Structurally diverse monoterpene indole alkaloids with vasorelaxant activities from the branches of Alstonia scholaris

Alscholarines A and B, two rearranged monoterpene indole alkaloids from Alstonia scholaris

“…The dried and crushed branches of A. scholaris (30 kg) were extracted as previously described. 24 The CHCl 3 extract was subjected to silica gel CC and eluted with a CH 2 Cl 2 /MeOH gradient (from 50/1 to 1/1) to obtain six fractions (Fr. A–Fr.…”

“…The dried and crushed branches of A. scholaris (30 kg) were extracted as previously described. 24 The CHCl…”

“…The vasorelaxant activity in vitro of alkaloids 1-3 were evaluated using the method of phenylephrine-induced contraction of rat mesenteric arteries as previously described. 24…”

“…7,[21][22][23] In our previous chemical study on the branches of A. scholaris, structurally diverse and biologically active MIAs have been identified, encouraging us greatly. 24 As part of our effort to discover structurally unique and biogenetically interesting MIAs, we conducted in-depth research phytochemical investigations of the branches of A. scholaris, leading to the isolation of two novel complex MIAs (Fig. 1), alscholarines A-B (1-2).…”

Polycyclic pyrroloindoline-containing natural products with a unique 3-heptyl-2a,4a-diazapentaleno[1,6-ab]indene core isolated from Alstonia scholaris

“…10 So far, nearly 135 compounds have been reported in this species and most of them are monoterpene indole alkaloids (MIAs). 11 Compared to the extensive investigation of MIAs, only fourteen PiNPs, namely echitamine, 12 N b -demethylechitamine, 12 17- O -acetylechitamine, 12 echitaminic acid, 13 3- epi -dihydrocorymine, 14 3- epi -dihydrocorymine 3-acetate, 14 3- epi -dihydrocorymine 17-acetate, 14 leuconoxine, 15 scholarisine G, 16 scholarisin VI, 17 alistonitrine A, 18 alstobrogaline, 19 scholarinine A, 20 and alstoscholarinine E, 21 were isolated from this species, and can be classified into five PiNP carbon skeletons.…”