ANTIBIOTICS FROM BASIDIOMYCETES .6. MERULINIC ACIDS A,B, AND C, NEW ANTIBIOTICS FROM MERULIUS-TREMELLOSUS AND PHLEBIA-RADIATA

  • 1 January 1978
    • journal article
    • research article
    • Vol. 33  (11-1) , 807-816
Abstract
Three new antibiotics, merulinic acids A, B and C, were isolated from fruiting bodies of M. tremellosus and P. radiata. They are closely related derivatives of .beta.-resorcylic and salicylic acid, carrying monounsaturated C17-alkyl side chains in 6-position. The merulinic acids are mixtures of the .DELTA.8''-compounds with minor amounts of the corresponding .DELTA.10'', dehydro, and dihydro derivatives, separable only by means of HPLC [high performance liquid chromatography]. .DELTA.8''-Merulinic acid A was synthesized via a biomimetic cyclization of a linear precursor. The merulinic acids inhibit a variety of bacteria and are not active against fungi. RNA, DNA and protein synthesis in Bacillus brevis and Ehrlich carcinoma ascites cells are inhibited shortly after the addition of the antibiotics. Almost complete hemolysis of human erythrocytes is caused by 25 .mu.g/ml of merulinic acid B and C or by 73 .mu.g/ml of merulinic acid A.