A new natural product and insecticidal amides from seeds of Piper nigrum Linn

Studies on the petroleum ether soluble and insoluble fraction of ethanol extract of dried ground seeds of Piper nigrum resulted in the isolation and structure elucidation of 1 new and 11 known compounds which include 3 hitherto unreported constituents, namely, cinnamylideneacetone, 3,4-methylenedioxyphenylpropiophenone and 2-hydroxy-4,5-methylenedioxypropiophenone from this plant.     

Morphology-controlled assembly of ZnO nanostructures: a bioinspired method and visible luminescence

In a bioinspired methodology, positively charged polypeptides and polyamines directly catalyse ZnO mineralization under "green" conditions of room temperature and neutral pH. The polyamines not only act as mineralizing agents for the formation of ZnO nanoparticles, but also self-assemble the nanoparticles to form spindle-like morphologies at these very ambient conditions. Both the directional growth of ZnO and its luminescent property have a pH dependency. At higher pH, the ZnO shape changes to a rodlike morphology that exhibits green photoluminescence with different intensity than that for ZnO spindles.     

A comparative study of the reactivity of unsaturated triosmium clusters [Os3(CO)8{μ3-Ph2PCH2P(Ph)C6H4}(μ-H)] and [Os3(CO)9{μ3-η-C7H3(2-Me)NS}(μ-H)] with BuNC

Treatment of unsaturated [Os₃(CO)₈{μ₃-Ph₂PCH₂P(Ph)C₆H₄}(μ-H)] (2) with ^tBuNC at room temperature gives [Os₃(CO)₈(CNBu^t)){μ₃-Ph₂PCH₂P(Ph)C₆H₄}(μ-H)] (3) which on thermolysis in refluxing toluene furnishes [Os₃(CO)₇(CNBu^t){μ₃-Ph₂PCHP(Ph)C₆H₄}(μ-H)₂] (4). Reaction of the labile complex [Os₃(CO)₉(μ-dppm)(NCMe)] (5) with ^tBuNC at room temperature affords the substitution product [Os₃(CO)₉(μ-dppm)(CNBu^t)] (6). Thermolysis of 6 in refluxing toluene gives 4. On the other hand, the reaction of unsaturated [Os₃(CO)₉{μ₃-η²-C₇H₃(2-Me)NS}(μ-H)] (7) with ^tBuNC yields the addition product [Os₃(CO)₉(CNBu^t){μ-η²-C₇H₃(2-Me)NS}(μ-H)] (8) which on decarbonylation in refluxing toluene gives unsaturated [Os₃(CO)₈(CNBu^t){μ₃-η²-C₇H₃(2-Me)NS}(μ-H)] (9). Compound 9 reacts with PPh₃ at room temperature to give the adduct [Os₃(CO)₈(PPh₃)(CNBu^t){μ-η²-C₇H₃(2-Me)NS(μ-H)] (10). Compound 8 exists as two isomers in solution whereas 10 occurs in four isomeric forms. The molecular structures of 3, 6, 8, and 10 have been determined by X-ray diffraction studies.     

Nematicidal natural products from the aerial parts of Lantana camara Linn

Lantanilic acid, camaric acid and oleanolic acid possessing nematicidal activity were isolated from the methanolic extract of the aerial parts of Lantana camara Linn. through bio-assay guided fractionation. These compounds exhibited 98%, 95% and 70% mortality respectively against root-knot nematode Meloidogyne incognita at 0.5% concentration. Conventional nematicide furadan showed 100% mortality at this concentration.     

Insecticidal amides from fruits of Piper nigrum Linn

The petroleum ether and ethyl acetate fractions of dried ground seeds of Piper nigrum Linn. afforded sixteen compounds (1-16) including one new insecticidal amide, pipwaqarine (1) and six constituents (3,4,6,7,11,15) previously unreported from this plant. The structure of (1) has been elucidated through extensive 1D-, 2D-NMR spectral studies as, 1-[13-(3',4'-methylenedioxyphenyl)-2E,4E,12E-tridecatrienoyl]-N-isopentylamide, while those of known constituents through comparison of spectral data. 1 exhibited toxicity of 30ppm against fourth instar larvae of Aedes aegypti Liston determined by WHO method. A portion of petroleum ether fraction was also subjected to GC and GC-MS analysis resulting in the identification of three compounds (17-19) using the NIST Mass spectral search program 1998 and Kovat's retention indices. Two of these compounds, 17 and 18, are reported for the first time from this plant.     

Lauric acid as biological active ligand for complexation with d-block metals

Complexes of lauric acid with general formula M(L)₂ · xH₂O (M = Cu, Co, Ni, Mn) and M(L)₂ (M = Zn, Hg) where L = (CH₃(CH₂)₁₀COOH) have been synthesized. Their elemental analyses show the good agreement between calculated and experimental values. These complexes have been characterized by spectroscopic techniques, such as IR, UV-visible, atomic absorption, and mass spectrometry, which show that the carboxylate group acts as bidentate in the solid state. Kinetic parameters, such as the order of reaction, activation energy, enthalpy, and entropy were calculated using the Coats and Horowitz methods. The calculated values are in a good agreement with the observed TG values that confirm the structural integrity of the complexes. These complexes were screened for their in vitro biological activities against different bacteria and fungi to establish their significance. The article was submitted by the authors in English.     

Controlled Orientation in a Bio‐Inspired Assembly of Ag/AgCl/ZnO Nanostructures Enables Enhancement in Visible‐Light‐Induced Photocatalytic Performance

In a bio‐inspired approach, polyamine‐mediated mineralization of ZnO was explored to develop an environmentally benign methodology for synthesizing Ag/AgCl/ZnO nanostructures. The assembling properties displayed by the polyamines to create composite structures was utilized to have the nanocomponents effectively interact with each other in a way that is desirable for the application envisaged. The polyamines, which act as a mineralizing agent for ZnO nanoparticles, also facilitate the formation of Ag/AgCl within ZnO under ambient conditions. Thus synthesized Ag/AgCl/ZnO nanostructures represent a multi‐heterojunction system in which the nanocomponents lead in a synergistic way to enhancement in the photocatalytic activity under visible‐light irradiation.     

Kernel ideals of a Stone JP-semilattice

A meet semilattice with a partial join operation satisfying some axioms is a JP-semilattice. A PJP-semilattice is a pseudocomplemented JP-semilattice. We characterize Stone JP-semilattices, give some characterizations of kernel ideals of a Stone JP-semilattice, and describe the join of two kernel ideals of a Stone JP-semilattice.     

A unique approach in ultra-flattened dispersion photonic crystal fibers containing elliptical air-holes

In this paper, we report that it is possible to control chromatic dispersion of index guiding PCFs in wide wavelength range by arranging the major axis of the first inner ring perpendicular to that of the second inner ring. Using this unique arrangement, a newly PCF with ultra-low and ultra-flattened dispersion is designed through a finite difference method with anisotropic perfectly matched layers absorbing boundary condition. As an example, we have design a unique PCF with flattened dispersion of ±0.23 ps/(nm·km) from 1.5 to 1.8 μm wavelength and confinement losses of less than 10⁻¹³ dB/m in the wavelength range shorter than 1.8 μm.