Pentaketide Ansamycin Microansamycins A–I from Micromonospora sp. Reveal Diverse Post-PKS Modifications

Overexpression of the pathway-specific positive regulator gene <i>mas13</i> activated the cryptic gene cluster <i>mas</i>, resulting in the isolation of nine novel pentaketide ansamycins, namely, microansamycins A–I (<b>1</b>–<b>9</b>). These results not only revealed a biosynthetic gene cluster of pentaketide ansamycins for the first time but also presented an unprecedented scenario of diverse post-PKS modifications in ansamycin biosynthesis

Microansamycins J and K from <i>Micromonospora</i> sp. HK160111mas13OE

Microansamycins were novel pentaketide ansamycins isolated from Micromonospora sp. HK160111mas13OE with AHBA-C2-C2-C3-C3 skeleton and diverse post-PKS modifications. In this paper, two new congeners, namely microansamycins J (1) and K (2), were identified based on their NMR, HRESIMS data and compared with those of microansamycins F and E. Neither showed antibacterial activity against Staphy­lococcus aureus ATCC25923 and Escherichia coli at 40 µg/mL.</p

Quantum Chemistry Calculations on the Mechanism of Isoquinoline Ring-Opening and Denitrogenation in Supercritical Water

Computational studies at the M06/6-311G­(d,p) and M06-2<i>X</i>/6-311+G­(d,p) levels were performed to explore the detailed mechanism of isoquinoline ring-opening and denitrogenation in a supercritical water system. Three reaction paths with the same product, 2-(2-oxoethyl) benzaldehyde, were supported by the computational results. The rate-limiting step in the major degradation reaction is an addition reaction at the N position. H₂O is added to both the 1C–2N double bond (1C–2N addition reaction) and the 2N–3C double bond (2N–3C addition reaction) of the isoquinoline molecule, where the oxygen of H₂O is added to the carbon atom. The energy barrier of the 1C–2N addition reaction is 52.7 kcal/mol, while that of 2N–3C addition (from Path 6) is 60.1 kcal/mol. From catalysis by two water molecules, the barrier of 1C–2N addition (Reaction (1)) is reduced to 27.5 kcal/mol. Catalysis from water molecule clusters is shown to considerably affect the process of isoquinoline ring-opening and denitrogenation, as indicated by comparing the reaction energy barrier heights with and without water catalysts

Детство последней вьюгой улетело

Детство последней вьюгой улетело, / И весной, как-то майским днем, / Юность на меня мундир одела, / Обхватила талию ремнем

PRISMA flow diagram showing the study selection process.

PRISMA flow diagram showing the study selection process.</p

Search strategy for PubMed.

BackgroundSchizophrenia is a chronic persistent disease with high recurrence rate and high disability rate in the field of psychiatry. Sodium nitroprusside is a nitric oxide (NO) donor and considered a promising new compound for the treatment of schizophrenia. New high-quality clinical trials of sodium nitroprusside in the treatment of schizophrenia have been published in recent years. It is necessary to re-conduct the meta-analysis after the inclusion of these new clinical trials. Our study will conduct a systematic review and meta-analysis of the relevant literature in this field, so as to lay an evidence-based medicine foundation for the efficacy of sodium nitroprusside in the treatment of schizophrenia.Methods and analysisRandomized controlled trials (RCTs) of sodium nitroprusside in the treatment of schizophrenia were searched through English databases (PubMed, Web of Science, Embase, and Cochrane Library) and Chinese databases (China Biology Medicine disc, VIP, WanFang Data, and CNKI). The extracted data will be inputted into Review Manager 5.3 for Meta-analysis. The included literature will be assessed for bias risk according to the bias risk assessment tools in the Cochrane Handbook for Systematic Reviews of Interventions. Funnel plots will be used to assess possible publication bias. Heterogeneity is tested by I2 and χ2 tests, and the existence of heterogeneity is defined as I2 ≥50% and P ≤0.1. If heterogeneity exists, the random-effect model will be used, and sensitivity analysis or subgroup analysis will be performed to further determine the source of heterogeneity.Prospero registration numberCRD42022341681.</div

PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) 2015 checklist: Recommended items to address in a systematic review protocol*.

PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) 2015 checklist: Recommended items to address in a systematic review protocol*.</p

MCAD mRNA in C, R, H, R+H groups of the three geno-type mice.

<p>* significantly different from the control group, p<0.05; ** p<0.01. # significantly different from the same group in WT, p<0.01; ## p<0.01.</p