Synthesis of 2,4-Disubstituted Oxazoles and Thiazoles via Brønsted Acid-Catalyzed Cyclization of α-diazoketones with Amides.

A novel method is described for the synthesis of 2,4-disubstituted oxazole and thiazole derivates via the coupling of α-diazoketones with (thio)amides or thioureas using trifluoromethanesulfonic acid (TfOH) as a catalyst. This protocol is characterized by mild reaction conditions, metal-free, and simplicity and also features good functional group tolerance, good to excellent yields, and a broad substrate scope with more than 40 examples. Experimental studies suggest a mechanism involving 2-oxo-2-phenylethyl trifluoromethanesulfonate as the key intermediate.

Multiple influence of immune cells in the bone metastatic cancer microenvironment on tumors.

Bone is a common organ for solid tumor metastasis. Malignant bone tumor becomes insensitive to systemic therapy after colonization, followed by poor prognosis and high relapse rate. Immune and bone cells in situ constitute a unique immune microenvironment, which plays a crucial role in the context of bone metastasis. This review firstly focuses on lymphatic cells in bone metastatic cancer, including their function in tumor dissemination, invasion, growth and possible cytotoxicity-induced eradication. Subsequently, we examine myeloid cells, namely macrophages, myeloid-derived suppressor cells, dendritic cells, and megakaryocytes, evaluating their interaction with cytotoxic T lymphocytes and contribution to bone metastasis. As important components of skeletal tissue, osteoclasts and osteoblasts derived from bone marrow stromal cells, engaging in 'vicious cycle' accelerate osteolytic bone metastasis. We also explain the concept tumor dormancy and investigate underlying role of immune microenvironment on it. Additionally, a thorough review of emerging treatments for bone metastatic malignancy in clinical research, especially immunotherapy, is presented, indicating current challenges and opportunities in research and development of bone metastasis therapies.

Enantioselective Tsuji-Trost α-Fluoroallylation of Amino Acid Esters with gem-Difluorinated Cyclopropanes.

A novel enantioselective Tsuji-Trost-type cross coupling reaction between gem-difluorinated cyclopropanes and N-unprotected amino acid esters enabled by synergistic Pd/Ni/chiral aldehyde catalysis is presented herein. This transformation streamlined the diversity-oriented synthesis (DOS) of optically active α-quaternary α-amino acid esters bearing a linear 2-fluoroallylic motif, which served as an appealing platform for the construction of other valuable enantioenriched compounds. The key intermediates were confirmed by HRMS detection, while DFT calculations revealed that the excellent enantioselectivity was attributed to the stabilizing non-covalent interactions between the Pd(II)-π-fluoroallyl species and the Ni(II)-Schiff base complex.

APIPred: An XGBoost-Based Method for Predicting Aptamer-Protein Interactions.

Aptamers are single-stranded DNA or RNA oligos that can bind to a variety of targets with high specificity and selectivity and thus are widely used in the field of biosensing and disease therapies. Aptamers are generated by SELEX, which is a time-consuming procedure. In this study, using in silico and computational tools, we attempt to predict whether an aptamer can interact with a specific protein target. We present multiple data representations of protein and aptamer pairs and multiple machine-learning-based models to predict aptamer-protein interactions with a fair degree of selectivity. One of our models showed 96.5% accuracy and 97% precision, which are significantly better than those of the previously reported models. Additionally, we used molecular docking and SPR binding assays for two aptamers and the predicted targets as examples to exhibit the robustness of the APIPred algorithm. This reported model can be used for the high throughput screening of aptamer-protein pairs for targeting cancer and rapidly evolving viral epidemics.

Cancer cells reprogram to metastatic state through the acquisition of platelet mitochondria.

Metastasis is the major cause of cancer deaths, and cancer cells evolve to adapt to various tumor microenvironments, which hinders the treatment of tumor metastasis. Platelets play critical roles in tumor development, especially during metastasis. Here, we elucidate the role of platelet mitochondria in tumor metastasis. Cancer cells are reprogrammed to a metastatic state through the acquisition of platelet mitochondria via the PINK1/Parkin-Mfn2 pathway. Furthermore, platelet mitochondria regulate the GSH/GSSG ratio and reactive oxygen species (ROS) in cancer cells to promote lung metastasis of osteosarcoma. Impairing platelet mitochondrial function has proven to be an efficient approach to impair metastasis, providing a direction for osteosarcoma therapy. Our findings demonstrate mitochondrial transfer between platelets and cancer cells and suggest a role for platelet mitochondria in tumor metastasis.

Characterization of benzylisoquinoline alkaloid methyltransferases in Liriodendron chinense provides insights into the phylogenic basis of angiosperm alkaloid diversity.

Benzylisoquinoline alkaloids (BIAs) are a class of plant secondary metabolites with great pharmacological value. Their biosynthetic pathways have been extensively elucidated in the species from the Ranunculales order, such as poppy and Coptis japonica, in which methylation events play central roles and are directly responsible for BIA chemodiversity. Here, we combined BIA quantitative profiling and transcriptomic analyses to identify novel BIA methyltransferases (MTs) from Liriodendron chinense, a basal angiosperm plant. We identified an N-methyltransferase (LcNMT1) and two O-methyltransferases (LcOMT1 and LcOMT3), and characterized their biochemical functions in vitro. LcNMT1 methylates (S)-coclaurine to produce mono- and dimethylated products. Mutagenesis experiments revealed that a single-residue alteration is sufficient to change its substrate selectivity. LcOMT1 methylates (S)-norcoclaurine at the C6 site and LcOMT3 methylates (S)-coclaurine at the C7 site, respectively. Two key residues of LcOMT3, A115 and T301, are identified as important contributors to its catalytic activity. Compared with Ranunculales-derived NMTs, Magnoliales-derived NMTs were less abundant and had narrower substrate specificity, indicating that NMT expansion has contributed substantially to BIA chemodiversity in angiosperms, particularly in Ranunculales species. In summary, we not only characterized three novel enzymes that could be useful in the biosynthetic production of valuable BIAs but also shed light on the molecular origin of BIAs during angiosperm evolution.

Anti-CRISPRdb v2.2: an online repository of anti-CRISPR proteins including information on inhibitory mechanisms, activities and neighbors of curated anti-CRISPR proteins.

We previously released the Anti-CRISPRdb database hosting anti-CRISPR proteins (Acrs) and associated information. Since then, the number of known Acr families, types, structures and inhibitory activities has accumulated over time, and Acr neighbors can be used as a candidate pool for screening Acrs in further studies. Therefore, we here updated the database to include the new available information. Our newly updated database shows several improvements: (i) it comprises more entries and families because it includes both Acrs reported in the most recent literatures and Acrs obtained via performing homologous alignment; (ii) the prediction of Acr neighbors is integrated into Anti-CRISPRdb v2.2, and users can identify novel Acrs from these candidates; and (iii) this version includes experimental information on the inhibitory strength and stage for Acr-Cas/Acr-CRISPR pairs, motivating the development of tools for predicting specific inhibitory abilities. Additionally, a parameter, the rank of codon usage bias (CUBRank), was proposed and provided in the new version, which showed a positive relationship with predicted result from AcRanker; hence, it can be used as an indicator for proteins to be Acrs. CUBRank can be used to estimate the possibility of genes occurring within genome island-a hotspot hosting potential genes encoding Acrs. Based on CUBRank and Anti-CRISPRdb, we also gave the first glimpse for the emergence of Acr genes (acrs). DATABASE URL: http://guolab.whu.edu.cn/anti-CRISPRdb.

Deep Fractional Max Pooling Neural Network for COVID-19 Recognition.

Aim: Coronavirus disease 2019 (COVID-19) is a form of disease triggered by a new strain of coronavirus. This paper proposes a novel model termed "deep fractional max pooling neural network (DFMPNN)" to diagnose COVID-19 more efficiently. Methods: This 12-layer DFMPNN replaces max pooling (MP) and average pooling (AP) in ordinary neural networks with the help of a novel pooling method called "fractional max-pooling" (FMP). In addition, multiple-way data augmentation (DA) is employed to reduce overfitting. Model averaging (MA) is used to reduce randomness. Results: We ran our algorithm on a four-category dataset that contained COVID-19, community-acquired pneumonia, secondary pulmonary tuberculosis (SPT), and healthy control (HC). The 10 runs on the test set show that the micro-averaged F1 (MAF) score of our DFMPNN is 95.88%. Discussions: This proposed DFMPNN is superior to 10 state-of-the-art models. Besides, FMP outperforms traditional MP, AP, and L2-norm pooling (L2P).

Horienoids A and B, Two Heterocoupled Sesquiterpenoid Dimers from Hedyosmum orientale.

Two eudesmane-guaiane/lindenane heterocoupled sesquiterpenoid dimers, horienoids A (1) and B (2) with new carbon skeletons, from Hedyosmum orientale were characterized by a combined method. Compound 1 featured a unique 2,10-dioxabicyclo[6.2.1]undecane core moiety with an anti-Bredt bridgehead double bond. Their biogenetic pathways were proposed to involve Diels-Alder and cascade rearrangement reactions as the key steps. Compound 2 exhibited a potent anti-inflammatory effect on LPS-induced BV-2 microglial cells.

Computed tomography-guided implantation of 125I radioactive seeds in patients with malignant airway compression induced by advanced lung cancer: effectiveness and safety in 40 patients.

PURPOSE: To evaluate the safety and efficacy of computed tomography (CT)-guided 125I radioactive seed implantation in patients with malignant airway compression induced by advanced lung cancer. MATERIAL AND METHODS: Between June 2015 and June 2018, 40 patients from three medical institutions with malignant airway compression induced by advanced lung cancer were treated with 125I seed implantation. The outcomes were measured in technical success and safety, objective response rate, complications, Karnofsky performance status (KPS) score, and survival time. RESULTS: All 40 patients successfully underwent implantation procedure. No procedure-associated death occurred. The most common complications were irritable cough, temporary hemoptysis, chest pain, fever, and pneumothorax, which occurred in 26 (65.0%), 31 (77.5%), 12 (30.0%), 15 (37.5%), and 11 (27.5%) patients, respectively. The objective response rates were 100%, 100%, 100%, 87.5%, and 83.3% at the 3rd, 6th, 12th, 24th, and 36th months post-procedure, respectively. The KPS score significantly improved at post-procedure. Median survival time was 25.1 months. Actuarial survival rates were 100%, 60%, and 15% at the 12th, 24th, and 36th months after the procedure, respectively. CONCLUSIONS: For patients with malignant airway compression induced by advanced lung cancer, implantation with 125I seed is a safe and effective alternative treatment option.

Morindolestatin, Naturally Occurring Dehydromorpholinocarbazole Alkaloid from Soil-Derived Bacterium of the Genus Streptomyces.

Novel antilipid peroxidative carbazole alkaloids, antiostatin A5 (1), antiostatin A6 (2), and (±)-morindolestatin (3), were isolated from a new soil-derived Streptomyces sp. Compound 2 possesses an unusual cyclohexene side chain. Compound 3 was a pair of enantiomers featuring an unprecedented [1,4]oxazino[2,3-c]carbazole ring system. The absolute configuration of 3 was determined by online HPLC-ECD and ECD calculation. A racemization mechanism and putative biosynthetic pathway are discussed.

Lycodine-type alkaloids from Lycopodiastrum casuarinoides and their acetylcholinesterase inhibitory activity.

Five previously undescribed lycodine-type alkaloids, named huperzine Y (1), 8,15-epoxy-N-demethylhuperzinine (2), 7-hydroxyl-huperzinine (3), huperzine Z (4), and huperzine D N-oxide (5), were isolated from the aerial parts and roots of Lycopodiastrum casuarinoides (Lycopodiaceae), along with ten known analogues. The structures of the new compounds were elucidated by means of spectroscopic technique (IR, UV, MS and NMR). The absolute configurations of the new compounds were established on the basis of comparison of their experimental and TD-DFT (time-dependent density functional theory) calculated ECD spectra. Moreover, all the isolates were evaluated for acetylcholinesterase (AChE) inhibitory activity. Only huperzine C showed moderate activity, with an IC50 value of 0.525 ±â€¯0.140 µM, which was comparable with the positive control, huperzine A (IC50 = 0.143 ±â€¯0.029 µM).

Prevalence of Concomitant Coronary Artery Disease and Its Impact on Acute Kidney Injury for Chinese Adult Patients Undergoing Valvular Heart Surgery.

INTRODUCTION: Significant coronary artery disease (CAD) in patients undergoing valvular heart surgery (VHS) is an indication for combined valvular heart surgery and coronary artery bypass grafting. However, the impact of nonsignificant CAD on postoperative outcomes is not well understood. This study illustrated the epidemiological characteristics of CAD in China and investigated the impact of CAD on postoperative acute kidney injury (AKI), intensive care unit (ICU) stay, and postoperative mortality. METHODS: This study comprised an epidemiological survey followed by a case-control investigation. The epidemiological characteristics of CAD were studied in 4,172 consecutive patients who underwent coronary angiography before planned VHS at a core cardiovascular center. Then, 3,618 patients were selected for the subsequent case-control study to further analyze the associations between CAD and postoperative advanced AKI (grade 2 or 3 by KDIGO criteria), longer ICU stay (highest quartile), and increased mortality by logistic regression. RESULTS: Of the participants, 5.1 and 9.3% had moderate and significant CAD, respectively. The incidence of CAD increased after 60 years of age. Although CAD was not related to longer postoperative ICU stay in a multivariate logistic model, moderate CAD (OR 1.539 [95% CI 1.078-2.199]) and significant CAD (OR 1.798 [95% CI 1.094-2.955]) remained independent risk factors for postoperative advanced AKI after adjusting for multiple traditional risk factors. Significant CAD, but not nonsignificant CAD, was associated with postoperative mortality. CONCLUSIONS: Concomitant CAD is common in Chinese patients who undergo VHS. Moderate and significant CAD might have detrimental effects on postoperative advanced AKI.

High hemoglobin is associated with increased in-hospital death in patients with chronic obstructive pulmonary disease and chronic kidney disease: a retrospective multicenter population-based study.

BACKGROUND: Chronic kidney disease (CKD) is a common comorbidity of chronic obstructive pulmonary disease (COPD). Although high hemoglobin (Hb) is detrimental to CKD patients, its relationship with poor outcomes in the COPD population has not been reported. This study aimed to investigate the relationship between high Hb and in-hospital mortality and to explore reference Hb intervals in patients with COPD and CKD. METHODS: This retrospective study was multicenter population-based. A total of 47,209 patients who presented with COPD between January 2012 and December 2016 were included. The average Hb level during hospitalization was used as the Hb level. CKD and advanced CKD were defined as estimated glomerular filtration rates < 60 and < 30 ml/min/1.73 m2, respectively. The association between Hb level (measured in 1 g/dL intervals) and in-hospital mortality was analyzed in different multivariable logistic regression models by CKD stratification. RESULTS: The Hb level was decreased in the CKD subgroup. In the non-CKD group, a higher Hb level was not associated with an increased risk of in-hospital death. However, the Hb level and mortality showed a U-shaped relationship in the CKD group. After adjusting for age and Charlson Comorbidity Index, multivariable regression analysis showed that an Hb level > 17 g/dL was associated with an increased risk of death in the CKD group with an odds ratio (OR) of 2.085 (95% CI, 1.019-4.264). Hb > 14 g/dL was related to an increased risk of death in advanced CKD patients (OR, 4.579 (95% CI, 1.243-16.866)). CONCLUSIONS: High Hb is associated with an increased risk of in-hospital death in COPD patients with CKD, especially among those with advanced CKD. In this group of patients, attention should be paid to those with high Hb levels.

Euphorkanlide A, a Highly Modified Ingenane Diterpenoid with a C24 Appendage from Euphorbia kansuensis.

Euphorkanlide A (1), a highly modified ingenane diterpenoid with a C24 appendage forming an additional hexahydroisobenzofuran-fused 19-membered macrocyclic bis-lactone ring system was isolated from the roots of Euphorbia kansuensis. Its structure was determined by extensive spectroscopic analysis and quantum-chemical calculations. Compound 1 showed significant cytotoxicities against a panel of cancer cell lines (IC50s < 5 µM). Mechanistic study revealed that 1 could induce the generation of ROS, leading to cell cycle arrest and cell apoptosis in drug-resistant cancer cell line HCT-15/5-FU.

[Analysis of Gene Mutation Types in 920 Cases of Thalassemia].

OBJECTIVE: To investigate the gene mutation types and distribution features of α- and ß-thalassemia in reproductive population of Xing bin district of Guangxi Lai bin city so as to provide the scientific basis for formulating the preventive and control measures. METHODS: The high risk population with thalassemia in 6 498 people of child-bearing age admited in department of antenatal care of our hospital from January 2017 to December 2017 were screened by blood cell test and hemoglobin electrophoresis. The gene mutation types and mutation frequency in αandßthalassemia positive cases were diagnosed and analyzied by Gap-PCR and PCR-RDB. RESULTS: The inital screening showed that there were 1 432 cases of thalassemia positive accounting for 22.04%; the gene diagnoses showed that there were 920 cases of thalassemia gene positive accounting for 14.16%. Among 920 cases, 593 cases were α-thalassemia accounting for 64.45% (593/920); the gene mutation types were 19 kinds. The α-deletion type gene was mainly --SEA (47.22%), the α-mutatin type gene was mainly -αcsα(13.66%); 260 cases were the ß-thalassemia accounting for 28.26%, (260/920), the gene mutation types were 9 kinds, out of which the ß41-42 ßN was main (50.38%), followed by ß17/ßN (38.08%)，there were 2 kinds of gene mutation types accounted for 88.46%; the αß-thalassemia numbered 67 cases (7.28%), the mutation types were mainly --SEA/ß41-42 (17.91%) and -α3.7/ß41-42 (17.91%). CONCLUSION: The α-and ß-thalassemia mostly observed in the childbearing population of Laibin city Xinbin district possess the gene comblexity and diversity as well as the significant genetic heterogeneily.The results of this study provide the reference basis for the prevention of thalassemia and eugenic works.

Benzofurans from Eupatorium chinense enhance insulin-stimulated glucose uptake in C2C12 myotubes and suppress inflammatory response in RAW264.7 macrophages.

Fourteen acetylbenzofuran derivatives, including three undescribed carbon skeletons with a newly formed hexane or benzene ring on the other side of the benzofuran ring, (±)-eupatonin A (1), (±)-eupatonin B (2), and eupatonin C (3), two new benzofurans (-)-12ß-hydroxygynunone (4) and (+)-12-hydroxyl-13-noreuparin (5), as well as 9 known ones (6-14), were isolated from 95% ethanol extract of the roots of Eupatorium chinense. Their structures were determined by spectroscopic methods and quantum chemical DFT and TDDFT calculations of the NMR chemical shifts and ECD spectra, which helped in the determination of the relative configurations of 1 and 2 and the absolute configurations of 4 and 5, respectively. 1 and 2 were further identified to be racemic mixtures by chiral HPLC analysis. All compounds were evaluated for insulin-stimulated glucose uptake in differentiated C2C12 myotubes. Compounds 1, 3, 4, 5, 11, 12, and 13 markedly enhanced insulin-mediated glucose uptake. (±)-Eupatonin A (1) activated the IRS-1/Akt/GSK-3ß signaling pathway and enhanced insulin stimulated GLUT4 membrane translocation in C2C12 myotubes. On LPS stimulated RAW264.7 macrophages, several compounds exhibited significant inhibitory effect on NO production with IC50 values ranging from 4.94 to 9.70 µΜ. (±)-Eupatonin A (1) again dose-dependently suppressed LPS-induced NO production and decreased the expression of inducible NO synthase (iNOS), through inhibiting NF-κB activity.

A stoichiometric CdS interlayer for the photovoltaic performance enhancement of quantum-dot sensitized solar cells.

The CdS interlayer plays an important role as the seed layer and energy barrier in photovoltaic performance enhancement of CdSe quantum-dot sensitized solar cells (QDSCs). However, the CdS (CdS-CBD) interlayer is generally synthesized by the chemical bath deposition method (CBD) and suffers from excessive Cd2+ due to the poor controllability of interfacial chemical reactions. Here, we employed a sol-gel method to prepare a CdS interlayer (CdS-SG) with a stoichiometric ratio of Cd2+ to S2- on a TiO2 mesoporous photoanode and then fabricated CdSe QDSCs. A power conversion efficiency of 3.37% was obtained in the CdS-SG QDSCs (Cell-SG), which is higher than that of 2.64% in the CdS-CBD QDSCs (Cell-CBD) under AM 1.5G solar illumination of 100 mW cm-2. Charge extraction measurements showed that the Cell-SG contained fewer trap states than the Cell-CBD. A comprehensive study of the electron dynamics based on open-circuit voltage decay (OCVD), electrochemical impedance spectroscopy (EIS), intensity-modulated voltage spectroscopy (IMVS), and intensity-modulated photocurrent spectroscopy (IMPS) measurements revealed that the stoichiometric CdS-SG interlayer significantly reduced the charge recombination and prolonged the lifetime of photogenerated electrons in contrast to the CdS-CBD interlayer in the QDSCs.

Euphorhelipanes A and B, Triglyceride-Lowering Euphorbia Diterpenoids with a Bicyclo[4.3.0]nonane Core from Euphorbia helioscopia.

Euphorhelipanes A (1) and B (2), two Euphorbia diterpenoids with a new 4-(5,5-dimethylheptan-2-yl)-2,7-dimethylbicyclo[4.3.0]nonane skeleton, were isolated from a 95% ethanol extract of the whole plants of Euphorbia helioscopia. Their structures were elucidated by spectroscopic data analysis, quantum chemical calculations, and single-crystal X-ray diffraction data. Compounds 1 and 2 represent the first examples of Euphorbia diterpenoids with a 5/6 fused carbon ring system, and their plausible biosynthetic pathways originating from jatrophanes are proposed. Compounds 1 and 2 showed a triglyceride-lowering effect in oleic-acid-stimulated HuH7 cells at concentrations of 1-50 µM.