Simon H. Wender

The effect of varying u.v. intensities on the concentration of scopolin and caffeoylquinic acids in tobacco and sunflower

Abstract Using a simple but reliable method involving one-dimensional paper chromatography for the quantitative determination of chlorogenic acid, neochlorogenic acid, 4- O -caffeoylquinic acid (“band 510”), and scopolin, the effect of varying u.v. light intensities on the concentration of these compounds in tobacco and sunflowers has been determined. With increased u.v. intensity, an increase in scopolin concentration was found in tobacco leaves and stems and in sunflower leaves. Chlorogenic acid concentration was higher in roots, stems, and leaves of tobacco plants treated with low, stimulatory u.v. radiation than in comparable plants grown under control or under higher u.v. conditions. Similar experiments with sunflowers indicated that the chlorogenic acid concentration of sunflower leaves was less under the low u.v. radiation than in comparable sunflower plants of control or of higher u.v. treatments. In stems and roots of sunflower, no consistent pattern of change in the chlorogenic acid concentration was found under the u.v. conditions tested. The concentration of chlorogenic acid increased in sunflower older leaves, but no consistent pattern of chlorogenic acid change with age was observed in sunflower stems and roots. Neochlorogenic acid and the third isomer (band 510) were found in both tobacco and sunflower, but in much higher concentrations in tobacco. Both of these isomers were found in all parts of the two test plants, except tobacco stems or roots. Postulates are presented which point out the possible significance of chlorogenic acid and/or scopolin in lignification and in mediating environmental conditions through effects on internal regulatory mechanisms. Internal concentrations of these compounds possibly are correlated with their release from the plant, and subsequently with allelopathic relations among plants.

URINARY PRODUCTS FROM QUERCETIN IN NEOMYCIN-TREATED RATS.

Abstract In order to learn whether urinary m -hydroxyphenyl acids are mainly microbial in orgin, following the oral administration of quercetin the phenolic acid content of urine from neomycin-treated rats has been compared with that of urine from rats not treated with neomycin. The three acids, 3,4-dihydroxyphenylacetic, homovanillic, and m -hydroxyphenylacetic, occurring characteristically in the urine from untreated rats following quercetin feeding, were not found in urine from neomycin-treated rats fed quercetin. However, dihydroferulic, p -hydroxyphenylpropionic, and p -hydroxybenzoic acids, and tentatively, isovanillic acid, were identified in the urine of the treated rats. None of these compounds was found in urine from neomycin-treated rats which were not fed queercetin. Several compounds whose identification has not been achieved have also been found, but no m -hydroxyphenyl acid have been identified thus far. These results strengthen the evidence for previous suggestions by others that urinary m -hydroxyphenyl acids appear to be primarily bacterial metabolites of certain dietary precursors, including flavonoid compounds.

Scopoletin: A substrate for an isoperoxidase from Nicotiana tabacum tissue culture W-38☆

Abstract Scopoletin was found to be a substrate for a single anodic isoperoxidase isolated from tobacco callus tissue W-38. Isolation of this peroxidase was accomplished using DEAE-cellulose chromatography. This isoperoxidase catalysed the destruction of scopoletin in the presence of H2O2 only. An enzyme assay for the scopoletin reaction was developed. The pH optimum of the enzyme was 5·5 and the apparent Kms for scopoletin and H2O2 were 0·6 and 0·9 rnM respectively.

The effect of nitrogen deficiency on the concentration of caffeoylquinic acids and scopolin in tobacco

Abstract Roots, stems, and leaves of tobacco plants grown on complete and on nitrogen-deficient nutrient solutions were each analyzed quantitatively for content of scopolin and of chlorogenic, neochlorogenic, and 4- O -caffeoylquinic acids. Increases in scopolin and chlorogenic acid concentrations were found in the nitrogen-deficient leaves, stems, and roots as compared to corresponding parts of control plants. These increases correlated approximately with the time of first observable deficiency symptoms.

Tissue age and caffeoylquinic acid concentration in sunflower

Abstract Through the use of one-dimensional paper chromatographic separation, followed by spectro-photometric analysis, chlorogenic acid, neochlorogenic acid and 4- O -caffeoylquinic acid concentrations have been determined in sections of field-grown Helianthus annuus L. Using similar procedures, relative concentrations of “isochlorogenic acid” were also determined. All these compounds decreased in concentration basipetally in stem and leaf sections except in leaves from the first six nodes where the monocaffeoylquinic acids increased in concentration down from the apex. These concentration changes are see to correlate with the postulated role of caffeoylquinic acids in lignification and in influencing internal regulatory mechanisms.

Effect of boron deficiency on polyphenol production in the sunflower

Abstract Sunflower plants deficient in boron have been found to accumulate at least two major blue-fluorescing compounds. One of these has been identified as scopolin, and the other has been shown to be a glucose derivative of gentisic acid. Esculin, isoquercitrin, and scopoletin have also been identified for the first time in sunflowers.

Metabolic studies of quercetin labeled with C14

Abstract Quercetin, randomly labeled with C 14 , was administered by stomach tube to adult rats. Twelve hours later, 44% of the radioactivity was still found in the intestinal tract and 15.1% was recovered in respiratory carbon dioxide. Small amounts were found in the blood and kidney, and an appreciable amount in the lungs and in the gastrointestinal walls. No other organs contained detectable amounts of radioactivity. The urine contained about 4% of the administered activity. Paper chromatography studies of the urine indicated the presence of radioactive homovanillic and m -hydroxyphenylacetic acids. Several unidentified radioactive areas were noted on the chromatograms. None of these was proved to be unchanged quercetin. Following intraperitoneal injection of the labeled quercetin, an area with the mobility of vanillic acid was found in the urine. It is suggested that quercetin may possibly be degraded in the rat by at least two metabolic pathways.

Ferulic acid: a substrate for two isoperoxidases from Nicotiana tabacum tissue cultures

Abstract An anodic isoperoxidase (A 2 ) from tobacco tissue culture W-38 and a cathodic isoperoxidase (C 4 ) from tobacco tissue suspension culture WR-132 have been separated and characterized. Both isoperoxidases catalysed oxidation of ferulic acid in the presence of H 2 O 2 . When the reaction mixture was subjected to TLC, ferulic acid was found to have been converted to an unknown compound which, after treatment with ammonia, fluoresces green in UV light. Both the isoperoxidases A 2 and C 4 appear to follow simple Michaelis-Menten kinetics with respect to guaiacol as the substrate. The K m s for guaiacol are 4 and 4·5 mM for isoperoxidases C 4 and A 2 , respectively. The pH optimum for both enzymes is about 6·0. The effect of various phenolic and related compounds on the activity of each isoperoxidase is reported and discussed.

Identification of rutin and isoquercitrin in cottonseed

SummaryThe flavonol glycosides, rutin and isoquercitrin, have been separated from crushed, delinted cottonseed (kernel and hull) by extensive use of paper chromatography. The identification of these flavonoid pigments has been achieved through paper chromatography, ultraviolet and infrared spectrophotometry, and qualitative and quantitative analysis of their hydrolysis products. Details of the separation and identification have been described.

Free phenolic acids in cigarette smoke and tobacco : Paper chromatography: Separation and identification

Abstract The following free phenolic acids have been identified in the smoke of regular market cigarettes: m -hydroxybenzoic, p -hydroxybenzoic, protocatechuic, vanillic, syringic, p -hydroxyphenyl-acetic, m -hydroxyphenyl-acetic, o -hydroxyphenyl-acetic, p -coumaric, ferulic, m -hydroxyphenyl-propionic, and p -hydroxyphenyl-propionic acids. These acids have also been identified in the smoke from cigarettes prepared without the usual flavorings or other additives, and in the ether and ethyl acetate extracts of the tobacco from both the regular and unflavored cigarettes. Paper chromatography separation and identification procedures have been described.