal [43] Alcoholic extract A new indole alkaloid, alstonamine, and a sitsirikine type indole alkaloid, rhazimanine [44] Methanol extract A new alkaloid, 19,20-Z-vallesamine, along with 19,20-E-vallesamine [45] Leaves extract 19,20-Dihydrocondylocarpine [46] Ethanolic extract A new alkaloid, scholaricine, has been isolated. It was elucidated as 2 (demethylscholarine) [47] Ethanolic percolate A new alkaloid designated scholaricine.…”

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.…”