Further dihydrochalcones from Crotolaria ramosissima

Abstract

Duas novas 2,3-diidrohalconas crotaramin (2) e crotin (3) foram isoladas da planta da Índia Crotolaria ramosissima. Suas estruturas foram elucidadas por meio de intenso uso de espectroscopia de RMN uni-e bidimensional, incluindo HMBC e NOESY.Two new dihydrochalcones, crotaramin (2) and crotin (3), have been isolated from the Indian plant Crotolaria ramosissima. Their structures have been elucidated by extensive one-and two-dimensional NMR spectroscopy including HMBC and NOESY.

Total Synthesis of Munchiwarin, a Triprenylated Chalcone from Crotalaria medicagenia

“…Scheme 2 Figure 2. 1 H (in parentheses) and 13 C NMR chemical shifts and selected HMBC ( 1 Hf 13 C) correlations of 5.…”

“…As a part of our ongoing interest in developing new antiparasitic agents, we have recently reported the antimalarial activity of a few naturally occurring prenylated chalcones 3 and the antileishmanial activity of chromenodihydrochalcones …”

“…12 As a part of our ongoing interest in developing new antiparasitic agents, we have recently reported the antimalarial activity of a few naturally occurring prenylated chalcones 3 and the antileishmanial activity of chromenodihydrochalcones. 13 In continuation of our search for an efficient antimalarial agent, munchiwarin (1) was isolated from the roots of Crotalaria medicagenia DC (yield: 0.0025% from 1 kg of roots). 14 Munchiwarin (1) was the first naturally occurring chalcone with a 2,2,6-triisoprenylcyclohex-5-ene-1,3-dione skeleton previously isolated from another Crotalaria species (C. trifoliastrum) and characterized by 2D NMR spectroscopy and X-ray crystallography; however, the antimalarial activity was not studied.…”

Synthesis of deuterated dihydrochalcones

“…1 New dihydrochalcones, variously methoxylated 2 and with chromyl, 3 galloyl, caffeoyl and hexahydroxydiphenoyl ester 4 and C-b-glucopyranosyl derivatives 5 continue to be reported. The dihydrochalcones, phloretin (3-(4-hydroxyphenyl)-1-(2,4,6-trihydroxyphenyl)propan-1-one, Figure 1 are found throughout the apple tree 1 and are regarded as the characteristic phenolics of apple fruit and of apple products, with concentrations of phloridzin in fruit ranging from 0.1 to 190 mg/kg.…”

Chromene‐Based Synthetic Chalcones as Potent Antileishmanial Agents: Synthesis and Biological Activity

“…The most studied antileishmanial chalcones are licochalcone A (1) isolated from the roots of Chinese liquorice, licochalcone C (2) and oxygenated chalcones 3 (19). Recently, Narender et al (20,21) have described the promising antileishmanial activity of few naturally occurring chromenochalcones 4, including crotaramosmin, crotaramin and crotin ( Figure 1). These compounds contain a benzopyran system, which is frequently found in many natural products.…”