Late-stage cascade of oxidation reactions during the biosynthesis of oxalicine B in Penicillium oxalicum.
10.1016/j.apsb.2022.09.008
- Author:
Tao ZHANG
1
;
Guowei GU
1
;
Guodong LIU
2
;
Jinhua SU
3
;
Zhilai ZHAN
4
;
Jianyuan ZHAO
1
;
Jinxiu QIAN
4
;
Guowei CAI
1
;
Shan CEN
1
;
Dewu ZHANG
1
;
Liyan YU
1
Author Information
1. Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
2. State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, China.
3. The Third Medical Center, The General Hospital of People's Liberation Army, Beijing 100039, China.
4. National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
- Publication Type:Journal Article
- Keywords:
Anti-IAV activity;
Biosynthesis;
Cytochrome P450;
Meroterpenoid;
Oxalicine B
- From:
Acta Pharmaceutica Sinica B
2023;13(1):256-270
- CountryChina
- Language:English
-
Abstract:
Oxalicine B ( 1) is an α-pyrone meroterpenoid with a unique bispirocyclic ring system derived from Penicillium oxalicum. The biosynthetic pathway of 15-deoxyoxalicine B ( 4) was preliminarily reported in Penicillium canescens, however, the genetic base and biochemical characterization of tailoring reactions for oxalicine B ( 1) has remained enigmatic. In this study, we characterized three oxygenases from the metabolic pathway of oxalicine B ( 1), including a cytochrome P450 hydroxylase OxaL, a hydroxylating Fe(II)/α-KG-dependent dioxygenase OxaK, and a multifunctional cytochrome P450 OxaB. Intriguingly, OxaK can catalyze various multicyclic intermediates or shunt products of oxalicines with impressive substrate promiscuity. OxaB was further proven via biochemical assays to have the ability to convert 15-hydroxdecaturin A ( 3) to 1 with a spiro-lactone core skeleton through oxidative rearrangement. We also solved the mystery of OxaL that controls C-15 hydroxylation. Chemical investigation of the wild-type strain and deletants enabled us to identify 10 metabolites including three new compounds, and the isolated compounds displayed potent anti-influenza A virus bioactivities exhibiting IC50 values in the range of 4.0-19.9 μmol/L. Our studies have allowed us to propose a late-stage biosynthetic pathway for oxalicine B ( 1) and create downstream derivatizations of oxalicines by employing enzymatic strategies.
