Optimization of Biocatalytic Rhododendrol Production from Biogenic Rhododendrol Glycosides

Area of Science:

• Biocatalysis and enzyme engineering
• Green chemistry and sustainable processes
• Natural product synthesis

Background:

• Rhododendrol is a key intermediate for raspberry ketone production.
• Rhododendrol glycosides are renewable resources from birch bark but have variable compositions.
• Enzymatic hydrolysis offers a sustainable route to rhododendrol.

Purpose of the Study:

• Investigate enzyme-catalyzed synthesis of rhododendrol from natural glycosides.
• Assess the feasibility and optimize the enzymatic hydrolysis process.
• Develop a mathematical model for process prediction and control.

Main Methods:

• Enzymatic hydrolysis of rhododendrol glycosides (betuloside and apiosylrhododendrin).
• Screening of approximately 50 enzymes, identifying RAPIDASE for apiosylrhododendrin.
• Development and validation of a mathematical model in batch, repetitive batch, and ultrafiltration membrane reactors.

Main Results:

• Ultrafiltration membrane reactors yielded the highest productivity (83.9–94.5 g L⁻¹ day⁻¹).
• RAPIDASE was effective for apiosylrhododendrin hydrolysis.
• Model-based optimization allowed prediction of input parameters for consistent output.

Conclusions:

• Enzymatic hydrolysis is a feasible and efficient method for rhododendrol production.
• Ultrafiltration membrane reactors are optimal for high-throughput enzymatic synthesis.
• Model-based optimization ensures consistent production from variable natural feedstocks.