Biogenetic Conversion of Tetrahydroisoquinoline−Monoterpene Glucosides into Benzopyridoquinolizine Alkaloids of Alangium lamarckii

Abstract

The biogenetic conversion of alangiside (6), a major tetrahydroisoquinoline−monoterpene glucoside of Alangium lamarckii, into (+)-alangimaridine (1), one of the benzopyridoquinolizine alkaloids of the same plant, was carried out confirming its absolute configuration. Isoalangimarine (3) and its possible precursor (+)-isoalangimaridine (19) were synthesized from 3-O-demethyl-2-O-methylalangiside (11).

Protoberberine Alkaloids and Cancer Chemopreventive Properties of Compounds from Alangium salviifolium

“…Previously, alangisides have been chemically transformed into the skeleton of alangimaridines, benzopyridoquinolizine alkaloids from Alangium lamarckii, which supports alangisides as biogenetic precursors of these alkaloids. [22] In the case of protoberberine alkaloids 1 and 2, their biosynthesis may involve the hydrolysis of alangiside 9, ring cleavage to give the intermediate A, and a bond rotation in A to furnish the intermediate B (Scheme 1). The intermediate B undergoes cyclization, dehydration, dehydrogenation, and oxidation to give alangiumkaloid A (1), which is further reduced to yield alangiumkaloid B (2; Scheme 1).…”

Bioactive Cardinane Sesquiterpenes from the Stems of Alangium salviifolium

“…The dichloromethane extract of the stems of A. salviifolium was subjected to columnc hromatography on silica gel, Sephadex LH-20, preparative TLC, and semipreparative RP-18 HPLC to provide twelve cardinane sesquiterpenes, of which seven are new compounds, alangenes A-G (1)(2)(3)(4)(5)(6)(7). The known compounds were identified as mansonone H( 8 ), [5,6] mansonone E (9), [5,7] mansonone G( 10), [8] dehydrooxoperezinone (11), [9] and (S)-(À)-lacinilene C( 12) [10,11] by comparison of their physical and spectroscopic data (NMR and MS) with those reported in the literature (Figure 1).…”

“…Various parts of this plant are used in Indian folk medicine. [1] In Thailand, the wood is used as at raditional medicine for the treatment of hemorrhoids, and as at onic, while the stem bark and fruits are used as an expectorant, and as an anti-asthmatic, antidiarrheal, anthelmintic, and antiflatulent medicine. [2] Phytochemical studies on this plant have shown the presence of iridoid glycosides, phenolic glycosides and several types of alkaloids, that is, tetrahydroisoquinoline monoterpene glucoside, tetrahydro-b-carboline monoterpene glucoside, benzoquinolizine, protoberberine, benzopyridoquinolizine, and ipecac alkaloids.…”

“…[2] Phytochemical studies on this plant have shown the presence of iridoid glycosides, phenolic glycosides and several types of alkaloids, that is, tetrahydroisoquinoline monoterpene glucoside, tetrahydro-b-carboline monoterpene glucoside, benzoquinolizine, protoberberine, benzopyridoquinolizine, and ipecac alkaloids. [1,3] Recently,t he isolation of two protoberberine alkaloids, two triterpene glycosides,ab -dglucopyranos-1-yl-N-methylpyrrole-2-carboxylate, and three tetrahydroisoquinoline monoterpene glucosides were reported from this laboratory from am ethanole xtract of the stems of this plant. The cytotoxic, cancer chemopreventive, and aroma-tase inhibition activities of some compounds werea lso reported.…”

“…A. lamarckii Thwaits) is a medium tree, 8‐10 m in height, belonging to the family of Cornaceae (Alangiaceae). Various parts of this plant are used in Indian folk medicine 1. In Thailand, the wood is used as a traditional medicine for the treatment of hemorrhoids, and as a tonic, while the stem bark and fruits are used as an expectorant, and as an anti‐asthmatic, antidiarrheal, anthelmintic, and antiflatulent medicine 2.…”