Significant Positive Correlation of Plasma BPDE-Albumin Adducts to Urinary 1-Hydroxypyrene in Coke Oven Workers

Objective To investigate the application of BPDE-albumin adducts as monitoring biomarkers for coke oven workers exposed to polycyclic aromatic hydrocarbons （PAHs） and to explore possible relationship between BPDE-albumin adducts and urinary 1-hydroxypyrene （1-OHP） levels in them. Methods Thirty-seven coke oven workers from a coke plant and 47 controls without the occupational exposure to PAHs were recruited in this study. The levels of plasma BPDE-albumin adducts and urinary 1-OHP were analyzed using high performance liquid chromatography. Results The median levels of BPDE-albumin adducts （42.10 fmol/mg albumin） and urinary 1-OHP （5.46 μmol/mol creatinine） were significantly higher in coke oven workers than in controls （14.16 fmol/mg albumin, 2.96μmol/mol creatinine, respectively; P〈0.01）. Multiple logistic regression analysis showed that coke oven workers were at higher risk of having BPDE-albumin adduct levels above 25.30 μmol/mg albumin （OR=1.79, P〈0.01） and urinary 1-OHP levels above 4.13 μmol/mol creatinine （OR=2.45, P〈0.05）. There was a positive correlation between the levels of BPDE-albumin adducts and urinary 1-OHP in all subjects （rs=0.349, P〈0.01）. Conclusion BPDE-albumin adduct is a useful biomarker for monitoring long-term exposure to PAHs, and plasma BPDE-albumin adducts level is significantly correlated to urinary 1-OHP levels in coke oven workers.

Chem oprevention of 2-amino-1-methyl-6-phenyli-midazo[4,5-b]pyridine-induced carcinogen-DNA adducts by Chinese cabbage in rats

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Synthesis and Crystal Structure of New Supramolecular Adducts of[PtCl_6]^(2-) with Cucurbit [7] uril:[(H_3O)_2 [PtCl_6]_3 [C_(42)H_(42)N_(28)O_ (14)_2·H_2O

A novel supramolecular adduct 3(C 42H 42N 28O 14) 2·H 2O (1) was synthesized by mixing 2- and cucurbit uril in solution of hydrochloric acid. The crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system and space group F dd2 with cell dimensions: a=4.705 33 (5) nm, b=7.153 80 (6) nm, c= 1.894 61 (2) nm, Z=16, V=63.7744 (11) nm3, D c= 1.534 g/cm3, μ=3.007 mm -1, F(000)=29 120, R 1= 0.070 7, wR 2=0.169 2. In crystal, the cucurb uril molecules form two zig-zag chains.

GSTM1 and XRCC3 Polymorphisms:Effects on Levels of Aflatoxin B1-DNA Adducts

Objective： Aflatoxin B1 （AFB1）, which can cause the formation of AFB1-DNA adducts, is a known human carcinogen. AFB1-exposure individuals with inherited susceptible carcinogen-metabolizing or repairing genotypes may experience an increased risk of genotoxicity. This study was designed to investigate whether the polymorphisms of two genes, the metabolic gene Glutathione S-transferase M1 （GSTM1） and DNA repair gene x-ray repair cross-complementing group 3 （XRCC3）, can affect the levels of AFB1-DNA adducts in Guangxi Population （n= 966） from an AFB1-exposure area. Methods： AFB1-DNA adducts were measured by ELISA, and GSTM1 and XRCC3 codon 241 genotypes were identified by PCR-RFLP. Results： The GSTM1-null genotype [adjusted odds ratio （OR） = 2.09; 95% confidence interval （CI） = 1.61-2.71] and XRCC3 genotypes with 241 Met alleles [i.e., XRCC3-TM and -MM, adjusted ORs （95% CI） were 1.43 （1.08-1.89） and 2.42 （1.13-5.22）, respectively] were significantly associated with higher levels of AFB1-DNA adducts. Compared with those individuals who did not express any putative risk genotypes as reference （OR = 1）, individuals featuring all of the putative risk genotypes did experience a significantly higher DNA-adduct levels （adjusted ORs were 2.87 for GSTM1-null and XRCC3-TM; 5.83 for GSTM1-null and XRCC3-MM）. Additionally, there was a positive joint effect between XRCC3 genotypes and long-term AFB1 exposure in the formation of AFB1-DNA adducts. Conclusion： These results suggest that individuals with susceptible genotypes GSTM1-null, XRCC3-TM, or XRCC3-MM may experience an increased risk of DNA damage elicited by AFB1 exposure.

Facile and Stereoselective Synthesis of N-Substituted Benzotriazole with Baylis-Hillman Adducts

A convenient method has been developed toward the stereoselective synthesis of N-substituted benzotriazole derivatives under mild conditions. The good stereolectivity, high yields and the simple procedure make the present protocol attractive.

Theoretical Investigation of Detailed Thermodynamic Character of Possible Difunctional Adducts Model

The B3LYP/6-31G^＊ level of theory was used to optimize trans-[Pt（NH3）（Am）G-L], where Am = quinoline or thiazole and L is chosen as the model for functional groups of peptide side chains, and for adenine and guanine sites of DNA as the ultimate target of platinum anticancer drugs. Bond dissociating energy and stability energy of complexes are chosen to study detailedly thermodynamic character of possible difunctional adducts model. In order to investigate the influence of a polarizable environment on the energy of the Pt-L bond formation, we adopt a new bonding energy formula brought forward by Lippard and his coworkers： △H（Sol） = △H（SCF） ＋ △G（Solv）, which is quite appropriate to compare with what is found in experimental studies. Our calculated results demonstrate that N-containing ligands are more favored in view of thermodynamics both in gas phrase and in solution. However, it is worthly to be noted that addition of solvation free energies result in moderate correction of bonding energy in relative ordering, and the largest ones both present in imidazole ligand, not in guanine ligand. Finally, the nature of bond is analyzed in terms of partial charges distribution based on NBO population.

CO_(2) Adducts of the Amino and Imino Groups Studied by ~1HNMR and ^(13)CNMR

CO2 adducts of L-(+)-asparaginic acid and some polyhydroxylated alkaloids was studied by 1HNMR and 13CNMR in this paper.

Non-covalent Bonded 3D Supramolecular Architectures Based on Acid-base Adducts

Two novel acid-base adducts,[H2L1^2＋]（Hpbda）2（1,L1 = 1,4-di（lH-imidazol-4-yl）benzene,H2pbda = 1,4-benzenedicarboxylic acid） and[H2L2^2＋]（NO3）2（2,L2 = l,4-di（l-carboxymethyl-imidazol-4-yl）benzene）,have been prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy and elemental analysis.Compound 1 crystallizes in monoclinic,space group P21/n with a = 5.3525（11）,b = 9.1471（19）,c = 19.314（4） ？,β = 92.342（3）°,V= 944.8（3） A°3,Z = 2,C16H16N6O（10）,Mr = 452.35,Dc = 1.590 g/cm^3,μ = 0.135 mm^-1,S = 1.058,F（000） = 468,the final R = 0.0661 and wR = 0.1887 for 2298 observed reflections（I〉 2σ（I））.Compound 2 crystallizes in monoclinic,space group P21/c with a = 9.6923（10）,b = 17.2950（17）,c = 7.1880（7） ？,β =94.801（2）°,V= 1200.7（2）A°3,Z = 2,C（28）H（22）N4O8,Mr = 542.50,Dc = 1.501 g/cm^3,μ = 0.112 mm^-1,S= 1.060,F（000） = 564,the final R = 0.0394 and wR = 0.1017 for 2768 observed reflections（I 〉2σ（I））.In the title compounds,both of L1 and L2 ligands act as weak base to accept protons to exhibit diprotonated H2L1^2＋ and H2L2^2＋ form,which can effectively employ as hydrogen bonding donors to combine anion moieties to form binary adducts respectively.In the crystal packing diagram of two polymers,there exist extensive noncovalent interactions including charge-transfer interactions,C（N）-H…π and N-H…O,C-H…O,O-H…O hydrogen bonding interactions between co-crystal moieties which consolidate the structures of supramolecular polymers,thus generating three-dimensional（3D） frameworks.

Active Oxygen Radical Scavenging Ability of Water-Soluble β-Alanine C_(60) Adducts

Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.

Four New Phloroglucinol-Terpene Adducts from the Leaves of Myrciaria cauliflora

Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria cauliflora.Their structures with absolute configurations were elucidated by combination of spectroscopic analysis,single crystal X-ray diffraction,and electronic circular dichroism(ECD)calculations.Compound 1 was a rearranged isobutylphloroglucinol-pinene adduct featuring an unusual 2,3,4,4a,10,11-hexahydro-1H-3,11a-methanodibenzo[b,f]oxepin backbone.Compound 4 showed moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.

Biological transformation,kinetics and dose-response assessments of bound musk ketone hemoglobin adducts in rainbow trout as biomarkers of environmental exposure

Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other environment.Thus,aquatic organisms can be continuously exposed to MK.In this study,kinetics and dose-response assessments of 2-amino-MK (AMK) metabolite,bound to cysteine-hemoglobin (Hb) in rainbow trout,formed by enzymatic nitro-reduction of MK have been demonstrated.Trout were exposed to a single exposure of 0.010,0.030,0.10,and 0.30 mg MK/g fish.Tw...

Analysis of styrene oxide-hemoglobin adducts at different binding sites

An assay was described for measures of adducts of styrene oxide (SO) with molecules of hemoglobin(Hb) which have been modified at residues containing either carboxylic acid or sulfhydryl groups. The method employs two steps. In the first, SO carboxylic acid adducts are hydrolyzed in basic medium to liberate styrene glycol(SG). Then, the remaining residues are reacted with a reductive catalyst (Raney nickel) to liberate the two positional isomers of SO cysteine adducts, i.e., 1 phenylethanol (1 PE) and 2 phenylethanol (2 PE). The liberated products are derivatized with pentafluorobenzoyl chloride and measured by GC NICI MS. The assay was evaluated with SO adducts of Hb which had been produced in the blood of Sprague Dawley rats following (a) in vitro modification(0—300m mol/L SO) or (b) i.p administration of either SO(0—1 mmol/kg) or styrene (0—3 mmol/kg). Levels of each of the three analytes (SG, 1 PE, and 2 PE) increased with dose in hemoglobin. The ratios of cysteine adducts to carboxylic acid adducts varied significantly among experiments. Ratios of 2 PE to 1 PE were much more consistent (2 PE/1 PE=6.9 (SE=1.5)) suggesting that binding of SO to cysteine residues of blood proteins is greatly preferred at the α position rather than the β position both in vitro and in vivo. The lowest detectable adduct concentration, using 10 mg of protein, was 8 pmol/g protein for SG,5 pmol/g protein for 1 PE, and 0.6 pmol/g protein for 2 PE. No significant change of adduct level was found during storage of proteins at -80℃ for 1 year.

Improved preparation and identification of aristolochic acid-DNA adducts by solid-phase extraction with liquid chromatography-tandem mass spectrometry

Aristolochic acid （AA） is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2′-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction （SPE）, and further purified by a reversed-phase high performance liquid chromatography （HPLC）. By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity （more than 94% as indicated by HPLC） were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry （LC-ESI-Q-TOF-MS/MS） and LC-Diode array detector-fluorescence （LC-DAD-FL） analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.

Theoretical Study of Nonclassical Platinum Complexes Bonding to Purine Bases: How the Long-lived Monofunctional Adducts Can Be in Existence?

The B3LYP/6-31G^＊ level of theory was used for the optimization of nonclassical platinum drugs with planar aromatic heterocycle ligands in addition to their monoaqua species, diaqua species and monofunctional adducts. Single point calculations were performed on optimized geometries using the MP2/6-31G^＊＊ method, and the Lanl2dz pseudo potential for the Pt atom remained constant in all calculations. It can be easily seen that the trans effect can influence both geometrical structures and bond dissociating energies （BDEs）. On the basis of our calculation, we get that the long-lived monofunctional adducts with chloride ligand may be in existence, because they possessed higher stability energies, easily dissociated chloride compared with the monoaqua species dissociating chloride and that replacement of the first chloride by bases became exothermic in solution. Our calculated results also demonstrate that the strongest H-bonds appear in the complexes of q-wG and t-wG using different methods. In comparison with adenine complexes, the corresponding guanine complexes possess larger interaction energies as well as higher stability energies either corrected by basis set superposition error （bsse） of Boys-Bernardi counterpoise method or uncorrected both in gas phase and in solution with one exception that the stability energy of q-CIA complex in solution is larger than that of q,CIG complex. Finally, the nature of bond was analyzed in terms of partial charges distribution based on NBO population.

Synthesis and Crystal Structure of 3-Nitrophthalic Acid·3-methyl-4-nitropyridine N-Oxide Adducts

The title compound, a 1：1 molecular adduct of 3-nitrophthalic acid and 3-methyl- 4-nitropyridine N-oxide （PPOM）, has been synthesized and characterized by X-ray single-crystal structure analysis. It crystallizes in triclinic, space group PI with α = 7.6076（15）, b = 7.8180（16）, c = 14.546（3）A, α= 93.90（3）, β = 97.21（3）, γ= 114.43（3）°, C14H1N3O9, Mr = 365.26, Z = 2, V = 774.6（3） A^3, Dc = 1.566 g/m^3,μ（MoKa） = 0.134 mm^-1, F（000） = 376, R = 0.0538 and wR = 0. 1460 for 885 observed reflections （1 〉 2σ（I））. The protons of the carbonylic acids in the molecule are not transferred and the O-H…O and C-H…O hydrogen bonds form zigzag chains in the molecule.

Chlorine-radical Induced Oxidation of Glyoxal and Glyoxal-S(IV) Adducts in the Aqueous Phase

A laser flash photolysis study of the reactivity of Cl˙with glyoxal, glyoxal mono- and dibisulfite adducts, 1-hydroxy-2, 2-diol-ethanesulfonate and 1, 2-dihydroxy-1, 2-ethanedi sulfonate in the aqueous phase was carried out. The obtained rate constants can be used for atmospheric modeling.

Pre-Chelates, Post-Adducts and Implexes: A perspective proposal for the future of medicinal chemistry

The title of this little assay coins three new words: Pre-Chelates, Post-Adducts and Implexes. These, very daring new excursions into the scientific English language, come from the developments of Quelamycin and Sodium L-Thioproline, through our different group studies arriving to cancer reversal by a dual strategy. It is enough to read all our published materials, cites and related papers, dealing more or less with the chemistry and possible mechanism of action of these compounds, to gather somewhat what signified our monomeric-triferric-doxorubicine, as possibly one of the first Pre-Chelates and our Sodium L-Thioproline, probably as one of the first Post-Adducts. Both molecules come to the human patients with cancer blood from the exterior. After this indication, it will be proposed a seed concept of a new type of molecules, the “Implexes” in which the metals will be embraced instead of being linked.

Review: Adducts and Clusters in Chromatography, Mass Spectrometry and Nature

The word “clusters” in scientific terminology as aggregated molecules or atoms appeared in chemistry relatively recently. The terms clusters have been used intensively since the discovery of fullerenes. The term cluster is not a new one for other branches of science such as astrophysics-star cluster, globular cluster, galaxy cluster, in biology and medicine-cancer cluster, genetic cluster, or in computing-data cluster. Adducts in chemistry were known significantly earlier. Both clusters and adducts are assemblies of atoms or molecules that are held together by weak van der Waals or London dispersion forces. Clusters are homogeneous and usually consist of one sort of atom or molecule. Clusters can also be a host for other types of atoms or molecules. Adducts usually consist of two different types of molecules, one of which is the host molecule. Both clusters and adducts are well defined by IUPAC. The present short review describes some important phenomena of these intriguing associations, which have interest for chemical extraction, separation, analysis, and for nature in general.

Thermochemical Parameters of Tetramethylthiourea Adducts of Certain Metal(II) Bromides

Complexes of the general formula [MBr2(TMTU)n] (where M is Mn, Fe, Co, Ni, Cu, Zn or Cd;TMTU is Tetramethylthiourea;n is 0.75, 2 or 3) were obtained by the reaction of salts and ligand in solution. The bromides were selected among several other salts because they had thermochemical data in the literature. Properties as capillary melting points;C, H, N, Br and metal contents;TG/DTG and DSC curves;and IR and electronic spectra were determined. The values of several thermodynamic parameters for the complexes were found by solution calorimetry. From them, the standard enthalpies of the metal-sulphur coordinated bonds were calculated. The standard enthalpies of the formation of the gaseous phase adducts also were estimated.