Extraction and Separation of the Bright-Greenish-Yellow Fluorescent Material from Aflatoxigenic Aspergillus spp. Infected Cotton Lint by HPLC−UV/FL

To isolate the bright-greenish-yellow-fluorescence (BGY-F) material associated with aflatoxin contamination on cotton lint, various in vitro chemical and in vivo natural BGY-F reaction products were prepared. BGY-F material was obtained from reactions involving (1) kojic acid (KA) and H 2 O 2, (b) KA, peroxidase, and H 2 O 2, (c) fresh cotton locules treated with KA and H 2 O 2, (d) detached cotton locules inoculated with an aflatoxigenic Aspergillus flavus spore suspension, and (e) live developing cotton bolls inoculated with aflatoxigenic A. flavus. BGY-F preparations separated on TLC resulted in the same R f value (0.52), indicating the possibility of the same compound. Under HPLC conditions, at a 380 nm wavelength setting, BGY-F retention times ranged 5.74−6.09 min; under fluorescent detection at 435 nm (excitation) and 494 nm (emission), retention times ranged from 5.75 to 6.09 min. Apparently, in all methods used to form the BGY-F compound, both in vivo and in vitro, only one compound with specific chromatographic characteristics was produced, and the product is likely an oxidized form of KA. Keywords: Cotton; Gossypium hirsutum L.; bright-greenish-yellow fluorescence (BGY-F); Aspergillus flavus; aflatoxin; HPLC − UV/F