Related Experiment Video
Updated: Mar 30, 2026

The Synthesis of RGD-functionalized Hydrogels as a Tool for Therapeutic Applications
Published on: October 7, 2016
4-Hydroxybenzyl-substituted amino acid derivatives from Gastrodia elata
Qinglan Guo1, Yanan Wang1, Sheng Lin1
1State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
Abstract:
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 Δδ RS values. The known compound 4-(hydroxymethyl)-5-nitrobenzene-1,2-diol (8) exhibited activity against Fe(2+)-cysteine induced rat liver microsomal lipid peroxidation with IC50 values of 9.99×10(-6) mol/L.
Related Concept Videos
Diazonium Group Substitution: –OH and –H
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...

