42 research outputs found
Supramolecular insulin assembly II for a sustained treatment of type 1 diabetes mellitus
Diabetes is a chronic disease requiring continuous medical supervision and patient education to prevent acute secondary complications. In this study, we have harnessed the inherent property of insulin to aggregate into an oligomeric intermediate on the pathway to amyloid formation, to generate a form that exhibits controlled and sustained release for extended periods. Administration of a single dose of the insulin oligomer, defined here as the supramolecular insulin assembly II (SIA-II), to experimental animals rendered diabetic by streptozotocin or alloxan, released the hormone capable of maintaining physiologic glucose levels for > 120 days for bovine and > 140 days for recombinant human insulin without fasting hypoglycemia. Moreover, the novel SIA-II described here not only improved the glycemic control, but also reduced the extent of secondary diabetic complications
Difluoromethyl Bioisostere: Examining the “Lipophilic Hydrogen Bond Donor” Concept
There
is a growing interest in organic compounds containing the
difluoromethyl group, as it is considered a lipophilic hydrogen bond
donor that may act as a bioisostere of hydroxyl, thiol, or amine groups.
A series of difluoromethyl anisoles and thioanisoles was prepared
and their druglike properties, hydrogen bonding, and lipophilicity
were studied. The hydrogen bond acidity parameters <i>A</i> (0.085–0.126) were determined using Abraham’s solute <sup>1</sup>H NMR analysis. It was found that the difluoromethyl group
acts as a hydrogen bond donor on a scale similar to that of thiophenol,
aniline, and amine groups but not as that of hydroxyl. Although difluoromethyl
is considered a lipophilicity enhancing group, the range of the experimental
Δlog <i>P</i>(water–octanol) values (log <i>P</i>(XCF<sub>2</sub>H) – log <i>P</i>(XCH<sub>3</sub>)) spanned from −0.1 to +0.4. For both parameters,
a linear correlation was found between the measured values and Hammett
σ constants. These results may aid in the rational design of
drugs containing the difluoromethyl moiety
Species-specific lipophilicities of fluorinated diketones in complex equilibria systems and their potential as multifaceted reversible covalent warheads
Abstract Combined molecular, physicochemical and chemical properties of electrophilic warheads can be applied to create covalent drugs with diverse facets. Here we study these properties in fluorinated diketones (FDKs) and their multicomponent equilibrium systems in the presence of protic nucleophiles, revealing the potential of the CF2(CO)2 group to act as a multifaceted warhead for reversible covalent drugs. The equilibria compositions of various FDKs in water/octanol contain up to nine species. A simultaneous direct species-specific 19F-NMR-based log P determination of these complex equilibria systems was achieved and revealed in some cases lipophilic to hydrophilic shifts, indicating possible adaptation to different environments. This was also demonstrated in 19F-MAS-NMR-based water-membrane partitioning measurements. An interpretation of the results is suggested by the aid of a DFT study and 19F-DOSY-NMR spectroscopy. In dilute solutions, a model FDK reacted with protected cysteine to form two hemi-thioketal regioisomers, indicating possible flexible regio-reactivity of CF2(CO)2 warheads toward cysteine residues