Fusagerins A–F,New Alkaloids from the Fungus Fusarium sp.

Fusagerins A–F(1–6),six new alkaloids including a unique one with the rare a-(N-formyl)carboxamide moiety(1),a hydantoin(imidazolidin-2,4-dione)derivative(2),and four fungerin analogues(3–6),were isolated from the crude extract of the fungus Fusarium sp.,together with the known compound fungerin(7).Compound 2 was isolated as a racemate and further separated into two enantiomers on a chiral HPLC column.The structures of 1–6 were determined mainly by NMR experiments,and the absolute configuration of 1 and 2 was assigned by electronic circular dichroism(ECD)calculations.Compound 7 showed antibacterial activity against Staphylococcus aureus and Streptococcus pneumoniae,and weak cytotoxicity against the T24 cells.

Multi-Omics-Guided Discovery of Omicsynins Produced by Streptomyces sp.1647:Pseudo-Tetrapeptides Active Against Influenza A Viruses and Coronavirus HCoV-229E

Many microorganisms have mechanisms that protect cells against attack from viruses.The fermentation components of Streptomyces sp.1647 exhibit potent anti-influenza A virus(IAV)activity.This strain was isolated from soil in southern China in the 1970s,but the chemical nature of its antiviral substance(s)has remained unknown until now.We used an integrated multi-omics strategy to identify the antiviral agents from this streptomycete.The antibiotics and Secondary Metabolite Analysis Shell(antiSMASH)analysis of its genome sequence revealed 38 biosynthetic gene clusters(BGCs)for secondary metabolites,and the target BGCs possibly responsible for the production of antiviral components were narrowed down to three BGCs by bioactivity-guided comparative transcriptomics analysis.Through bioinformatics analysis and genetic manipulation of the regulators and a biosynthetic gene,cluster 36 was identified as the BGC responsible for the biosynthesis of the antiviral compounds.Bioactivity-based molecular networking analysis of mass spectrometric data from different recombinant strains illustrated that the antiviral compounds were a class of structural analogues.Finally,18 pseudo-tetrapeptides with an internal ureido linkage,omicsynins A1–A6,B1–B6,and C1–C6,were identified and/or isolated from fermentation broth.Among them,11 compounds(omicsynins A1,A2,A6,B1–B3,B5,B6,C1,C2,and C6)are new compounds.Omicsynins B1–B4 exhibited potent antiviral activity against IAV with the 50%inhibitory concentration(IC_(50))of approximately 1μmol·L^(-1)and a selectivity index(SI)ranging from 100 to 300.Omicsynins B1–B4 also showed significant antiviral activity against human coronavirus HCoV-229E.By integrating multi-omics data,we discovered a number of novel antiviral pseudo-tetrapeptides produced by Streptomyces sp.1647,indicating that the secondary metabolites of microorganisms are a valuable source of novel antivirals.

Carrimycin inhibits coronavirus replication by decreasing the efficiency of programmed–1 ribosomal frameshifting through directly binding to the RNA pseudoknot of viral frameshift-stimulatory element

The pandemic of SARS-CoV-2 worldwide with successive emerging variants urgently calls for small-molecule oral drugs with broad-spectrum antiviral activity.Here,we show that carrimycin,a new macrolide antibiotic in the clinic and an antiviral candidate for SARS-CoV-2 in phase III trials,decreases the efficiency of programmed–1 ribosomal frameshifting of coronaviruses and thus impedes viral replication in a broad-spectrum fashion.Carrimycin binds directly to the coronaviral frameshift-stimulatory element(FSE)RNA pseudoknot,interrupting the viral protein translation switch from ORF1a to ORF1b and thereby reducing the level of the core components of the viral replication and transcription complexes.Combined carrimycin with known viral replicase inhibitors yielded a synergistic inhibitory effect on coronaviruses.Because the FSE mechanism is essential in all coronaviruses,carrimycin could be a new broad-spectrum antiviral drug for human coronaviruses by directly targeting the conserved coronaviral FSE RNA.This finding may open a new direction in antiviral drug discovery for coronavirus variants.

Phomaketals A and B,pentacyclic meroterpenoids from a eupC overexpressed mutant strain of Phoma sp.

Phomaketals A(1)and B(2),two tropolonic meroterpenoids with the unprecedented pentacyclic skeletons,were isolated from the solid-substrate fermentation cultures of a eupC overexpressed mutant strain of the fungus Phoma sp.,together with a biogenetically related secondary metabolite pughiinin B(3),and the known one noreupenifeldin B(4).The structures of 1–3 were elucidated primarily by nuclear magnetic resonance(NMR)experiments.The absolute configurations of 1 and 2 were assigned by electronic circular dichroism calculations and the calculated NMR with DP4+analysis,while that of 3 was established by single-crystal X-ray diffraction analysis using Cu Kαradiation.Biogenetically,phomaketals A(1)and B(2)could be derived from the hypothetical tropolonic sesquiterpene intermediates neosetophomone B(6)and 9-R-neosetophomone B(6),respectively,via different reactions cascades.Compound 1 showed antiproliferative effect only against the SUPB15 cells,with an 50%inhibitory concentration(IC50)value of 4.85μmol/L,while the co-isolated known meroterpenoid 4 displayed potent effects against three tumor cell lines,SUPB15,EL4,and H9,showing IC50values of 0.36–27.08μmol/L.

异源物代谢的表观遗传学变异影响抗癫痫药3,4-DCPB药物代谢动力学表型个体差异

抗癫痫药物治疗是控制癫痫的主要方法,但由于个体间对药物处置的差异性,患者对目前治疗的反应性并不一致。本研究通过在健康志愿者中进行的临床Ⅰ期剂量递增试验,考察了遗传和表观遗传变异是否影响抗癫痫药物氯桂丁胺(3,4-DCPB)的药代动力学表型。采用液相色谱-串联质谱(LC-MS/MS)法测定血浆中3,4-DCPB母药及其主要代谢物M1的浓度。通过基因分型和DNA甲基化水平分析细胞色素P4502D6(CYP2D6)、CYP2C9、CYP1A2、CYP2C19、CYP3A5、转运体ABCB1(C1236T)、核受体AhR、CAR和PXR的单核苷酸多态性(SNPs)。与野生型CYP2D6*1/*1纯合子(广泛代谢型,EMs)相比,变异等位基因CYP2D6*10携带者(中间代谢型,IMs)中,代谢产物M1与3,4-DCPB母药的药时曲线下面积(AUC0–t)的比值更低,血浆半衰期(t1/2)更久,DNA甲基化水平更高。这些数据表明胞嘧啶的丢失(CYP2D6*10,C>T)所诱导的表观基因突变可能解释3,4-DCPB基因型、表观基因型和药代动力学表型在个体差异之间的关系,为癫痫的个性化治疗提供新的思路。

Repurposing carrimycin as an antiviral agent against human coronaviruses,including the currently pandemic SARS-CoV-2

COVID-19 pandemic caused by SARS-CoV-2 infection severely threatens global health and economic development.No effective antiviral drug is currently available to treat COVID-19 and any other human coronavirus infections.We report herein that a macrolide antibiotic,carrimycin,potently inhibited the cytopathic effects(CPE)and reduced the levels of viral protein and RNA in multiple cell types infected by human coronavirus 229 E,OC43,and SARS-CoV-2.Time-of-addition and pseudotype virus infection studies indicated that carrimycin inhibited one or multiple post-entry replication events of human coronavirus infection.In support of this notion,metabolic labelling studies showed that carrimycin significantly inhibited the synthesis of viral RNA.Our studies thus strongly suggest that carrimycin is an antiviral agent against a broad-spectrum of human coronaviruses and its therapeutic efficacy to COVID-19 is currently under clinical investigation.

Azvudine is a thymus-homing anti-SARS-CoV-2 drug effective in treating COVID-19 patients

Azvudine(FNC)is a nucleoside analog that inhibits HIV-1 RNA-dependent RNA polymerase(RdRp).Recently,we discovered FNC an agent against SARS-CoV-2,and have taken it into Phase III trial for COVID-19 patients.FNC monophosphate analog inhibited SARS-CoV-2 and HCoV-OC43 coronavirus with an EC_(50) between 1.2 and 4.3 μM,depending on viruses or cells,and selective index(SI)in 15-83 range.Oral administration of FNC in rats revealed a substantial thymus-homing feature,with FNC triphosphate(the active form)concentrated in the thymus and peripheral blood mononuclear cells(PBMC).Treating SARS-CoV-2 infected rhesus macaques with FNC(0.07 mg/kg, qd,orally)reduced viral load,recuperated the thymus,improved lymphocyte profiles,alleviated in flammation and orga n damage,and lessened grou nd・glass opacities in chest X-ray.Sin gle-cell seque ncing suggested the promotion of thymus function by FNC.A randomized,single-arm clinical trial of FNC on compassionate use(n=31)showed that oral FNC(5 mg,qd)cured all COVID-19 patients,with 100%viral ribonucleic acid negative conversion in 3.29±2.22 days(range:1-9 days)and 100%hospital discharge rate in 9.00±4.93 days(range:2-25 days).The side-effect of FNC is minor and transient dizziness and nausea in 16.12%(5/31)patients.Thus,FNC might cure COVID-19 through its anti-SARS-CoV-2 activity concentrated in the thymus,followed by promoted immunity.