Hydroxyl Methyl Research Articles

Identifying Drugs that Bind Selectively to Intersubunit General Anesthetic Sites in the α1β3γ2 GABAAR Transmembrane Domain

GABAA receptors (GABAARs) are targets for important classes of clinical agents (e.g., anxiolytics, anticonvulsants, and general anesthetics) that act as positive allosteric modulators (PAMs). Previously, using photoreactive analogs of etomidate ([3H]azietomidate) and mephobarbital [[3H]1-methyl-5-allyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid ([3H]R-mTFD-MPAB)], we identified two homologous but pharmacologically distinct classes of general anesthetic binding sites in the α1β3γ2 GABAAR transmembrane domain at β +-α - (β + sites) and α +-β -/γ +-β - (β - sites) subunit interfaces. We now use competition photolabeling with [3H]azietomidate and [3H]R-mTFD-MPAB to identify para-substituted propofol analogs and other drugs that bind selectively to intersubunit anesthetic sites. Propofol and 4-chloro-propofol bind with 5-fold selectivity to β +, while derivatives with bulkier lipophilic substitutions [4-(tert-butyl)-propofol and 4-(hydroxyl(phenyl)methyl)-propofol] bind with ∼10-fold higher affinity to β - sites. Similar to R-mTFD-MPAB and propofol, these drugs bind in the presence of GABA with similar affinity to the α +-β - and γ +-β - sites. However, we discovered four compounds that bind with different affinities to the two β - interface sites. Two of these bind with higher affinity to one of the β - sites than to the β + sites. We deduce that 4-benzoyl-propofol binds with >100-fold higher affinity to the γ +-β - site than to the α +-β - or β +-α - sites, whereas loreclezole, an anticonvulsant, binds with 5- and 100-fold higher affinity to the α +-β - site than to the β + and γ +-β - sites. These studies provide a first identification of PAMs that bind selectively to a single intersubunit site in the GABAAR transmembrane domain, a property that may facilitate the development of subtype selective GABAAR PAMs.

Natural flavonoid α-glucosidase inhibitors from Retama raetam: Enzyme inhibition and molecular docking reveal important interactions with the enzyme active site

Retama raetam (Forsk.) Webb & Berthel plant has been traditionally used for the treatment of diabetes mellitus and hypertension. Interest in the medicinal chemistry of the plant in the past resulted in the isolation of a number of compounds with anti-hyperglycemic activity. The current work is a further extension of our recent work in which we isolated and characterized seven new flavonoids from Retama raetam with preliminary biological activity screening. It addresses the α-glucosidase inhibitory activity and molecular docking studies of the flavonoids. Retamasin D, G, H, and erysubin A and B noncompetitively inhibited the enzyme whereas retamasin C and F exhibited competitive inhibition. Moreover, retamasin C, F, G, and erysubin A and B carry dual activity in addition to α-glucosidase inhibition. Our previous studies have shown that they also caused significant stimulation of insulin from the blood-perfused pancreatic islets of Langerhans of mice. The C6 and C8 substituent groups greatly influenced the inhibition potency of the compounds. The most potent inhibitor was retamasin H with the γ-lactone ring substituent at C6 position of the main flavonoid moiety. Notable active chemical groups in the target compounds include γ-lactone, dihydropyran and dihydrofuran rings with hydroxyl and geminal methyl groups. Molecular modeling studies revealed that the compounds fit well in the α-glucosidase active site by interacting with important active site residues. These findings will incorporate new chemical, structural and functional diversity to the search and drug development of α-glucosidase inhibitors as anti-diabetic drugs.

Stereochemical Insights into the Anaerobic Degradation of 4-Isopropylbenzoyl-CoA in the Denitrifying Bacterium Strain pCyN1.

The constitutions and absolute configurations of two previously unknown intermediates, (1S,2S,4S)-2-hydroxy-4-isopropylcyclohexane-1-carboxylate and (S)-3-isopropylpimelate, of anaerobic degradation of p-cymene in the bacterium Aromatoleum aromaticum pCyN1 are reported. These intermediates (as CoA esters) are involved in the further degradation of 4-isopropylbenzoyl-CoA formed by methyl group hydroxylation and subsequent oxidation of p-cymene. Proteogenomics indicated 4-isopropylbenzoyl-CoA degradation involves (i) a novel member of class I benzoyl-CoA reductase (BCR) as known from Thauera aromatica K172 and (ii) a modified β-oxidation pathway yielding 3-isopropylpimeloyl-CoA analogously to benzoyl-CoA degradation in Rhodopseudomonas palustris. Reference standards of all four diastereoisomers of 2-hydroxy-4-isopropylcyclohexane-1-carboxylate as well as both enantiomers of 3-isopropylpimelate were obtained by stereoselective syntheses via methyl 4-isopropyl-2-oxocyclohexane-1-carboxylate. The stereogenic center carrying the isopropyl group was established using a rhodium-catalyzed asymmetric conjugate addition. X-ray crystallography revealed that the thermodynamically most stable stereoisomer of 2-hydroxy-4-isopropylcyclohexane-1-carboxylate is formed during p-cymene degradation. Our findings imply that the reductive dearomatization of 4-isopropylbenzoyl-CoA by the BCR of A. aromaticum pCyN1 stereospecifically forms (S)-4-isopropyl-1,5-cyclohexadiene-1-carbonyl-CoA.

Identification, isolation and elucidation of compounds from fraction of methyl hydroxyl chalcone polymer from aqueous extract of Cinnamomum Zeylaynicum

Identification, isolation and elucidation of compounds from fraction of methyl hydroxyl chalcone polymer from aqueous extract of Cinnamomum Zeylaynicum

Novel tris-buffer based Schiff base bearing long flexible alkoxy arm and its lanthanide complexes: Mesomorphism and photoluminescence

A new liquid crystalline salicylaldimine Schiff base having pendant hydroxymethyl (CH2OH) groups and a series of lanthanide(III) complexes of the type, [Ln(LH)3(NO3)3] {Ln = La, Pr, Sm, Gd, Tb; LH=(E)-2-((1, 3-dihydroxy-2-(hydroxyl methyl) propan- 2-ylimino)methyl)-5-(hexadecyloxy) phenol} have been synthesised. The compounds were characterised by FT-IR, 1H NMR, 13C NMR, UV–Vis, and FAB-mass spectroscopy. Thermal behaviour of these compounds was studied using polarising optical microscopy (POM) and differential scanning calorimetry. The phase confirmation and molecular organization in the mesophase was ascertained by variable temperature powder X-ray diffraction (XRD) study. The ligand and the complexes both showed highly viscous smecticA and columnar mesophase, respectively. A bilayer self organization of the ligand molecules with interdigitation of the alkyl chains in the mesophase is proposed. Molecular organizations of the complexes in the mesophase involve arrangement of all the aliphatic chain pointing in same direction leading to lamellar columnar phase. The ligand showed an intense blue emission at 452 nm while the gadolinium(III) complex exhibited an intense emission at 458 nm (λex = 310 nm). The samarium(III) complex is a bright orange light emitter over a wide range upon UV irradiation.

EFFECT OF RUMEN-PROTECTED LYSINE (HYDROXY METHYL LYSINE) SUPPLEMENTATION ON PERFORMANCE AND BLOOD METABOLITES IN BARKI SHEEP

Effect of rumen-protected lysine in the form of Hydroxyl methyl lysine (HML) on average daily gain (ADG), dry matter intake (DMI), nutrient digestibility, nitrogen balance blood metabolites, were evaluated in two experiments using growing Barki lambs. In first experiment, fifteen lambs were housed individually and assigned into three equal groups fed on basal diet (no lysine-control), free lysine (positive control, F-LYS) and protected lysine (P-LYS) equivalent to 3 g/d of lysine. The experiment lasted for 10 week to evaluate feed intake, ADG and blood metabolites. No effect (P>0.05) of treatment on ADG, DMI and feed efficiency was observed. Whereas, treatment × time interaction tendency (P=0.07) as showed an increased in ADG as lysine supplemented as P-LYS compared to F-LYS (P=0.05) and control (P 0.05) of treatment was observed on serum total protein (TP), albumin (Alb), globulin (Glob), urea, glucose (G), cholesterol (CH) and triglycerides (TG) concentrations. However, treatment × time interaction (P=0.06) tendency existed as P-LYS increased (P 0.05) was found on rumen ammonia nitrogen (NH3-N), pH and protozoa numbers. In Exp.2, (digestibility trial), twelve lambs from Exp.1 were kept in metabolic cages and received their respective treatments for 7 days as collection period. No response (P>0.05) to P-LYS supplementation was observed on nutrient digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) compared to F-LYS and control. A tendency (P=0.09) for treatment on nitrogen balance (NB) and retained nitrogen (RN, P=0.06) was found. P-LYS increased (P=0.05) NB to 7.1±0.14 vs. 4.8±0.3g/d and RN (P<0.05) from 37.9 vs. 25.59% in the control. However, P-LYS did not improve lambs performance under the basal diet fed that might have not been deficient enough in LYS amino acid, the improved ADG and decreased plasma urea at the last two weeks along with the slight improvement in NB and RN indicates the P-LYS has a potential under specific feeding regimes.

α-Amine Desaturation of d-Arginine by the Iron(II)- and 2-(Oxo)glutarate-Dependent l-Arginine 3-Hydroxylase, VioC.

When challenged with substrate analogues, iron(II)- and 2-(oxo)glutarate-dependent (Fe/2OG) oxygenases can promote transformations different from those they enact upon their native substrates. We show here that the Fe/2OG enzyme, VioC, which is natively an l-arginine 3-hydroxylase, catalyzes an efficient oxidative deamination of its substrate enantiomer, d-Arg. The reactant complex with d-Arg retains all interactions between enzyme and substrate functional groups, but the required structural adjustments and opposite configuration of C2 position this carbon more optimally than C3 to donate hydrogen (H•) to the ferryl intermediate. The simplest possible mechanism, C2 hydroxylation followed by elimination of ammonia, is inconsistent with the demonstrated solvent origin of the ketone oxygen in the product. Rather, the reaction proceeds via a hydrolytically labile C2-iminium intermediate, demonstrated by its reductive trapping in solution with NaB2H4 to produce racemic [2H]Arg. Of two alternative pathways to the iminium species, C2 hydroxylation followed by dehydration versus direct desaturation, the latter possibility appears to be more likely, because the former mechanism would be expected to result in detectable incorporation of 18O from 18O2. The direct desaturation of a C-N bond implied by this analysis is analogous to that recently posited for the reaction of the l-Arg 4,5-desaturase, NapI, thus lending credence to the prior mechanistic proposal. Such a pathway could also potentially be operant in a subset of reactions catalyzed by Fe/2OG N-demethylases, which have instead been purported to enact C-N bond cleavage by methyl hydroxylation and elimination of formaldehyde.

Biotransformation of Artemisinin to 14-Hydroxydeoxyartemisinin: C-14 Hydroxylation by Aspergillus flavus.

The biotransformation of the front-line antimalarial drug, artemisinin (1) by the filamentous fungus Aspergillus flavus MTCC-9167 was investigated. Incubation of compound 1 with A. flavus afforded a new hydroxy derivative (2) along with three known metabolites (3-5). The new compound was characterized as 14-hydroxydeoxyartemisinin (2) by extensive spectroscopic data analysis (IR, 1H and 13C NMR, HSQC, HMBC, COSY, NOESY, and HR-ESIMS). The known metabolites were identified as deoxyartemisinin (3), artemisinin G (4), and 4α-hydroxydeoxyartemisinin (5). This is the first report of hydroxylation of a secondary methyl of artemisinin at C-14 by the fungus A. flavus, which is synthetically not accessible. In addition, these compounds were evaluated for their in vitro antiplasmodial activity. Artemisinin G (4) exhibited IC50 values in the submicromolar range, which was better than those of the nonperoxidic metabolites.

Effect of heat treatment on hydrophobic silica aerogel.

Hydrophobic silica aerogels were heat treated under various conditions. Physical and chemical analyses were conducted to study the effect of the heat treatments on the silica aerogels. The O/Si and C/Si values in the hydrophobic silica aerogels increased and decreased, respectively, with the increase in the heating temperature. C-O, -OH, and CO were detected during pyrolysis. Pyrolysis of the silica aerogels in air could be divided into 3 steps: the hydroxylation of methyl groups, the splitting of the alcoholic hydroxyl, and the oxidisation of CO. When the heat treatment temperature was lower than 350 °C, the properties of the silica aerogels showed little change. With further increase in the heat treatment temperature, the variation in the relevant parameters became more prominent. The secondary particles coalesced with one another, and the mesopores were destroyed. Consequently, the thermal conductivity and bulk density rose greatly. The carbon within the silica aerogels was released after heat treatment. As a result, the heat released in the thermal gravimetry and oxygen bomb analyses dropped remarkably with the increase in the heat treatment temperature.

Quantitative structure-activity relationship for estrogenic flavonoids from Psoralea corylifolia

A combination of in vitro and in silico approaches was employed to investigate the estrogenic activities of flavonoid compounds from Psoralea corylifolia. In order to develop fluorescence polarization (FP) assay for flavonoids, a soluble recombinant protein human estrogen receptor α ligand binding domain (hERα-LBD) was produced in Escherichia coli strain. The competition binding experiment was performed by using coumestrol (CS) as a tracer. The result of FP assay suggested that the tested flavonoids can bind to hERα-LBD as affinity ligands, except for corylin. Then, molecular modeling was conducted to explore the binding modes between hERα-LBD and flavonoids. All the tested compounds fit into the hydrophobic binding pocket of hERα-LBD. The hydrophobic and hydrogen-bonding interactions are dominant forces to stabilize the flavonoids-hERα-LBD binding. It can be speculated from molecular docking study that the hydroxyl groups and prenyl group are essential for flavonoid compounds to possess estrogenic activities. Both methylation of hydroxyl group and cyclization of prenyl group significantly diminish the estrogenic potency of flavonoids. Furthermore, quantitative structure-activity relationship (QSAR) analysis was performed by the calculated binding energies of flavonoids coupled with their determined binding affinities. Comparison between the docking scores and the pIC50 values yields an R-squared value of 0.9722, indicating that the estrogenic potency of flavonoids is structure-dependent. In conclusion, molecular docking can potentially be applied for predicting the receptor-binding properties of undescribed compounds based on their molecular structure.

Enhanced mineralization of dimethyl phthalate by heterogeneous ozonation over nanostructured Cu-Fe-O surfaces: Synergistic effect and radical chain reactions

Cu-Fe-O nanoparticles (CFO NPs), synthesized with zero-valent iron (ZVI) and Cu(NO3)2 as the metal precursors, were used to enhance ozonation to degrade dimethyl phthalate (DMP). Great DMP degradation and mineralization rates were achieved in a wide range of the initial pH values (3–9); the amount of OH in catalytic ozonation was much higher than that of O3 alone at the initial pH of 5.70. The generation of hydroxyl radicals (OH), methyl radicals (CH3) and superoxide radicals (O2−) were identified and OH mainly contributed to DMP removal. The potential of Fe(III)/Fe(II) and Cu(II)/Cu(I) cycles have largely been overlooked, which was found to be the key for producing more OH in CFO/O3 system. The underlying mechanisms were probably initiated by a chain reaction: initiated O3 reaction with Cu(I)/Fe(II)OH to form OH and O2−, accelerated reaction between Cu(II)/Fe(III) and the in situ generated O2− with a relatively high reaction constant, redox reaction between Cu(I) and Fe(III), OH oxidizing reaction with DMP to produce CH3. In addition, different degradation pathways of DMP were proposed based on the intermediates in the presence of CH3. This study sheds new light on the specific radical chain reaction mechanisms of catalytic ozonation.

Mechanistic Study of the Reactions of Methyl Peroxy Radical with Methanol or Hydroxyl Methyl Radical.

An ab initio and direct dynamic study of the reactions of CH3O2 + CH3OH and CH3O2 + CH2OH has been carried out over the temperature range of 300-1500 K. All stationary points were calculated at the MP2/aug-cc-pVTZ level of theory for CH3O2 + CH3OH or at the M06-2X/MG3S level of theory for CH3O2 + CH2OH and identified for the local minimum. The energetic parameters were refined at the QCISD(T)/cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels of theory. For the reaction of CH3OO + CH3OH, two hydrogen abstraction channels producing CH3OOH + CH2OH (R1) and CH3OOH + CH3O (R2) were confirmed. These two channels consist of the same reversible first step involving the formation of a prereactive complex in the entrance channel. The rate constants of these two channels have been calculated by canonical transition station theory (TST) and canonical variational transition station theory (VTST) with Eckart tunneling correction and compared with the available literature data. The positive temperature dependence of the rate constants was observed. The tunneling effect is important at low temperature and decreases with an increase of the temperature. The contribution of R1 to the total rate constant is dominant, with branching ratios of 0.93 at 500 K and 0.67 at 1000 K, although the branching ratio for R2 increases dramatically with the increase of the temperature from 500 K. For the reaction of CH3OO + CH2OH, eight channels were explored on the lowest singlet and triplet surfaces, and an excited intermediate was found to be formed on the singlet surface. A channel proceeding through the formation of an excited intermediate followed by its impulsive dissociation was confirmed as the dominant channels with a branching ratio more than 0.99 in the temperature range of 300-1500 K, where products of CH3O and OCH2OH were given. The rate constant of the dominant channel calculated by multichannel RRKM-VTST is comparable with the available literature data.

A combined computational and experimental study on selective flucloxacillin hydroxylation by cytochrome P450 BM3 variants

The 5′-hydroxymethyl metabolite of the penicillin based antibiotic flucloxacillin (FLX) is considered to be involved in bile duct damage occurring in a small number of patients. Because 5′-hydroxymethyl FLX is difficult to obtain by organic synthesis, biosynthesis using highly active and regioselective biocatalysts would be an alternative approach. By screening an in-house library of Cytochrome P450 (CYP) BM3 mutants, mutant M11 L437E was identified as a regioselective enzyme with relatively high activity in production of 5′-hydroxymethyl FLX as was confirmed by mass spectrometry and NMR. In contrast, incubation of M11 L437E and other mutants with oxacillin (OX, which differs from FLX by a lack of aromatic halogens) resulted in formation of two metabolites. In addition to 5′-hydroxymethyl OX we identified a product resulting from aromatic hydroxylation. In silico studies of both FLX and OX with three CYP BM3 mutants revealed substrate binding poses allowing for 5′-methyl hydroxylation, as well as binding poses with the aromatic moiety in the vicinity of the heme iron for which the corresponding product of aromatic hydroxylation was not observed for FLX. Supported by the (differences in) experimentally determined ratios of product formation for OX hydroxylation by M11 and its L437A variant and M11 L437E, Molecular Dynamics simulations suggest that the preference of mutant M11 L437E to bind FLX in its catalytically active pose over the other binding orientation contributes to its biocatalytic activity, highlighting the benefit of studying effects of active-site mutations on possible alternative enzyme-substrate binding poses in protein engineering.

Quality evaluation of Omani honey

This study was intended to evaluate the quality parameters of 58 Apis mellifera honey samples, from different regions in the Sultanate of Oman. Physicochemical analyses were carried out and examined according to the Gulf Standardization Organization (GSO).The results revealed that 64.4% of the samples were failing to meet the GSO standards due to acidity, hydroxyl methyl furfural (HMF), diastase, sucrose, and glucose & fructose. Acidity and HMF were above the limits in 30% and 29% of the failed samples respectively, where diastase and total glucose & fructose were below the limits in 25% and 5% respectively. Sucrose was above the limits in 11% of the failed samples.The unconformity of the analyzed honey samples to GSO standards could be due to stage of harvesting, process and storage conditions. Therefore, it’s important to reconsider the whole process of honey production in Oman in order to improve the technology and honey quality.

Rheological and breaking studies of a novel single-phase surfactant-polymeric gel system for hydraulic fracturing application

Fewer studies have dealt with the interactions between polymer gel and surfactant fluids and their applications in hydraulic fracturing as a mutual system. Conventional polymer fracturing fluids employed in the early decades exhibited residue deposition within the fracture while surfactant fluids with lower thermal stability have been inefficient in stimulating hydrocarbon production, urging the need for an improved fluid system with improved rheology, proppant carrying capacity, lower fluid loss and better post-fracture cleanup. In this paper, a novel fracturing fluid is synthesized by combining a polymer gel system (carboxy methyl hydroxyl propyl guar-CMHPG) and a surfactant based viscoelastic fluid (sodium oleate-an anionic surfactant) and it is reported to have improved properties due to the synergistic effects of the dual systems at slightly reduced polymer loading. The microemulsion gel region was identified by preparing the pseudo-ternary phase diagram and the optimum gel formulations were selected for the present study. The prepared SPME gel showed improved rheology with higher thermal stability, better clean up properties with lesser residues as compared to the individual one.

Identification of Active Compounds in the Root of Merung (Coptosapelta tomentosa Valeton K. Heyne)

The roots of Merung (Coptosapelta tomentosa Valeton K. Heyne) are a group of shrubs usually found on the margins of secondary dryland forest. Empirically, local people have been using the roots of Merung for medical treatment. However, some researches show that the plant extract is used as a poisonous material applied on the tip of the arrow (dart). Based on the online literature study, there are less than 5 articles that provide information about the active compound of this root extract. This study aimed to give additional information more deeply about the content of active compound of Merung root extract in three fractions, n-hexane (nonpolar), ethyl acetate (semi polar) and methanol (polar). The extract was then analysed using Gas Chromatography-Mass Spectrometry (GC-MS). GC-MS analysis of root extract in n-hexane showed there were 56 compounds, with the main compound being decanoic acid, methyl ester (peak 5, 10.13%), 11-Octadecenoic acid, methyl ester (peak 15, 10.43%) and 1H-Pyrazole, 3- (4-chlorophenyl) -4, 5-dihydro-1-phenyl (peak 43, 11.25%). Extracts in ethyl acetate fraction obtained 81 compounds. The largest component is Benzoic acid (peak 19, 22.40%), whereas in methanol there are 38 compounds, of which the main component is 2-Furancarboxaldehyde, 5-(hydroxyl methyl) (peak 29, 30.46%).

Crystal structures of 5,5'-bis(-hydroxy-methyl)-3,3'-biisoxazole and 4,4',5,5'-tetrakis-(hydroxy-methyl)-3,3'-biisoxazole.

The mol-ecular structure of 5,5'-bis(-hydroxy-methyl)-3,3'-biisoxazole, C8H8N2O4 (1), is composed of two trans planar isoxazole rings [r.m.s deviation = 0.006 (1) Å], each connected with a methyl hydroxyl group. Similarly, the structure of 4,4',5,5'-tetrakis-(hydroxy-methyl)-3,3'-biisoxazole, C10H12N2O6 (2), is composed of two planar isoxazole rings [r.m.s. deviation = 0.002 (1) Å], but with four hydroxymethyl groups as substituents. Both mol-ecules sit on a center of inversion, thus Z' = 0.5. The crystal structures are stabilized by networks of O-H⋯N [for (1)] and O-H⋯O hydrogen-bonding inter-actions [for (2)], giving rise to corrugated supra-molecular planes. The isoxazole rings are packed in a slip-stacked fashion, with centroid-to-centroid distances of 4.0652 (1) Å for (1) (along the b-axis direction) and of 4.5379 (Å) for (2) (along the a-axis direction).

Mild and Regioselective Hydroxylation of Methyl Group in Neocuproine: Approach to an N,O-Ligated Cu6 Cage Phenylsilsesquioxane

The self-assembly synthesis of Cu(II)-silsesquioxane involving 2,9-dimethyl-1,10-phenanthroline (neocuproine) as an additional N ligand at copper atoms was performed. The reaction revealed an unprecedented aerobic hydroxylation of only one of the two methyl groups in neocuproine to afford the corresponding geminal diol. The produced derivative of oxidized neocuproine acts as a two-centered N,O ligand in the assembly of the hexacopper cage product [Cu6(Ph5Si5O10)2·(C14H11N2O2)2] (1), coordinating two of the six copper centers in the product. Two siloxanolate ligands [PhSi(O)O]5 in the cis configuration coordinate to the rest of the copper(II) ions. Compound 1 is a highly efficient homogeneous precatalyst in the oxidation of alkanes and alcohols with peroxides.

Role of water on the H-abstraction from methanol by ClO

The influence of a single water molecule on the reaction mechanism and kinetics of hydrogen abstraction from methanol (CH3OH) by the ClO radical has been investigated using ab initio calculations. The reaction proceeds through two channels: abstraction of the hydroxyl H-atom and methyl H-atom of CH3OH by ClO, leading to the formation of CH3O+HOCl (+H2O) and CH2OH+HOCl (+H2O), respectively. In both cases, pre- and post-reactive complexes were located at the entrance and exit channel on the potential energy surfaces. Results indicate that the formation of CH2OH+HOCl (+H2O) is predominant over the formation of CH3O+HOCl (+H2O), with ambient rate constants of 3.07×10−19 and 3.01×10−23cm3/(molecule·sec), respectively, for the reaction without water. Over the temperature range 216.7–298.2K, the presence of water is seen to effectively lower the rate constants for the most favorable pathways by 4–6 orders of magnitude in both cases. It is therefore concluded that water plays an inhibitive role on the CH3OH+ClO reaction under tropospheric conditions.

Spectroscopic, Physical, Thermal, and Magnetic Studies of N-[Tris(Hydroxyl Methyl)Methyl]Glycine (Tricine, L) Complexes and Their Applications Against Tumor Activity

New metal complexes derived from the interaction of tricine with some metal salts (Cu2+, Co2+, Zn2+, Cd2+, and Ni2+) were synthesized and characterized by spectral (IR, UV-vis., EPR, mass, 1H-NMR), magnetic, conductance, and thermal (TGA measurements) analyses. The results suggest that L coordinates in a mono-, bi- and/or tridentate manners via the COO, NH, and OH groups. Also, the results suggest that the carboxylate group is bonded to the metal ions in two forms depending on the type of solvent and the pH of the reaction mixture. Spectral and magnetic studies suggest an octahedral geometry around the investigated metal ions. Moreover, L coordinates in a tridentate manner. Material studio program has been used for calculating HUMO, LUMO, and DFT parameters on the atoms to confirm the geometry of complexes. The cytotoxic activities of complexes against human tumor cells have been screened. The Cu2+ complex showed the highest activities using colorimetric assay.