Learn More
To observe the effect of Chinese herbal medicine by stages combined with chemotherapy in treating patients with non-small-cell lung cancer (NSCLC) of stage III or IV. Adopting prospective, randomized, controlled, multi-centered trial design, 121 patients enrolled were assigned to the treatment group (n = 65) and the control group (n = 56). All the patients(More)
Holomycin and its derivatives belong to a class of broad-spectrum antibacterial natural products containing a rare dithiolopyrrolone heterobicyclic scaffold. The antibacterial mechanism of dithiolopyrrolone compounds has been attributed to the inhibition of bacterial RNA polymerase activities, although the exact mode of action has not been established in(More)
This review outlines the recent developments in uncovering the enzymes and intermediates involved in fluorometabolite biosyntheses in the bacterium Streptomyces cattleya. A particular emphasis is placed on the purification and characterisation of the fluorinase, the C-F bond forming enzyme which initiates the biosynthesis. Nature has hardly developed a(More)
Fluorine is the thirteenth most abundant element in the earth's crust, but fluoride concentrations in surface water are low and fluorinated metabolites are extremely rare. The fluoride ion is a potent nucleophile in its desolvated state, but is tightly hydrated in water and effectively inert. Low availability and a lack of chemical reactivity have largely(More)
The fluorinase from Streptomyces cattleya and chlorinase from Salinispora tropica have a commonality in that they mediate nucleophilic reactions of their respective halide ions to the C-5' carbon of S-adenosyl-L-methionine (SAM). These enzyme reactions fall into the relatively small group of S(N)2 substitution reactions found in enzymology. These enzymes(More)
The stereochemical course of the recently isolated fluorination enzyme from Streptomyces cattleya has been evaluated. The enzyme mediates a reaction between the fluoride ion and S- adenosyl-L-methionine (SAM) to generate 5'-fluoro-5'-deoxyadenosine (5'-FDA). Preparation of (5'R)-[5-(2)H(1)]-ATP generated (5'R)-[5-(2)H(1)]-5'-FDA in a coupled enzyme assay(More)
The fluorinase enzyme from Streptomyces cattleya displays an unusual ability in biocatalysis in that it forms a C-F bond. We now report that the enzyme will accept 2'-deoxyadenosine in place of adenosine substrates, and structural evidence reveals a reorganisation in hydrogen bonding to accommodate this substrate series. It emerges from this study that the(More)