1
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Li FR, Wang Q, Pan X, Xu HM, Dong LB. Discovery, Structure, and Engineering of a cis-Geranylfarnesyl Diphosphate Synthase. Angew Chem Int Ed Engl 2024; 63:e202401669. [PMID: 38651244 DOI: 10.1002/anie.202401669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/15/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
cis-Prenyltransferases (cis-PTs) catalyze the sequential head-to-tail condensation of isopentenyl diphosphate (IPP) to allylic diphosphates, producing mixed E-Z prenyl diphosphates of varying lengths; however, the specific enzymes synthesizing cis-C25 prenyl diphosphates have not been identified. Herein, we present the discovery and characterization of a cis-geranylfarnesyl diphosphate synthase (ScGFPPS) from Streptomyces clavuligerus. This enzyme demonstrates high catalytic proficiency in generating six distinct cis-polyisoprenoids, including three C25 and three C20 variants. We determined the crystal structure of ScGFPPS. Additionally, we unveil the crystal structure of nerylneryl diphosphate synthase (NNPS), known for synthesizing an all-cis-C20 polyisoprenoid. Comparative structural analysis of ScGFPPS and NNPS has identified key differences that influence product specificity. Through site-directed mutagenesis, we have identified eight single mutations that significantly refine the selectivity of ScGFPPS for cis-polyisoprenoids. Our findings not only expand the functional spectrum of cis-PTs but also provide a structural comparison strategy in cis-PTs engineering.
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Affiliation(s)
- Fang-Ru Li
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Qingling Wang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Hui-Min Xu
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing, 211198, China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
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2
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Yang Q, Tian J, Chen S, Yang Z, Wang Z, Xu HM, Dong LB. Discovery of sesquiterpenoids from an actinomycete Crossiella cryophila through genome mining and heterologous expression. Bioorg Chem 2024; 146:107308. [PMID: 38531151 DOI: 10.1016/j.bioorg.2024.107308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/07/2024] [Accepted: 03/21/2024] [Indexed: 03/28/2024]
Abstract
Genome mining of the Actinomycete Crossiella cryophila facilitated the discovery of a minimal terpenoid biosynthetic gene cluster of cry consisting of a class I terpene cyclase CryA and a CYP450 monooxygenase CryB. Heterologous expression of cry allowed the isolation and characterization of two new sesquiterpenoids, ent-viridiflorol (1) and cryophilain (2). Notably, cryophilain (2) possesses a 5/7/3-fused tricyclic skeleton bearing a distinctive bridgehead hydroxy group. The combined in vivo and in vitro experiments revealed that CryA, the first ent-viridiflorol terpene cyclase, catalyzes farnesyl diphosphate to form the 5/7/3 sesquiterpene core scaffold and P450 CryB serves as a tailoring enzyme responsible for installing a hydroxy group at the bridgehead carbon.
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Affiliation(s)
- Qian Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Jupeng Tian
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Shungen Chen
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Ziyi Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Zengyuan Wang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Hui-Min Xu
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing 211198, China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
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Zhang D, Du W, Pan X, Lin X, Li FR, Wang Q, Yang Q, Xu HM, Dong LB. Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus. Beilstein J Org Chem 2024; 20:815-822. [PMID: 38655553 PMCID: PMC11035983 DOI: 10.3762/bjoc.20.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
Drimane-type sesquiterpenoids (DMTs) are characterized by a distinctive 6/6 bicyclic skeleton comprising the A and B rings. While DMTs are commonly found in fungi and plants, their presence in bacteria has not been reported. Moreover, the biosynthetic pathways for DMTs have been primarily elucidated in fungi, with identified P450s only acting on the B ring. In this study, we isolated and characterized three bacterial DMTs, namely 3β-hydroxydrimenol (2), 2α-hydroxydrimenol (3), and 3-ketodrimenol (4), from Streptomyces clavuligerus. Through genome mining and heterologous expression, we identified a cav biosynthetic gene cluster responsible for the biosynthesis of DMTs 2-4, along with a P450, CavA, responsible for introducing the C-2 and C-3 hydroxy groups. Furthermore, the substrate scope of CavA revealed its ability to hydroxylate drimenol analogs. This discovery not only broadens the known chemical diversity of DMTs from bacteria, but also provides new insights into DMT biosynthesis in bacteria.
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Affiliation(s)
- Dongxu Zhang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Wenyu Du
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xiaoxu Lin
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Fang-Ru Li
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Qingling Wang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Qian Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Hui-Min Xu
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing 211198, China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
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Abstract
Covering: up to July 2023Terpene cyclases (TCs) catalyze some of the most complicated reactions in nature and are responsible for creating the skeletons of more than 95 000 terpenoid natural products. The canonical TCs are divided into two classes according to their structures, functions, and mechanisms. The class II TCs mediate acid-base-initiated cyclization reactions of isoprenoid diphosphates, terpenes without diphosphates (e.g., squalene or oxidosqualene), and prenyl moieties on meroterpenes. The past twenty years witnessed the emergence of many class II TCs, their reactions and their roles in biosynthesis. Class II TCs often act as one of the first steps in the biosynthesis of biologically active natural products including the gibberellin family of phytohormones and fungal meroterpenoids. Due to their mechanisms and biocatalytic potential, TCs elicit fervent attention in the biosynthetic and organic communities and provide great enthusiasm for enzyme engineering to construct novel and bioactive molecules. To engineer and expand the structural diversities of terpenoids, it is imperative to fully understand how these enzymes generate, precisely control, and quench the reactive carbocation intermediates. In this review, we summarize class II TCs from nature, including sesquiterpene, diterpene, triterpene, and meroterpenoid cyclases as well as noncanonical class II TCs and inspect their sequences, structures, mechanisms, and structure-guided engineering studies.
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Affiliation(s)
- Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Jeffrey D Rudolf
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7011, USA.
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
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Pan X, Dong LB. Deciphering magnesium binding site and structure-function insights in a class II sesquiterpene cyclase. Methods Enzymol 2024; 699:25-57. [PMID: 38942506 DOI: 10.1016/bs.mie.2024.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024]
Abstract
Magnesium ions (Mg2+) are crucial in class II terpene cyclases that utilize substrates with diphosphate groups. Interestingly, these enzymes catalyze reactions without cleaving the diphosphate group, instead initiating the reaction through protonation. In our recent research, we discovered a novel class II sesquiterpene cyclase in Streptomyces showdoensis. Notably, we determined its crystal structure and identified Mg2+ within its active site. This finding has shed light on the previously elusive question of Mg2+ binding in class II terpene cyclases. In this chapter, we outline our methods for discovering this novel enzyme, including steps for its purification, crystallization, and kinetic analysis.
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Affiliation(s)
- Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, P.R. China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, P.R. China.
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Xiao Z, Yang Q, Lin X, Li FR, Zhang X, Xu HM, Wang Z, Wang J, Dong LB. Cytochrome P450-Mediated Skeleton Rearrangement of Taxadiene in an Engineered Escherichia coli System. Org Lett 2024; 26:1640-1644. [PMID: 38382064 DOI: 10.1021/acs.orglett.4c00103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
In this study, we constructed a taxadiene overproduction platform and identified a cytochrome P450, CYP701A8, that activates the inert C-H bonds in taxadiene to produce three oxidized products (1-3). Compound 1 possesses a newly identified 1 (15→11) abeotaxane skeleton, while 3 features a distinctive 6/10-fused carbocyclic core with an α,β-unsaturated ketone moiety. Our quantum computations suggested a carbocation-driven rearrangement in the formation of 1. These results support CYP701A8 as a promising biocatalyst for the generation of novel taxane diterpenoids.
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Affiliation(s)
- Zhixi Xiao
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Qian Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xiaoxu Lin
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Fang-Ru Li
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xiaowei Zhang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Hui-Min Xu
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing 211198, China
| | - Zengyuan Wang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Jie Wang
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing 211198, China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
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Zhang W, Jiang X, Wang M, Zhang Z, Wang N. Origin of the 6/5/6/5 Tetracyclic Cyclopiazonic Acids. Mar Drugs 2024; 22:74. [PMID: 38393045 PMCID: PMC10890092 DOI: 10.3390/md22020074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 02/25/2024] Open
Abstract
The natural product α-cyclopiazonic acid (α-CPA) is a very potent Ca2+-ATPase inhibitor. The CPA family of compounds comprise over 80 chemical entities with at least five distinct skeletons. While α-CPA features a canonical 6/5/6/5/5 skeleton, the 6/5/6/5 skeleton is the most prevalent among the CPA family. However, the origin of the unique tetracyclic skeleton remains unknown. The 6/5/6/5-type CPAs may derive from a precursor of acetoacetyl-l-tryptophan (AATrp) generated from a hypothetic thioesterase-like pathway. Alternatively, cleavage of the tetramic acid ring would also result in the formation of the 6/5/6/5 scaffold. Aspergillus oryzae HMP-F28 is a marine sponge-associated filamentous fungus known to produce CPAs that act as primary neurotoxins. To elucidate the origin of this subfamily of CPAs, we performed homologous recombination and genetic engineering experiments on strain HMP-F28. Our results are supportive of the ring cleavage pathway through which the tetracyclic 6/5/6/5-type CPAs are generated from 6/5/6/5/5-type pentacyclic CPAs.
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Affiliation(s)
- Wenyuan Zhang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Xuejian Jiang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Minjun Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Zhizhen Zhang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Nan Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China
- Hainan Institute of Zhejiang University, Sanya 572025, China
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Sokolova N, Peng B, Haslinger K. Design and engineering of artificial biosynthetic pathways-where do we stand and where do we go? FEBS Lett 2023; 597:2897-2907. [PMID: 37777818 DOI: 10.1002/1873-3468.14745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/29/2023] [Accepted: 09/12/2023] [Indexed: 10/02/2023]
Abstract
The production of commodity and specialty chemicals relies heavily on fossil fuels. The negative impact of this dependency on our environment and climate has spurred a rising demand for more sustainable methods to obtain such chemicals from renewable resources. Herein, biotransformations of these renewable resources facilitated by enzymes or (micro)organisms have gained significant attention, since they can occur under mild conditions and reduce waste. These biotransformations typically leverage natural metabolic processes, which limits the scope and production capacity of such processes. In this mini-review, we provide an overview of advancements made in the past 5 years to expand the repertoire of biotransformations in engineered microorganisms. This ranges from redesign of existing pathways driven by retrobiosynthesis and computational design to directed evolution of enzymes and de novo pathway design to unlock novel routes for the synthesis of desired chemicals. We highlight notable examples of pathway designs for the production of commodity and specialty chemicals, showcasing the potential of these approaches. Lastly, we provide an outlook on future pathway design approaches.
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Affiliation(s)
- Nika Sokolova
- Department of Chemical and Pharmaceutical Biology, University of Groningen, The Netherlands
| | - Bo Peng
- Department of Chemical and Pharmaceutical Biology, University of Groningen, The Netherlands
| | - Kristina Haslinger
- Department of Chemical and Pharmaceutical Biology, University of Groningen, The Netherlands
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Wang Z, Yang Q, He J, Li H, Pan X, Li Z, Xu HM, Rudolf JD, Tantillo DJ, Dong LB. Cytochrome P450 Mediated Cyclization in Eunicellane Derived Diterpenoid Biosynthesis. Angew Chem Int Ed Engl 2023; 62:e202312490. [PMID: 37735947 PMCID: PMC11212149 DOI: 10.1002/anie.202312490] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/23/2023]
Abstract
Terpene cyclization, one of the most complex chemical reactions in nature, is generally catalyzed by two classes of terpene cyclases (TCs). Cytochrome P450s that act as unexpected TC-like enzymes are known but are very rare. In this study, we genome-mined a cryptic bacterial terpenoid gene cluster, named ari, from the thermophilic actinomycete strain Amycolatopsis arida. By employing a heterologous production system, we isolated and characterized three highly oxidized eunicellane derived diterpenoids, aridacins A-C (1-3), that possess a 6/7/5-fused tricyclic scaffold. In vivo and in vitro experiments systematically established a noncanonical two-step biosynthetic pathway for diterpene skeleton formation. First, a class I TC (AriE) cyclizes geranylgeranyl diphosphate (GGPP) into a 6/10-fused bicyclic cis-eunicellane skeleton. Next, a cytochrome P450 (AriF) catalyzes cyclization of the eunicellane skeleton into the 6/7/5-fused tricyclic scaffold through C2-C6 bond formation. Based on the results of quantum chemical computations, hydrogen abstraction followed by electron transfer coupled to barrierless carbocation ring closure is shown to be a viable mechanism for AriF-mediated cyclization. The biosynthetic logic of skeleton construction in the aridacins is unprecedented, expanding the catalytic capacity and diversity of P450s and setting the stage to investigate the inherent principles of carbocation generation by P450s in the biosynthesis of terpenoids.
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Affiliation(s)
- Zengyuan Wang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Qian Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Jingyi He
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Haixin Li
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Zining Li
- Department of Chemistry, University of Florida, Gainesville, FL-32611, USA
| | - Hui-Min Xu
- The Public Laboratory Platform, China Pharmaceutical University, Nanjing, 211198, China
| | - Jeffrey D Rudolf
- Department of Chemistry, University of Florida, Gainesville, FL-32611, USA
| | - Dean J Tantillo
- Department of Chemistry, University of California-Davis, Davis, CA-95616, USA
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
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Pan X, Du W, Zhang X, Lin X, Li FR, Yang Q, Wang H, Rudolf JD, Zhang B, Dong LB. Discovery, Structure, and Mechanism of a Class II Sesquiterpene Cyclase. J Am Chem Soc 2022; 144:22067-22074. [PMID: 36416740 PMCID: PMC10064485 DOI: 10.1021/jacs.2c09412] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Terpene cyclases (TCs), extraordinary enzymes that create the structural diversity seen in terpene natural products, are traditionally divided into two classes, class I and class II. Although the structural and mechanistic features of class I TCs are well-known, the corresponding details in class II counterparts have not been fully characterized. Here, we report the genome mining discovery and structural characterization of two class II sesquiterpene cyclases (STCs) from Streptomyces. These drimenyl diphosphate synthases (DMSs) are the first STCs shown to possess β,γ-didomain architecture. High-resolution X-ray crystal structures of DMS from Streptomyces showdoensis (SsDMS) in complex with both a farnesyl diphosphate and Mg2+ unveiled an induced-fit mechanism, with an unprecedented Mg2+ binding mode, finally solving one of the lingering questions in class II TC enzymology. This study supports continued genome mining for novel bacterial TCs and provides new mechanistic insights into canonical class II TCs that will lead to advances in TC engineering and synthetic biology.
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Affiliation(s)
- Xingming Pan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Wenyu Du
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Xiaowei Zhang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Xiaoxu Lin
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Fang-Ru Li
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Qian Yang
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Hang Wang
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
| | - Jeffrey D Rudolf
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7011, United States
| | - Bo Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, School of Life Sciences, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Liao-Bin Dong
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, Jiangsu, China
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