Mini-review: recent developments in hydroxynitrile lyases for industrial biotechnology

Area of Science:

• Biocatalysis and Enzymology
• Organic Synthesis
• Chiral Chemistry

Background:

• Hydroxynitrile lyases (HNLs) catalyze reversible cyanohydrin formation, a key step in stereoselective C-C bond construction.
• Cyanohydrins are versatile chiral building blocks for synthesizing complex organic molecules.
• A growing number of HNLs with diverse substrate specificities and enantioselectivities are being discovered and engineered.

Purpose of the Study:

• To review and update recent applications of HNLs in synthesizing highly functionalized chiral compounds.
• To focus on the latest advancements in both scientific literature and patent filings related to HNLs.
• To provide insights into the development of tailor-made HNLs for industrial-scale cyanohydrin production.

Main Methods:

• Comprehensive literature search focusing on recent publications (2020-present) and patent databases.
• Analysis of enzyme characteristics, including substrate scope, enantioselectivity, and sequence/structure diversity.
• Review of enzymatic reaction conditions and downstream processing for cyanohydrin synthesis.

Main Results:

• Numerous (R)- and (S)-selective HNLs have been identified, expanding the toolkit for asymmetric synthesis.
• Significant progress has been made in engineering HNLs for improved yield, enantiomeric excess, and stability.
• Patents reflect strong industrial interest in HNLs for large-scale manufacturing of valuable chiral intermediates.

Conclusions:

• HNLs are powerful biocatalysts enabling efficient and stereoselective synthesis of chiral cyanohydrins.
• Ongoing research and patent activity underscore the potential of HNLs in pharmaceutical and fine chemical industries.
• Further enzyme engineering and application development will continue to drive innovation in chiral compound synthesis.