ascorbic-acid and 1--methylascorbigen

The effect of ascorbigen and 1'-methylascorbigen on the disease resistance of bean (Phaseolus vulgaris L.,. cv. Debreceni Tarka) to the fungal pathogen Uromyces phaseoli Pers. is reported. Contrary to ascorbigen, pretreatment of bean plants with l'-methylascorbigen, as in the case of other endogenous N-, O- and S-methyl compounds, induced the double immune response leading to the biochemical immunization of plants. The effectiveness of protection depended on the dosage of the applied l'-methylascorbigen and on the time interval between the chemical pretreatment and inoculation. Results of our greenhouse experiments revealed, in accordance with previous results, that the presence of the N-methyl group in the 1'-methylascorbigen molecule is the precondition of the effect, and formaldehyde formed from this N-methyl group and its reaction products (e.g. singlet oxygen, ozone) can have a determining role in the manifestation of the effect.

Topics: Ascorbic Acid; Basidiomycota; Immunity, Innate; Indoles; Phaseolus; Plant Diseases; Time Factors

The effect of ascorbigen and 1'-methylascorbigen as a model compound pair was studied on the phytopathogenic bacterium Pseudomonas savastanoi pv. phaseolicola in the BioArena experimental system after overpressured layer chromatography. Results showed a characteristic, strong antibacterial effect of 1'-methylascorbigen and weak effect of ascorbigen present on the adsorbent layer as chromatographic spot. Addition of formaldehyde capture compounds (L-arginine, glutathione, dimedone) partially or totally reduced the antibacterial effect of 1'-methylascorbigen and ascorbigen. On adding Cu(II) ions--which mobilize and coordinate formaldehyde--to the culture medium, the antibacterial effect of both compounds became stronger. It is supposed that the weak antibacterial effect of ascorbigen may have originated from the 1'-methylascorbigen formed in situ on the adsorbent layer by partial enzymatic methylation of ascorbigen.

Topics: Anti-Bacterial Agents; Arginine; Ascorbic Acid; Chromatography, Thin Layer; Copper; Cyclohexanones; Formaldehyde; Glutathione; Indoles; Pseudomonas

Some formaldehyde generating chemicals due to reduction of apoptosis in lymphocytes may slow down the progress of immune decline of HIV-infected individuals. N(G)-hydroxy-methylated-L-arginine (MAX) and 1'-methyl-ascorbigen (MeAsc) could enter this way the biochemical pathway of cells and affect the apoptotic process. Separated peripheral blood lymphocytes of five asymptomatic HIV-positive persons were cultured. Unstimulated, IL-2 stimulated and IL-2 stimulated plus 0.1, 1.0, 10.0 microg/ml MAX or MeAsc treated lymphocytes were investigated for apoptosis morphologically (HE) and by flow cytometrical DNA fragmentation method. IL-2 stimulation lowered the apoptotic rate in lymphocytes of HIV-positive persons related to unstimulated ones. MAX and MeAsc reduced the apoptotic activity of stimulated lymphocytes in the least or the middle doses while in the higher dose did not. MAX and MeAsc reduced the apoptotic activity of stimulated lymphocytes originated from HIV-positive patients in vitro. This compounds may have the same effect in vivo and may prolong the symptomless period of HIV-infected patients. The role of methylation and production of formaldehyde in this process is discussed.

Topics: Apoptosis; Arginine; Ascorbic Acid; Cells, Cultured; Flow Cytometry; HIV Infections; Humans; Indoles; Lymphocytes

We have studied the effect of 1'-methylascorbigen, an immunostimulating substance in animal systems on the resistance potential of barley, bean and wheat plants to the fungal pathogens Erysiphe graminis, Uromyces phaseoli and Puccinia recondita, respectively. The effectiveness of protection depends - as in the case of other endogenous, N-methylated compounds - on the dosage of applied 1'-methylascorbigen and on the time interval between the chemical pretreatment and inoculation. The time- and dose-dependent double immune response was clearly demonstrated in case of the barley - Erysiphe graminis and bean - Uromyces phaseoli host-parasite relationships while in case of the wheat -Puccinia recondita relationship the relatively long-time interval between pretreatment and inoculation allowed manifestation of only a single immune response.

Topics: Ascorbic Acid; Fungi; Indoles; Plants

Ascorbigens are indole-containing derivatives of L-ascorbic acid, some of them (e.g., 1'-methylascorbigen) have been shown to inhibit growth of experimental murine tumors. Immunomodulating properties of 1'-methylascorbigen correlated with its antitumor effect. The immunomodulating action of 1'-methylascorbigen is to a marked degree based on its influence on arachidonic acid metabolism in murine spleen cells. A single injection of 50 mg/kg 1'-methylascorbigen leads to pronounced and immediate increase of the cells' ability to produce PGE2 and LTB4 (up to 550% and 460%, correspondingly). Till the tenth day after injection the levels of these metabolites of arachidonic acid were double that of the control.

Topics: Animals; Arachidonic Acid; Ascorbic Acid; Calcimycin; Calcium; Cells, Cultured; Dinoprostone; In Vitro Techniques; Indoles; Leukotriene B4; Male; Mice; Mice, Inbred BALB C; Spleen

Topics: Adjuvants, Immunologic; Animals; Ascorbic Acid; Bacterial Infections; Escherichia coli Infections; Indoles; Mice; Staphylococcal Infections