Intermolecular [4+2]-cycloaddition reaction to biotransform morachalcone a into kuwanon j, catalyzed by diels-alderase from a root culture of morus alba var. Shalun (m. shalun)
Kurniawan R.a, Hermawati E.a, Hertadi R.a, Abe I.b, Morita H.c, Piow W.C.c, Hakim E.H.a
a Organic Chemistry Division, Faculty of Mathematic and Natural Sciences, Bandung Institute of Technology, Bandung, 40132, Indonesia
b Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
c Institute of Natural Medicine, University of Toyama, Toyama, 930-0194, Japan
Abstract
© 2020 Kurniawan et al.Morus is one of the main genera of the Moraceae family and widely cultivated in Southeast Asia for silkworm feeding. This genus also produces valuable bioactive phenolic compounds such as flavonoids, stilbenes, 2-arylbenzofurans, and Diels-Alder adducts. Previous phytochemical investigation of Morus shalun reported the Diels-Alder adducts as the mayor phenolic compounds isolated from root cultures. The Diels-Alder adduct is considered formed by the intermolecular [4+2]-cycloaddition between a diene of dehydroprenyl phenol with a dienophile of the α, β-unsaturated carbonyl group of a chalcone. This reaction in plant tissues is naturally catalyzed by the enzyme Diels-Alderase. The experiment was designed to determine the existence of Diels-Alderase isolated from a root culture of M. shalun by evaluating its activity in the biotransformation process of morachalcone A to produce kuwanon J. Biotransformation was detected using HPLC and LCMS. Kuwanon J showed significantly higher cytotoxic activities against the three human cancer cell lines HeLa, A459, and MCF7 compared with morachalcone A.
Author keywords
Indexed keywords
Biotransformation,Cytotoxicity,Diel-alderase,Intermolecular cycloaddition,Morus shalun,Plant culture
Funding details
We acknowledge The Ministry of Research, Technology and Higher Education (Ristek Dikti) for PMDSU scholarship. And JSPS program which funded very important initiation part of this work.