Presence Of Lactams Research Articles

Review on Isatin- A Remarkable Scaffold for Designing Potential Therapeutic Complexes and Its Macrocyclic Complexes with Transition Metals.

Role of synthetic coordination chemistry in pharmaceutical science is expeditiously increased due to its sundry relevances in this field. The present review endows the synthesized macrocyclic complexes of transition metal ions containing isatin and its derivatives as ligand precursors, their characterization and their copious pharmaceutical applications. Isatin (1H-Indole-2,3-dione) is a protean compound (presence of lactam and keto moiety permits to change its molecular framework) that can be obtained from marine animals, plants, and is also found in mammalian tissues and in human fluids as a metabolite of amino acids. It can be used for the synthesis of miscellaneous organic and inorganic complexes and for designing of drugs since it has remarkable utility in pharmaceutical industry due to its wide range of biological and pharmacological activities, for instance anti-microbial, anti-HIV, anti-tubercular, anti-cancer, anti-viral, anti-oxidant, anti-inflammatory, anti-angiogenic, analgesic activity, anti-Parkinson’s disease, anti-convulsant etc. This review provides extensive information about the latest methods for the synthesis of isatin or its substituted derivatives based macrocyclic complexes of transition metals and their plentiful applications in medicinal chemistry.

The Effect of Organic Acids in the Presence of Cyclic Lactams on Kinetics of Electrodeposition and Morphology of Nickel Coatings Modified with Polymer

Using stationary electrolysis, the effect of the structure and concentration of some organic acids on kinetic parameters of electrodeposition of nickel from sulfate electrolytes containing cyclic lactams, such as e-caprolactam (CL) and N-methylpyrrolidone (MP), microstructure, mean grain size, and crystallite orientation has been studied. Integrated analysis of the data of polarization, adsorption, and spectral investigations has shown that enhancement of adsorption of amino acids in the presence of lactams leads not only to an increase in the polarization of the process, but also to significant changes of surface morphology. According to X-ray phase analysis and SEM data, the surface becomes smoother in the presence of amino acids, the grain size decreases, and a predominant orientation of crystallites appears in some cases. The formation of metal–polymer sharp-edged grains in the coatings prepared in the presence of CL and glycine has resulted in the formation of continuous smoothed layer and appearance of mirror shine of the deposits.

Lactam inhibiting Streptococcus mutans growth on titanium

The aim of this work was to analyze the activity of novel synthetic lactams on preventing biofilm formation on titanium surfaces. Titanium (Ti6Al4V) samples were exposed to Streptococcus mutans cultures in the presence or absence of a synthetic lactam. After 48h incubation, planktonic growth was determined by spectrophotometry. Biofilm was evaluated by crystal violet staining and colony forming units (CFU·ml−1), followed by scanning electron microscopy (SEM). Results showed that the average of adhered viable cells was approximately 1.5×102CFU/ml in the presence of lactam and 4×102CFU/ml in its absence. This novel compound was considerable active in reducing biofilm formation over titanium surfaces, indicating its potential for the development of antimicrobial drugs targeting the inhibition of the initial stages of bacterial biofilms on dental implants abutments.

Spectroscopic investigations to understand the enhanced dissolution of heavy crude oil in the presence of lactam, alkyl ammonium and hydroxyl ammonium based ionic liquids

The deposition of crude oil in various production and surfaces facilities such as oil storage tanks in the form of tank-bottom sludge, pipeline deposition, skin formation at the near well-bore, deposition in the tubing leads to blockage which invites several operational challenges. These challenges, in turn bring about huge production losses, involvement of scarce human resources, and threatening the environmentally safe operation, thus needing safer solutions. An environmental-friendly method for the dissolution of heavy crude oil (HCO) with the use of ionic liquids (ILs) along with a paraffinic liquid hydrocarbon (organic solvent) is developed which is considered to be very helpful for easy pumping, reducing the risk of manual cleaning and time consumption. In this work, eleven ILs are selected from lactam, alkyl ammonium and hydroxyl ammonium families with various anions, such as, [HCOO]−, [CH3COO]−, [CF3COO]−, [C6H13COO]−. The results on the quantitative and qualitative dissolution of the HCO using organic solvents (with and without ionic liquids) are presented. Studies on the quantitative dissolution of crude oil are performed with the use of UV–vis spectrophotometer, while the qualitative information on the dissolution of HCO are carried out using FT-IR and 13C NMR techniques. In the case of sample system (HCO+solvent+ILs), the increase in solubility observed is up to a maximum of 80%. Time-hold study was conducted for a prolonged period of 30days where the increase in solubility is improved in the range of 80–335% with the addition of ILs along with organic solvents, whereas standard system (without ILs), showed improvement in the range of 11–16% only. This method helps in increasing the efficacy of organic solvents, such as, the liquid hydrocarbons which would be suitable for upstream petroleum engineering application. Moreover, the used ionic liquids were recycled and can also be reused.

Aminoborohydrides. 13. Facile reduction of N-alkyl lactams with 9-borabicyclo[3.3.1]nonane (9-BBN) and lithium aminoborohydrides (LAB) reagents

Two methods to reduce N-alkyl lactams to the corresponding cyclic amines using 9- borabicyclo(3.3.1)nonane (9-BBN) and lithium aminoborohydride (LAB) reagents are reported. The lactam reductions required 2.2 molar equivalents of 9-BBN or 1.5 molar equivalents of LAB reagent and were complete within two hours in refluxing THF (65 °C). Reductions with these reagents are chemoselective and complementary in nature. A lactam can be reduced in the presence of an ester with 9BBN. At lowered temperature, an ester can be reduced in the presence of lactam with LAB reagents. At elevated temperature, LAB reagents act as powerful reducing agents, and reduce both lactam and ester functional groups in a difunctional molecule. The reaction products were easily isolated in good to excellent yields after simple work-ups.

Autolysis control hypotheses for tolerance to wall antibiotics.

Antibiotics are divided into two classes: bacteriostatic and bactericidal. The reasons for their classification are usually self-evident, although seldom proven. For example, chloramphenicol stops protein synthesis and is bacteriostatic, probably because when it is removed growth can recommence. Penicillin and congeners are bactericidal, probably because continued cytoplasmic synthesis should lead to increased cellular pressure and eventually to the rupture of the wall and to cell death. Lethality is not always the outcome, and certain strains may neither grow nor lyse in the presence of lactams (46–51, 55, 57, 60); they are called “tolerant.”

Copolymerization of α-piperidone with ε-caprolactam and α-pyrrolidone

Abstract A study has been made of the increase in polymerizability of α-piperidone in the presence of lactams with different degrees of strain in the ring. It is shown that the degree of conversion of piperidone to polymer increases as the concentration of caprolactam in the monomer mixture or the reaction temperature are increased. Separation of the copolymers as precipitates also brings about increase in the proportion of piperidone in the copolymer. On the other hand, when piperidone is copolymarized with the less strained lactam α-pyrrolidone there is no activation effect. These results can be explained on the basis of the thermodynamics of copolymerization of lactams.