The synthesis of 11-betero steroids

With the object of synthesizing nucleo-hetero steroids of potential biological interest and of correlating chemical structure and biological activity in this field, we undertook a program on the synthesis of 11-oxa and 11-aza steroids...Montréal Trigonix inc. 201

Encapsulation of Vitamin C into β‐Cyclodextrin for Advanced and Regulatory Release

Host‐guest inclusion complex (IC) of vitamin C with β‐cyclodextrin (β‐CD) in aqueous medium has been explored by spectroscopic, physicochemical and calorimetric methods as stabilizer, carrier and regulatory releaser. Job plot has been drawn by UV‐visible spectroscopy to confirm the 1:1 stoichiometry of the host‐guest assembly. Stereo‐chemical nature of the inclusion complex has been explained by two‐dimensional (2D) NMR spectroscopy. Surface tension and conductivity studies further support the inclusion process. Association constants for the vitamin C‐β‐CD inclusion complex have been calculated by UV‐visible spectroscopy using both Benesi‐Hildebrand method and non‐linear programme, while the thermodynamic parameters have been estimated with the help of van’t Hoff equation. Isothermal titration calorimetric study has been performed to determine the stoichiometry, association constant and thermodynamic parameters with high accuracy

Molecular interactions with reference to manifestation of solvation effects in binary mixtures of ethyl acetoacetate with some methane derivatives by physicochemical techniques

Density, ρ, viscosity, η, speed of sound, u, and refractive index, nD, were measured for the binary systems of ethyl acetoacetate with dichloromethane, chloroform, carbon tetrachloride, nitromethane, methyl acetate, acetonitrile and acetic acid at 298.15 K over the entire composition range. From the experimental results, the excess molar volume, VE and the deviation in viscosity, Δη, were calculated. Isentropic compressibility, kSE, and deviation in molar refractive index, ΔR, were also calculated. These results were fitted to Redlich-Kister polynomial equation. The density and viscosity data were analyzed by some semi-empirical viscosity models, and the results have been discussed in terms of molecular interactions and structural effects. The excess properties were found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures. To explore the nature of the interactions, various thermodynamic parameters (e.g., intermolecular free length, specific acoustic impedance, etc.) have also been derived from the density and ultrasonic speed data.KEY WORDS: Density, Viscosity, Speed of sound, Isentropic compressibility, Molar refractive index, Ethyl acetoacetateBull. Chem. Soc. Ethiop. 2010, 24(1), 103-114

Synthesis and Characterization of Host Guest Inclusion Complexes of Cyclodextrin Molecules with Theophylline by Diverse Methodologies

Steady host–guest inclusion complexes have been produced with medicinally important guest molecule theophylline within aqueous α-Cyclodextrin and HP-β-Cyclodextrin. α-and HP-β-Cyclodextrins have been established with favorable structural features for inclusion with Theophylline which include diversified applications in modern science such as controlled delivery in the field of pharmaceuticals, food processing, pesticides, foodstuffs etc. Theophylline is one of the most widely accepted drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD) worldwide, even if it has been used clinically for many years. With both α and HP-β-Cyclodextrins it is found that 1:1 hosts-guest inclusion complexes are formed with the guest molecule theophylline. The construction and quality of the inclusion complexes have been characterized by using conductivity measurement, surface tension study, and Job’s method. The inclusion phenomenon has been confirmed by FTIR spectroscopy, proton NMR study. Association constants and thermodynamic parameters have been evaluated for the created inclusion complexes by ultraviolet spectroscopy

Exploring Existence of Host-Guest Inclusion Complex of β-Cyclodextrin of a Biologically Active Compound with the Manifestation of Diverse Interactions

The host–guest interaction of p-nitro benzaldehyde as guest β-Cyclodextrins have been investigated which have significant applications in the field of medicine such as controlled drug delivery. The 1H NMR study confirms the formation of inclusion complex while surface tension and conductivity studies support the formation inclusion complex with 1:1 stoichiometry. The stoichiometry of the inclusion complex was also supported with Job’s plot method by UV-Visible spectroscopy. FT-IR spectra and SEM study also support the inclusion process. Association constants of  the inclusion complexes have  been  calculated using  the  Benesi–Hildebrand  method,  while  the  thermodynamic  parameters  have  been  estimated  with  the help  of  van’t  Hoff  equation

Off-shell effects in pion-nucleus interactions / by M.N. Sinha Roy

Typescript (photocopy)119 leaves : ill. ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dept. of Mathematical Physics, 198

Studies of viscous antagonism, excess molar volumes, viscosity deviation and isentropic compressibility of ternary mixtures containing N,N-dimethylformamide, benzene and some ethers at 298.15 K

The densities (r) and viscosities (h) for ternary liquid mixtures of N,N-dimethylformamide + benzene + an ether were measured as a function of composition at 298.15 K. From experimental measurements, the excess molar volumes (VE), viscosity deviation (Δh), antagonic interaction index (IA) and Gibbs free energy of activation for viscous flow (ΔGE) were evaluated. The speeds of sound were also measured and excess isentropic compressibilities (KsE) were calculated at the experimental temperature. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding