摘要:

Sap beetles (Coleoptera: Nitidulidae) are important in vectoring mycotoxigenic species ofAspergillusandFusariumto maize. Species examined are attracted to fungal and maize volatiles, and are resistant to most mycotoxins compared to maize ear‐infesting caterpillars. They will invade ears damaged by birds or caterpillars or those ears that have poor husk coverage. An integrated control programme for these insects under development presently includes pheromones and host coattractants for trapping; identification and dispersal of pathogenic nematodes and fungi; identification of maize varieties cross‐resistant to mycotoxigenic fungi and other insects, and the potential mechanisms involved; and formulations of insecticides for single treatment, low active ingredient, selective control of insect pests of ears including sap beetles and caterpillars that preserve naturally occurring predators and parasites.

ISSN:0265-203X    

DOI:10.1080/02652039509374336

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Mycotoxigenic fungi were isolated and identified from selected food and feed samples obtained in Metro Manila public markets, a Laguna coconut mill, and FNRI rat breeder's diet using the serial dilution and moisture chamber techniques. The majority of the isolates identified belong to the generaAspergillusandMucoralesand a few to thePenicillium.Taxonomical identification was based on the morphological characteristics of the fungi as observed under the microscope.

ISSN:0265-203X    

DOI:10.1080/02652039509374337

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The major compound responsible for toxicity toArtemia salinaof someFusarium tricinctumstrains has been isolated, and its structure has been elucidated by spectroscopical methods, i.e. UV, IR, MS,1H‐NMR and13C‐NMR. The novel compound, trivially named visoltricin, is the first imidazole derivative produced byFusariumspp., and its structure has been established as the methyl ester of 3‐[l‐methyl‐4‐(3‐methyl‐2‐butenyl)‐imidazol‐5yl]‐2‐propenoic acid (molecular formula C13H18N2O2; MW = 234.297). Visoltricin was toxic toA. salinalarvae (LD50= 8.5 × 10‐7M), and inhibited the growth of six human tumour cell lines (out of 60 lines tested) at concentrations lower than10–5M. Tested on rabbit eye it showed an interesting miotic activity similar to that of pilocarpine, a miotic agent largely used in the therapy of glaucoma. This biological activity could be explained in part by the anticholinesterase properties shown by visoltricin towards both human serum and pure enzymes (EC 3.1.1.7 and EC 3.1.1.8). Kinetics studies showed for visoltricin a mixed‐type and reversible inhibition of the EC 3.1.1.7 enzyme with the competitive inhibition constant (Ki) = l.9×10−4M.

ISSN:0265-203X    

DOI:10.1080/02652039509374338

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Production of aflatoxins B1, B2, G1, and G2in pure and mixed cultures ofAspergillus parasiticusandaspergillus flavuswere compared. Differing percentages of A.parasiticus(NRRL 2999) andA. flavus(NRRL 5520) conidia were used as inoculum and allowed to grow in static liquid culture for 10 days. The pure and mixed cultures of A.parasiticus/A. flavuswere extracted and the aflatoxins partially purified. High‐performance liquid chromatography was then used to determine aflatoxin concentrations. The maximal decreases of G1and G2production occurred when the inocula went from 0 to 12.5% or 25%A. flavus.Aflatoxins G1and G2comprised less than 10% of the total aflatoxins when the A.parasiticuslA. flavusinocula contained greater than 25%A. flavus.Production of aflatoxins B1and B2increased slightly as the percentage ofA. flavusin the A.parasiticuslA. flavusmixed inoculum increased.A. flavusis apparently capable of suppressing accumulation of aflatoxins G1and G2by A.parasiticuswhen these fungi are grown in mixed culture.

ISSN:0265-203X    

DOI:10.1080/02652039509374339

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652039509374305

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor