ANTAGONISM BY SPECIES OF ALTERNARIA AND THE ISOLATION OF A CRYSTALLINE SUBSTANCE FROM THE FILTRATE OF CULTURES OF A. RADICINA

Abstract

Culture filtrates of five species of Altermaria were antagonistic $0 PkytoQhtko~a eryLkroseptica. Those of A. rcedkz'nu exerted the greatest effect and they were foliou~ed in order of effectiveness by A. diantkico%a, A. sodaazi, A. brassa'cicoia, and A. ienuis, The antagonistic principle in the filtrate of A, radicina was readily removed by activated carbon. By extracting this carbon with acetone, substantial yields were obtained of colorless, needlelike crystals, quite in~soluble in water, but readily soluble in acetone, ethyl alcohol, ether, benzene, cotrcentrated strlphuric acid, and 10yo ssocliarrza hydroxide. 'The m.p. of the cryetals, 204°C. t o 208DC., and the deep pink color in solutions of sodium hydroxide distinguish the substance from alternaric acid.Water suspensions of the crystals were much less antagonistic t o P. euythroseptica than the original filtrate and had little or no effect upon several species of bacteria.8. BRIAN, p. Iv., CURTIS, 9. J.

Stereoselective Reduction of Radicinin by Liquid Cultures of Alternaria longipes

“…trol of members of the genus Alternaría, a series of Alternaría strains were grown in paired plate culture. This technique is used to observe antagonistic interactions between fungal species and to stimulate secondary metabolite production (2,3).…”

Radicinols and Radicinin Phytotoxins Produced byAlternaria radicinaon Carrots

“…Radicinin has been reported to be produced by A. radicina, Alternaria chrysanthemi, Alternaria helianthi, Bipolaris coicis, Cochliobolus lunata, and Phoma andina, radicinol by A. chrysanthemi and C. lunata, and epi-radicinol by A. chrysanthemi (12)(13)(14)(18)(19)(20)(21)(22). The coproduction of these toxins by the same fungus has been reported only for A. chrysanthemi (14).…”

“…Carrots were maintained in plastic boxes and incubated in a climatic cabinet with controlled conditions (WTB Binder Labortechnik GmbH, Tuttlingen, Germany) for 17 weeks at 1 °C, followed by 4 weeks at 10 °C and 4 weeks at 20 °C. Six carrots were collected from both A. radicinainoculated samples and control samples eight times at regular intervals during storage (after 9,17,19,20,21,23,24, and 25 weeks), blended, and analyzed for epi-radicinol, radicinin, and radicinol.…”