Three new pterocarpans from the aerial parts of Abrus Precatorius

Abstract

Three new pterocarpans, named abrusprecatins A-C (1–3), along with three known ones, namely medicarpin (4), maackiain (5), and 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (6) were isolated from the aerial parts of Abrus precatorius. The structures of these compounds were established by extensive analysis of mass spectrometric data, 1?D and 2?D NMR spectroscopic data. In addition, the absolute configurations were determined by a combination of single crystal X-ray diffraction analysis and circular dichroism spectroscopy.     

Complete NMR data assignments for novel pterocarpans from Harpalyce brasiliana

A NMR study of two new pterocarpans isolated from the roots of Harpalyce brasiliana is described. In addition to 1D NMR, 2D shift-correlated NMR pulse sequences ((1)H-(1)H-COSY, HSQC and HMBC) were used to establish the structures, and unambiguously perform the (1)H and (13)C chemical shift assignments.     

Determination of 3-hydroxy pterocarpan, a novel osteogenic compound in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetics study

A rapid, sensitive and selective LC‐MS/MS method for the quantitative analysis of 3‐hydroxy pterocarpan (S006‐1709) in female rat plasma has been developed and validated. A Discovery RP₁₈ column was used for the chromatographic elution using acetonitrile and 0.1% acetic acid in water as mobile phase (80:20 v/v) at the flow rate of 0.5 mL/min. MS/MS analysis was performed using a triple quadrupole mass spectrometer with electrospray ionization in negative ion mode using biochanin as an internal standard (IS). Extraction of S006‐1709 and IS from rat plasma was done by liquid–liquid extraction method using diethyl ether. The LC‐MS/MS method was sensitive with 1.95 ng/mL as the limit of detection and 3.9 ng/mL as the lower limit of quantification. The method was linear in the concentration range of 3.9–1000 ng/mL. The percentage bias for intraday and interday accuracy was not greater than 4.2 and the %RSD for intraday and interday precision was not greater than 13.2. The recoveries of S006‐1709 and IS were 73.9–79.3 and 85.7%, respectively. S006‐1709 was found to be stable in various stability studies. The validated LC‐MS/MS method was successfully applied for the oral pharmacokinetics study of S006‐1709 at 10 mg/kg in female Sprague–Dawley rats. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of New (±) Pterocarpans by Heck Oxyarylation

Among a wide variety of synthetic routes to pterocarpan prototypes, a mild approach uses a reaction known as Heck oxyarylation. This method involves a reaction between 2H-chromenes and 2-chloromercuriophenols in the presence of Li₂PdCl₄. __________ Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 311–312, July–August, 2005.