Alkaloids from Pandanus amaryllifolius: Isolation and Their Plausible Biosynthetic Formation

Abstract

Pandanus amaryllifolius Roxb. (Pandanaceae) is used as a flavor and in folk medicine in Southeast Asia. The ethanolic crude extract of the aerial parts of P. amaryllifolius exhibited antioxidant, antibiofilm, and anti-inflammatory activities in previous studies. In the current investigation, the purification of the ethanolic extract yielded nine new compounds, including N-acetylnorpandamarilactonines A (1) and B (2); pandalizines A (3) and B (4); pandanmenyamine (5); pandamarilactones 2 (6) and 3 (7), and 5(E)-pandamarilactonine-32 (8); and pandalactonine (9). The isolated alkaloids, with either a γ-alkylidene-α,β-unsaturated-γ-lactone or γ-alkylidene-α,β-unsaturated-γ-lactam system, can be classified into five skeletons including norpandamarilactonine, indolizinone, pandanamine, pandamarilactone, and pandamarilactonine. A plausible biosynthetic route toward 1-5, 7, and 9 is proposed.

Structural classification and biological activities of Stemona alkaloids

“…Pandanamine was originally isolated from the leaves of Pandanus amaryllifolius Roxb. (Pandanaceae) (Takayama et al 2001) and was shown to be accompanied by a series of closely related derivatives (Greger 2006) collectively called Pandanus alkaloids (Tsai et al 2015).…”

Photooxygenation of Furylalkylamines: Easy Access to Pyrrolizidine and Indolizidine Scaffolds

“…Finally, the synthesis of both pandalizine A and B ( 8 and 9 ; Scheme ) was accomplished. These natural alkaloids have only just very recently been isolated from the medicinal plant Pandanus amaryllifolius Roxb . Here, the substrate for the photooxygenation was the meta ‐methyl substituted furylalkylamine 1 h which was directly converted to the indolizidine 3 h (not shown).…”

Photooxygenation of Furylalkylamines: Easy Access to Pyrrolizidine and Indolizidine Scaffolds

“…[26] Here,t he substrate for the photooxygenation was the meta-methyl substituted furylalkylamine 1h which was directly converted to the indolizidine 3h (not shown). Finally, the synthesis of both pandalizine Aand B(8 and 9;Scheme 6) was accomplished.…”

“…These natural alkaloids have only just very recently been isolated from the medicinal plant Pandanus amaryllifolius Roxb. [26] Here,t he substrate for the photooxygenation was the meta-methyl substituted furylalkylamine 1h which was directly converted to the indolizidine 3h (not shown). Theisolation report suggests that 3his the biogenetic precursor to pandalizines Aand B, [26] and indeed, the natural products could be obtained upon addition of TFAinCHCl 3 or MeOH, respectively,a st he culmination of the one-pot process (68 %o verall isolated yield for pandalizine Aa nd 61 %f or pandalizine B).…”