Pyridine alkaloids from Senna multijuga as acetylcholinesterase inhibitors.

As part of an ongoing research project on Senna and Cassia species, five new pyridine alkaloids, namely, 12'-hydroxy-7'-multijuguinol (1), 12'-hydroxy-8'-multijuguinol (2), methyl multijuguinate (3), 7'-multijuguinol (4), and 8'-multijuguinol (5), were isolated from the leaves of Senna multijuga (syn. Cassiamultijuga). Their structures were elucidated on the basis of spectroscopic data analysis.

Nitrosyl hydride (HNO) replaces dioxygen in nitroxygenase activity of manganese quercetin dioxygenase.

Quercetin dioxygenase (QDO) catalyzes the oxidation of the flavonol quercetin with dioxygen, cleaving the central heterocyclic ring and releasing CO. The QDO from Bacillus subtilis is unusual in that it has been shown to be active with several divalent metal cofactors such as Fe, Mn, and Co. Previous comparison of the catalytic activities suggest that Mn(II) is the preferred cofactor for this enzyme.

Acetylcholinesterase inhibitory pyridine alkaloids of the leaves of Senna multijuga.

Two unusual pyridine alkaloids, 7'-multijuguinone (1) and 12'-hydroxy-7'-multijuguinone (2), were isolated from the leaves of Senna multijuga, together with the known flavonoid rutin. The structures of the new alkaloids were established on the basis of spectroscopic data interpretation. Compounds 1 and 2 exhibited moderate in vitro acetylcholinesterase (AChE) inhibitory activity, in comparison with the standard compound physostigmine.

Isolation and enrichment of secreted proteins from filamentous fungi.

Filamentous fungi have been recognized as extraordinary producers of secreted proteins and are known to produce novel proteins and enzymes through dispensable metabolic pathways. Here, methods are described for the isolation and enrichment of samples of secreted proteins from cultures of filamentous fungi for analysis by gel electrophoresis and mass spectrometry techniques. These methods can be readily applied to the study of differential protein expression and secretion and metabolic pathways in filamentous fungi by proteomic approaches.

[In vitro antimicrobial susceptibility of coagulase negative staphylococcal ocular isolates].

Purpose: To assess the in vitro susceptibility of conjunctival and corneal coagulase negative Staphylococcus (CoNS) to methicillin, fluoroquinolones and aminoglycosides.

Methods: A total of 707 conjunctival and corneal CoNS disk diffusion test results were retrospectively analyzed, from January 2000 through December 2003.

Results: From 2000 to 2003, there was an increase in number of CoNS isolated from conjunctiva (n=57 to n=153) and cornea (n=28 to n=78).