Glutathione Modulates Hydrogen Sulfide Release and the Ocular Hypotensive Action of Diallyl Polysulfide Compounds.

Background: Hydrogen sulfide (HS) is an endogenous transmitter with the potential to regulate aqueous humor dynamics and protect retinal neurons from degeneration. The aim of the present study was two-fold: (a) to evaluate the release of HS from two polysulfides, diallyl disulfide (DADS), and diallyl trisulfide (DATS); and (b) to investigate their ocular hypotensive actions in normotensive male and female rabbits in the presence and absence of GSH.

Materials And Methods: HS was quantified hourly for up to 6 h using a HS-Biosensor (World Precision Instruments, Sarasota, Fl).

Comparison of colorimetric, spectroscopic and electrochemical techniques for quantification of hydrogen sulfide.

Hydrogen sulfide (HS), an endogenous gasotransmitter, has potential applications in several conditions. However, its quantification in simulated physiological solutions is a major challenge due to its gaseous nature and other physicochemical properties. This study was designed to compare four commonly used HS detection and quantification methods in aqueous solutions.

New rifamycins produced by a recombinant strain of Nocardia mediterranei.

A recombinant strain of Nocardia mediterranei was found to produce a number of new rifamycins which are structurally related to rifamycin S, rifamycin W and rifamycin G. This strain was derived from two Nocardia mediterranei mutants by intraspecific recombination.

Papulacandins, a new family of antibiotics with antifungal activity, I. Fermentation, isolation, chemical and biological characterization of papulacandins A, B, C, D and E.

Papulacandin, a new antibiotic complex, active against Candida albicans and several other yeasts, was isolated from a strain of Papularia sphaerosperma. The fermentation, isolation, physico-chemical properties and biological activity of the five structurally related papulacandins A, B, C, D and E are reported. Papulacandin B, the main component, was assigned the formula of C47H64O17.

Determination of specific growth stages of plant cell suspension cultures by monitoring conductivity changes in the medium.

Conductivity changes in the medium of cultured soybean (Glycine max L.) cells were shown to be strictly correlated with nitrate uptake and growth of the cultures. A continuous record of the conductivity was used as a simple and reliable method of determining specific growth stages and concomitant peaks in the activities of nitrate reductase and phenylalanine ammonia-lyase.