Danshen, the dried roots and rhizomes of Salvia miltiorrhiza Bunge (S. miltiorrhiza), is widely used in the treatment of cardiovascular and cerebrovascular diseases. Tanshinones, the bioactive compounds from Danshen, exhibit a wide spectrum of pharmacological properties, suggesting their potential for future therapeutic applications. Tanshinone biosynthesis is a complex process involving at least six P450 enzymes that have been identified and characterized, most of which belong to the CYP76 and CYP71 families. In this study, CYP81C16, a member of the CYP71 clan, was identified in S. miltiorrhiza. An in vitro assay revealed that it could catalyze the hydroxylation of four para-quinone-type tanshinones, namely neocryptotanshinone, deoxyneocryptotanshinone, and danshenxinkuns A and B. SmCYP81C16 emerged as a potential broad-spectrum oxidase targeting the C-18 position of para-quinone-type tanshinones with an impressive relative conversion rate exceeding 90%. Kinetic evaluations andin vivo assays underscored its highest affinity towards neocryptotanshinone among the tested substrates. The overexpression of SmCYP81C16 promoted the accumulation of (iso)tanshinone in hairy root lines. The characterization of SmCYP81C16 in this study accentuates its potential as a pivotal tool in the biotechnological production of tanshinones, either through microbial or plant metabolic engineering.
Humans ; Salvia miltiorrhiza/metabolism* ; Biosynthetic Pathways ; Quinones/metabolism* ; Plant Roots/metabolism* ; Gene Expression Regulation, Plant

Natural plant-derived diterpenoids are a class of compounds with diverse structures and functions. These compounds are widely used in pharmaceuticals, cosmetics and food additives industries because of their pharmacological properties such as anticancer, anti-inflammatory and antibacterial activities. In recent years, with the gradual discovery of functional genes in the biosynthetic pathway of plant-derived diterpenoids and the development of synthetic biotechnology, great efforts have been made to construct a variety of diterpenoid microbial cell factories through metabolic engineering and synthetic biology, resulting in gram-level production of many compounds. This article summarizes the construction of plant-derived diterpenoid microbial cell factories through synthetic biotechnology, followed by introducing the metabolic engineering strategies applied to improve plant-derived diterpenoids production, with the aim to provide a reference for the construction of high-yield plant-derived diterpenoid microbial cell factories and the industrial production of diterpenoids.
Diterpenes/metabolism* ; Biotechnology ; Metabolic Engineering ; Biosynthetic Pathways/genetics* ; Plants/genetics* ; Synthetic Biology

The active ingredients in traditional Chinese medicine(TCM)are the foundation for the efficiency of TCM and the key to the formation of Dao-di herbs. It is of great significance to study the biosynthesis and regulation mechanisms of these active ingredients for analyzing the formation mechanism of Daodi herbs and providing components for the production of active ingredients in TCM by synthetic biology. With the advancements in omics technology, molecular biology, synthetic biology, artificial intelligence, etc., the analysis of biosynthetic pathways for active ingredients in TCM is rapidly progressing. New methods and technologies have promoted the analysis of the synthetic pathways of active ingredients in TCM and have also made this area a hot topic in molecular pharmacognosy. Many researchers have made significant progress in analyzing the biosynthetic pathways of active ingredients in TCM such as Panax ginseng, Salvia miltiorrhiza, Glycyrrhiza uralensis, and Tripterygium wilfordii. This paper systematically reviewed current research me-thods for analyzing the biosynthetic functional genes of active ingredients in TCM, elaborated the mining of gene elements based on multiomics technology and the verification of gene functions in plants in vitro and in vivo with candidate genes as objects. Additionally, the paper summarized new technologies and methods that have emerged in recent years, such as high-throughput screening, molecular probes, genome-wide association studies, cell-free systems, and computer simulation screening to provide a comprehensive reference for the analysis of the biosynthetic pathways of active ingredients in TCM.
Medicine, Chinese Traditional ; Drugs, Chinese Herbal ; Artificial Intelligence ; Biosynthetic Pathways ; Computer Simulation ; Genome-Wide Association Study

Tanshinones are one of the main effective components of Salvia miltiorrhiza, which play important roles in the treatment of cardiovascular diseases. Microbial heterogony production of tanshinones can provide a large number of raw materials for the production of traditional Chinese medicine(TCM) preparations containing S. miltiorrhiza, reduce the extraction cost, and relieve the pressure of clinical medication. The biosynthetic pathway of tanshinones contains multiple P450 enzymes, and the catalytic element with high efficiency is the basis of microbial production of tanshinones. In this study, the protein modification of CYP76AK1, a key P450-C20 hydroxylase in tanshinone pathway, was researched. The protein modeling methods SWISS-MODEL, Robetta, and AlphaFold2 were used, and the protein model was analyzed to obtain the reliable protein structure. The semi-rational design of mutant protein was carried out by molecular docking and homologous alignment. The key amino acid sites affecting the oxidation activity of CYP76AK1 were identified by molecular docking. The function of the obtained mutations was studied with yeast expression system, and the CYP76AK1 mutations with continuous oxidation function to 11-hydroxysugiol were obtained. Four key amino acid sites that affected the oxidation acti-vity were analyzed, and the reliability of three protein modeling methods was analyzed according to the mutation results. The effective protein modification sites of CYP76AK1 were reported for the first time in this study, which provides a catalytic element for different oxidation activities at C20 site for the study of the synthetic biology of tanshinones and lays a foundation for the analysis of the conti-nuous oxidation mechanism of P450-C20 modification.
Oxidoreductases ; Biosynthetic Pathways ; Molecular Docking Simulation ; Reproducibility of Results ; Salvia miltiorrhiza/chemistry* ; Amino Acids/metabolism* ; Plant Roots/genetics*

Tyrosine-decahydrofluorene derivatives are a class of hybrid compounds that integrate the properties of polyketides and nonribosomal peptides. These compounds feature a [6.5.6] tricarbocyclic core and a para-cyclophane ether moiety in their structures and exhibit anti-tumor and anti-microbial activities. In this study, we constructed the biosynthetic pathway of xenoacremones from Xenoacremonium sinensis ML-31 in the Aspergillus nidulans host, resulting in the identification of four novel tyrosine-decahydrofluorene analogs, xenoacremones I-L (1-4), along with two known analogs, xenoacremones A and B. Remarkably, compounds 3 and 4 contained a 12-membered para-cyclophane ring system, which is unprecedented among tyrosine-decahydrofluorene analogs in X. sinensis. The successful reconstruction of the biosynthetic pathway and the discovery of novel analogs demonstrate the utility of heterologous expression strategy for the generation of structurally diverse natural products with potential biological activities.
Aspergillus nidulans/metabolism* ; Biological Products/metabolism* ; Polyketides/metabolism* ; Peptides/metabolism* ; Biosynthetic Pathways ; Multigene Family

Monoterpenoids that belong to the terpenoids family are usually volatile and have strong aroma. Some monoterpenoids also have antioxidant, antibacterial and anti-inflammatory activities, which make them important raw materials for medicine, food and cosmetics industry. In recent years, the heterologous synthesis of monoterpenoids by microorganisms has attracted extensive attention. However, its large-scale application is greatly hampered by the low yield and high production cost. Nowadays, the rapid development of synthetic biology provides new approaches for enhancing the production of monoterpenoids by microorganisms. Different kinds of recombinant strains can be obtained via engineering of microbial cells to produce a variety of monoterpenoids with different properties. This paper summarized the latest strategies and progress in the application of synthetic biology to produce monoterpenoids by microorganisms, including the design and modification of biosynthetic pathway, as well as the design and optimization of high-yield monoterpenoids producing chassis cells.
Biosynthetic Pathways ; Metabolic Engineering ; Monoterpenes/metabolism* ; Synthetic Biology ; Terpenes

Flavonoids have a variety of biological activities and have important applications in food, medicine, cosmetics, and many other fields. Naringenin is a platform chemical for the biosynthesis of many important flavonoids. Ubiquitination plays a pivotal role in the post-translational modification of proteins and participates in the regulation of cellular activities. Ubiquitinated proteins can be degraded by the ubiquitin-protease system, which is important for maintaining the physiological activities of cells, and may also exert a significant impact on the expression of exogenous proteins. In this study, a real-time in-situ detection system for ubiquitination modification has been established in Saccharomyces cerevisiae by using a fluorescence bimolecular complementation approach. The ubiquitination level of protein was characterized by fluorescence intensity. By using the approach, the potential ubiquitination sites of proteins involved in the naringenin biosynthesis pathway have been obtained. The lysine residues of the relevant ubiquitination sites were mutated to arginine to reduce the ubiquitination level. The mutants of tyrosine ammonia-lyase (FjTAL) and chalcone synthase (SjCHS, SmCHS) showed decreased fluorescence, suggested that a decreased ubiquitination level. After fermentation verification, the S. cerevisiae expressing tyrosine ammonia-lyase FjTAL mutant FjTAL-K487R accumulated 74.2 mg/L p-coumaric acid at 72 h, which was 32.3% higher than that of the original FjTAL. The strains expressing chalcone synthase mutants showed no significant change in the titer of naringenin. The results showed that mutation of the potential ubiquitination sites of proteins involved in the naringenin biosynthesis pathway could increase the titer of p-coumaric acid and have positive effect on naringenin biosynthesis.
Biosynthetic Pathways ; Flavanones/metabolism* ; Saccharomyces cerevisiae/metabolism* ; Ubiquitination

Unnatural amino acids are widely used in medicine, pesticide, material, and other industries and the green and efficient synthesis has attracted a lot of attention. In recent years, with the rapid development of synthetic biology, microbial cell factories have become a promising means for biosynthesis of unnatural amino acids. This study reviewed the construction and application of microbial cell factories for unnatural amino acid, including the synthetic pathway reconstruction, design/modification of key enzymes and their coordinated regulation with precursors, blocking of competitive alternative pathways, and construction of cofactor circulation systems. Meanwhile, on the basis of the new principles for designing the microbial cell factories, new biosynthetic pathways adapted to cells and the production environment, as well as new biomanufacturing system established based on cell adaptive evolution and intelligent fermentation regulation, we looked forward to the further construction and application of microbial cell factories for industrial bio-production.
Amino Acids/genetics* ; Biosynthetic Pathways ; Fermentation ; Metabolic Engineering ; Synthetic Biology

It is among the goals in metabolic engineering to construct microbial cell factories producing high-yield and high value-added target products, and an important solution is to design efficient synthetic pathway for the target products. However, due to the difference in metabolic capacity among microbial chassises, the available substrate and the yielded products are limited. Therefore, it is urgent to design related metabolic pathways to improve the production capacity. Existing metabolic engineering approaches to designing heterologous pathways are mainly based on biological experience, which are inefficient. Moreover, the yielded results are in no way comprehensive. However, systems biology provides new methods for heterologous pathway design, particularly the graph-based and constraint-based methods. Based on the databases containing rich metabolism information, they search for and uncover possible metabolic pathways with designated strategy (graph-based method) or algorithm (constraint-based method) and then screen out the optimal pathway to guide the modification of strains. In this paper, we reviewed the databases and algorithms for pathway design, and the applications in metabolic engineering and discussed the strengths and weaknesses of existing algorithms in practical application, hoping to provide a reference for the selection of optimal methods for the design of product synthesis pathway.
Algorithms ; Biosynthetic Pathways ; Metabolic Engineering ; Metabolic Networks and Pathways/genetics* ; Systems Biology

Plant diterpenoids are widely distributed and abundant natural products with diverse structures and functions in nature, which have been commonly used in pharmaceutical, agricultural and industrial production. In recent years, plant diterpenoids have attracted increasing attention, including their biosynthetic pathways, transcriptional regulatory networks, and biological functions. Herein, the biosynthetic pathways of diterpenoids are summarized in a modular fashion. Further, the regulatory network between diterpene biosynthesis and environmental factors is reviewed. Insights into diterpene metabolism may drive elucidation of complex active diterpene pathways and serve as a knowledge repository for metabolic engineering and cell factory construction.
Plants, Medicinal/metabolism* ; Diterpenes/chemistry* ; Metabolic Engineering ; Biosynthetic Pathways ; Biological Products/metabolism*