Related Experiment Video
Updated: May 24, 2026

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Biocatalytic conversion of aloeresin A to aloesin
Lucia Steenkamp1, Kgama Mathiba, Paul Steenkamp
1Protein Technologies, CSIR Biosciences, P.O. Box 395, Pretoria, 0001, South Africa. lsteenkamp@csir.co.za
Abstract:
Leaf exudates from Aloe species, such as the Southern African Aloe ferox, are used in traditional medicines for both humans and livestock. This includes aloesin, a skin bleaching product that inhibits the synthesis of melanin. Aloesin, (a C-glycoside-5-methylchromone) can be released from aloeresin A, an ester of aloesin, through hydrolysis. The objective of the current study was to identify an enzymatic hydrolysis method for converting aloeresin A to aloesin, resulting in increased concentrations of aloesin in the aloe bitters extract. More than 70 commercially available hydrolytic enzymes were screened for the conversion of aloeresin A. An esterase (ESL001-02) from Diversa, a lipase (Novozym 388) and a protease (Aspergillus oryzae) preparation were identified during screening as being capable of providing conversion of pure aloeresin A, with the protease giving the best conversion (~100%). It was found that a contaminating enzyme in Novo 388 was responsible for the conversion of aloeresin A to aloesin. This contaminating enzyme, possibly a protease, was able to give almost complete conversion using crude aloe bitters extract, doubling the concentration of aloesin in aloe bitters extract via the hydrolysis of aloeresin A.
Related Concept Videos
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
The carbonyl center is activated by...
Base-Catalyzed Aldol Addition Reaction
Crossed Aldol Reaction Using Weak Bases
α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview
Production of Pharmaceuticals
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis

