Purification of xanthorrhizol and screening of selected microbes for its biotransformation

• Main Authors: Aminudin, Nurul Iman, Yahya, Nadia Farhana, Zainal Abidin, Zaima Azira, Darnis, Deny Susanti, Bakhtiar, M. Taher
• Format: Article
• Language: English
• Published: The Malaysian Analytical Sciences Society 2021
• Subjects: QD Chemistry
• Online Access: http://irep.iium.edu.my/95382/7/95382_Purification%20of%20xanthorrhizol%20and%20screening.pdf; http://irep.iium.edu.my/95382/; https://mjas.analis.com.my/mjas/v25_n6/pdf/Iman_25_6_6.pdf
• Institution: Universiti Islam Antarabangsa Malaysia

Xanthorrhizol is a bisabolene-type sesquiterpenoid and is present abundantly in the essential oil of Curcuma xanthorrhiza (temulawak). It was reported to possess various pharmacological activities, including antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, antihypertensive, and antiplatelet activities. To further evaluate its pharmacological potency based on the structure-activity relationship, a large amount of xanthorrhizol needs to be purified and subjected to chemical synthesis to yield xanthorrhizol analogues. Common approaches to synthesise the analogues are through chemical reactions. Biotransformation utilising microbes as biocatalysts is one of the green alternatives to replace chemical synthesis methods for producing xanthorrhizol analogues. In this study, xanthorrhizol was purified from the crude essential oil by utilising repetitive chromatographic separation and two-step chemical synthesis involving acetylation and hydrolysis reactions. The purification successfully yielded xanthorrhizol with a purity of 98.1%, as indicated by gas chromatography-mass spectrometry (GC-MS) analysis. The structure of xanthorrhizol was also characterised using nuclear magnetic resonance spectroscopy (NMR). Four selected microbes (Aspergillus niger, Streptomyces sp. K1-18, K3-20, and K7-11) were screened for the biotransformation of xanthorrhizol. The results from thin layer chromatography (TLC) and GC-MS showed that only A. niger could biotransform xanthorrhizol into its derivatives.