EUrotiU711 echinulalum, a (ungus isolated (rom a vertisoJ in southcrn Spain, formcd humic acid-like pigments duriog growth in glucose-asparagine or gluoosc-NaNO;¡ media. After 6 to 7 days the phenols, orscllinic; ¡l·hydroxycinnamic, and p-hydroxyhcnzoic ncids, and the anthra<]uinones, cndocrocin, emodin, and physcion \Verc dctcctcd in the culture media. Upoo further dcvelopment of the mycclinJ mats additionaI aromatic compounds \Vere produccd and afte .. 4 to 6 wccks more than 50 different cther-extractahle phenoIs amI anthraquinoncs were detected. With further illcubation the nmounts and number oC these compounds dccreascd and pigment Cormation in the media increased. After 2 to 3 months the culture media were dark brown to black amI about 1 to 3.5 g/liter of polymer could be recovered upon acidification of the culture medium. Sodium amalgam rcduction of this polymer yielded numerous phcnols, anthraquinones, anthroncs, and possibly anthracene derivatives. Trcatment with sodium dithionite yieIded largely anthraquinones. The polymer contained 1 to 4.5% N depending upon the N source. From 50 to 60% of this N was released in the form of amino acids upon acid hydroIysis. With both asparagine and NaNO a as N sources the same amino acids were isoJated Crom ON Hel hydroIysates. Quantitatively, however, there were differences in the percentage distribution oC the amino acids. (24, 25. 26, 32). Jt is possibJe that the condensed hydrocarbons isolated either directly from the soil (5, 39) or upon zinc dust distilIation of humic acids (8.11, 13) mal' origina te by reduction of more highly condensed quinoid or phenolic structures. The fringelites of sea sediments discussed hy Blumer (4) and by Albrecht and Durisson (l) are dimeric anthraquinones with tetra-hydroxy-naphthodianthrone structures. They are derived from fossil crinoids and undergo a series of hydrations and dehydrations.For the present paper a study was made of anthraquinones -and phenols formed hy Eurotium echinulatum, a soil fungus isolated from a Vertizol in southern Spain. The linkage of these compounds into darkMcolored pigments similar to humic acid hy either phenolase or autoxidative polymerization proces.c;es in the culture medium and in the ceI1s during and after terminatíon of growth was followed.
METHODSThe methods for cultivation and some properties of the darkcolored pigment have been described (22,23). The fungus was cultured in Czapek-Dox medium (20% glucose and 0.2% NaNO a ) or in glucose-asparagine medium (3% glucose and 0.5% asparagine) as described by Martin et al. (21). Growth and polymer formation was much better in the glucose~aspara gine medium. bu! the Czapek-Dox was preferred for monitoring the formation and transformation of phenols and anthraquinones. The phenols and anthraquinones were isolated from the culture media by acidification to pH 1.0 and extraction with peroxide-free ether. Concentrated cthcr extracts were spotted on thin layer silica gel (KGF 254. Fa, Merck, DarmstadO plates and chromatographed in two directions (9....