Preparation, Characterization, and Evaluation of Emission and Performance Characteristics of Thumba Methyl Ester (Biodiesel).

Thumba oil with a higher triglyceride content can be a promising feed for synthesizing a fatty acid alkyl ester as an alternative to pure diesel. The current study investigates the emission and performance characteristics of thumba methyl ester (TME) in compression ignition (CI) engines corresponding to variable loads and compression ratios (CRs), respectively. TME was prepared at an optimized pressure of 5 bar by hydrodynamic cavitation.

The growing relevance of biological ene reactions.

The ene reaction involves the addition of an 'ene' to an 'enophile.' The retro-ene reaction is the reverse of the ene reaction. In recent years various biological molecules have been found to form covalent intermediates (ene-adducts) that might be the result of an ene reactions.

Models for potential dendritic nitric oxide donors: crystal structures of two 2-nitroanilino precursors and nitric oxide-release behavior of the nitrosated derivatives.

Two molecular precursors to dendrimeric materials that could serve as slow and sustained NO-releasing therapeutic agents have been synthesized and characterized. N,N-Bis(2-nitrophenyl)butane-1,4-diamine, CHNO, (I), crystallizes in a lattice with equal populations of two molecules of different conformations, both of which possess inversion symmetry through the central C-C bond. One molecule has exclusively anti conformations along the butyl chain, while the other has a gauche conformation of the substituents on the first C-C bond.

Dichotomous effects of isomeric secondary amines containing an aromatic nitrile and nitro group on human aortic smooth muscle cells via inhibition of cystathionine-γ-lyase.

Excessive proliferation of vascular smooth muscle cells (SMC) is an important contributor to the progression of atherosclerosis. Inhibition of proliferation can be achieved by endogenously produced and exogenously supplied nitrogen monoxide, commonly known as nitric oxide (NO). We report herein the dichotomous effects of two isomeric families of secondary amines, precursors to the N-nitrosated NO-donors, on HASMC proliferation.

Nicotine exposure induces bronchial epithelial cell apoptosis and senescence via ROS mediated autophagy-impairment.

Waterpipe smoking and e-cigarette vaping, the non-combustible sources of inhaled nicotine exposure are increasingly becoming popular and marketed as safer alternative to cigarette smoking. Hence, this study was designed to investigate the impact of inhaled nicotine exposure on disease causing COPD-emphysema mechanisms. For in vitro studies, human bronchial epithelial cells (Beas2b) were treated with waterpipe smoke extract (WPSE, 5%), nicotine (5mM), and/or cysteamine (250μM, an autophagy inducer and anti-oxidant drug), for 6hrs.

Two N-(2-phenylethyl)nitroaniline derivatives as precursors for slow and sustained nitric oxide release agents.

Notwithstanding its simple structure, the chemistry of nitric oxide (NO) is complex. As a radical, NO is highly reactive. NO also has profound effects on the cardiovascular system.

The Thermal Instability of 2,4 and 2,6--Alkylamino Disubstituted and 2--Alkylamino Substituted Nitrobenzenes in Weakly Alkaline Solution: -Amino Effect.

We report herein the preparation of two families of secondary amines by the reactions of two equivalents of monoamines with either 2,4 or 2,6-difluoronitrobenzenes in -dimethylacetamide in the presence of anhydrous potassium carbonate, as precursors of biologically important nitric oxide donating -nitrosamines. In both instances, these compounds could be prepared in quantitative yield when the reaction temperature was held below 130°C. Above this reaction temperature, an unexpected cyclization reaction between the nitro and newly formed adjacent secondary amine group leads to the formation of benzimidazole or quinoxaline rings in low yields.

Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death.

Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries.

A series of N-(2-phenylethyl)nitroaniline derivatives as precursors for slow and sustained nitric oxide release agents.

2,4-Dinitro-N-(2-phenylethyl)aniline, C14H13N3O4, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N-H..

Sustained nitric oxide (NO)-releasing compound reverses dysregulated NO signal transduction in priapism.

We evaluated the therapeutic potential of a sustained nitric oxide (NO)-releasing compound to correct the molecular hallmarks and pathophysiology of priapism, an important but poorly characterized erectile disorder. 1,5-Bis-(dihexyl-N-nitrosoamino)-2,4-dinitrobenzene (C6') and an inactive form of the compound [1,5-bis-(dihexylamino)-2,4-dinitrobenzene (C6)] were tested in neuronal cell cultures and penile lysates for NO release (Griess assay) and biological activity (cGMP production). The effect of local depot C6' or C6 was evaluated in mice with a priapic phenotype due to double neuronal and endothelial NO synthase deletion (dNOS(-/-)) or human sickle hemoglobin transgenic expression (Sickle).

Secondary amines containing one aromatic nitro group: preparation, nitrosation, sustained nitric oxide release, and the synergistic effects of released nitric oxide and an arginase inhibitor on vascular smooth muscle cell proliferation.

Atherosclerosis, a leading cause of death worldwide, is associated with the excessive proliferation of vascular smooth muscle cells. Nitrogen monoxide, more commonly known as nitric oxide, inhibits this uncontrolled proliferation. Herein we report the preparation of two families of nitric oxide donors; beginning with the syntheses of secondary amine precursors, obtained through the reaction between 2 equiv of various monoamines with 2,4 or 2,6-difluoronitrobenzene.

Effects of slow, sustained, and rate-tunable nitric oxide donors on human aortic smooth muscle cells proliferation.

Smooth muscle cell (SMC) proliferation has been accepted as a common event in the pathophysiology of vascular diseases, including atherogenesis and intimal hyperplasia. Delivery of the nitric oxide synthase (NOS) substrate l-arginine, pharmacological nitric oxide (NO) donors, NO gas or overexpression of NOS proteins can inhibit SMC proliferation and reduce the injury responses within the blood vessel wall. Although commercial development of NO donors that attempt to provide exogenous delivery of NO has accelerated over the last few years, none of the currently available products can provide controlled, sustained, time-tunable release of NO.

N,N'-diethyl-4-nitrobenzene-1,3-diamine, 2,6-bis(ethylamino)-3-nitrobenzonitrile and bis(4-ethylamino-3-nitrophenyl) sulfone.

N,N'-diethyl-4-nitrobenzene-1,3-diamine, C(10)H(15)N(3)O(2), (I), crystallizes with two independent molecules in the asymmetric unit, both of which are nearly planar. The molecules differ in the conformation of the ethylamine group trans to the nitro group. Both molecules contain intramolecular N-H.

4,6-Dinitro-N,N'-di-n-octylbenzene-1,3-diamine, 4,6-dinitro-N,N'-di-n-undecylbenzene-1,3-diamine and N,N'-bis(2,4-dinitrophenyl)octane-1,8-diamine.

4,6-Dinitro-N,N'-di-n-octylbenzene-1,3-diamine, C(22)H(38)N(4)O(4), (I), 4,6-dinitro-N,N'-di-n-undecylbenzene-1,3-diamine, C(28)H(50)N(4)O(4), (II), and N,N'-bis(2,4-dinitrophenyl)octane-1,8-diamine, C(20)H(24)N(6)O(8), (III), are the first synthetic meta-dinitroarenes functionalized with long-chain aliphatic amine groups to be structurally characterized. The intra- and intermolecular interactions in these model compounds provide information that can be used to help understand the physical properties of corresponding polymers with similar functionalities. Compounds (I) and (II) possess near-mirror symmetry, with the octyl and undecyl chains adopting fully extended anti conformations in the same direction with respect to the ring.

1,3-Bis(ethylamino)-2-nitrobenzene, 1,3-bis(n-octylamino)-2-nitrobenzene and 4-ethylamino-2-methyl-1H-benzimidazole.

1,3-Bis(ethylamino)-2-nitrobenzene, C(10)H(15)N(3)O(2), (I), and 1,3-bis(n-octylamino)-2-nitrobenzene, C(22)H(39)N(3)O(2), (II), are the first structurally characterized 1,3-bis(n-alkylamino)-2-nitrobenzenes. Both molecules are bisected though the nitro N atom and the 2-C and 5-C atoms of the ring by twofold rotation axes. Both display intramolecular N-H.

N-(n-Dec-yl)-4-nitro-aniline.

N-(n-Dec-yl)-4-nitro-aniline, C(16)H(26)N(2)O(2), crystallizes with two essentially planar mol-ecules in the asymmetric unit. The decyl chains are fully extended in an anti conformation. The mol-ecules pack in planar layers, within which mol-ecules are linked into chains by two approximately linear N-H⋯O hydrogen bonds between the amine N atom and one O atom of the nitro group of an adjacent mol-ecule.

Molecular dynamics simulation of polyamidoamine dendrimer-fullerene conjugates: generations zero through four.

Previously the synthesis of the polyamidoamine (PAMAM) (G4)-C60 conjugate with a molar ratio of 1 : 30 was reported. Because PAMAM G4 has sixty-four primary amine groups, it was hypothesized that approximately two surface amine groups react with each fullerene molecule to form the conjugates. A computational energy minimization study of various G4 PAMAM-fullerene conjugates containing 1 dendrimer but different amounts of fullerenes shows excellent stability for the 1 : 30 dendrimer to fullerene product.

Preparation of fullerene-shell dendrimer-core nanoconjugates.

Generation 4 amine-terminated polyamidoamine dendrimer (PAMAM G4) was allowed to react with an excess of buckminsterfullerene (C60) to form a nanoconjugate containing a PAMAM core and C60 shell. The PAMAM-C60 conjugate was characterized by MALDI-TOF, TGA, UV-vis, and IR spectroscopy. Approximately thirty shell fullerenes surround each dendrimer core.

A simple polyacrylamide gel electrophoresis procedure for separation of polyamidoamine dendrimers.

A simple, inexpensive, and rapid electrophoresis technique was developed for use as a routine tool for evaluating purity of polyamidoamine (PAMAM) dendrimers. A variety of factors influencing migration of generations 0-7 dendrimers on nongradient polyacrylamide gels were evaluated. The low generation dendrimers were found to be very sensitive to diffusion during or after electrophoresis.