Isolation, structures and biological activities of colletotrichins, phytotoxic substances from Colletotrichum nicotianae.

Abstract

From the phytopathogenic fungus, Colletotrichum nicotianae, three phytotoxic substances have been isolated and named colletotrichin, colletotrichins B and C (1, 2 and 3). The struc tures of these compounds have been elucidated from the physical and chemical evidence. When applied on the tobacco leaves, colletotrichins induced the symptom similar to that of the tobacco anthracnose caused by C. nicotianae. The compounds were also toxic to the lettuce and rice seedlings. with C. nicotianae. 1 was identified to acetyl colletotriehin3> isolated from C. capsi by J. F. Grove through the comparison of physico chemical data of 1 with those of authentic sample kindly gifted by Dr. Grove. Because of the complexity and intimate relations in their structures, the structure determination of those compounds was made by the X-ray crystallographic analysis on the crystal of I along with the correlations of their structures. Just after accomplishment of the X-ray analysis, we noticed that J. MacMillan briefly reported the X-ray analysis on the acetyl derivative (4) of acetylcolletotrichin and changed the name of I to colletotrichin." Then the compounds of 2 and 3 were named as colletotrichins B and C, respectively. We have reported the structure elucidation of 1 and 2 preliminarily.' ' This paper deals with the details of isolation, structures and biological

In vitro selection at cellular level for red rot resistance in sugarcane (Saccharum sp.)

“…1a) associated with necrosis suggests the involvement of phenolic compounds and their oxidation products similar to symptoms observed in sugarcane plants infected with the red rot pathogen (Rao et al 1968). Similar influences of toxins on different crops have been reported by Gohbara et al (1978) on lettuce, Jin et al (1996) on soybean, Boonchitsirikul et al (1997) and Narong et al (1998) on rice and Prasad and Naik (2000) on sugarcane. Growth inhibition of sugarcane calli by the PCF provides a positive selection system in which susceptible cells presumably die and/or grow slowly, while more resistant cells proliferate faster.…”

Responses of embryogenic mango cultures and seedling bioassays to a partially purified phytotoxin produced by a mango leaf isolate of Colletotrichum gloeosporioides penz

“…(Sahni et al, 1974), C. musae (Berk. and M. A. Curtis) (Chen, 1968) and C. nicotianae (Gohbara et al, 1978;Duke et al, 1992) have also been shown to produce phytotoxins that are involved in the disease process. Colletotrichum gloeosporioides produces phytotoxic metabolites in vitro and in vivo in Citrus aurantifolia L. (Sharma and Sharma, 1969;Sahni et al, 1974), northern jointvetch (Aeschynomene virginica L.) (Walker and Templeton, 1978), olive (Olea europaea L.) (Ballio et al, 1969;Bosquet et al, 1971) and Stylosanthes scabra L. (Szabados et al, 1987).…”

Bioherbicides: Research and Risks

“…Colletotrichin, a norditerpene-pyrone, is a non-host-specific phytotoxin produced by species of Colletotrichum (Gohbara et al, 1977;Gohbara et al, 1978). Originally called acetylcolletotrichin (Grove et al, 1966), it is related to other analogs, colletotrichin B and colletotrichin C, which are precursors of colletotrichin .…”