Cospatial σ-Hole and Lone Pair Interactions of Square-Pyramidal Pentavalent Halogen Compounds with π-Systems: A Quantum Mechanical Study.

In the spirit of the mounting interest in noncovalent interactions, the present study was conducted to scrutinize a special type that simultaneously involved both σ-hole and lone pair (lp) interactions with aromatic π-systems. Square-pyramidal pentavalent halogen-containing molecules, including X-Cl-F4, F-Y-F4, and F-I-X4 compounds (where X = F, Cl, Br, and I and Y = Cl, Br, and I) were employed as σ-hole/lp donors. On the other hand, benzene (BZN) and hexafluorobenzene (HFB) were chosen as electron-rich and electron-deficient aromatic π-systems, respectively. The investigation relied upon a variety of quantum chemical calculations that complement each other. The results showed that (i) the binding energy of the X-Y-F4···BZN complexes increased (i.e., more negative) as the Y atom had a larger magnitude of σ-hole, contrary to the pattern of X-Y-F4···HFB complexes; (ii) the interaction energies of X-Y-F4···BZN complexes were dominated by both dispersion and electrostatic contributions, while dispersive interactions dominated X-Y-F4···HFB complexes; and (iii) the X4 atoms in F-I-X4···π-system complexes governed the interaction energy pattern: the larger the X4 atoms were, the greater the interaction energies were, for the same π-system. The results had illuminating facets in regard to the rarely addressed cases of the σ-hole/lp contradictory scene.

Density Functional Theory, Chemical Reactivity, Pharmacological Potential and Molecular Docking of Dihydrothiouracil-Indenopyridopyrimidines with Human-DNA Topoisomerase II.

In this work, three computational methods (Hatree-Fock (HF), Møller-Plesset 2 (MP2), and Density Functional Theory (DFT)) using a variety of basis sets are used to determine the atomic and molecular properties of dihydrothiouracil-based indenopyridopyrimidine (TUDHIPP) derivatives. Reactivity descriptors of this system, including chemical potential (µ), chemical hardness (η), electrophilicity (ω), condensed Fukui function and dual descriptors are calculated at B3LYP/6-311++ G (d,p) to identify reactivity changes of these molecules in both gas and aqueous phases. We determined the molecular electrostatic surface potential (MESP) to determine the most active site in these molecules. Molecular docking study of TUDHIPP with topoisomerase II α and ß is performed, predicting binding sites and binding energies with amino acids of both proteins. Docking studies of TUDHIPP versus etoposide suggest their potential as antitumor candidates. We have applied Lipinski, Veber's rules and analysis of the Golden triangle and structure activity/property relationship for a series of TUDHIPP derivatives indicate that the proposed compounds exhibit good oral bioavailability. The comparison of the drug likeness descriptors of TUDHIPP with those of etoposide, which is known to be an antitumor drug, indicates that TUDHIPP can be considered as an antitumor drug. The overall study indicates that TUDHIPP has comparable and even better descriptors than etoposide proposing that it can be as effective antitumor drug, especially 2H, 6H and 7H compounds.

Antifouling evaluation of extracts from Red Sea soft corals against primary biofilm and biofouling

Objectives:To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and biofouling.Methods:Seven species of soft corals Sarcophyton glaucum (a),Sinularia compressa,Sinularia cruciata (a),Heteroxenia fuscescens (a),Sarcophyton glaucum (b),Heteroxenia fuscescens (b) and Sinularia cruciata (b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria,Mediterranean Sea.Bioactive compounds of soft corals were extracted by using methanol and concentrated under vacuum.The residues of extracts were mixed in formulation of inert paint which consisted of rosin,chlorinated robber and ferrous oxide against micro and macro fouling organisms.The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic recordings.Results:After 185 days of immersion in seawater,the antifouling results agreed with the antibactedal results where extracts of Sinularia compressa and Heteroxenia fuscescens (b) gave the best activity against marine fouling tubeworms and barnacles.The inhibition activity was correlated with the major functional groups (hydroxyl,amino,carbonyl,aliphatic (fatty acids),C=C of alkene or aromatic rings and C—Cl of aryl halites) of the extracts.Conclusions:The strong antifouling activity makes them promising candidates for new antifouling additives.After the screening and application of natural organic compounds from soft corals,marine organisms show activity against micro and macro fouling organisms.

DFT calculations and electronic absorption spectra of some, α- and γ-pyrone derivatives.

The electronic absorption spectra of 6-ethyl-4-hydroxy-2,5-dioxo-pyrano[3,2-c] quinoline 1, 6-ethyl-4-hydroxy-3-nitro-2,5-dioxo-pyrano[3,2-c] quinoline 2, 6-ethyl-4-chloro-2,5-dioxo-pyrano[3,2-c] quinoline 3, 6-ethyl-3-nitro-4-chloro-2,5-dioxo-pyrano[3,2-c] quinoline 4, 6-ethyl-4,5-dioxopyrano[3,2-c] quinoline 5, and 6-ethyl-3-nitro-6H-pyrano [3,2-c]quinoline-4,5-dione 6, were measured in polar (methanol) as well as nonpolar (dioxane) solvents. The geometries were optimized using B3LYB/6-311G (p,d) method. The most stable geometry of the studied compounds, 1-6, is the planar structure as indicates by the values of the dihedral angles. The insertion of a nitro group in position 3 in both α- and γ-pyrone ring decreases the energy gap and hence increases the reactivity of 3 and 6 compounds. Assignment of the observed bands as localized, delocalized and/or of charge transfer (CT) has been facilitated by TD-DFT calculations. The correspondences between the calculated and experimental transition energies are satisfactory. The solvent and substituent effects have been investigated. Chloro-substituent has a higher band position and intensity effects on the spectra more than hydroxyl or nitro groups.

Changes of serum omentin-1 levels and relationship between omentin-1 and insulin resistance in chronic hepatitis C patients.

OBJECTIVES: Omentin-1 is a novel adipokine that has a pivotal role in modulating the insulin sensitivity, immunity and inflammation. The current study was conducted to evaluate the serum omentin-1 level in hepatitis C virus (HCV) infected patients, with or without type 2 diabetes, and to investigate its correlation with liver function parameters and insulin resistance. METHODS: Eighty subjects were enrolled in this study divided into four groups: chronic HCV infected patients (n=20), chronic hepatitis C patients with concomitant type 2 diabetes (n=18), type 2 diabetic patients (n=22) and 20 healthy controls. Serum omentin-1 levels were assessed using enzyme-linked immunosorbent assay (ELISA). Fasting blood glucose, insulin levels, and liver parameters including aminotransferases (ALT and AST) were determined. RESULTS: Serum omentin-1 levels were significantly elevated in HCV infected patients compared to all other groups. Omentin-1 levels were positively correlated with AST and ALT levels (r =0.43, p< 0.001; r =0.423, p<0.001, respectively). Additionally, a significant negative correlation was found between omentin-1 and both fasting insulin levels and homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.238, p<0.05; r = -0.277, p<0.05, respectively). Furthermore, fasting blood glucose, HbA1c and HOMA-ß were negatively correlated to serum omentin-1 levels however these correlations were not statistically significant. CONCLUSION: Serum omentin-1 level is elevated in HCV infected patients and is positively associated with liver enzymes AST and ALT. This suggested that omentin-1 may be implicated in the pathogenesis of hepatitis C and its metabolic complications. However its role needs to be elucidated by further studies.