Antibiotic Substances from Basidiomycetes

Abstract

In a survey' conducted in this laboratory it was noted that 213 of the 332 species of Basidiomycetes studied produced substances that inhibited the growth of Staphylococcus aureus. Among the species that seemed worthy of further investigation was Pleurotus griseus.2 P. griseus grew with medium rapidity on a thiamine-peptone agar' and a modified Czapek-Dox agar to which corn steep solids had been added. It formed a pink pigment which diffused intio the agar. After the fungus had grown for one to several weeks, discs 5.5 mm. in diameter were cut on a radius extending from the center of the colony into the agar adjacent to the colony. These discs were placed on a yeast-peptone agar seeded with Staph. aureus and the plates incubated overnight at 37 4 2°C. Clear zones of inhibition were found around the discs indicating that some substance or substances had diffused from the agar discs into the surrounding seeded medium in sufficient concentration to inhibit the growth of the staphylococci in the agar. A disc cut from the agar at as great a distance as 20 mm. from the edge of the colony frequently produced a zone of inhibition. The zones, while small, were clear, indicating that bacteria resistant to the antibiotic substance or substances were absent. Disc tests, with strains of Staph. aureus resistant to other antibiQtic substances, indicated that P. griseus produced an antibiotic substance which was different from penicillin and different from the active substances produced by several other Basidiomycetest The antibiotic substance or substances from P. griseus did not inhibit the growth of Escherichia coli. P. griseus was grown on several types of nutrient media, differing from *one another in the source of nitrogen and carbon, to determine the effect of the medium on the production of the antibacterial substances by the fungus. Cane sugar, dark brown sugar, galactose, lactose, mannitol and corn steep solids were ineffective carbon sources; maltose and soluble starch were -poor; dextrose and levulose were the best and nearly equal so far as the 171

Discovery of anti-cancer activity for benzo[1,2,4]triazin-7-ones: Very strong correlation to pleurotin and thioredoxin reductase inhibition

“…The latter naturally occurring antibiotic is a para-quinone with a perhydroanthracene core, which was first isolated in the 1940s from the basidiomycete, Pleurotus griseus. 9 Though pleurotin has been synthesized, 10 a multi-gram fermentation process using Hohenbuehelia atrocaerulea for supply of pleurotin to the NCI has been reported. 11 Pleurotin possesses antibacterial, 9 antifungal, 12 and anti-cancer activity, including inhibiting the hypoxia-induced factor (HIF-1α), a transcription factor associated with many aspects of tumor growth.…”

“…9 Though pleurotin has been synthesized, 10 a multi-gram fermentation process using Hohenbuehelia atrocaerulea for supply of pleurotin to the NCI has been reported. 11 Pleurotin possesses antibacterial, 9 antifungal, 12 and anti-cancer activity, including inhibiting the hypoxia-induced factor (HIF-1α), a transcription factor associated with many aspects of tumor growth. 13 The underlying pathway to much of this biological activity is pleurotin's ability to act as a potent inhibitor (IC 50 0.17 μM) of the thioredoxin (Trx)-thioredoxin reductase (TrxR) system.…”

A novel assay of bacterial peptidoglycan synthesis for natural product screening

“…F-11334A1 was earlier reported as an inhibitor of neutral sphingomyelinase. 36 Pleurotin was discovered as an anti-bacterial substance by Robbin et al 37 and (À)-epigallocatechin gallate was reported to have an anti-bacterial activity. 38 The relationship between the reported activities for these compounds and our current observation remains to be further studied.…”

Activity-Directed Fractionation ofPleurotus ostreatus. in the Search for Analgesics

“…Gillet (Pleurotaceae). Pleurotin, with a quinonoid skeleton, was isolated from P. griseus (Robbins et al, 1947) and shown to have antimicrobial properties and anticancer properties (Welsh et al, 2003). We were unable to prove the presence of any such chemical constituents in AqFrA-3.…”