Novel p-terphenyl glycoside with a rare 2,6-dideoxyhexopyranose moiety from Actinomycete strain SF2911 that inhibits cancer cell migration.

In the course of our search for inhibitors of LPS-induced NO production from microbial strains, an ethyl acetate extract of Actinomycete SF2911, isolated from a soil sample collected in Okinawa Prefecture, Japan, showed the inhibitory activity. The active principle was purified and structure determination led to the isolation of one new compound. Since the structure belongs to the terfestatin family, we named it terfestatin D (1). It was found to inhibit cellular migration of breast carcinoma cells as well as NO production. We herein report the isolation, structure elucidation and biological activities of this new compound.

Isolation of a novel paxilline analog pyrapaxilline from fungus that inhibits LPS-induced NO production.

We have screened microbial culture filtrates for nitrogen monoxide (NO) production inhibitors using mouse macrophage cell line RAW264.7. As a result, paxilline, 21-isopentenylpaxilline and a novel analog of paxilline have been isolated from the culture filtrate of fungus Eupenicillium shearii. The novel analog possesses an additional dihydropyran ring, and was named as pyrapaxilline. This compound inhibited the NO production with lower toxicity than paxilline.

Pseurotin A and its analogues as inhibitors of immunoglobulin E [correction of immunoglobuline E] production.

A natural product, pseurotin A inhibits IgE production in vitro. Wide variety of chemical modification of pseurotin A was performed. Structure-activity relationship studies of pseurotin analogues elucidated that 10-deoxypseurotin A strongly inhibits IgE production with IC(50) of 0.066 microM. An immunosuppressive activity of another natural product, synerazol was also found.

PF1270A, B and C, novel histamine H3 receptor ligands produced by Penicillium waksmanii PF1270.

Three novel histamine H3 receptor (H3R) ligands, PF1270A (1), PF1270B (2) and PF1270C (3) were isolated from the culture broth of the fungal strain PF1270. The strain was identified as Penicillium waksmanii on the basis of morphological characteristics. These compounds were obtained from the culture broth by solvent extraction and chromatographic purification. Their structures were established by spectroscopic methods and X-ray crystallographic analysis. They possess pentacyclic spiroindolinone skeletons. 1, 2 and 3 displayed high affinity for the rat H3R (Ki=0.058, 0.17 and 0.19 microM, respectively) and human H3R (Ki=0.047, 0.12 and 0.22 microM, respectively). Moreover, 1, 2 and 3 acted as potent agonists with the EC50 values of 0.12, 0.15 and 0.20 microM, respectively.

Isolation of temperature-sensitive Saccharomyces cerevisiae with a mutation in erg25 for C-4 sterol methyl oxidase.

C-4 sterol methyl oxidase encoded by the ERG25 gene is a key enzyme in the ergosterol biosynthetic pathway in fungi. ERG25p contains three histidine clusters common to nonheme iron binding enzymes and endoplasmic reticulum retrieval signal. In order to characterize ERG25p, we generated a series of temperature-sensitive(ts) erg25 mutants by random mutagenesis. One of the resulting mutants, the mERG25 strain, accumulated 4,4-dimethlzymosterol at the nonpermissive temperature. Sequence analysis of the mERG25 mutant indicated three amino acid substitutions in ERG25p, namely N48D, V133A, and F135S. These results indicate that the ERG25 gene product is a new antifungal target.