Hydrolysis Of Cyano Group Research Articles

Insights into Mechanism of Hypochlorite-Induced Functionalization of Polymers toward Separating BFR-Containing Components from Microplastics.

Surface functionalization of polymers is significant for an emerging flotation technique for separation of microplastics toward the recycling of plastic wastes. In this study, the hypochlorite-induced functionalization of polymers, including ABS, PMMA, PS, and PVC polymers, was intensively investigated. Afterward, its emerging application in flotation separation of microplastic mixtures was assessed based on a Box-Behnken design of the response surface methodology. The functionalization favorably induced decreases in the contact angle and zeta potential of polymers, suggesting hydrophilic and negatively charged surfaces. Particularly, the functionalization of ABS polymers was the most effective, leading to the obviously decreased contact angle (from 92.5° to 67.8°) and zeta potential (from -26.4 mV to -41.7 mV) at neutral condition. The major mechanism for these variations was the oxidation of the sp3-C and butenyl group by hydroxyl radical and the hydrolysis of cyano group, which introduced the hydroxyl, carboxyl, and amide groups and rough topographies on the surface of ABS polymers. Oxygen functionalities introduced on the surfaces of other polymers were far less than those of ABS polymers. This selectivity inspired us to apply the functionalization in flotation separation of ABS microplastics from microplastic mixtures. After functionalization, ABS microplastics showed a significantly decreased floatability in flotation tests since the hydrophilic surface was repulsive to the adhesion of air bubbles. An empirical model was built to optimize the separation efficiency using the overall desirability function. Under optimum conditions, ABS microplastics were efficiently separated, and their removal rate, recovery, and purity were 99.8%, 99.8%, and >99.9%, respectively. These findings provide significant insights into the mechanism of the functionalization of polymers and show a promising prospect for pollution control of plastic wastes.

Absorption, Metabolism, and Excretion of [14C]Vildagliptin, a Novel Dipeptidyl Peptidase 4 Inhibitor, in Humans

The absorption, metabolism, and excretion of (1-[[3-hydroxy-1-adamantyl) amino] acetyl]-2-cyano-(S)-pyrrolidine (vildagliptin), an orally active and highly selective dipeptidyl peptidase 4 inhibitor developed for the treatment of type 2 diabetes, were evaluated in four healthy male subjects after a single p.o. 100-mg dose of [(14)C]vildagliptin. Serial blood and complete urine and feces were collected for 168 h postdose. Vildagliptin was rapidly absorbed, and peak plasma concentrations were attained at 1.1 h postdose. The fraction of drug absorbed was calculated to be at least 85.4%. Unchanged drug and a carboxylic acid metabolite (M20.7) were the major circulating components in plasma, accounting for 25.7% (vildagliptin) and 55% (M20.7) of total plasma radioactivity area under the curve. The terminal half-life of vildagliptin was 2.8 h. Complete recovery of the dose was achieved within 7 days, with 85.4% recovered in urine (22.6% unchanged drug) and the remainder in feces (4.54% unchanged drug). Vildagliptin was extensively metabolized via at least four pathways before excretion, with the major metabolite M20.7 resulting from cyano group hydrolysis, which is not mediated by cytochrome P450 (P450) enzymes. Minor metabolites resulted from amide bond hydrolysis (M15.3), glucuronidation (M20.2), or oxidation on the pyrrolidine moiety of vildagliptin (M20.9 and M21.6). The diverse metabolic pathways combined with a lack of significant P450 metabolism (1.6% of the dose) make vildagliptin less susceptible to potential pharmacokinetic interactions with comedications of P450 inhibitors/inducers. Furthermore, as vildagliptin is not a P450 inhibitor, it is unlikely that vildagliptin would affect the metabolic clearance of comedications metabolized by P450 enzymes.

Facile synthesis of novel nonpeptide angiotensin II receptor antagonists

AbstractA series of Losartan analogues 1‐12 with different functional groups were synthesized and characterized. In comparison with the previous reports, the synthetic procedures described in this paper have been optimized as follows below: 1) preparation of aromatic amine 15 and 18 through hydrogenation by employing Raney Ni and hydrazine as catalysts in place of palladium; 2) preparation of nitro‐compound 17 by using pure fuming nitric acid at ‐20 ‐ ‐15 °C; 3) alkylation of 21 with 22 or 23 in the presence of sodium hydride in place of potassium tert‐butylate; 4) preparation of carboxylic acid 4 by ester cleavage rather than hydrolysis of cyano group.

ChemInform Abstract: Anchimeric Assistance of the Sulfinyl Group in the Hydrolysis of Cyano Groups: A New Mild Method for the Reduction of Sulfoxides.

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Anchimeric assistance of the sulfinyl group in the hydrolysis of cyano groups: A new mild method for the reduction of sulfoxides

Conditions to achieve reductive hydrolysis of β-cyanosulfoxides into their corresponding β-sulfenylamides are reported. The anchimeric assistance of the sulfinyl oxygen in the hydrolysis of the cyano group is proposed to explain the mild conditions required to achieve it and several proofs supporting this assumption are indicated. From these results a new mild method to transform sulfoxides into sulfides has been developed.

Characterization of cyano bonded silica phases from solid-phase extraction columns : Correlation of surface chemistry with chromatographic behavior

Cyano bonded phases from six solid-phase extraction cartridge vendors (identified as A to F) have been characterized by elemental analysis, chromatography of probe molecules, and infrared and solid-state nuclear magnetic resonance spectroscopy. The results indicate that cyano solid-phase extraction cartridges from different vendors possess diverse surface properties presumably arising from differences in bonding chemistry and manufacturing methods. For example, nuclear magnetic resonance and infrared spectra indicate that vendors E and F use mono- and difunctional cyanopropyl silane, respectively, while all others use trifunctional. A wide range of hydrophobicities (determined using the alkylarylketone retention index scale) was observed among these bonded phases, determined primarily by degree of cyano group loading, whether the product has been endcapped or not and ratio of cyano functional group to endcapping reagent. Products from vendors A and D showed the presence of carboxyl groups, possibly arising from hydrolysis of cyano groups during silane bonding, thus imparting them with ion-exchange character. One would expect that extraction properties of cyano cartridges from different vendors may be very different. These results help explain the difficulty in transfer of procedures from cyano cartridges of one vendor to another and lend insight into the possible origin of lot-to-lot variability of cyano bonded phase from a single vendor.