Related Experiment Video
Updated: Aug 20, 2026

Transient Expression in Nicotiana Benthamiana Leaves for Triterpene Production at a Preparative Scale
Published on: August 16, 2018
Tyrosinase-inhibitory long-chain esters from Amberboa ramosa
Sher Bahadar Khan1, Azhar-Ul-Haq, Nighat Afza
1International Center for Chemical Sciences, H.E.J. Research Institute of Chemistry, University of Karachi, Karachi, Pakistan.
Abstract:
Long-chain esters 1 and 2 have been isolated from the chloroform-soluble fraction of Amberboa ramosa and their structures assigned to be methyl 2beta(2S)-hydroxyl-7(E)-tritriacontenoate (1) and methyl 2beta(2S)-O-beta-D-galactopyranosyl-7(E)-tetratriacontenoate (2). In addition, tricontane (3) and apigenin (4) are also reported for the first time from this species. The structures were assigned on the basis of 1D and 2D NMR techniques. Compounds 1 and 2 showed strong to moderate inhibitory activity against tyrosinase.
Related Concept Videos
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview
Carboxylic Acids to Esters: Acid-Catalyzed (Fischer) Esterification Mechanism
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
Esters to Carboxylic Acids: Saponification
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
