Synthesis and pharmacological activity evaluation of 2-(2-Phenylethyl)chromone analogues: The principal components in agarwood.

2-(2-Phenylethyl)chromones (PECs), the pivotal constituents responsible for the distinctive aroma and pharmacological potential of agarwood, are primarily obtained through extraction from natural materials. The restricted availability of agarwood has, however, hindered a comprehensive and systematic evaluation of their biological properties. In this study, we have chemically synthesized a total of 38 PEC derivatives, including 23 new compounds that had not been previously isolated from agarwood.

Tanshinone I inhibits the functions of T lymphocytes and exerts therapeutic effects on delayed-type hypersensitivity reaction via blocking STATs signaling pathways.

Delayed-type hypersensitivity (DTH) reactions are a kind of chronic inflammatory diseases initiated by antigens and antigen-specific T cells. Currently, the therapy of DTH reactions is limited by the poor curative effects and serious adverse reactions of existing agents. In this study, we investigated the regulatory effects of tanshinone Ⅰ, a natural compound isolated from Salvia miltiorrhiza, on the functions of multiple immune cells and its therapeutic effects on DNFB-induced DTH reaction, and then explored its immunosuppressive mechanisms.

Molecular characterization and structure basis of a malonyltransferase with both substrate promiscuity and catalytic regiospecificity from .

Enzymatic malonylation of natural glycosides provides a promising alternative method for drug-like malonylated glycosides supply. However, the catalytic potential and structural basis of plant malonyltransferase are far from being fully elucidated. This work identified a new malonyltransferase CtMaT1 from It displayed unprecedented mono- and/or di-malonylation activity toward diverse glucosides with different aglycons.

Discovery of plant chemical defence mediated by a two-component system involving β-glucosidase in Panax species.

Plants usually produce defence metabolites in non-active forms to minimize the risk of harm to themselves and spatiotemporally activate these defence metabolites upon pathogen attack. This so-called two-component system plays a decisive role in the chemical defence of various plants. Here, we discovered that Panax notoginseng, a valuable medicinal plant, has evolved a two-component chemical defence system composed of a chloroplast-localized β-glucosidase, denominated PnGH1, and its substrates 20(S)-protopanaxadiol ginsenosides.

[Mining and identification of a biosynthetic gene cluster producing xanthocillin analogues from MT-40, an endophytic fungus of ].

Xanthocillin is a unique natural product with an isonitrile group and shows remarkable antibacterial activity. In this study, the genome of an endophytic fungus MT-40 isolated from was sequenced, and the gene clusters with the potential to synthesize xanthocillin analogues were mined by local BLAST and various bioinformatics analysis tools. As a result, a biosynthetic gene cluster (named ) responsible for the biosynthesis of xanthocillin analogues was identified by further heterologous expression of the key genes in NSAR1.

[Advances of the novel immunosuppressant brasilicardin A].

Brasilicardin A (BraA) is a natural diterpene glycoside isolated from the pathogenic actinomycete IFM 0406 with highly potent immunosuppressive activity (=0.057 μg/mL). BraA potently inhibits the uptake of amino acids that are substrates for amino acid transport system L of T cells, which is different from the existing clinical immunosuppressants.

Identification of a diarylpentanoid-producing polyketide synthase in the biosynthesis of 2-(2-phenylethyl)chromones in agarwood.

Agarwood has been valued as an exquisite, high-grade fragrant wood since ancient times. Due to the scarcity of high-quality agarwood, it is quite expensive, and the number of original plants has been drastically reduced due to overharvesting, including illegal logging. Despite this, a reliable method of agarwood cultivation has yet to be developed.

Seven new 3,4-dihydro-furanocoumarin derivatives from .

Objective: To study the chemical constituents of the roots of , a well-known Chinese herbal medicine named Baizhi in Chinese.

Methods: Compounds were separated by various chromatographies, and the structures of new compounds were elucidated based on the analysis of their spectroscopic and spectrometric data (1D, 2D NMR, HRESI MS, IR, and UV). The absolute configurations of new compounds were determined by the calculated electronic circular dichroism and chemical derivatization.

[LC-MS analysis of 2-(2-phenylethyl) chromones in sodium chloride-treated suspension cells of Aquilaria sinensis].

Qualitative and quantitative analysis of 2-(2-phenylethyl) chromones in sodium chloride(NaCl)-treated suspension cells of Aquilaria sinensis was conducted by UPLC-Q-Exactive-MS and UPLC-QQQ-MS/MS. Both analyses were performed on a Waters T3 column(2.1 mm×50 mm, 1.

Gastroprotective 2-(2-phenylethyl)chromone-sesquiterpene hybrids from the resinous wood of Aquilaria sinensis (Lour.) Gilg.

Six previously unprecedented 2-(2-phenylethyl)chromone-sesquiterpene hybrids, aquisinenins A-F (1 - 6), were isolated from the resinous wood of Aquilaria sinensis by a LC-MS-guided fractionation procedure. Their structures were determined by extensive spectroscopic analysis (1D and 2D NMR, UV, IR, and HRMS) and experimental and computed ECD data. Compounds 1 - 6 were rare dimeric 2-(2-phenylethyl)chromone-sesquiterpene derivatives featuring 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone hybridized with different sesquiterpene (eudesmane/guaiane type) moieties via ester bond.

[Research progress on application of multi-enzyme-catalyzed cascade reactions in enzymatic synthesis of natural products].

As a biocatalyst, enzyme has the advantages of high catalytic efficiency, strong reaction selectivity, specific target products, mild reaction conditions, and environmental friendliness, and serves as an important tool for the synthesis of complex organic molecules. With the continuous development of gene sequencing technology, molecular biology, genetic manipulation, and other technologies, the diversity of enzymes increases steadily and the reactions that can be catalyzed are also gradually diversified. In the process of enzyme-catalyzed synthesis, the majority of common enzymatic reactions can be achieved by single enzyme catalysis, while many complex reactions often require the participation of two or more enzymes.

Biosynthesis Investigations of Terpenoid, Alkaloid, and Flavonoid Antimicrobial Agents Derived from Medicinal Plants.

The overuse of antibiotics in the past decades has led to the emergence of a large number of drug-resistant microorganisms. In recent years, the infection rate caused by multidrug-resistant microorganisms has been increasing, which has become one of the most challenging problems in modern medicine. Plant-derived secondary metabolites and their derivatives have been identified to display significant antimicrobial abilities with good tolerance and less adverse side effects, potentially having different action mechanisms with antibiotics of microbial origin.

Glycosylation of Aromatic Glycosides by a Promiscuous Glycosyltransferase UGT71BD1 from .

Multiple-glycosylated glycosides are a major source of bioactive leads. However, most of the currently reported glycosyltransferases (GTases) mainly catalyze glycosylation of aglycones without sugar group substitution. GTases accepting diverse glycosides as substrates are rarely reported.

Characterization of a coumarin -/-prenyltransferase and a quinolone -prenyltransferase from .

Prenyltransferases (PTs) play important roles in the biosynthesis and structural diversification of natural products. In the present study, two new PTs were characterized from a medicinal plant . MePT1 unprecedentedly catalyses the formation of two -geranylated products 8/6--geranylumbelliferone together with a trace product 7--geranylumbelliferone from umbelliferone.

A Multifunctional Cytochrome P450 and a Meroterpenoid Cyclase in the Biosynthesis of Fungal Meroterpenoid Atlantinone B.

The biosynthetic gene cluster of atlantinone B () was discovered in MT-40. A multifunctional cytochrome P450 (AtlD) encoded by the cluster is responsible for the formation of the unique lactone-bridged ring and the 16β-hydroxyl of atlantinone B, and a new terpene cyclase (AtlC) can unprecedentedly accept the demethylated substrate epoxyfarnesyl-DMOA () to generate three bicyclic meroterpenoids (-). This study paves the way for combinatorial synthesis of structurally diverse meroterpenoids for drug discovery.

Identification of a diarylpentanoid-producing polyketide synthase revealing an unusual biosynthetic pathway of 2-(2-phenylethyl)chromones in agarwood.

2-(2-Phenylethyl)chromones (PECs) are the principal constituents contributing to the distinctive fragrance of agarwood. How PECs are biosynthesized is currently unknown. In this work, we describe a diarylpentanoid-producing polyketide synthase (PECPS) identified from Aquilaria sinensis.

Molecular cloning and biochemical characterization of a new coumarin glycosyltransferase CtUGT1 from Cistanche tubulosa.

UDP-glycosyltransferases (UGTs) are an important and functionally diverse family of enzymes involved in secondary metabolite biosynthesis. Coumarin is one of the most common skeletons of natural products with candidate pharmacological activities. However, to date, many reported GTs from plants mainly recognized flavonoids as sugar acceptors.

[Production of curcumin by engineered Escherichia coli].

Curcumin is exclusively isolated from Zingiberaceae plants with a broad spectrum of bioactivities. In the present study, we used the diketide-CoA synthase (DCS) and curcumin synthase (CURS) genes to construct a non-natural fusion gene encoding diketide-CoA synthase::curcumin synthase (DCS::CURS). This fusion protein, together with the acetyl coenzyme A carboxylase (ACC) and the 4-coumarate coenzyme A ligase (4CL), were introduced into Escherichia coli for the production of curcumin from ferulic acid.

Deciphering the Biosynthetic Mechanism of Pelletierine in Alkaloid Biosynthesis.

Pelletierine, a proposed building block of alkaloids (LAs), was demonstrated to be synthesized via the non-enzymatic Mannich-like condensation of Δ-piperideine and 3-oxoglutaric acid produced by two new type III PKSs (HsPKS4 and PcPKS1) characterized from and , respectively. The findings provide new insights for further understanding the biosynthesis of LAs such as huperzine A.

Two new diterpenoids from MT-12, an endophytic fungus isolated from .

Two new diterpenoids, penicichrysogene A () and penicichrysogene B (), were isolated from the solid substrate fermentation cultures of MT-12, an endophytic fungus isolated from the medicinal plant of . Their structures were elucidated on the basis of extensive spectroscopic and spectrometric data (1D and 2D NMR, UV, IR, and HRESIMS). The absolute configurations of and were assigned on the basis of experimental and calculated electronic circular dichroism spectra.

Enzymatic synthesis of 2-hydroxy-4-quinolizin-4-one scaffolds by integrating coenzyme a ligases and a type III PKS from .

2-Hydroxy-4-quinolizin-4-one scaffolds were enzymatically synthesized by integrating three enzymes including phenylacetate-CoA ligase (PcPCL) from an endophytic fungus MT-12, malonyl-CoA synthase (AtMatB) from , and a type III polyketide synthase (HsPKS3) from Chinese club moss . The findings paved the way to produce these kinds of structurally interesting alkaloids by engineered microorganisms.

[Isolation and identification of endophytic fungi from Huperzia serrata and their metabolites' inhibitory activities against acetylcholinesterase and anti-inflammatory activities].

A total of 27 endophytic fungal strains were isolated from Huperzia serrata,which were richly distributed in the stems and leaves while less distributed in roots. The 27 strains were identified by Internal Transcribed Spacer( ITS) r DNA molecular method and one of the strains belongs to Basidiomycota phylum,and other 26 stains belong to 26 species,9 general,6 families,5 orders,3 classes of Ascomycota Phylum. The dominant strains were Colletotrichum genus,belonging to Glomerellaceae family,Glomerellales order,Sordariomycetes class,Ascomycota Phylum,with the percentage of 48.

Lignan Glycosides from .

Four new lignan glycosides; urenalignosides A-D (-), along with 12 known ones (-) were isolated from . Their structures were determined on the basis of extensive spectroscopic and spectrometric data (1D and 2D NMR; IR; CD; and HRESIMS). Compounds -; ; ; ; and showed inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.

Polyketides from Alternaria alternata MT-47, an endophytic fungus isolated from Huperzia serrata.

Four new polyketides, alternatains A-D (1-4), along with 17 known compounds (5-21) were obtained from the solid substrate fermentation cultures of Alternaria alternata MT-47, an endophytic fungus isolated from the medicinal plant of Huperzia serrata. Their structures were elucidated by extensive spectroscopic and spectrometric techniques (1D and 2D NMR, IR, and HRESIMS) and calculated electronic circular dichroism (ECD) method. Compounds 4, 6, 15, and 21 exhibited inhibitory activities on ATP release of thrombin-activated platelets with IC values in the range of 18.