On the deformed aeral spaces. — II

Summary This paper deals with the generalization of the Lie-derivatives in an Areal space of the general type with the use of the m-dimensional area element p^i[m] and thereafter the theory of the deformed Areal spaces and the covariant derivations in it have been discussed. Moreover, several commutation formulae concerning the operators of Lie and covariant differentiations have been deduced here. Dedicated to the memory of Late Prof.J. A. Schouten Entrata in Redazione il 20 gennaio 1975.     

Mixed ligand derivatives of Th(IV)-EDTA,-CDTA or-DTPA chelate with glycollic and malic acids

The interaction of 11 Th(IV)-EDTA,-CDTA or-DTPA chelate with glycollic and malic acids has been investigated potentiometrically and the formation of 111 mixed ligand chelates inferred from the potentiometric curves. The hydrolysis and dimerization constants of the binary chelates and the equilibrium constants of the ternary derivatives have been evaluated at 30±1° and 35±1°C and also the thermodynamic functions, viz. F ⁰, H and S.With 3 Figures     

Intramolecular hydrogen bond strength and pK(a) determination of N,N'-disubstituted imidazole-4,5-dicarboxamides

N,N'-Disubstituted imidazole-4,5-dicarboxamides (I45DCs) form an intramolecular hydrogen bond worth an estimated 14 +/- 1 kcal/mol, as measured with a model structure in DMSO-d6 at 3 mM, thereby predisposing the molecular conformation to a folded rather than extended form. The I45DCs also show evidence of aggregation in both CDCl3 (>1 mM) and DMSO-d6 (>10 mM) solutions. These compounds are uncharacteristically weak bases in comparison with imidazoles bearing similar electron-withdrawing groups.     

Solvohyperiodination. A comparison with solvothallation

C₆H₅IO/CH₃OH and a catalyst such as FSO₃H , CF₃SO₃H or BF₃-Et₂O as well as C₆H₅(OH)OTs-CH₃OH,react with chalcones, acetophenones and styrenes to yield rearranged products. The overall course of these reactions is analogous to that of Tl(NO₃)₃-CH₃OH in reaction with the same compounds.     

Reactions of trifluoroamine oxide: a new method for selective fluorination of 1,3-diketones and β-ketoesters

Fluorination of 1,3-diketones and β-ketoesters with trifluoroamine oxide in the presence of tetrabutylammonium hydroxide (TBAH) provides a one step route to mono- and difluoro-products selectively fluorinated at the α-position in good yields.     

Active site fingerprinting and pharmacophore screening strategies for the identification of dual inhibitors of protein kinase C $$(\hbox {PKC}{\upbeta })$$ and poly (ADP-ribose) polymerase-1 (PARP-1)

Current clinical studies have revealed that diabetic complications are multifactorial disorders that target two or more pathways. The majority of drugs in clinical trial target aldose reductase and protein kinase C (\(\text {PKC}{\upbeta }\)), while recent studies disclosed a significant role played by poly (ADP-ribose) polymerase-1 (PARP-1). In light of this, the current study was aimed to identify novel dual inhibitors of \(\text {PKC}{\upbeta }\) and PARP-1 using a pharmaco-informatics methodology. Pharmacophore-based 3D QSAR models for these two targets were generated using HypoGen and used to screen three commercially available chemical databases to identify dual inhibitors of \(\text {PKC}{\upbeta }\) and PARP-1. Overall, 18 hits were obtained from the screening process; the hits were filtered based on their drug-like properties and predicted binding affinities (docking analysis). Important amino acid residues were predicted by developing a fingerprint of the active site using alanine-scanning mutagenesis and molecular dynamics. The stability of the complexes (18 hits with both proteins) and their final binding orientations were investigated using molecular dynamics simulations. Thus, novel hits have been predicted to have good binding affinities for \(\text {PKC}{\upbeta }\) and PARP-1 proteins, which could be further investigated for in vitro/in vivo activity.     

Antifungal and phytotoxic activity of essential oil from root of Senecio amplexicaulis Kunth. (Asteraceae) growing wild in high altitude-Himalayan region

This work was aimed to evaluate the essential oil from root of medicinally important plant Senecio amplexicaulis for chemical composition, antifungal and phytotoxic activity. The chemical composition analysed by GC/GC–MS showed the presence of monoterpene hydrocarbons in high percentage with marker compounds as α-phellandrene (48.57%), o-cymene (16.80%) and β-ocimene (7.61%). The essential oil exhibited significant antifungal activity against five phytopathogenic fungi, Sclerotium rolfsii, Macrophomina phaseolina, Rhizoctonia solani, Pythium debaryanum and Fusarium oxysporum. The oil demonstrated remarkable phytotoxic activity in tested concentration and significant reduction in seed germination percentage of Phalaris minor and Triticum aestivum at higher concentrations. The roots essential oil showed high yield for one of its marker compound (α-phellandrene) which makes it important natural source of this compound.     

Self-assembly of ionic liquid (BMI-PF6)-stabilized gold nanoparticles on a silicon surface: chemical and structural aspects

Ultrafine monodisperse gold nanoparticles (AuNPs) were synthesized by an elegant sputtering of gold onto 1- n-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF(6)) ionic liquid. It was found that the BMI-PF(6) supramolecular aggregates were loosely coordinated to the gold nanoparticles and were replaceable with thiol molecules. The self-assembly of BMI-PF(6)-stabilized AuNPs onto a (3-mercaptopropyl)trimethoxysilane (MPS)-functionalized silicon surface in 2D arrays, followed by dodecanethiol (DDT) treatment, have been demonstrated using X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and contact angle measurements. DDT treatment of tethered AuNPs revealed two types of interactions between AuNPs and the MPS-functionalized surface: (a) AuNPs anchor through Au-S chemisorption linkage resulting in strong immobilization and (b) some of the AuNPs are supported by physisorption, driven by BMI-PF(6). The attachment of these particles remains unchanged with sonication. The replacement of BMI-PF(6) aggregates from physisorbed AuNPs with DDT molecules advances the dilution of their interaction with the MPS-functionalized surface, and they subsequently detach from the silicon surface. The present finding is promising for the immobilization of ionic liquid-stabilized nanoparticles, which is very desirable for electronic and catalytic device fabrication. Additionally, these environmentally friendly AuNPs are expected to replace conventional citrate-stabilized AuNPs.     

The chemistry of α,β-ditosyloxyketones: new and convenient route for the synthesis of 1,4,5-trisubstituted pyrazoles from α,β-chalcone ditosylates

The reaction of α,β-chalcone ditosylates with various reagents such as phenylhydrazine hydrochloride, semicarbazide hydrochloride and thiosemicarbazide in suitable conditions leads to 1,2-aryl shift, thereby providing a novel route for the synthesis of 1,4,5-trisubstituted pyrazoles.     

Hot Branching Dynamics in a Light-Harvesting Iron Carbene Complex Revealed by Ultrafast X-ray Emission Spectroscopy

Iron N-heterocyclic carbene (NHC) complexes have received a great deal of attention recently because of their growing potential as light sensitizers or photocatalysts. We present a sub-ps X-ray spectroscopy study of an Fe^IINHC complex that identifies and quantifies the states involved in the deactivation cascade after light absorption. Excited molecules relax back to the ground state along two pathways: After population of a hot ³MLCT state, from the initially excited ¹MLCT state, 30 % of the molecules undergo ultrafast (150 fs) relaxation to the ³MC state, in competition with vibrational relaxation and cooling to the relaxed ³MLCT state. The relaxed ³MLCT state then decays much more slowly (7.6 ps) to the ³MC state. The ³MC state is rapidly (2.2 ps) deactivated to the ground state. The ⁵MC state is not involved in the deactivation pathway. The ultrafast partial deactivation of the ³MLCT state constitutes a loss channel from the point of view of photochemical efficiency and highlights the necessity to screen transition-metal complexes for similar ultrafast decays to optimize photochemical performance.