Theory and Applications of Chemistry Vol. 4

Plants remain an important source of new drugs, new drug leads for making more effective drugs in the pharmaceutical industry. Plant based discovery resulted mainly in the development of anticancer and anti-infective agents providing new leads to the drug industry.

The present article focuses on a unifying mode of action for the nutrients, namely, resveratrol, epigallocatechin, polyene-ß-carotene, polyene lycopene, piperine, curcumin, genistein, luteolin, sulforaphane and pomegranate extract. The mechanism is based on electron transfer, reactive oxygen species and oxidative stress, which comprises an extension of earlier reports involving agents. Most of the compounds are precursors of electron transfer quinones, whereas others fit into the polyene category. The nutrients are better known as antioxidants. The dichotomy is addressed.   

The organo-amino compound of title 2-(4-methyl-2-phenyl-4,5-dihydro-oxazol-4-ylmethyl)-isoindole-1,3-dione was synthesized by the mixture of (4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl-4-methylbenzenesulfonate and isoindoline-1,3-dione in N,N’-dimethylformamide with a yield of around 65%. The structural study of the compound, C₁₉H₁₆N₂O₃, is realized using single crystal X-Ray diffraction which shows that this compound crystallizes in the monoclinic system (P21/c, Z = 4) with the unit cell parameters: A = 14.3728 (13) Å, b = 9.6829 (10) Å, c = 11.8964 (12) Å and β = 107.384 (3). The refinement of the structure by the least-squares method with complete matrix leads to the following reliability factors R/Rw are 0.044/0.130. In the crystal, the molecules are linked together by hydrogen bonds and π…π interactions. The Infrared spectroscopic studies show the bands confirming the presence of the groups C=O, C-O, C-N, -CH₃, -CH₂ and =CH.

The Systemic assessment [SA] strategy changes the assessment from traditional linear bothering exams to enjoyable puzzle games in the form of systemics. Systemic Assessment (SA) aims a more effective evaluation of the systemically oriented objectives articulated by the SATL model. SA raising the level of student’s academic achievements, increasing students learning outcomes, develops the ability to think systemically, assesses students’ higher-order thinking skills in which students are required to analyze, synthesize and evaluate, measures the students' ability to correlate between concepts with reduced working memory load. Systemic Assessment Questions (SAQ,s) are the building units of the systemic assessment. In this chapter, we use SA as a tool to assess student achievement in inorganic chemistry by taking sodium chemistry as a module. We use five types of systemic assessment questions, namely Systemic Sequencing Questions (SSQ’s) Systemic Synthesis Questions (SSynQ, s), Systemic Analysis Questions (SAnQ, s), Systemic Synthetic-Analytic Questions (SSyn-AQ, s) and complete Systemics (SCompQs). This chapter is suitable for students at the secondary level and could be used as an applicable model to assess students learning in sodium chemistry and other metals of the periodic table by changing the metal.

We describes in this chapter, the assignment of the 1,4- and 1,5-regioisomer structures of N-protected 2-(1H-1,2,3-triazol-1-yl)-glycine derivatives on the basis of ¹H NMR, IR and chemical pathway. A subsequent assignment of 1,4- and 1,5-regioisomer structures of biheterocyclic glycine derivatives and their phosphonic analogues were based on spectroscopic study in ¹H NMR and ¹³C NMR.

Trans-3,4-dibenzyl-2-oxo-tetrahydrofuran (6) a substituted tetrahydrofuranoid lignan was synthesized in 70% yield via the Stobbe condensation between (1) benzaldehyde and (2) diethyl succinate. The structure was confirmed by the spectral data such as infra-red, proton magnetic resonance and mass spectrum. It has two similar but non equivalent aromatic groups which appeared at δ: 6.48 - 6.76 and 7.06-7.25 as multiplets.

Chlorpyrifos pesticides are endocrine disruptors, inhibitors of acetyl cholinesterase, used to control pests and prime contributors to indoor pollution in retail stores. Seven selected locally sourced adsorbents; Bone charcoal (BCA), corncobs, cotton seed, kokoli, sawdust, coconut shell (CSA) and Muruchi were evaluated. Only BCA and CSA shows peaks and were further examined at adsorptive temperatures of 283, 293, 303 and 313K. Adsorbents physical properties that is, micro pore surface area, total pore volume; micro pore volume, particle density and true density were measured and compared. Results from gas chromatography and surface characterization revealed that the adsorptive capacities of carbon (CSA) at various temperatures were higher than that of carbon (BCA). The plots of Langmuir and Freundlich Isotherms were well fitted by the measured adsorption data. The parameters of adsorption equation for both Langmuir and Freundlich were determined for the two adsorbents, which indicates increased values of adsorptive capacity at low temperature and decreases at high temperature. This study shows that activated carbon made from coconut shell has high surface area, micro porous structure, high degree of surface reactivity and higher heterogeneous properties that suggest it to be a better adsorbent sufficient for the adsorption of chlorpyrifos vapour in an indoor environment.

In order to improve the mechanical properties of acrylic films, Poly methyl-methacrylate (PMMA)/ Aluminum oxide (Al₂O₃) films are prepared following solution casting technique. The mechanical behavior of prepared films has been analyzed by employing Ultrasonic Pulse Echo method. The morphology of films is examined via XRD and SEM analysis. The synergetic effect is observed in films from obtained ultrasonic data. The elastic modulus is calculated and compared for better utilization.

The compound, diethyl 1-((4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl)-1H-1,2,3-triazole-4,5-dicarboxylate 2, was synthesized in high yield, through 1,3-dipolar cycloaddition reaction of 4-(azidomethyl)-4-methyl-2-phenyl-4,5-dihydrooxazole and diethyl but-2-ynedioate in the absence of a solvent. The structure of the synthesized compound was established on the basis of NMR spectroscopy (¹H, ¹³C), X-ray crystallography and MS data. The prepared compound was also tested in vitro for its antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The calculation of MBC/MIC ratio showed that this triazole derivative 2 had a bactericidal effect on the two strains tested.

The amino ester derivative was synthesized via N-alkylation of methyl α-azido glycinate N-benzoylated 1 with methyl 2-amino-2-phenylacetate in methylene chloride and in presence of triethylamine as basic catalyst. The structure of the prepared compound was determined by spectroscopic methods: ¹H-NMR, ¹³C-NMR, MS data, elemental analysis and confirmed by X-Ray diffraction. This compound was screened in vitro for its antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Salmonella enteric). The synthesized compound showed an interesting inhibitory effect against all the strains tested.

Tetrazoles are an important class of nitrogen containing heterocycles with a wide range of medicinal and commercial applications. Tetrazolyl analogs of amino acids exhibit versatile biologic activity, and some of them are known pharmaceuticals. In addition, compounds of this type may be using in development of radiopharmaceuticals for positron emission tomography.

In continuation of our investigations in the tetrazolic amino acids, we described in this presentation the synthesis and characterization of some aminoalkyl and tetrazolic amino acid derivatives basing on different spectroscopic methods as NMR 2D.

A simple synthetic approach to N-((tetrazol-5-yl)methyl)cyclohexanamine in two steps starting from chloroacetonitrile and cyclohexylamine is reported. The synthesized compound was characterized by 2D NMR spectroscopy (¹H, ¹³C) and elemental analysis data.

The compound, 4-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-4-methyl-2-phenyl-4,5-dihydrooxazole 2 was prepared in high yield, through nucleophilic substitution reaction of the O-tosyloxazoline derivative 1, by heating in dimethyl sulfoxide (DMSO) and in presence of KOH as base. The structure of the synthesized compound was established on the basis of NMR spectroscopy (¹H, ¹³C), MS data and elemental analysis.

The 1,3-dipolar cycloaddition reaction between 4-(azidomethyl)-4-methyl-2-phenyl-4,5-dihydrooxazole and 9-(prop-2-ynyl)-9H-carbazole, in toluene at reflux, leads to obtain two regioisomers with different proportions where the 1,4-regioisomer is generally more prominent than 1,5-regioisomer. The assignment of structures to 1,2,3-triazolic regioisomers was established in base of a comparative study of NMR spectral data (¹H, ¹³C, ¹⁵N and 2D ¹H-¹⁵N HMBC spectra) in addition to the elemental analysis and MS data.

The alkylation reaction of 1H-1,2,4-triazole with (4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl-4-methylbenzenesulfonate in presence of K₂CO₃ as base and a catalytic amount of tetrabutylammonium bromide in N,N’-dimethylformamide, followed by an oxazoline ring-opening reaction in an acidic medium, and protection of amine function, leads normally to obtain two regioisomers of N-protected β-aminoalcohols with prevalence of the N₁-isomer. After purification by column chromatography of the crude reaction product, only a single product is obtained in 97% yield. Hence, there is need of its identification by spectroscopic study.

The title compound, methyl N-[1-(benzoylamino)-2-methoxy-2-oxoethyl]tryptophanate 2, have been synthesized in high yield, via N-alkylation reaction of methyl 2-azido-2-benzamidoacetate with methyl 2-amino-3-(1H-indol-3-yl)propanoate in acetone, with the presence of diisopropylethylamine as a base. The structure of the prepared compound was characterized by ¹H, ¹³C NMR in addition to MS, X-Ray diffraction data, and elemental analysis. This compound was tested in vitro for its antibacterial activity against Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, and Gram-negative bacteria, Escherichia coli, Pseudomonas aeruginosa and Salmonella enteric. The MIC values showed that the synthesized compound had a bactericidal effect against the strains tested.