Numerous natural compounds have a potential for therapeutic applications, but may have to be chemically modified to alter toxic side effects. We investigated structural parameters that could affect the cytotoxicity of isocoumarins similar to 9,10-dihydroxy-5,7-dimethoxy-1H-naphtho(2,3c)pyran-1-one (paepalantine 1). Paepalantine 1 has antimicrobial activity, as well as significant in vitro cytot...

Nanostructured lipid carriers (NLCs) were employed to formulate a lipophilic drug into hydrophilic polymeric microneedles (MNs). Hyaluronic acid (HA) was selected as a hydrophilic and bioerodible polymer to fabricate MNs, and nile red (NR) was used as a model lipophilic molecule. NR-loaded NLCs were consolidated into the HA-based MNs to prepare NLC-loaded MNs (NLC-MNs). A dispersion of NLCs was...

A photoactivated neutral organic super electron donor cleaves challenging arenesulfonamides derived from dialkylamines at room temperature. It also cleaves a) ArCNR and b) ArNC bonds. This study also highlights the assistance given to these cleavage reactions by the groups attached to N in (a) and to C in (b), by lowering LUMO energies and by stabilizing the products of fragmentation.

I investigations carried out in this laboratory have been concerned with the initial responses of the corneal stromal cells to injury. One reaction which occurs in the stromal cells within a few hours after injury to the cornea is the activation of the fibrocytes to take up the vital dye, neutral red.' This reaction does not occur in the normal corneal stromal cells of the rat, but cells activa...

A spectrophotometric study of the system heptanol—Nile red (NR)—water was carried out, where, for first time such studies, a non-colloidal surfactant that does not form micelles taken as surfactant. The dependence solubility NR on concentration heptanol in an aqueous solution studied. experiments were out at given chemical potential NR, which provided by excess solid phase NR. existence solubil...

The New Zealand white (NZW) rabbit fed a 0.1% cholesterol-enriched diet (CD) typically responds (normoresponsive, NR) by quickly developing hypercholesterolemia. To study the underlying mechanisms responsible for the widespread phenomenon of inter-individual variability of response to dietary cholesterol, a unique hypercholesterolemia-resistant (RT) rabbit model was developed. These animals wer...

Assessment of the cellular effects of natural and/or synthetic products is one of the major goals in biological experiments. This assessment may be conducted at different levels; cellular viability, cellular biological activity, and cellular structure and morphology. Different assays are available for any of above purposes. It is becoming of a routine exercise to apply any of these assays, and ...

Tandem mass spectrometry methods were used to study the sites of protonation and for identification of 3-amino-1,2,4-benzotriazine 1,4-dioxide (1, tirapazamine), and its metabolites (3-amino-1,2,4-benzotriazine 1-oxide (3), 3-amino-1,2,4-benzotriazine 4-oxide (4), 3-amino-1,2,4-benzotriazine (5), and a related isomer 3-amino-1,2,4-benzotriazine 2-oxide (6). Fragmentation pathways of 3 and 5 ind...

After treatment with neutral red at low concentrations (10(-6), 10(-5) M), the chromatin of chicken erythrocytes shows an intensive red fluorescence, which is reduced or practically abolished when nuclei become stained by using the dye at concentrations higher than 10(-4) M. Both the fluorescence and staining reactions are dependent on the DNA content of chromatin. Neutral red fluorescence of n...

Bacterial nitroreductases are NAD(P)H-dependent flavoenzymes which catalyze the oxygen-insensitive reduction of nitroaromatics, quinones, and riboflavin derivatives. Despite their broad substrate specificity, their reactivity is very specific for two-electron, not one-electron, chemistry. We now describe the thermodynamic properties of the flavin mononucleotide cofactor of Enterobacter cloacae ...