Acta Pharmaceutica Sinica B (Jul 2015)

4-Hydroxybenzyl-substituted amino acid derivatives from Gastrodia elata

  • Qinglan Guo,
  • Yanan Wang,
  • Sheng Lin,
  • Chenggen Zhu,
  • Minghua Chen,
  • Zhibo Jiang,
  • Chengbo Xu,
  • Dan Zhang,
  • Huailing Wei,
  • Jiangong Shi

DOI
https://doi.org/10.1016/j.apsb.2015.02.002
Journal volume & issue
Vol. 5, no. 4
pp. 350 – 357

Abstract

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Seven new 4-hydroxybenzyl-substituted amino acid derivatives (1−7), together with 11 known compounds, were isolated from an aqueous extract of the rhizomes of Gastrodia elata Blume. Their structures were determined by spectroscopic and chemical methods. Compounds 1−3 are pyroglutamate derivatives containing 4-hydroxybenzyl units at the N atom and 4−7 are the first examples of natural products with the 4-hydroxybenzyl unit linked via a thioether bond to 2-hydroxy-3-mercaptopropanoic acid (4−6) and 2-hydroxy-4-mercaptobutanoic acid (7), which would be biogenetically derived from cysteine and homocysteine, respectively. The structures of 1 and 2 were verified by synthesis, while the absolute configurations of 4, 5 and 7 were assigned using Mosher’s method based on the MPA determination rule of ΔδRS values. The known compound 4-(hydroxymethyl)-5-nitrobenzene-1,2-diol (8) exhibited activity against Fe2+-cysteine induced rat liver microsomal lipid peroxidation with IC50 values of 9.99×10−6 mol/L.

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