INNOVATIVE BIOLOGICAL AND CHEMICAL STUDIES OF HERBAL MEDICINES APPLICATION OF MASSLYNX AND UNIFI PLATFORM SOLUTION TO ACCELERATE THE IDENTIFICATION OF INGREDIENTS AND THEIR METABOLITES OF TCM

Traditional Chinese Medicine(TCM)has been used in prevention and treatment of disease in clinical practice for thousands of years,with an indispensable role of multiple ingredients.Thus,a rapid and effective chemical ingredients analysis was of necessary to be established for the evaluation of the holistic quality of TCM.As could afford the data with high resolution and high sensitivity,

Electrochemical and Quantum Chemical Studies of Azoles as Corrosion Inhibitors for Mild Steel in Hydrochloric Acid

The inhibition effect of three azole compounds, 2-aminobenzimidazole（ABM）, 2-aminothiazole（AT） and 2-aminobenzothiazole（ABT）, on the corrosion of mild steel in a 1 mol/L HCI solution was investigated by means of potentiodynamic polarization measurement, electrochemical impedance spectroscopy（EIS） and scanning electron microscopy（SEM）. The correlation between inhibition efficiency and molecular structure of inhibitor was theoretically studied via quantum chemical calculations. The results show that the inhibition efficiency（η） of the inhibitors follows the order of ηABT〉ηAT〉ηABM. Moreover, ABM, AT and ABT belong to mixed-type inhibitors. The adsorption of the inhibitors on the steel surface follows the Langmuir adsorption isotherm, with both physisorption and chemisorption.

STUDIES ON THE CHEMICAL CONSTITUENTS OF CLAUSENA LANSIUM(LOUR.)SKEELS Ⅲ.The structural elucidation of homo-and zeta-clausenamide(1)

The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lactam.

STUDIES ON THE CHEMICAL CONSTITUENTS OF CLAUSENA LANSIUM (LOUR.) SKEELS Ⅳ THE STRUCTURAL ELUCIDATION OF SECO-AND SECODEMETHYL-CLAUSENAMIDE

The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.

LOCALIZED STUDIES ON ELECTRONIC STRUCTURE AND CHEMICAL BOND FOR [NCCuS_2MoS_2]^(2-) CLUSTER

The canonical and locatized molecutar orbiters of [NCCuS_2NoS_2]^(2-) cluster were calculated by means of CNDO quantum chemistry method. Then the energy and properties of corresponding chemicat bonds were discussed, especially, Cu-Sb-No three center conjugated π bonds and No-St-No conjugated π bonds were accounted for.

Study of aquatic chemical characteristic in some bays along the coastal region of Zhejiang Province

In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical elements are obvious. The distribution of silicate in Hangzhou Bay and contents of dissolved oxygen and nutrient in the Xiangshan Bay are found to be unusual in winter. Correlations among the elements are complex. The content of nutrient in the Hangzhou Bay is higher than that in Xiangshan Bay and the content of nutrient in the Xiangshan Bay is higher than that in the Leqing Bay . The variation of the ratio of N/P is obvious. This reflects the aquatic chemical characteristics in the bay. Finally, this paper also discusses the reason why the aquatic chemical characteristics in the bays are unusual.

STUDY ON THE CHEMICAL CONSTITUENTS OF BIDENS BIPINNATA A NEW POLYACETYLENE GLYCOSIDE

A new naturally occurring compound 1-polyacetylene glycoside has been isolated form the n- butanol soluble fraction of the leaves of Bidens bipinnata. The chemical structure of 1 was shown to be 3E, 11E—Diethenylene 5. 7. 9—triacetylene, 1, 13—tridecanglycol-2-O-β-D-glycoside named bipinnatpolyacetyloside according to spectral analyses of UV. IR. FDMS, ~1H-NMR, ~H-~H COSY, ^(13)C-NMR and DEPT.

A study of the chemical composition and transport of marine aerosols over the ocean near China

In this paper the authors cite the aerosol samples collected with a KA-200 Anderson cascade Impactor and a KB-120 sampler during the first cruise of the Kuroshio investigation operated by the People's Republic of China and Japan cooperative program, from July 23 to August 21, 1987. The concentration size distributions and composition of marine aerosols over the Kuroshio area are analyzed. Neutron activation analysis is used to determine the elemental composition of the aerosols. The authors also discuss some characteristics of marine aerosols relating to long-range transport of crustal and anthropogenic elements from the continent to the remote ocean. Analytical results indicate that elements Al, Fe, Sc and Sb over this area are obviously influenced by the continent of Asia, and the size distributions are changed after long-range transport. The concentration of large particles increase. The concentrations of the elements C1 and Na are closely related to ocean conditions; the source of the elements Cl and Na is mainly the ocean. Besides coal combustion, the ocean is also a very important source for the element Se. The amount of Se is related to the distribution of marine life.

A study on chemical forms of heavy metals in the sediments of Zhujiang River and its estuary

The five chemical bound forms of Fe, Al and Mn in sediments in the main channel of the Zhujiang River.and its estuary, namely, exchangeable, carbonic, oxidative, organic and residual (in crystal) forms, were determined. The method of sequential extraction was used for separating the five bound forms.The main chemical form of the three elements in the sediments of the Zhujiang River and its estuarine zone is the residual one. The exchangeable form exists only in a small fraction.Correlationships between the concentration of a certain form of heavy metals and Eh. pH and salinity were discussed. The principles of geochemistry are used to explain the mechanism of heavy metal transport in the river.It was also found that the distribution rule of the chemical forms of Fe, Al and Mn in sediments in the lower reaches of the Zhujiang River was similar to the one in the lower reaches of the Yamaska River.

Pharmacotechnical and Chemical Study of Paracetamol Sold in Kinshasa-DR Congo: Comparative Quality Assessment of Five Brands

Paracetamol/Acetaminophen was assessed in different 5 brands comparatively to study its physicochemical and pharmaceutical parameters. We also evaluated the similarity among those brands. Widely used as an antipyretic and analgesic agent to cure fever and pain, the therapeutic efficacy of this product depends on both physicochemical and pharmaceutical qualities which include its conformity to standard specifications according to the active ingredient dosage in the formulation. This research work aimed to assess comparatively 5 paracetamol brands tablet form sold in the Democratic Republic of the Congo (particularly in Kinshasa), on their physicochemical and pharmaceutical tests conformities compared to the standard specifications. Based on tests, we evaluated the uniformity of weight, disintegration time, friability, crushing strength (hardness), and the active ingredient dosage per brand. The tests were performed using the SotaxTM apparatus according to standard methods following the pharmacopoeia protocols. And according to the performed tests, only the fifth brand of Paracetamol coded P5 did not satisfy the friability test. About the hardness test, we have also observed the unconformity of three brands (P1, P2, and P3) while both P4 and P5 satisfied the test. This leads us to conclude that among all the studied brands, only P5 satisfy to all the tests either pharmacotechnically or chemically (identification and dosage). And this study allowed us to re-examine the equivalence concept between several princeps (original brand) with their generics since that similarity depends on many parameters that need to be improved during the manufacturing process including in-process analysis in all the phases of preparation to evaluate the rate of either active ingredient or inactive ingredient because each component can affect seriously the final pharmaceutical formulation quality.

Theoretical Study on the Electronic Structures of Small Ti_nN_m(n+m=5,6)Clusters

45 isomers of TinNm （n ＋ m = 5, 6） clusters, including linear, some planar and some stero configurations, have been predicted by density functional theory method. For five-atom clusters Ti3N2 and Ti2N3, the most stable structures are trigonal bipyramid in D3h symmetry, and for TiaN cluster, the isomer with one nitrogen atom occupying the center of quasi-tetrahedron is the most stable. In the isomers of Ti4N2 and Ti3N3, the planar networks are more stable, but for Ti2N4, the six-membered ring configuration is the most favorable. Most linear structures can form weak-strong bonds alternately with higher energy. As regards to planar structures, the more Ti-N bonds are formed, the more stable they will be; for stero closed polyhedral isomers, their energies are lower.

Studies on the chemical constituents of Chinese azalea——Ⅰ.The structure of rhodomollein-Ⅰ,a new toxic diterpenoid

Two unknown toxic diterpenoids,rhodomollein-I and rhodompllein-Ⅱ,and the known rhodojaponin-Ⅲ,have been isolated from Chinese azalea (Ericaceae,Rhododendron molle G.Don). rhodomollein-I,C_(20)H_(32)O_6,colorless thin needles,[a]D^(20)-6.65 (c 3.76×10^(-2),EtOH),m.p.241— 242.5℃.Its structure has been established as 1 through spectral analysis of ^(13)C NMR,~1H NMR, MS,IR and UV.Moreover,its stereostructure was unambiguously identified from the different threshold level line of ~1H—~1H NOESY.

Studies on the chemical constituents of the South China Sea sponge Phacellia fusca

Three pyrrololactam alkaloids have been isolated from the marine sponge Phacellia fusca Schmidt collected from the South China Sea,and their structures were determined as 1—3,on the grounds of spectral data.This is the first report of these compounds from this sponge.The structure of 1 was confirmed by X-ray analysis.

Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311++G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311++G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.

Study Raises Concerns Over Chemicals in Household Plastic

在最近进行的尿检中发现:邻苯二甲酸盐(Phthalates)的含量比以前预想的要高。而Phthalates are used as stabilizer(稳定剂)in cosmetics and softeningagents in plastics like polyvinyl([化]乙烯聚合物的)chloride(氯化物)(PVC)。这就值得引起我们的密切注意。 这些毒物残留在人体内时,会导致何种疾病,尚有待探究:The only questionremaining is what types of illnesses might be related to the exposure。然而,有一点是肯定的,我们所熟悉的PVC应该停止使用: In 1997,Greenpeace(保护动物不遭捕猎等的绿色和平组织)testedchildren’s toys and identified five of the seven phthalates mentioned in the currentCDC report.Greenpeace has since called for an international phase out(逐步停止使用)of PVC。

Quantum chemical study on the mechanism of the consecutive addition of HCN to aminoacetonitrile

MINDO/3 method has been used to study the mechanism of the consecutive addition of HCN to aminoacetonitrile.The results obtained for the first three steps show that the reaction is exothermic,and step I is the rate determining step.

CO oxidation on MXene(Mo_(2)CS_(2)) supported single-atom catalyst: A termolecular Eley-Rideal mechanism

Finding transition metal catalysts for effective catalytic conversion of CO to CO_(2)has attracted much attention.MXene as a new 2D layered material of early transition metal carbides,nitrides,and carbo-nitrides is a robust support for achoring metal atoms.In this study,the electronic structure,geometries,thermodynamic stability,and catalytic activity of MXene (Mo_(2)CS_(2)) supported single noble metal atoms (NM=Ru,Rh,Pd,Ir,Pt and Au) have been systematically examined using first-principles calculations and ab initio molecular dynamic (AIMD) simulations.First,AIMD simulations and phonon spectra demonstrate the dynamic and thermal stabilities of Mo_(2)CS_(2)monolayer.Three likely reaction pathways,LangmuirHinshelwood (LH),Eley-Rideal (ER),and Termolecular Eley–Rideal (TER) for CO oxidation on the Ru1-and Ir_(1)@Mo_(2)CS_(2)SACs,have been studied in detail.It is found that CO oxidation mainly proceeds via the TER mechanism under mild reaction conditions.The corresponding rate-determining steps are the dissociation of the intermediate (OCO-Ru_(1)-OCO) and formation of OCO-Ir_(1)-OCO intermediate.The downshift d-band center of Ru1-and Ir_(1)@Mo_(2)CS_(2)help to enhance activity and improve catalytst stability.Moreover,a microkinetic study predicts a maximum CO oxidation rate of 4.01×10^(2)s^(-1)and 4.15×10^(3)s^(-1)(298.15K) following the TER pathway for the Ru_(1)-and Ir_(1)@Mo_(2)CS_(2)catalysts,respectively.This work provides guideline for fabricating and designing highly efficient SACs with superb catalyts using MXene materials.

Mechanism and kinetics study on the ozonolysis reaction of 2,3,7,8-TCDD in the atmosphere

The ozonolysis of 2,3,7,8-tetra-chlorodibenzo-p-dioxin （2,3,7,8-TCDD） is an efficient degradation way in the atmosphere. The ozonolysis process and possible reactions path of Criegee Intermediates with NO and H2O are introduced in detail at the method of MPWB1K/6-31＋G（d,p）//MPWB1K/6- 311＋G（3df,2p） level. In ozonolysis, H2O is an important source of OH radical formation and initiated the subsequent degradation reaction. The Rice-Ramsperger-Kassel-Marcus （RRKM） theory was applied to calculate rate constants with the temperature ranging from 200 to 600 K. The rate constant of reaction between 2,3,7,8-TCDD and 03 is 4.80 × 10^-20 cm3/（mole.sec） at 298 K and 760 Tort. The atmospheric lifetime of the reaction species was estimated according to rate constants, which is helpful for the atmospheric model study on the degradation and risk assessment of dioxin.