A co-adaptive duality-aware framework for biomedical relation extraction.

MOTIVATION: Biomedical relation extraction is a vital task for electronic health record mining and biomedical knowledge base construction. Previous work often adopts pipeline methods or joint methods to extract subject, relation, and object while ignoring the interaction of subject-object entity pair and relation within the triplet structure. However, we observe that entity pair and relation within a triplet are highly related, which motivates us to build a framework to extract triplets that can capture the rich interactions among the elements in a triplet. RESULTS: We propose a novel co-adaptive biomedical relation extraction framework based on a duality-aware mechanism. This framework is designed as a bidirectional extraction structure that fully takes interdependence into account in the duality-aware extraction process of subject-object entity pair and relation. Based on the framework, we design a co-adaptive training strategy and a co-adaptive tuning algorithm as collaborative optimization methods between modules to promote better mining framework performance gain. The experiments on two public datasets show that our method achieves the best F1 among all state-of-the-art baselines and provides strong performance gain on complex scenarios of various overlapping patterns, multiple triplets, and cross-sentence triplets. AVAILABILITY AND IMPLEMENTATION: Code is available at https://github.com/11101028/CADA-BioRE.

Integration of multiple terminology bases: a multi-view alignment method using the hierarchical structure.

MOTIVATION: In the medical field, multiple terminology bases coexist across different institutions and contexts, often resulting in the presence of redundant terms. The identification of overlapping terms among these bases holds significant potential for harmonizing multiple standards and establishing unified framework, which enhances user access to comprehensive and well-structured medical information. However, the majority of terminology bases exhibit differences not only in semantic aspects but also in the hierarchy of their classification systems. The conventional approaches that rely on neighborhood-based methods such as GCN may introduce errors due to the presence of different superordinate and subordinate terms. Therefore, it is imperative to explore novel methods to tackle this structural challenge. RESULTS: To address this heterogeneity issue, this paper proposes a multi-view alignment approach that incorporates the hierarchical structure of terminologies. We utilize BERT-based model to capture the recursive relationships among different levels of hierarchy and consider the interaction information of name, neighbors, and hierarchy between different terminologies. We test our method on mapping files of three medical open terminologies, and the experimental results demonstrate that our method outperforms baseline methods in terms of Hits@1 and Hits@10 metrics by 2%. AVAILABILITY AND IMPLEMENTATION: The source code will be available at https://github.com/Ulricab/Bert-Path upon publication.

Marinicella meishanensis sp. nov., a novel Marinicella member isolated from coastal mudflat sediment of Meishan Islandin the East China Sea.

A Gram-negative, rod-shaped, non-motile and strictly aerobic strain, designated NBU2979T, was isolated from a coastal mudflat located on Meishan Island in the East China Sea. Strain NBU2979T grew optimally at 32 °C, with 2.0 % NaCl (w/v) and at pH 7.0-7.5. The predominant fatty acid (>10 %) was iso-C15 : 0. The major polar lipids included phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylcholine, an unidentified glycolipid, two unidentified aminophospholipids, an unidentified phospholipid and an unidentified lipid. The only respiratory quinone was ubiquinone-8. Comparative analysis of 16S rRNA gene sequences showed that strain NBU2979T exhibited highest similarity to Marinicella sediminis F2T (98.0 %), Marinicella marina S1101T (97.5 %), Marinicella litoralis KMM 3900T (96.6 %), Marinicella rhabdoformis 3539T (95.5 %), Marinicella pacifica sw153T (95.2 %) and Marinicella gelatinilytica S6413T (94.9 %). Phylogenetic analyses indicated that strain NBU2979T clustered with the genus Marinicella and was closely related to strain M. sediminis F2T. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU2979T and related species of genus Marinicella were well below the threshold limit for prokaryotic species delineation. The DNA G+C content of strain NBU2979T was 51.6 mol%. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU2979T (=KCTC 82911T=MCCC 1K06402T) is considered to be a representative of a novel species in the genus Marinicella, for which the name Marinicella meishanensis sp. nov. is proposed.

Birinapant Reshapes the Tumor Immunopeptidome and Enhances Antigen Presentation.

Birinapant, an antagonist of the inhibitor of apoptosis proteins, upregulates MHCs in tumor cells and displays a better tumoricidal effect when used in combination with immune checkpoint inhibitors, indicating that Birinapant may affect the antigen presentation pathway; however, the mechanism remains elusive. Based on high-resolution mass spectrometry and in vitro and in vivo models, we adopted integrated genomics, proteomics, and immunopeptidomics strategies to study the mechanism underlying the regulation of tumor immunity by Birinapant from the perspective of antigen presentation. Firstly, in HT29 and MCF7 cells, Birinapant increased the number and abundance of immunopeptides and source proteins. Secondly, a greater number of cancer/testis antigen peptides with increased abundance and more neoantigens were identified following Birinapant treatment. Moreover, we demonstrate the existence and immunogenicity of a neoantigen derived from insertion/deletion mutation. Thirdly, in HT29 cell-derived xenograft models, Birinapant administration also reshaped the immunopeptidome, and the tumor exhibited better immunogenicity. These data suggest that Birinapant can reshape the tumor immunopeptidome with respect to quality and quantity, which improves the presentation of CTA peptides and neoantigens, thus enhancing the immunogenicity of tumor cells. Such changes may be vital to the effectiveness of combination therapy, which can be further transferred to the clinic or aid in the development of new immunotherapeutic strategies to improve the anti-tumor immune response.

Function Switch of a Fungal Sesterterpene Synthase through Molecular Dynamics Simulation Assisted Alteration of an Aromatic Residue Cluster in the Active Pocket of PfNS.

Terpene synthases (TPSs) play pivotal roles in generating diverse terpenoids through complex cyclization pathways. Protein engineering of TPSs offers a crucial approach to expanding terpene diversity. However, significant potential remains untapped due to limited understanding of the structure-function relationships of TPSs. In this investigation, using a joint approach of molecular dynamics simulations-assisted engineering and site-directed mutagenesis, we manipulated the aromatic residue cluster (ARC) of a bifunctional terpene synthase (BFTPS), Pestalotiopsisfici nigtetraene synthase (PfNS). This led to the discovery of previously unreported catalytic functions yielding different cyclization patterns of sesterterpenes. Specifically, a quadruple variant (F89A/Y113F/W193L/T194W) completely altered PfNS's function, converting it from producing the bicyclic sesterterpene nigtetraene to the tricyclic ophiobolin F. Additionally, analysis of catalytic profiles by double, triple, and quadruple variants demonstrated that the ARC functions as a switch, unprecedently redirecting the production of 5/11 bicyclic (Type B) sesterterpenes to 5/15 bicyclic (Type A) ones. Molecular dynamics simulations and theozyme calculations further elucidated that, in addition to cation-π interactions, C-H∙∙∙π interactions also play a key role in the cyclization patterns. This study offers a feasible strategy in protein engineering of TPSs for various industrial applications.

Efficacy of Replacing Linezolid with OTB-658 in Anti-Tuberculosis Regimens in Murine Models.

Linezolid (LZD) was the first oxazolidinone approved for treating drug-resistant tuberculosis. A newly approved regimen combining LZD with bedaquiline (BDQ) and pretomanid (PMD) (BPaL regimen) is the first 6-month oral regimen that is effective against multidrug- and extensively drug-resistant tuberculosis. However, LZD toxicity, primarily due to mitochondrial protein synthesis inhibition, may undermine the efficacy of LZD regimens, and oxazolidinones with higher efficacy and lower toxicity during prolonged administration are needed. OTB-658 is an oxazolidinone anti-TB candidate derived from LZD that could replace LZD in TB treatment. We previously found that OTB-658 had better anti-TB activity and safety than LZD in vitro and in vivo. In the present work, two murine TB models were used to evaluate replacing LZD with OTB-658 in LZD-containing regimens. In the C3HeB/FeJ murine model, replacing 100 mg/kg LZD with 50 mg/kg OTB-658 in the BDQ + PMD backbone significantly reduced lung and spleen CFU counts (P < 0.05), and there were few relapses at 8 weeks of treatment. Replacing 100 mg/kg LZD with 50 or 100 mg/kg OTB-658 in the pyrifazimine (previously called TBI-166) + BDQ backbone did not change the anti-TB efficacy and relapse rate. In BALB/c mice, replacing 100 mg/kg LZD with 100 mg/kg OTB-658 in the TBI-166 + BDQ backbone resulted in no culture-positive lungs at 4 and 8 weeks of treatment, and there were no significant differences in relapses rate between the groups. In conclusion, OTB-658 is a promising clinical candidate that could replace LZD in the BPaL or TBI-166 + BDQ + LZD regimens and should be studied further in clinical trials.

Pontibacter liquoris sp. nov. and Pontibacter vulgaris sp. nov., two novel bacteria isolated from the pit mud of Chinese liquor.

Two pink-pigmented bacterial strains, designated NBU2971T and NBU2972T, were isolated from the pit mud of a Chinese liquor. Phylogenetic analyses based on 16S rRNA gene sequences suggested that strains NBU2971T and NBU2972T formed a distinct lineage within the family Hymenobacteraceae and were closely related to members of the genus Pontibacter. 16S rRNA gene sequences revealed that strain NBU2971T showed highest similarity of 97.9 % to Pontibacter arcticus 2b14T, and strain NBU2972T showed the highest similarity of 96.9 % to Pontibacter deserti JC215T. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two novel strains were 95.2, 73.8 and 19.6 %, respectively, suggesting that they represent different species. The ANI and dDDH values between two novel strains and related species of genus Pontibacter were well below the threshold limit for prokaryotic species delineation. The genomic DNA G+C contents of strains NBU2971T and NBU2972T were 51.3 and 44.5 mol%, respectively. The major cellular fatty acids of the two novel strains were iso-C15 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The major polar lipid of both novel strains was phosphatidylethanolamine. The only respiratory quinone was MK-7. Combining results of phenotypic, chemotaxonomic and genotypic data, strains NBU2971T and NBU2972T are considered to be two representatives in the genus Pontibacter, which the name Pontibacter liquoris sp. nov. and Pontibacter vulgaris sp. nov. are proposed. The type strains of the new species are NBU2971T (=KCTC 82916T=MCCC 1K06395T) and NBU2972T (=KCTC 82917T=MCCC 1K06396T), respectively.

Muricauda meishanensis sp. nov., a facultative anaerobic bacterium belonging to the family Flavobacteriaceae isolated from marine sediment in the East China Sea.

A facultative anaerobic, Gram-strain-negative, rod-shaped bacterium (strain NBU2970T) was isolated by using modified ichip in situ cultivation from a marine sediment sample collected from Meishan Island in the East China Sea. Strain NBU2970T grew optimally at 37 °C, with a NaCl concentration of 2.0 % (w/v) and at pH 7.0. The 16S rRNA gene sequence analyses revealed that strain NBU2970T represents a novel species with the genus Muricauda, sharing highest sequence identities with Muricauda beolgyonensis BB-My12T (96.1 %), Muricauda alvinocaridis SCR12T (96.0 %), Muricauda taeanensis 105T (96.0 %) and Muricauda ruestringensis B1T (95.6 %). Phylogenetic analyses also indicated that strain NBU2970T clustered with the genus Muricauda and was closely related to M. beolgyonensis BB-My12T and M. ruestringensis B1T. The draft genome sequence of strain NBU2970T was composed of six contigs with a size of 3.2 Mbp, containing 3045 protein-coding genes and 38 RNA genes. The DNA G+C content was 43.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU2970T and related species of the genus Muricauda were well below the threshold limit for prokaryotic species delineation. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The only respiratory quinone was MK-6. The major polar lipid was phosphatidylethanolamine. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU2970T is considered to be a representative of a novel species in the genus Muricauda, for which the name Muricauda meishanensis sp. nov. is proposed. The type strain is NBU2970T (=KCTC 82915T=MCCC 1K06394T).

Oricola nitratireducens sp. nov., a novel nitrate reducing bacterium isolated from marine sediment in East China Sea.

A novel strain designated NBU1457T, was isolated from marine sediment sampled on Meishan Island located in the East China Sea. Cells of strain NBU1457T was Gram-negative, facultatively anaerobic, non-motile and ovoid-shaped. Strain NBU1457T grew optimally at 37 °C, NaCl concentration of 2.0-3.0% (w/v) and pH 6.5-7.5. Catalase and oxidase activities, urease, nitrate reduction and H2S production were positive. Indole production, methyl red reaction, hydrolysis of starch, gelatin, casein, Tweens 20, 40, 60 and 80 were negative. Comparative analysis of the 16S rRNA gene sequence showed highest similarities to the species with validated name Oricola thermophila MEBiC13590T (98.8%), Oricola cellulosilytica CC-AMH-0 T (97.9%) and Oricola indica JL-62 T (97.9%). Phylogenetic analyses indicated that strain NBU1457T clustered with the genus Oricola and closely related to strains Oricola thermophila MEBiC13590T, Oricola cellulosilytica CC-AMH-0 T and Oricola indica JL-62 T. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU1457T and related species of genus Oricola were well below the threshold limit for prokaryotic species delineation. The DNA G + C content was 63.2%. The major cellular fatty acid was summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylmonomethylethanolamine, sulfoquinovosyldiacylglycerol and phosphatidylglycerol. The only respiratory quinone was ubiquinone-10 (Q-10). Combining results of our phenotypic, chemotaxonomic and genotypic data, strain NBU1457T is considered to be a representative in the genus Oricola, which the name Oricola nitratireducens sp. nov. is proposed. The type strain of the new species is NBU1457T (= KCTC 82225 T = MCCC 1K04764T).

How I do it? The surgical resection of the fourth ventricle choroid plexus papilloma.

BACKGROUND: The surgical resection of the large fourth ventricle choroid plexus papilloma (CPP) is complicated, where the challenge is to minimize the impairment of the vermis and the brainstem and restore the cerebrospinal fluid circulation. METHOD: We report a case of large CPP that wholly occluded the fourth ventricle, extended to the Luschka foramen, and underwent radical resection via telovelar approach. The intraoperative endoscope was applied to inspect the tumor residue and the aqueduct's opening. CONCLUSION: This case demonstrates the surgical nuance of the fourth ventricle CPP.

Superior Efficacy of a TBI-166, Bedaquiline, and Pyrazinamide Combination Regimen in a Murine Model of Tuberculosis.

TBI-166, derived from riminophenazine analogues, shows more potent anti-TB activity than clofazimine and is being assessed against tuberculosis (TB) in a phase IIa clinical trial in China. Preclinical regimen studies containing TBI-166 will support the phase IIb clinical trials of TBI-166. In the present study, we compared the efficacy in three murine TB models of an all-oral drug-resistant TB drug regimen of TBI-166 with bedaquiline (BDQ) and pyrazinamide (PZA) with the first-line regimen of isoniazid (INH) with rifampin (RFP) and PZA (HRZ regimen), the most effective reported TBI-166-containing regimen of TBI-166 with BDQ and linezolid (LZD), and the Nix-TB clinical trial regimen of BDQ with pretomanid and LZD (BPaL regimen). In the C3HeB/FeJ murine TB model, for the TBI-166+BDQ+PZA regimen, the lungs of mice were culture negative at 4 weeks, and there were no relapses at 8 weeks of treatment. The reduction in bacterial burden and relapse rate were greater than those of the HRZ regimen and the TBI-166+BDQ+LZD regimen. Compared with the BPaL regimen, the TBI-166+BDQ+PZA regimen had similar or stronger early bactericidal activity, bactericidal activity, and sterilizing activity in the BALB/c murine TB model. The bacterial burden in the TBI-166+BDQ+PZA regimen group decreased significantly more than that in the BPaL regimen group and was almost or totally relapse free (<13.33% after 8 weeks). In conclusion, oral short-course three-drug regimens, including TBI-166 with high efficacy, were identified. The TBI-166+BDQ+PZA regimen is recommended for further study in a TBI-166 phase IIb clinical trial.

First Indirect Drive Experiment Using a Six-Cylinder-Port Hohlraum.

The new hohlraum experimental platform and the quasi-3D simulation model are developed to enable the study of the indirect drive experiment using the six-cylinder-port hohlraum for the first time. It is also the first implosion experiment for the six laser-entrance-hole hohlraum to effectively use all the laser beams of the laser facility that is primarily designed for the cylindrical hohlraum. The experiments performed at the 100 kJ Laser Facility produce a peak hohlraum radiation temperature of ∼222 eV for ∼80 kJ and 2 ns square laser pulse. The inferred x-ray conversion efficiency η∼87% is similar to the cylindrical hohlraum and higher than the octahedral spherical hohlraum at the same laser facility, while the low laser backscatter is similar to the outer cone of the cylindrical hohlraum. The hohlraum radiation temperature and M-band (>1.6 keV) flux can be well reproduced by the quasi-3D simulation. The variations of the yield-over-clean and the hot spot shape can also be semiquantitatively explained by the calculated major radiation asymmetry of the quasi-3D simulation. Our work demonstrates the capability for the study of the indirect drive with the six-cylinder-port hohlraum at the cylindrically configured laser facility, which is essential for numerically assessing the laser energy required by the ignition-scale six-cylinder-port hohlraum.

Luteolibacter marinus sp. nov., a novel bacterium in the family Verrucomicrobiaceae, isolated from marine sediment.

A Gram-negative, rod-shaped, non-motile and strictly aerobic bacterium, designated NBU1238T, was isolated from marine sediment sampled on Meishan Island located in the East China Sea. Strain NBU1238T was able to grow optimally at 28-32 °C, at pH 7.5 and with no NaCl. Catalase and oxidase activities, H2S production and hydrolysis of Tweens 40 and 60 were positive. Methyl red reaction, Voges-Proskauer test and hydrolysis of starch, casein and Tweens 20 and 80 were negative. The major cellular fatty acids were iso-C14 : 0, C16 : 0, C16 : 1 ω9c and C14 : 0. The only respiratory quinone was menaquinone-9. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylmethylethanolamine. The 16S rRNA gene sequence of strain NBU1238T showed 95.6, 95.6, 94.8 and 93.8% sequence similarity to Luteolibacter flavescens GKXT, Luteolibacter luteus G-1-1-1T, Luteolibacter arcticus MC 3726T and Luteolibacter pohnpeiensis A4T-83T, respectively. Phylogenetic analyses indicated that strain NBU1238T clustered with the genus Luteolibacter and was closely related to strains L. flavescens GKXT, L. arcticus MC 3726T and L. luteus G-1-1-1T. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU1238T and related species of genus Luteolibacter were well below the threshold limit for prokaryotic species delineation. The DNA G+C content of the genomic DNA was 65.0 mol%. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU1238T is considered to be a representative of a novel species in the genus Luteolibacter, for which the name Luteolibacter marinus sp. nov. is proposed. The type strain is NBU1238T (=KCTC 82227T=MCCC 1K04772T).

Pelagibius marinus sp. nov., a novel bacterium isolated from marine sediment, and emended description of the genus Pelagibius.

A Gram-stain-negative, rod-shaped, motile and aerobic marine bacterium, designated strain NBU2595T, was isolated from marine sediment sampled on Meishan Island, located in the East China Sea. Strain NBU2595T grew at 10-40 °C (optimum, 37 °C), at NaCl concentration of 0-10.0 % (w/v; optimum, 0.5 %) and at pH 6.0-8.0 (optimum, pH 7.0). Catalase and oxidase activities and H2S production were positive. Methyl red reaction and hydrolysis of casein, starch and Tweens 20, 40, 60 and 80 were negative. The major cellular fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C18 : 1 2-OH and C18 : 0 3-OH. The sole respiratory quinone was ubiquinone 10. The major polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylmonomethylethanolamine. Comparative analysis of 16S rRNA gene sequences showed highest similarity to Pelagibius litoralis CL-UU02T (97.9%), and low similarities (<92.9 %) to other species. Phylogenetic analyses indicated that strain NBU2595T clustered with the genus Pelagibius and was closely related to P. litoralis CL-UU02T. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU2595T and the related species of the genus Pelagibius were well below the thresholds for prokaryotic species delineation. The DNA G+C content was 66.5 mol%. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU2595T should be placed in the genus Pelagibius as representing a novel species, for which the name Pelagibius marinus sp. nov. is proposed. The type strain is NBU2595T (=MCCC 1K04773T=KCTC 82223T).

Targeted Discovery of Amantamide B, an Ion Channel Modulating Nonapeptide from a South China Sea Oscillatoria Cyanobacterium.

Amantamide B (1) is a new linear nonapeptide analogue of the cyanobacterial natural product amantamide A (2), and both have methyl ester and butanamide termini. These compounds were discovered in this study from the organic extract of a tropical marine filamentous cyanobacterium, Oscillatoria sp., collected around the Paracel Islands in the South China Sea. The use of LC-MS/MS molecular networking for sample prioritization and as an analytical dereplication tool facilitated the targeted isolation of 1 and 2. These molecules were characterized by spectroscopy and spectrometry, and configurational assignments were determined using chemical degradation and chiral-phase HPLC analysis. Compounds 1 and 2 modulated spontaneous calcium oscillations without notable cytotoxicity at 10 µM in short duration in vitro testing on primary cultured neocortical neurons, a model system that evaluates neuronal excitability and/or the potential activity on Ca2+ signaling. Both molecules were also found to be moderately cytotoxic in longer duration bioassays, with in vitro IC50 values of 1-10 µM against CCRF-CEM human T lymphoblastoid cells and U937 human histiocytic lymphoma cells. These formerly undiscovered bioactivities of known compound 2 expand upon its previously reported function as a selective CXCR7 agonist among 168 GPCR targets.

Angiogenesis-Inhibitory Piperidine Alkaloids from the Leaves of Microcos paniculata.

Eight new 2,6-disubstituted piperidin-3-ol alkaloids (1-8), featuring a C10 unsaturated alkyl side chain, together with three previously reported analogues (9-11) were isolated from the leaves of medicinal plant Microcos paniculata. Their structures and absolute configurations were elucidated unambiguously by means of 1D and 2D NMR spectroscopic data analysis, modified Mosher's method, Snatzke's method, and quantum chemical electronic circular dichroism (ECD) calculations, as well as single-crystal X-ray crystallography. The isolates were evaluated for their antiangiogenic effects on human umbilical vein endothelial cells (HUVECs). Compound 2 displayed an inhibitory effect on tube formation of HUVECs in a concentration-dependent manner.

Schultriene and nigtetraene: two sesterterpenes characterized from pathogenetic fungi via genome mining approach.

Fungal bifunctional terpene synthases (BFTSs) have been reported to contribute to the biosynthesis of a variety of di/sesterterpenes via different carbocation transportation pathways. Genome mining of new BFTSs from unique fungal resources will, theoretically, allow for the identification of new terpenes. In this study, we surveyed the distribution of BFTSs in our in-house collection of 430 pathogenetic fungi and preferred two BFTSs (CsSS and NnNS), long distance from previously characterized BFTSs and located in relatively independent branches, based on the established phylogenetic tree. The heterologous expression of the two BFTSs in Aspergillus oryzae and Saccharomyces cerevisiae led to the identification of two new sesterterpenes separately, 5/12/5 tricyclic type-A sesterterpene (schultriene, 1) for CsSS and 5/11 bicyclic type-B sesterterpene (nigtetraene, 2) for NnNS. In addition, to the best of our knowledge, 2 is the first 5/11 bicyclic type-B characterized sesterterpene to date. On the basis of this, the plausible cyclization mechanisms of 1 and 2 were proposed based on density functional theory calculations. These new enzymes and their corresponding terpenes suggest that the chemical spaces produced by BFTSs remain large and also provide important evidences for further protein engineering for new terpenes and for understanding of cyclization mechanism catalyzed by BFTSs. KEY POINTS: • Genome mining of two BFTSs yields two new sesterterpenoids correspondingly. • Identification of the first 5/11 ring system type-B product. • Parse out the rational cyclization mechanism of isolated sesterterpenoids.

Discovery of New Secondary Metabolites from Marine Bacteria Hahella Based on an Omics Strategy.

Hahella is one characteristic genus under the Hahellaceae family and shows a good potential for synthesizing new natural products. In this study, we examined the distribution of the secondary metabolite biosynthetic gene cluster (SMBGC) under Hahella with anti-SMASH. The results derived from five genomes released 70 SMBGCs. On average, each strain contains 12 gene clusters, and the most abundant ones (45.7%) are from the family of non-ribosomal peptide synthetase (NRPS) and non-ribosomal peptide synthetase hybrid with polyketide synthase (NRPS/PKS), indicating a great potential to find bioactive compounds. The comparison of SMBGC between H. chejuensis and other species showed that H. chejuensis contained two times more gene clusters than H. ganghwensis. One strain, designed as NBU794, was isolated from the mangrove soil of Dongzhai Port in Haikou (China) by iChip. The 16S rRNA gene of NBU794 exhibited 99% identity to H. chejuensis KCTC 2396 and clustered with the H. chejuensis clade on the phylogenetic trees. Genome mining on strain NBU794 released 17 SMBGCs and two groups of bioactive compounds, which are chejuenolide A-C and nine prodiginines derivatives. The prodiginines derivatives include the well-known lead compound prodigiosin and two new compounds, 2-methyl-3-pentyl-4-O-methyl-prodiginine and 2-methyl-3-octyl-prodiginine, which were identified through fragmentation analysis based on LC-MS/MS. The anti-microbial activity assay showed prodigiosin and 2-methyl-3-heptyl-prodiginine exhibited the best performance in inhibiting Escherichia coli, Salmonella paratyphi B, MASA Staphylococcus aureus, Bacillus subtilis, and Candida albicans. Moreover, the yield of prodigiosin in H. chejuensis NBU794 was also evaluated, which could reach 1.40 g/L under the non-optimized condition and increase to 5.83 g/L in the modified ISP4 medium with macroporous adsorption beads added, indicating that NBU794 is a promising source of prodigiosin.

6'-O-galloylpaeoniflorin alleviates inflammation and oxidative stress in pediatric pneumonia through activating Nrf2 activation.

OBJECTIVE: To assess the therapeutic effect and mechanism of 6'-o-galloylpaeoniflorin (GPF) in pediatric pneumonia. METHODS: The effects of lipopolysaccharide (LPS) and GPF on cell viability and apoptosis were examined by cell counting kit-8 assay and flow cytometry analysis. The oxidative stress and inflammatory response were assessed by detecting expression levels of superoxide dismutase, glutathione, r-glutamyl cysteingl+glycine, myeloperoxidase, and malondialdehyde as well as tumor necrosis factor-α, Interleukin-18, and Interleukin-10 by using enzyme-linked-immunosorbent serologic assay. Moreover, the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was detected by immunoblot assay, and the influence of Nrf2-knockdown on cell viability, oxidative stress, and inflammation response was also investigated. RESULTS: The results established that GPF increased the viability of LPS-induced pneumonia cells. In addition, GPF reduced LPS-induced oxidative stress in pneumonia cells. It was further discovered that GPF reduced LPS-induced inflammation in pneumonic cell. GPF improved the activity of Nrf2 in LPS-treated pneumonic cells, and therefore alleviated inflammation and oxidative stress in pediatric pneumonia. CONCLUSION: GPF could serve as a promising drug for treating pediatric pneumonia.

In Vitro and In Vivo Activity of Oxazolidinone Candidate OTB-658 against Mycobacterium tuberculosis.

In this work, we assess antituberculosis activity of OTB-658 in vitro and in vivo. In vitro, OTB-658 showed bacteriostatic effectiveness with a lower MIC than linezolid against Mycobacterium tuberculosis. The minimal bactericidal concentrations and time-kill curves for OTB-658 indicated inhibition activity similar to that of linezolid. OTB-658 entered macrophages to inhibit M. tuberculosis growth. OTB-658 had a low mutation frequency (10-8), which would prevent drug-resistant mutations from emerging in combination regimens. In vivo, OTB-658 reduced CFU counts in the lungs and slightly inhibited bacterial growth in the spleen in the early stage and steady state in acute and chronic murine TB models. These results support the preclinical evaluation of OTB-658 and further clinical trials in China.