AAL Toxin TC1

Pestic. Sci.,1995, 43, 181-187

AAL-toxin, a potent natural herbicide which disrupts sphingolipid metabolism of plants[Reference: WebLink]

METHODS AND RESULTS:
AAL-toxin, a natural product, has a wide range of phytotoxicity. It has potential as a natural herbicide because several important weeds including jimsonweed, black nightshade, prickly sida and hemp sesbania are quite sensitive, while some crops such as cotton and maize are not affected. This differential susceptibility may allow its exploitation for weed control.
CONCLUSIONS:
The data obtained to date a r e consistent with the hypothesis that the toxin disrupts sphingolipid metabolism and it is hoped that future studies will confirm these preliminary findings. More research is needed in the field to determine feasibility of commercial development of the toxin and its analogues as natural herbicides. Attention to human and mammalian toxicity will also be required.

Journal of Agricultural and Food Chemistry, 1994, 42(2):327-333.

Structural characterization of three new AAL toxins produced by Alternaria alternata f. sp. lycopersici.[Reference: WebLink]

METHODS AND RESULTS:
Three new pairs of biologically active regioisomeric toxins (toxins TC, TD, and TE) were isolated from liquid cultures of alternata f.sp. lycopersici, purified using standard chromatographic procedures, and their structures elucidated following interpretation of spectra obtained from and mass spectrometry experiments. Each of the toxin congeners is structurally similar to the toxin TA, which was characterized earlier from culture filtrates of this fungus. toxin TC resembles TA but differs in its lack of at C4 and C5. toxin TE is the N-acetylated form of TC. Spectroscopic data are reported to confirm that TB is similar to TA but lacks a at C5, as suggested earlier. toxin TD is the N-acetylated form of TB.
CONCLUSIONS:
All five pairs of regioisomers arise as products of fungal and do not appear to be generated during isolation. All regioisomeric pairs induce the genotype-specific necrosis characteristic of toxin TA in bioassays but differ markedly in relative toxicity.