Takao Homma

On a color change from yellow to red in the floral tissues of a dyer's saffron cultivar

Summary By using a spot scanning technique, the color change from yellow to red manifested in the floral tissues of Mogami-Benibana, a cultivar of dyers saffron ( Carthamus tinctorius L.), was investigated. Stamens and pistils were separated from fresh florets of the herbaceous flowering plant for microscopic observation of the zones of red color development. In pistils, color change is localized in the stigma and the peripheral region of the stylar canal. Observations of the fibrovascular bundle are especially indicative that the pollination process coincides with induction of the red shift. GA 3 was found to be a stimulator of tissue reddening, while IAA showed no effect. All red products isolated from the test samples were identical with authentic carthamine.

An Advanced Technique for Monitoring the Color Change from Yellow to Red in Floral Tissues of Dyer's Saffron

Summary Corollas, styles, anthers, and ovaries separated from fresh capitula of dyers saffron ( Carthamus tinctorius L.) were laid on microscope slides, and their reddening capacities were investigated by a technique of spot scanning. Styles reddened the most, followed by corollas, anthers, and finally ovaries with little or no capacity for tissue reddening. Red color accumulated more in larger styles than in smaller ones. Styles were divided longitudinally into three parts, and the appearance of red color in each part was scanned. The most activity was found in the middle part; reddening of the upper part ranked second, and reddening was least in the basal part. The observed differences in red-color-accumulating capacities are discussed briefly in relation to precursor translocation and enzyme activity distribution.

Promotive effect of supersonic oscillation on carthamin bleaching induced by peroxidatic enzyme oxidation

Abstract The effect of supersonic oscillation on carthamin bleaching by peroxidatic enzyme oxidation was investigated in an experimental model system under varied pH and temperature conditions. The loss of the red colour with enzyme after sonosound irradiation (due to the high sensitivity of carthamin towards peroxidative species) was greater than with no added enzyme preparation. The progress curves from light absorption spectra indicated that the oscillatory promotion is pH- and temperature-dependent. The rates of carthamin bleaching at three different pH values were as follows (enzyme-containing and non-treated control = 1·0): pH 3·0 = 1·32, pH 5·0 = 1·27, pH 7·0 = 2·03. Another experiment at three given temperatures showed the following ratios (enzyme-containing and non-treated control = 1·0): 20°C = 0·93, 30°C = 1·27, 40°C = 1·45. The data are briefly discussed.

Scanning electron microscopic observation of stamen and pistil from a cultivar of Carthamus tinctorius : Influence of pollination process

Summary Florets of Mogami-Benibana, a cultivar of Carthamus tinctorius L., were collected from the flowering heads at the stage of pre-blooming or of post-blooming and separated into several groups. Stamen and pistil thus obtained were subjected to scanning electron microscopy and localized the damaged regions on the surface of the gamete generating tissues. Both stamen and pistil are wounded drastically after floret blooming: various gaps, scratches, tears, disturbed puckers, and broken and/or crushed hairs are scattered all over the outer surface, indicating that they are occurred during the pollination process — the resulting tissue damage triggers directly the reddening of florets. Hormonal control of the flower reddening appeared to involve the transpigmentation process: GA 3 is inducible the flower reddening through promoting activities of β-D-glucosidase and glucose oxidase. The experimental findings are discussed in relation to the induction of a bathochromatic color change in matured florets, where floral tissues lost their fresh and vivid appearance.

Assessment test for the isolation of phenolic substances by cross-linked insoluble polymers

ZusammenfassungDie Kapazität zum Freisetzen verschiedener Phenole wurde durch Verwendung quervernetzter Polymere in einem Modellsystem untersucht. Unter den Polymeren war die Endgruppe substituierter Cellulose hierfür am besten geeignet. Sephadexgele zeigten wenig oder keine Affinität im Phenoltest. Carthanin wurde von allen Polymeren bevorzugt aufgenommen. Andere Phenole, ausgenommenl-3,4-Dihydroxyphenylalanin (Dopa), wurden nur im geringen Ausmaß abgefangen. Das zu vernachlässigende Dopa wurde lediglich an beschichtete Polymere fixiert. Die festgesetzten Stoffe konnten durch polare Lösungsmittel dissoziiert werden.SummaryThe trapping capacities of various phenolic substances were assessed by the use of a number of crosslinked polymers in an experimental model system. Among the polymers, end-group substituted celluloses were found to be the most promising. Sephadex gels showed little or no affinity for the test phenolics. Carthamin was taken up favourably by all polymers used. Other polyphenols, exceptl-3,4-dihydroxyphenylalanine (DOPA), were also trapped, but to a lesser event. Only negligible DOPA was fixed with the fed polymers. The trapped matter could be dissociated by polar solvents.