Organic Chemistry

In this research, phytochemical screening and antibacterial properties of Phyllanthus muellerianus were investigated to confirm the potency of the plant on the basis of ethno medicinal significance. The percentage yield of crude methanolic leave extract of Phyllanthus muellerianus was 12.58% while the phytochemical screening of crude methanolic leave extract of Phyllanthus muellerianus revealed the presence of anthraquinone, carbohydrates, tannins, alkaloids, flavonoids, cardiac glycosides, saponin and lipids. The result of the antibacterial activities showed that the crude methanolic leave extract of the plant exhibits high potency against all the tested organisms. These properties above may be the reason Phyllanthus muellerianus plant has been reported to be useful in the treatment of several ailments.

The FT-Raman and FT-Infrared spectra of Guaiacol have been recorded in the regions 3500?100 cm?1 and 4000?500 cm?1 respectively. The observed frequencies were assigned to various modes of vibrations on the basis of normal coordinate calculations, assuming C1 point group symmetry. The assignment of fundamental vibrations agrees well with the calculated frequencies. Second order perturbation energies and electron density (ED) transfer from filled lone pairs of Lewis base to unfilled Lewis acid sites of Guaiacol are discussed on the basis of NBO analysis. The theoretically calculated harmonic frequencies are scaled by common scale factor. The observed and the calculated frequencies are found to be in good agreement. The thermodynamic functions were obtained for the range of temperature 100–1000 K. The polarizability, first hyperpolarizability, anisotropy polarizability invariant has been computed using quantum chemical calculations. The chemical parameters were calculated from the HOMO and LUMO values. The NMR chemical shielding anisotropy (CSA) parameters were also computed for the title molecule.

Pulverized leaves of red and yellow varieties of Caesalpina pulcherrima yielded 0.50 and 0.52% v/w of essential oils on hydrodistillation. GC and GC-MS analyses of the oils revealed the presence of fifty eight and fifty three compounds in the oil of red and yellow varieties respectively. Percentage compositions of oxygenated monoterpenes in the oil of red and yellow varieties were 70.4 and 85.1%. Sesquiterpenes constituted 28.8% of the leaf oil of red variety, while 5.1% of the oil of yellow variety was sesquiterpenes. The principal constituents of the oil of red variety were; ?-terpinene (44.4%), germacrene B (14.3%), myrcene (5.6%), allo-ocimene (5.9%), ?-caryophylene (5.1%) and ?-pinene (4.2%). Major compounds identified in the oil of yellow variety were; citronellal (58.0%), geranial (17.5%), ?-caryophylene (5.1%), linalool (2.5%) and ?-terpineol (2.3%). With the abundance of ?-terpinene and citronellal in the oils of red and yellow varieties, the oils are of ?-terpinene and citronellal chemotypes respectively.

The effects of substituents and solvents have been studied through the absorption spectra of nearly twelve meta,para and ortho-substituted N-Pheny maaleimide in the range of 200-400 nm. The effects of substituents on the absorption spectra of compounds under investigation are interpreted by correlation of absorption frequencies with simple and extended Hammett equations. With the help of Kamlet equation the effect of solvent polarity and hydrogen bonding on the absorption spectra are interpreted and the results are discussed.

During the synthesis of bis - benzothiazols via condensation of 2-aminothiophenol and oxalic, malonic acids an interesting product was obtained during the workup of the reaction products, which upon characterization by spectroscopic methods was found to be bis-(2-aminophenyl) disulfide (NH2PhSSPhNH2).

The novel ligand, 5-((N,N-diphenylamino)methyl)-8-hydroxyquinoline (DPMHQ) was synthesized by reaction of 5-chloromethyl-8-hydroxyquinoline (CMQ) hydrochloride with N,N-diphenylamine. Metal complexes of DPMHQ were synthesized with Cu(II), Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) salts. The ligand DPMHQ and all its metal complexes were further investigated for elemental content, IR-NMR spectral features, metal: ligand ratio and magnetic properties. The samples were also screened for antifungal activities.

Aqueous media containing heavy metals from industries are directly or indirectly discharged into the environment to cause pollution and threat to human life. The bio-polymer chitin was synthesised using local snail shell to study the adsorption of lead, zinc and nickel from aqueous solution. The synthesis of chitin involves the following stages: (i) pre-concentration, (ii) demineralization, (iii) deprotonization and (iv) deacetylation. Chitin is characterized using analytical technique such as Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron microscope (SEM) and X-ray fluorescence (XRF) to confirm the presence of chitin. This study shows the effect of pH, time, and adsorbent dosage removal efficiency of the metals in solution. The concentrations of Pb2+, Ni2+ and Zn2+ absorbed under different conditions was evaluated using atomic adsorption spectroscopy (AAS). The result shows that the optimum pH adsorption for Pb2+, Ni2+ and Cu2+ using chitin was found to be at pH 2 for the all metals (Pb2+, Ni2+ and Zn2+) with percentage removal efficiency (92.5%, 82.4%, 80%). The synthesized chitin has a potential of an adsorbent for the removal of heavy metals in aqueous solution.

Cyclotriphosphazenes are prominent inorganic N-heterocycles.They consist of six-membered ring structures of alternating phosphorus and nitrogen atoms. The tetravalent phosphorus atoms carry two exocyclic substituents, which can be widely varied enabling fine-tuning of the size and shape of the molecular periphery. This study involved the synthesis and characterization of hexa (diethanolamino) cyclotriphosphazene by an enveremently and friendly system catalyst consist of clay layered called Maghnite-H+ (Algerian MMT) and diethyl ether. The effect of different synthesis parameters such as amount of catalyst, effect of time, temperature and solvent are discussed.

Osthol, 7-methoxy-8-(3-methylbut-2-enyl) coumarin, was isolated from the root parts of Prangos pabularia and was subjected to modification in the isopentenyl side chain to get an aldehyde 2- Methyl-4-(7-methoxy-2-oxo-2H-chromen-8-yl)-but-2-en-1-al (1). The structures of osthol and compound 1 were elucidated on the basis of MS, IR, 1H and 13C-NMR spectroscopy. Compound 1 on bio-evaluation displayed significant antimicrobial and antifungal activity.

The 4-benzylidene-2-(4-methoxyphenyl)oxazol-5(4H)-one (B) has been prepared from cyclocondensation reaction between hippuric acid (A) with p-anisaldehyde. A series of 4-benzylidene-1-(substitued-2-benzothiazolyl)-2-(4-methoxyphenyl)-1H-imidazol-5(4H)-one (D1-6) have been synthesized from 2-amino substituted benzothiazole (C1-6) by condensation reaction with 4-benzylidene-2-(4-methoxyphenyl)oxazol-5(4H)-one (B). The synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR and Mass spectral data. All the compounds were screened for their antibacterial and antifungal activities.