Aflatoxin B₁ (AFB₁,) is a potent liver carcinogen to a number
of animal species including rainbow trout (Salmo gairdneri).
Microsomal activation is required for the in vitro conversion of
AFB, to a reactive metabolite, thought to be the AFB₁,-2,3-oxide,
which will bind nucleic acids, produce toxicity, and cause mutagenesis.
Nucleic...
The effect of cycling temperatures on production of aflatoxin
by Aspergillus flavus (V3734-10) when grown upon various substrates
was studied. The parameters of temperature and time were selected
to simulate environmental conditions in Oregon during harvest of
filberts and walnuts. The heat input required for aflatoxin synthesis
in terms of...
Aflatoxins B₁, Q₁ and aflatoxicol, R [subscript o] F, but not B₂ were activated in the presence of NADPH by the 105,000 x g pellet from rainbow
trout (Salmo gairdneri), Mt. Shasta strain, liver to products lethal to
Bacillus subtilis GSY 1057 (metB4, hisAl, uvr-1). Electron microscopy
confirmed the microsomal...
A new method for the preparation of the 2, 3, 3a,8a-tetrahydro-2-hydroxyfuro[2, 3-b] benzofuran, XXX, ring system has been developed. The synthesis envolved a substitution reaction of phenol, XXIV, with 1-bromo-2, 5-hexadiene, XXV, to give 2, 5-hexadien-l -yl phenyl ether, XXVII. The ether was rearranged via an ortho-Claisen rearrangement to 3-(o-hydroxyphenyl)-l,...
Selected parameters that affect crude toxin production in both
primary culture (growing cell culture) and resting culture were
examined during efforts to produce sufficient crude toxin for purification.
The parameters included carbohydrate and label source and
concentration, cell concentration, incubation time and temperature
and shaker speed. A higher yield of...
Indole-3-carbinol (I3C) and butylated hydroxyanisole (BHA), anti-carcinogens
present in the human diet, were tested for their in vivo
and in vitro effect on aflatoxin B₁. (AFB₁) metabolism, and DNA adduct
formation in the rainbow trout. Dietary BHA at either 0.3 or 0.03%
had no effect on the hepatic tumor incidence...
The question of how the presence of nucleosomal
packing of DNA modifies carcinogen interaction at
specific sites cannot be answered by studies on whole
chromatin or bulk nucleosomes because of the
heterogeneity of DNA sequences in the particles. This
problem was circumvented by constructing nucleosomes that
are homogenous in DNA-histone...
In rodent models as well as in fish models there are significant
species differences in the susceptibility toward aflatoxin B₁ (AFB₁)
carcinogenesis. Mouse is less susceptible toward AFB₁ carcinogenesis
than rat. Researchers have come to the conclusion that the lower
susceptibility of mice is not a result of less effective...