2-{[{2-Hydroxy-3-[2-methyl-5-(propan-2-yl)phenoxy]propyl}(pyridin -2-ylmethyl)amino]methyl}phenol

In the title racemic compound, C(26)H(32)N(2)O(3), an intramolecular O-H center dot center dot center dot N hydrogen bond is formed between the phenolic OH group and the tertiary amine N atom. Another O-H center dot center dot center dot N hydrogen bond that is formed between the OH group and the pyridine N atom links the molecules into a polymeric chain extending along the a axis. The structure is further stabilized by intramolecular and intermolecular C-H center dot center dot center dot O interactions.

A multi-sheeted three-dimensional potential-energy surface for the H-atom photodissociation of phenol

Extending the previous work of Lan et al. J. Chem. Phys., 122, 224315 (2005)], a multi-state potential model for the H atom photodissociation is presented. All three ``disappearing coordinates'' of the departing H atom have been considered. Ab initio CASSCF computations have been carried out for the linear COH geometry of C-2v symmetry, and for several COH angles with the OH group in the ring plane and also perpendicular to the ring plane. By keeping the C6H5O fragment frozen in a C-2v-constrained geometry throughout, we have been able to apply symmetry-based simplifications in the constructions of a diabatic model. This model is able to capture the overall trends of twelve adiabats at both torsional limits for a wide range of COH bend angles.

Iodine promoted alpha-hydroxylation of ketones

A novel method for alpha-hydroxylation of ketones using substoichiometric amount of iodine under metalfree conditions is described. This method has been successfully employed in synthesizing a variety of heterocyclic compounds, which are useful precursors. alpha-Hydroxylation of diketones and triketones are illustrated. This strategy provides a novel, efficient, mild and inexpensive method for alpha-hydroxylation of aryl ketones using a sub-stoichiometric amount of molecular iodine.

Vesicular Nanostructure Formation by Self-Assembly of Anisotropic Penta-phenol-Substituted Fullerene in Water

A study on self-assembly of anisotropically substituted penta-aryl fullerenes in water has been reported. The penta-phenol-substituted amphiphilic fullerene derivative C60Ph5(OH)(5)],exhibited self-assembled vesicular nanostructures in water under the experimental conditions. The size of the vesicles Was observed to depend upon the kinetics of self-assembly and could be varied from similar to 300 to similar to 70 nm. Our mechanistic study indicated that the self-assembly of C60Ph5(OH)(5) is driven by extensive intermolecular as well as water-mediated hydrogen :bonding along with fullerene-fullerene hydrophobic interaction in water. The cumulative effect of these interactions is responsible for the stability of vesicular structures even on the removal of solvent. The substitution of phenol with anisole resulted in different packing and interaction of the fullerene derivative, as Indicated in the molecular dynamics studies, thus resulting in different self-assembled nanostructures. The hollow vesicles were further encapsulated with a hydrophobic conjugated polymer and water-soluble dye as guest molecules. Such confinement of pi-conjugated polymers in fullerene has significance in bulk heterojunction devices for efficient exciton diffusion.

Selective hydroxylation of small alkanes by the particulate methane monooxygenase

The particulate methane monooxygenase (pMMO) catalyzes the oxidation of methane to methanol under ambient temperatures and pressures. Other small alkanes and alkenes are also substrates of this enzyme. We measured and compared the initial rate constants of oxidation of small alkanes (C1 to C5) catalyzed by pMMO. Both primary and secondary alcohols were formed from oxidation of n-butane and n-pentane. The alcohols produced from alkane oxidation can be further oxidized, probably by pMMO, to aldehydes and ketones. The apparent regioselectivity for n-butane and n-pentane is 100% 2-alcohols because the formation of primary alcohols is slower than further oxidation of these alcohols. The hydroxylation at the secondary carbons is highly stereoselective: (R)-alcohols are preferentially formed. The enantiomeric excess increases slightly with decreasing reaction temperature. The steric course of hydroxylation on primary carbons was also studied by using isotopically substituted ethane: (S)- or (R)-CH_3-CHDT, and (S)- or (R)-CD_3- CHDT and the reactions were found to proceed with 100% retention of configuration. A primary isotopic effect of k_H/k_D=5.0 was observed in these experiments.

Mechanistic studies of a model reaction for enzymatic hydroxylation

A study has been made of the reaction mechanism of a model system for enzymatic hydroxylation. The results of a kinetic study of the hydroxylation of 2-hydroxyazobenzene derivatives by cupric ion and hydrogen peroxide are presented. An investigation of kinetic orders indicates that hydroxylation proceeds by way of a coordinated intermediate complex consisting of cupric ion and the mono anions of 2-hydroxyazobenzene and hydrogen peroxide. Studies with deuterated substrate showed the absence of a primary kinetic isotope effect and no evidence of an NIH shift. The effect of substituents on the formation of intermediate complexes and the overall rate of hydroxylation was studied quantitatively in aqueous solution. The combined results indicate that the hydroxylation step is only slightly influenced by ring substitution. The substituent effect is interpreted in terms of reaction by a radical path or a concerted mechanism in which the formation of ionic intermediates is avoided. The reaction mechanism is discussed as a model for enzymatic hydroxylation.

I. Studies on the activation of Drosophila phenol oxidase. II. Studies on serum insulin in normal subjects and diabetics

Part I

Phenol oxidase is the enzyme responsible for hardening and pigmentation of the insect cuticle. In Drosophila, phenol oxidase is a latent enzyme. Enzyme activity is produced by the interaction of a number of protein components. A minimal activation scheme consisting of six protein components, designated Pre S, S activator, S, P. P' and Ʌ₁ is described. Quantitative assays have been developed for the S activator, S, P and P' proteins and these components have been partially purified. Experiments describing the interactions of the six components have been conducted and a model for the activation of phenol oxidase in a minimal system is proposed. Possible mechanisms of the reactions between the constituents of the activating system and potential regulatory mechanisms involved in phenol oxidase production and function are discussed.

Part II

A method has been developed for the partial purification of insulin from human serum. A procedure for the determination of the electrophoretic mobility of serum insulin on polyacrylamide gels is described. An electrophoretic analysis of insulin isolated from a normal subject is reported and in addition to a major band, the existence of a number of minor bands of immunoreactive insulin is described. A comparison of the electrophoretic patterns of insulin isolated from normal and diabetic subjects was carried out and indications that differences between them may occur are reported.

Proposed Environmental Quality Standards for Phenol in Water

This is the Proposed Environmental Quality Standards (EQS) for Phenol in Water prepared for the National Rivers Authority, and published by the Environment Agency in 1995. The report reviews the properties and uses of phenol, its fate, behaviour and reported concentrations in the environment and critically assesses the available data on its toxicity and bioaccumulation. The information is used to derive EQSs for the protection of fresh and saltwater life and for the abstraction of water to potable supply. Phenol is widely used as a chemical intermediate and the main sources for phenol in the environment are of anthropogenic origin. Phenol may also be formed during natural decomposition of organic material. The persistence of phenol in the aquatic environment is low with biodegradation being the main degradation process (half-lives of hours to days). Phenol is moderately toxic to aquatic organisms and its potential to bioaccumulate in aquatic organisms is low.