[Superoxide dismutase and catalase activities in carotenoid-synthesizing fungi Blakeslea trispora and Neurospora crassa under the oxidative stress].

The addition of menadione into the medium during cultivation of Neurospora crassa in the dark activated its constitutive superoxide dismutase. Exposure to light not only activated superoxide dismutase and catalase, but also increased the content of neurosporaxanthin. Superoxide dismutase activity in the mixed (+/-) mycelium of Blakeslea trispora synthesizing beta-carotene in the dark was much lower than that in Neurospora crassa.

[Biosynthesis and use of coproporphyrins and uroporphyrins and their metal complexes in immune analysis and diagnostic methods].

Methods of synthesis of coproporphyrin and uroporphyrin by using bacteria of the genus Arthrobacter are proposed. Metal complexes of coproporphyrin and uroporphyrin with Pt, Pd, and Zn were synthesized. Their structures were identified by spectrophotometry, IR spectrometry, 1H-NMR, mass spectrometry, and HPLC.

Free radical lipid peroxidation inhibits enzymatic conversion of beta-carotene into vitamin A.

Free radical oxidation of arachidonic acid with soybean lipoxygenase was accompanied by inhibition of retinal synthesis from beta-carotene catalyzed by enzyme preparation from rabbit intestinal mucosa. Lipoxygenase inhibitor salicylhydroxamic acid and antioxidants suppressing free radical reactions (ethyl gallate, alpha-tocopherol, astaxanthine, and quercetin) promoted conversion of beta-carotene into retinal catalyzed by beta-carotene-15,15'-dioxygenase. These results indicate that lipoperoxides and/or products of their homolysis attenuate enzymatic conversion of beta-carotene and confirm the important role of natural antioxidants in the maintenance of stable vitamin A content in mammals.

[Features of the elemental composition of medicinal plants, synthesizing phenolic compounds].

A total of 52 species of medicinal plants capable of synthesizing phenolic compounds were subjected to mass-scale screening for 24 chemical elements. The screening was performed by atomic absorption spectrometry in combination with spectrophotometric detection. The plant species tested were found to accumulate groups of two to ten chemical elements (Fe, Cr, Cu, Co, Mn, etc.

[Conversion of beta-carotene and some beta-apocarotinoids under the effect of substances from the intestinal mucosa].

Products of cleavage of beta-carotene and certain apocarotenoids (beta-apo-4', 8', 10', and 12'-carotenols and citranaxanthol) were studied, and the dynamics of their generation in the presence of an enzyme preparation isolated from rabbit intestinal mucosa was determined. The data suggest that metabolism of beta-apocarotenols involves the production of retinal and beta-apo-14'-carotenal mediated by enzymes different from beta-carotene-15,15'-dioxygenase, which converts beta-carotene to retinal. A scheme of metabolic conversion of beta-carotene is discussed.