TLC Identification and Extraction Process of Rubiasin-1-methyl Ether from Yao Medicine Chuanlianzhu

[Objectives]To establish a thin-layer chromatography(TLC)method for the determination of rubiadin-1-methyl ether in Yao Medicine Chuanlianzhu(Damnacanthus giganteus).[Methods]A silica gel G thin-layer plate was adopted for TLC.Petroleum ether(60-90℃)-chloroform-methanol-water(7:15:3:1)was used as the developing solvent and inspected under ultraviolet lamp(365 nm).The content was determined by Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm),mobile phase:acetonitrile-0.2%phosphoric acid gradient elution,detection wavelength 277 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The spots of 10 Chuanlianzhu samples from different origins showed the same color at the same position as the control,and the spots were clear and specific.The injection volume of rubiadin-1-methyl ether showed a good linear relationship in the range of 2.90-145μg(R=0.9996).The average recovery rate of rubiadin-1-methyl ether in the low,medium and high dose groups of Yao Medicine Chuanlianzhu was 98.72%,and RSD=1.78%.[Conclusions]This method can effectively identify Yao Medicine Chuanlianzhu medicinal materials and accurately determine the content of rubiadin-1-methyl ether in the medicinal materials.It provides a scientific basis for the development and utilization of Yao Medicine Chuanlianzhu medicinal resources.

MONOMER REACTIVITY RATIO AND THERMAL PERFORMANCE OFα-METHYL STYRENE AND GLYCIDYL METHACRYLATE COPOLYMERS

Synthesis and characterization of the copolymers （PAG） of α-methyl styrene （AMS） and glycidyl methacrylate （GMA） are presented. The copolymers of PAG were characterized by gel permeation chromatography （GPC）, Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （^1H-NMR） and thermogravimetery （TG）. Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.

Characterization ofanovel deep-seamicrobial esterase EstC 10 and its use in the generation o f(R)-methyl 2-chloropropionate

A novel esterase Est C10 from B acillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of Est C10 was characterized. At present, the reports about the kinetic resolution of racemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase Est C10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate( R)-methyl 2-chloropropionate with high enantiomeric excess(>99%) after the optimization of process parameters such as p H, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration(80 mmol/L) of esterase Est C10 was higher than the kinetic resolution of another esterase, Est12-7(50 mmol/L). The novel microbial esterase Est C10 identified from the deep sea was a promising green biocatalyst in the generation of( R)-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.

Microwave-assisted synthesis of new N^4-[bi-(4-fluorophenyl)-methyl]-piperazine thiosemicarbazones under solvent-free conditions

Six new N4-[bi-（4-fluorophenyl）-methyl]-piperazine thiosemicarbazones 3a-f have been prepared starting from [bi-（4-fluorophenyl）-methyl]-piperazine in solvent-free condition under microwave irradiation with excellent yields. Their structures have been determined by elemental analysis, IR, MS and 1H NMR data.

Controlled Self-assembly of Two Coordination Polymers via subtly Varying Bis(2-methyl imidazole) Ligands:from 3-Connected(6,3) Net to 4-Connected sql Net

Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis（2-methyl imidazole） ligands, namely, {[Cd2（tdc）2（bip）2]·7H20}n （1） and [Cd（tdc）（bib）]n （2） （Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-（imidazol-2-methyl）propane and bib = 1,4-bis（imidazol-2-methyl）butane）, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional （2D） layered network with 3-connected （6,3） topology, which is further connected into a three- dimensional （3D） supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis（imidazol-2-methyl） ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.

Urinary Concentrations of Hydroxyproline and 3-Methyl Histidine in Postpartum Cow

The urinary concentrations of hydroxyproline (HYPRO)and 3 -methyl histidine (3 - MEHIS) were de- termined in 16 Chinese-Holstein cows. The objectives of the experiment were to find out thhe relationship between collagen and myosin ddegradation and uterine involution in the postpartum cow. The results in the experiment showed that the mean concentrations of HYPRO and 3-MEHIS were 138.32±22.99 and 37.09 ±3.90 nmol·mL-1,respectively,for the cows during the days between 60-90 postpartum,and for the cows immediately after calving the concentrations of HYPRO and 3 -MEHIS reduced from 284.30 and 65.48 nmol ·mL-1 on the day one after calving to the normal level of 109.18 and 33.51 nmol·mL^-1 on the day 50 post- partum,respectively. There was a good correlation between the urinary concentrations of both HYPRO and 3 -MEHIS and the diameters of the involuting uterus (r = 0. 79).

Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol;and the reaction heat being 10.06 kJ·mol;. The dominant product predicted theoretically is in agreement with the experiment results.

Interaction of N-(2-Methyl Thio Phenyl)-2-Hydroxy-1-Naphthaldimine with Tin Dioxide Nanoparticles: A Spectroscopic Approach

The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.

Comparison of HPLC-DAD and GC-FID Methods for Determination of 6-Methyl Coumarin in Cosmetics

The methods of determination of 6-methyl coumarin in cosmetics by HPLC-DAD and GC-FID were compared. The positive samples were confirmed by GC-MS. Methanol was used to extract 6-methyl coumarin from cosmetics. The chromatographic conditions of the two methods were optimized and the samples were determined. The recovery, precision, correlation coefficient, detection limit and quantitative limit of the two methods were compared. The results showed that the linear relationship between the two methods was good. The percentage recovery of standard addition by HPLC-DAD was 92.20%~102.80%, by RSD was 0.77%~2.00%;the detection limit was 0.05 mg/kg, the quantitative limit was 0.17 mg/kg. The percentage recovery of standard addition by GC-FID was 97.30%~103.28%, by RSD was 0.47%~4.87%;the detection limit was 1.3 mg/kg, the quantitative limit was 5.0 mg/kg. The detection limit by HPLC-DAD was lower and more sensitive than that by GC-FID , which also shows that HPLC-DAD has more advantages for the detection of low content samples.

Base-controlled NHC-Ru-catalyzed transfer hydrogenation andα-methylation/transfer hydrogenation of ketones using methanol

Herein,we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol.By simply changing the base,a broad range of structurally diverse ketones,could be selectively and efficiently converted to the correspondingβ-methylated secondary alcohols or secondary alcohols.Remarkably,this catalytic system was very effective for the synthesis of bio-related molecules and deuterated alcohols,as well as the three-component coupling between methyl ketones,primary alcohols,and methanol.The reaction mechanism was further revealed by experiment and DFT mechanistic investigations.

Effects of Garcinia kola “Bitter Kola” Powder on Sex Reversal, Survival and Growth Performance of Tilapia (Oreochromis niloticus L.)

This study was carried out in 2022 at the Itato agriculture community estate of fish hatchery in eastern Senegal with the aim of finding an alternative method to 17-α-methyl testosterone (MT) by using Garcinia kola “Bitter kola” powder to obtain Oreochromis niloticus male sex populations. 1800 fry of average size between 0.01 and 0.02 g were distributed in 12 aboveground tanks of 1 m3 each at a rate of 150 individuals/tank, following 6 duplicate treatments. The negative (B1 and B2) and positive (B3 and B4) control diets, to which between 0 and 60 mg/kg of 17alpha-methyl testosterone had been added respectively, were mixed with industrial feed containing 40% protein;the tank diets (B5 and B6), (B7 and B8), (B9 and B10) and (B11 and B12) contained 10 g, 20 g, 30 g and 40 g of Garcinia kola powder respectively for 1 kg of industrial feed con-taining 40% protein. These different treatments resulted in high proportions of males in the order of 97.03%;98.09% for the hormone and proportions of 94.03%;93.26% for 20 g of Garcinia kola extracts. In terms of weight growth, the best average weights for the hormone and Garcinia kola were 0.896 g and 0.980 g respectively. With regard to fish survival, the following results were recorded: 95.53% and 94.56% respectively for additions of 20 g and 30 g of Garcinia kola extracts to the feed supplied to the fish. On the other hand, a significant difference in the mortality rate of 35% and 5% respectively for the conventional hormone and 20 g of Garcinia kola extracts was observed. To conclude the study, it is recommended that further studies be carried out to determine the quality of the flesh, their life stages and the profile of the amino acids present in their proteins.

一种胶粘剂的裂解GC-MS分析

目前胶粘剂广泛应用于木材加工、建筑、轻纺工业、交通运输、电工工业、机械工业、医疗卫生、日用生活、军事工业等各个领域,已成为不可缺少的重要材料之一,因此对各种胶粘剂的分析就显得十分重要.……

Chemical Composition of the Essential Oil of Mastic Gum and their Antibacterial Activity Against Drug-Resistant Helicobacter pylori

Mastic gum is derived from the tree named Pistacia lentiscus that is grown only in Island Hios of Greek.Since Mastic was first reported to kill Helicobacter pylori(H.pylori)in 1998,there has been no further study to elucidate which component of mastic specifically shows the antimicrobial activity against H.pylori.In this study,we examined which component of mastic gum was responsible for anti-H.pylori activity.We prepared the essential oil of mastic gum and identified 20 constituents by GC–MS analysis.Ten standard components were assayed for anti-H.pylori activity,and it clarified that a-terpineol and(E)-methyl isoeugenol showed the anti-H.pylori activity against four different H.pylori strains that were established from patients with gastritis,gastric ulcer and gastric cancer.These components could be useful to overcome the drug-resistance H.pylori growth in stomach.

Even-carbon predominance of Monomethyl branched alkanes in Humic coal from Junggar Basin,NW China

A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of the compounds.It is worth noting that the2-methyl alkanes in the humic coal samples show an obvious distribution of even carbon predominances rarely reported in the literature.The results show that with the increase of Pr/Ph(pristane/phytane),the even carbon dominance of 2-methyl alkanes is more obvious,while the odd carbon number distribution of 3-methyl alkanes is weakened.As Pr/Ph increases in the humic coal,the relative content of the hopanes increased,while the relative content of 2-methyl alkanes and 3-methyl alkanes increases first and then decreases.

Distribution and Significance of Methyl Steranes in Bohai Bay Basin, East China

31 samples of shales and mudstones developed in reducing hypersaline andfreshwater setting and 20 oil samples of Bamianhe oilfield, Bohai Bay basin were collected for adetailed study of petroleum system. Composition and distribution, especially significance ofsteroids, are discussed as a part of those. Abundant steroidal biomarkers, including C_(27-29)regular Steranes, C_(28-30) 4-methyl steranes, di-nosteranes and aromatic steranes, were detected.Results show that the composition and distribution of the steroids in samples studied are functionsof thermal maturity, organic source, paleoenvironment and lithology of potential source rocks.Alga-rich Es_4 shales (brackish water) developed in the south slope of depocenter (Niuzhuang sag)were found particularly rich in steroidal biomarkers including C_(30) 4-methyl steranes anddinosteranes. Es_3 mudstones (fresh water) were found devoid of dinosteranes. Distribution patternsof regular steranes are completely different from methyl steranes indicating different origins ofthe specific compounds of the fractioa Diagnostic distribution of steranes in rock extracts ofdiverse intervals makes the compounds to be essential indictors of source-rock tracing. Methylsteranes prove to be much more useful in oil-source rock correlation than regular steranes. Resultsalso show that alga-rich Es_4 shales located in the south slope are not likely the primary sourcerock responsible for the oils discovered based on the composition and distribution of steroids.

Global hypomethylation in hepatocellular carcinoma and its relationship to aflatoxin B_1 exposure

AIM:To determine global DNA methylation in paired hepatocellular carcinoma(HCC) samples using several different assays and explore the correlations between hypomethylation and clinical parameters and biomarkers,including that of aflatoxin B 1 exposure.METHODS:Using the radio labeled methyl acceptance assay as a measure of global hypomethylation,as well as two repetitive elements,including satellite 2(Sat2) by MethyLight and long interspersed nucleotide elements(LINE1),by pyrosequencing.RESULTS:By all three assays,mean methylation levels in tumor tissues were significantly lower than that in adjacent tissues.Methyl acceptance assay log(mean ± SD) disintegrations/min/ng DNA are 70.0 ± 54.8 and 32.4 ± 15.6,respectively,P = 0.040;percent methylation of Sat2 42.2 ± 55.1 and 117.9 ± 88.8,respectively,P < 0.0001 and percent methylation LINE1 48.6 ± 14.8 and 71.7 ± 1.4,respectively,P < 0.0001.Aflatoxin B 1 albumin(AFB 1-Alb) adducts,a measure of exposure to this dietary carcinogen,were inversely correlated with LINE1 methylation(r =-0.36,P = 0.034).CONCLUSION:Consistent hypomethylation in tumor compared to adjacent tissue was found by the three different methods.AFB 1 exposure is associated with DNA global hypomethylation,suggesting that chemical carcinogens may influence epigenetic changes in humans.

Indole Alkaloids from the Roots of Ervatamia hainanensis

Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isolated from Ervatamia hainanensis. Their structures were elucidated on the basis of spectroscopic methods.

Accurate quantification of 3'-terminal 2'-O-methylated small RNAs by utilizing oxidative deep sequencing and stem-loop RT-qPCR

The continuing discoveries of novel classes of RNA modifications in various organisms have raised the need for improving sensitive,convenient,and reliable methods for quantifying RNA modifications.In particular,a subset of small RNAs,including microRNAs(miRNAs)and Piwi-interacting RNAs(piRNAs),are modified at their 3'-terminal nucleotides via 2'-0-methylation.However,quantifying the levels of these small RNAs is difficult because 2'-0-methylation at the RNA 3'-terminus inhibits the activity of polyadenylate polymerase and T4 RNA ligase.These two enzymes are indispensable for RNA labeling or ligation in conventional miRNA quantification assays.In this study,we profiled 3'-terminal 2'-0-methyl plant miRNAs in the livers of rice-fed mice by oxidative deep sequencing and detected increasing amounts of plant miRNAs with prolonged oxidation treatment.We further compared the efficiency of stem-loop and poly(A)-tailed RT-qPCR in quantifying plant miRNAs in animal tissues and identified stem-loop RT-qPCR as the only suitable approach.Likewise,stem-loop RT-qPCR was superior to poly(A)-tailed RT-qPCR in quantifying 3'-terminal 2'-0-methyl piRNAs in human seminal plasma.In summary,this study established a standard procedure for quantifying the levels of 3'-terminal 2'-0-methyl miRNAs in plants and piRNAs.Accurate measurement of the 3'-terminal 2'-0-methylation of small RNAs has profound implications for understanding their pathophysiologic roles in biological systems.

GAS SORPTION,DIFFUSION AND PERMEATION OF ORDERED POLYMERIC MEMBRANES

He, CO_2, O_2, N_2, CH_4, C_3H_8, and t-C_4H_(10) gas permeability coefficients and diffusion coefficients of poly(4-methylpentene-1) (PMP) with various degrees of crystallization were plotted against the degree of crystallization. The plotdemonstrated a linear relationship. The gas permeability coefficient and diffusion coefficient of pure amorphous and purecrystalline PMPs were evaluated by a linear extrapolation to zero and 100% crystallinity, respectively. The relationshipbetween the diffusion coefficient of crystalline parts of PMP and the kinetic diameter of penetrant gases was discussed.Syndiotactic polystyrene (SPS) could exist as δ form crystals complexed with organic solvents such as benzene, toluene,xylene, and ethylbenzene. The mesophase of SPS is prepared by annealing the δ form of crystalline complexes at a certaintemperature for 1 h. The desorption of solvent during annealing almost does not result in changes of both the conformation ofbackbone chains and the crystal lattice. We could prepare the mesophase containing molecular cavities with the size andshape of the organic solvent molecules. The mesophase could sorb the same solvent after the manner of Langmuir sorption atlow vapor pressure range while this would not be the case for solvents of different size and shape. This suggests a molecularrecognition of organic solvent, and mesophase SPS might be useful for separation membrane and adsorptive material.

Screening of chemokine receptor CCR4 antagonists by capillary zone electrophoresis

Abstract CC chemokine receptor 4 （CCR4） is a kind of G-protein-coupled receptor, which plays a pivotal role in allergic inflammation. The interaction between 2-（2-（4-chloro-phenyl）-5-{[（naphthalen-1- ylmethyl）-carbamlyl]-methyl-4-oxo-thiazolidin-3-yl）-N-（3-morpholin-4-yl-propyi）-acetamide （S009） and the N-terminal extracellular tail （ML40） of CCR4 has been validated to be high affinity by capillary zone electrophoresis （CZE）.The S009 is a known CCR4 antagonist. Now, a series of new thiourea derivatives have been synthesized. Compared with positive control S009, they were screened using ML40 as target by CZE to find some new drugs for allergic inflammation diseases. The synthesized compounds XJH-5, XJH-4, XJH-17 and XJH-1 displayed the interaction with ML40, but XJH-9, XJH-10, XJH-I 1, XJH-12, XJH-13, XJH-14, XJH-3, XJH-8, XJH-6, XJH-7, XJH-15, XJH-16 and XJH-2 did not bind to ML40. Both qualification and quantification characterizations of the binding were determined. The affinity of the four compounds was valued by the binding constant, which was similar with the results of chemotactic experiments. The established CEZ method is capable of sensitive and fast screening for a series of lactam analogs in the drug discovery for allergic inflammation diseases.