A new approach for the synthesis of biologically active chromene compounds using a photo catalyst TiO2-Ag

2021 ◽  
pp. 1-21
Author(s):  
George Kupar Kharmawlong ◽  
Ridaphun Nongrum ◽  
John Elisa Kumar ◽  
Bhusan Chhetri ◽  
Arun Kumar Yadav ◽  
...  
Keyword(s):  
Biologically Active ◽  
New Approach ◽  
Photo Catalyst

Nickel(II)- and Silver(I)-Catalyzed C–H Bond Halogenation of Anilides and Carbamates

Synthesis ◽  
2020 ◽  
Author(s):  
Ebrahim Kianmehr ◽  
Hadi Afaridoun
Keyword(s):  
Biologically Active Compounds ◽  
Biologically Active ◽  
Silver Catalyst ◽  
Active Compounds ◽  
Available N ◽  
New Approach

Abstract ortho-C–H bond halogenation of anilides and N-aryl carbamates using easily available N-halosuccinimides (NXS) as the active halogenation reagent in the presence of nickel or silver catalyst has been developed. This method provides a new approach to 2-haloanilides and carbamates, which may serve as starting materials for the synthesis of pharmaceutically and biologically active compounds.

A NEW APPROACH FOR INVESTIGATING HYPOTHALAMO-PITUITARY-GONADAL AND ADRENAL FEEDBACK CONTROL MECHANISMS: ACTIVE IMMUNIZATION WITH STEROIDS

1974 ◽  
Vol 76 (3) ◽  
pp. 556-569 ◽  
Author(s):  
E. Nieschlag ◽  
K. H. Usadel ◽  
H. K. Kley ◽  
U. Schwedes ◽  
K. Schöffling ◽  
...  
Keyword(s):  
Feedback Control ◽  
Leydig Cells ◽  
Positive Response ◽  
Active Immunization ◽  
Biologically Active ◽  
Control Group ◽  
Control Mechanisms ◽  
New Approach ◽  
Biological Neutralization ◽  
Group Serum

ABSTRACT A new method for the investigation of hypothalamo-pituitary-gonadal and adrenal feedback control mechanisms based on the biological neutralization of gonadal and adrenal steroids by active immunization is proposed. The regulatory influence of a given steroid in the feedback control is proved when reduction of the free, biologically active fraction of this steroid caused by antibody binding induces a positive response of the pituitary, thus effecting gonadal or adrenal hypertrophy and hyperfunction. The advantages and limitations of the new model are demonstrated by the effects of active immunization of rabbits with cortisol (F), aldosterone (Aldo), dehydroepiandrosterone (DHA), androstenedione (Δ4-A), testosterone (T), 5α-dihydrotestosterone (5α-DHT), 5β-DHT and oestradiol (E2). In the immunized animals and in a control group serum concentrations of total corticosteroids (TC), DHA, T, Δ4-A, E1, E2, LH and FSH, the percentage of binding of steroids in serum and the specificity of the antisera are determined. The testes are evaluated by histometry and the nuclear volume of the adrenocortical and Leydig cells is measured.

scholarly journals Exosome: A New Player in Translational Nanomedicine

2020 ◽  
Vol 9 (8) ◽  
pp. 2380 ◽  
Author(s):  
Houssam Aheget ◽  
María Tristán-Manzano ◽  
Loubna Mazini ◽  
Marina Cortijo-Gutierrez ◽  
Pablo Galindo-Moreno ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Cell Types ◽  
Structural Features ◽  
Biologically Active ◽  
Biological Processes ◽  
New Approach ◽  
Current State ◽  
Exosome Biogenesis ◽  
Production Techniques

Summary: Exosomes are extracellular vesicles released by the vast majority of cell types both in vivo and ex vivo, upon the fusion of multivesicular bodies (MVBs) with the cellular plasma membrane. Two main functions have been attributed to exosomes: their capacity to transport proteins, lipids and nucleic acids between cells and organs, as well as their potential to act as natural intercellular communicators in normal biological processes and in pathologies. From a clinical perspective, the majority of applications use exosomes as biomarkers of disease. A new approach uses exosomes as biologically active carriers to provide a platform for the enhanced delivery of cargo in vivo. One of the major limitations in developing exosome-based therapies is the difficulty of producing sufficient amounts of safe and efficient exosomes. The identification of potential proteins involved in exosome biogenesis is expected to directly cause a deliberate increase in exosome production. In this review, we summarize the current state of knowledge regarding exosomes, with particular emphasis on their structural features, biosynthesis pathways, production techniques and potential clinical applications.

Asymmetric cyclopropanation of chiral (1-phosphoryl)vinyl sulfoxides: A new approach to constrained analogs of biologically active compounds

2005 ◽  
Vol 77 (12) ◽  
pp. 2091-2098 ◽  
Author(s):  
Marian Mikołajczyk
Keyword(s):  
Transition State ◽  
Total Synthesis ◽  
Bioactive Compounds ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Biologically Active ◽  
Active Compounds ◽  
New Approach ◽  
Cyclic Analog ◽  
Asymmetric Cyclopropanation

This account outlines the results obtained in the author's laboratory on the asymmetric cyclopropanation of enantiopure 1-phosphorylvinyl p-tolyl sulfoxides with sulfur ylides and diazoalkanes. Based on experimental results and theoretical calculations, the transition-state model for asymmetric cyclopropanation is proposed. A great synthetic value of the reaction investigated is exemplified by the total synthesis of constrained analogs of bioactive compounds, namely, enantiopure cyclic analog of phaclofen and cyclopropylphosphonate analogs of nucleotides.

Theoretical interpretation of retention data of polychlorinated biphenyls in liquid chromatography

1991 ◽  
Vol 56 (12) ◽  
pp. 2833-2848
Author(s):  
Vladimír Jakuš ◽  
Stanislav Miertuš
Keyword(s):  
Polychlorinated Biphenyls ◽  
Biologically Active ◽  
Dominant Factor ◽  
Theoretical Interpretation ◽  
Retention Data ◽  
Theoretical Evaluation ◽  
Retention Model ◽  
New Approach ◽  
Rp Hplc ◽  
Mobile Phases

The new approach to the theoretical evaluation of Gibbs free energy of solvation is applied to the estimation of retention data in RP-HPLC. Simple models of stationary and mobile phases in RP-HPLC are used. The correlation between retention data of a series of 15 polychlorinated biphenyls (measured on chemically bonded stationary phase with C18 alkyl chains) and the contribution of the Gibbs solvation energy is investigated in order to determine the dominant factor controlling retention. The retention in RP-HPLC can be predicted on the basis of our thermodynamic retention model. This approach is suitable especially when no standards are available for some derivatives (e.g. metabolites of biologically active substances) and when the interpretation of experimental elution is not clear.

A New Approach to the Production of Bioresorbable Suture Materials with Biological Activity

2018 ◽  
Vol 935 ◽  
pp. 94-99
Author(s):  
Mukhamed A. Khavpachev ◽  
E.S. Trofimchuk ◽  
N.I. Nikonorova
Keyword(s):  
Biological Activity ◽  
Biologically Active ◽  
Degree Of Crystallinity ◽  
Uniaxial Deformation ◽  
Suture Materials ◽  
Ethanol Mixture ◽  
New Approach ◽  
Low Temperature Crystallization ◽  
Solvent Crazing ◽  
Temperature Crystallization

The advantages of structural-mechanical modification of fibers by the mechanism of crazing for obtaining bioresorbable suture materials with biological activity are shown. Optimal conditions for realization of solvent crazing of polylactide fibers are determined as the stretching rate is not more than 75% / min and the ethanol content in the water-ethanol mixture is not less than 30-40% by weight. In this case, the value of yield stress decreases by 3-5 times, and the breaking elongation increases to 400-600%. The process of uniaxial deformation of fibers under these conditions is accompanied by the formation of a highly dispersed oriented structure with a pore diameter and fibrils of about 20-30 nm and bulk porosity up to 60% by volume. Moreover, the crazing of fibers based on polylactide under these conditions is accompanied by low-temperature crystallization, reaching a degree of crystallinity of 40%. The monofilaments based on polylactide containing biologically active additives (brilliant green, fuchsine) by the crazing mechanism are obtained. Such materials are promising for use in medicine as bioresorbable sutures with antibacterial activity.

New approach to the synthesis of biologically active derivatives of pyranocoumarins

2019 ◽  
Author(s):  
A. K. Inyutina ◽  
R. F. Fatykhov ◽  
I. A. Khalymbadzha ◽  
A. D. Sharapov ◽  
M. V. Bobkina ◽  
...  
Keyword(s):  
Biologically Active ◽  
New Approach ◽  
Derivatives Of ◽  
Biologically Active Derivatives

ChemInform Abstract: Synthesis and Biological Properties of Novel Phosphotriesters: A New Approach to the Introduction of Biologically Active Nucleotides into Cells.

ChemInform ◽  
1990 ◽  
Vol 21 (48) ◽  
Author(s):  
S. N. FARROW ◽  
A. S. JONES ◽  
A. KUMAR ◽  
R. T. WALKER ◽  
J. BALZARINI ◽  
...  
Keyword(s):  
Biological Properties ◽  
Biologically Active ◽  
New Approach
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