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Reversible methylation by means of N6-methyladenosine (m6A) is the most prevalent internal modification in mammalian mRNA. This RNA chemical mark is created by proteins that are m6A "writers" and can be reversed by proteins that are m6A "erasers" (i.e., demethylases). Some other proteins serving as "readers" can recognize m6A-containing mRNA and regulate downstream molecular mechanisms accordingly. Although m6A bases in RNA perform critical functions in important biological processes, their roles in cancer biology and cancer stem cells remain largely unknown. In this review, we focus on the m6A-associated mechanisms and modification landscapes in several major malignant tumors. Global and detailed analyses were both conducted on relevant high-throughput sequencing data. Possible interventions against m6A demethylases are also explored in this review, which may be advantageous for the treatment of m6A related cancers. [ABSTRACT FROM AUTHOR]

Abstract: Ecotoxicity of residual solvents of pharmaceuticals on daphnia magna was studied by acute test. The results showed the order of toxicity of residual solvents of terramycin, thiamine hydrochloride and thiamine mononitrate was benzene > carbon tetrachloride > 1, 2-dichloroethane > 1, 1-dichloroethylene > 1, 1, 1-trichloroethane, dichloromethane > tetrahydrofuran > toluene > methanol> ethyl acetate = acetic acid = ethanol, Nmethylpyrrolidon > N, N-dimethylacetamide > methanol > aether, respectively. The ecotoxicity of methanol in combined system was more severe than that of in single system. The LC50s of methanol were 72.21, 91.94 and 3.357×104mg/L in thiamine hydrochloride, thiamine mononitrate and in single system, respectively. It was likely that the toxic effect of residual solvents increased in the presence of potential competitors. The study provided baseline information which was necessary to assess the potential hazard of some residual solvents released into water ecosystems. [Copyright &y& Elsevier]

Abstract: Effect of single and combined pollution of oxytetracycline (OTC) and Pb on enzyme activity was researched by using incubation experiments. The results showed catalase activity was inhibited in single and binary system at all incubation time except 100mg (OTC+Pb)/kg treated soil at seventy-fifth day. Catalase activity of binary system was not significantly different from single pollution from fiftieth to seventy-fifth day. Urease activity was inhibited in single system (except Pb polluted soil at the first day) and binary system ((50mg OTC + 100mg Pb)/kg treated soil) from 1d to 15d, but the changes of urease activity was complicated at the later stage. It is difficult to assess the pollution level by enzyme activity. [Copyright &y& Elsevier]

Abstract: Potency is an important parameter for evaluation of quality of heparin active pharmaceutical ingredient (API). In this paper the feasibility to determine potency of heparin API with near infrared reflectance spectroscopy (NIRS) coupled with partial least squares (PLS) algorithm is attempted. PLS factors, correlation coefficient of calibration set (R c), the root mean square of cross-validation (RMSECV), correlation coefficient of prediction set (R p) and the root mean square of prediction (RMSEP) were used to evaluate the performance of the models. The optimal calibration model was obtained with R p =0.9721 and RMSEP=0.55 in the 1700–1898nm spectral region when using SG-1st derivative spectral transform method and division of calibration/prediction samples was 1/1. Three other additional samples demonstrated good prediction capability of the final model and three validation samples gave good repeatability result. NIRS has the potential to be a final lot release test to be performed in a QC laboratory. [Copyright &y& Elsevier]

[Display omitted] • Chemical investigation of a marine-derived fungus Alternaria sp. HDN19-690 led to the isolation of three new perylenequinone derivatives. • Xanalterate A (1) possesses a unique pyran ring at E ring with only 4 cases have been reported so far and altertoxin VIII (2) is a third example of chlorinated perylenequinone derivative. • Compounds 1 – 4 showed broad antibacterial activity with compound 1 the best (MIC values ranging from 3.13 to 12.5 µM). Three new perylenequinone derivatives, namely xanalterate A (1), altertoxin VIII and IX (2 and 3), together with one known analogue, stemphyperylenol (4), were isolated from the extract of the Antarctic sponge-derived fungus Alternaria sp. HDN19-690. The structures of compounds 1 – 3 , including absolute configurations, were confirmed based on the analysis of MS, NMR and ECD data. Compound 1 exhibited promising antimicrobial activity against the tested strains with MIC values ranging from 3.13 to 12.5 µ M. [ABSTRACT FROM AUTHOR]

Pyrazinopyrimidine-type alkaloids bearing a pyrazino[1,2-a] pyrimidine moiety, often have different functional groups substituted at C-8′ or C-2′/C-8′, generally further forming unique spiro-/conjugated ring systems. Four undescribed pyrazinopyrimidine-type alkaloids, including three natural products pyrasplorines A-C and an artifact deg-pyrasplorine B, as well as a biogenetically related versicoloid A were discovered from the extract of a mangrove-derived fungus Apergillus verisicolor HDN11-84. Pyrasplorine A contains unique spiral-type skeleton (composed of cyclopentenone ring with the pyrazino[1,2-a] pyrimidine core) which is unprecedented in pyrazinopyrimidine-type alkaloids. The deg-pyrasplorine B could be spontaneously converted from pyrasplorine B in mild conditions. Their structures including absolute configurations were elucidated based on NMR spectroscopic analysis, computational calculations and Marfey's method. The absolute configuration of versicoloid A was re-assigned in this study. All the isolated compounds are non-cytotoxic and deg-pyrasplorine B showed anti-influenza A virus H1N1 activity with the IC 50 of 50 μ M. [Display omitted] • Four new pyrazinopyrimidine-type alkaloids were identified. • Pyrasplorine A is the first compound with spiro-cyclopentane in pyrazinopyrimidine-type alkaloids. • The absolute configuration of compound versicoloid A was revised. • Pyrasplorine B can convert to deg-pyrasplorine B which showed anti-influenza A virus H1N1 activity. • The absolute configuration was deduced by ECD calculations and DP4+ analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new phenalenone derivatives were isolated from a marine-derived fungus. • Peniciphenalenin G (1) is the first chloric acenaphthenquinone derivative. • Compounds 1 , 2 , 4 , 5 displayed broad antimicrobial effects against tested strains. Three new phenalenone derivatives, namely peniciphenalenins G − L (1 – 3), together with two related compounds (4 and 5), were isolated from the marine sediment-derived fungus Pleosporales sp. HDN1811400 guided by HPLC-UV profile. Structures including absolute configurations were elucidated by detailed spectroscopic analyses, DFT calculations as well as chemical method. Peniciphenalenin G (1) represents the first example of chlorinated acenaphthenquinone derivative, and compounds 1 , 2 , 4 , and 5 showed broad antibacterial activities with the best MIC value of 6.25 μM against MRSA. [ABSTRACT FROM AUTHOR]

Five undescribed 12-membered macrolides containing thioethers, thiocladospolides F-J, together with the known biogenetic related analogues, were isolated from a mangrove-derived endophytic fungus Cladosporium oxysporum. The absolute configuration of thiocladospolide F was deduced by single-crystal X-ray diffraction, and those of thiocladospolides G-J were determined based on specific optical rotation and electronic circular dichroism (ECD) data, as well as the biogenetic considerations. Thiocladospolide G display the best antimicrobial activity against the aquatic pathogen Edwardsiella tarda with minimal inhibit concentration (MIC) value of 4 μ g/mL. Image 1 • Five undescribed 12-membered macrolides were isolated from Cladosporium oxysporum. • Thiocladospolide F showed the first single crystal of 12-membered macrolide dimer. • Thiocladospolide G revealed antimicrobial activity against Edwardsiella tarda. [ABSTRACT FROM AUTHOR]

Abstract Seven compounds including four undescribed fusaric acid derivatives, namely fusaricates H-K, and two undescribed γ -pyrone derivatives, named fusolanones A-B, as well as a known compound fusaric acid, were isolated from a mangrove endophytic fungus Fusarium solani. Fusaricates H-K represent the first cases of fusaric acid butanediol esters and are diastereoisomers. Their structures including absolute configurations were elucidated based on NMR, MS, chemical synthesis, chiral HPLC analysis and ECD calculations. The antibacterial activity of all undescribed compounds were tested and fusolanone B showed the best activity with MIC value 6.25 μg/mL on Vibrio parahaemolyticus. Graphical abstract Four undescribed fusaric acid derivatives and two undescribed γ -pyrone derivatives as well as fusaric acid were isolated from an endophytic fungus Fusarium solani , with fusolanone B showed the best antibacterial activity. Image 1 Highlights • Seven previously undescribed compounds were isolated from a mangrove endophytic fungus Fusarium solani. • Fusaricates H-K represent the first cases of fusaric acid butanediol esters and are diastereoisomers. • Fusolanone B showed antibacterial activity on Vibrio parahaemolyticus with MIC value 6.25 μg/mL. [ABSTRACT FROM AUTHOR]

Abstract: The object of this study was to explore the feasibility of support vector machine (SVM) to identify the origin of chondroitin sulfate (CS) by near infrared spectroscopy. 96 batches CS from three different origins were collected in this research, 66 batches of which were chosen for training set by Kennard–Stone (KS) method and the rest were used for testing. Through the comparison of pretreatment methods of standard normal variate transformation (SNV), multiplicative scatter correction (MSC), Savitzky-Golay (SG) smoothing and derivative with SG smoothing, a SVM discrimination model was constructed, of which the prediction result is 100% accurate with the pretreatment of first derivative and SG smoothing with 15 points. The result indicated that it had great potential using SVM to identify the origin of CS. [Copyright &y& Elsevier]

Abstract: This paper attempted the feasibility to determine the molecular weight of hyaluronic acid with near-infrared (NIR) diffuse reflectance spectroscopy. In this work, 46 experimental samples of hyaluronic acid powder were analyzed by partial least square (PLS) regression multivariate calibration method in the selected region of NIR spectra. The leave-one-out cross-validation method was used for the PLS model selection criterion. The accuracy of the final model was evaluated according to correlation coefficient of prediction set (Rp) and root mean square error of prediction set (RMSEP). The repeatability was verified through repeated measurement of spectra coupled with an appropriate chi-square test. Finally, the optimal calibration model was obtained with Rp=0.9814 and RMSEP=88.32 when using Savitzky-Golay first (SG-1st) derivative with 9 smoothing points spectral preprocessing method. The parameters above and repeatability of NIR spectroscopy obtained from chi-square test were both within the range of permissible error in factories. This study demonstrated that NIR spectroscopy was superior to conventional methods for the fast determination of molecular weight of hyaluronic acid. [Copyright &y& Elsevier]