UV-C (254 nm)- and UV-B (280-320 nm)-light were irradiated onto bright-yellow capitula of dyer's saffron and their effects on carthamine accumulation compared. UV-C light promotes reddening of florets more prominently than UV-B light, yielding higher amounts of carthamine after the radiation process. The enhancement of carthamine synthesis by UV-C light was investigated on cellulose columns loa...

The dye used on the silk textiles in an as yet undated relic shrine in a church in Antwerp was analysed by reflectance UV-Vis spectrometry. The natural dyestuff carthamin from safflower (Carthamus tinctorius) was detected; because of its very poor light fastness this does not allow the shrine to be exhibited. Neither does it allow dating of the silk, since safflower has been used over a period ...

Two Carthamus tinctorius varieties (Jawhara and 104) were studied in order to investigate their natural dyes contents and biological activities. Obtained results showed that quinochalcone contents and antioxidant activities varied considerably as function of flowering stages. So flowers at fructification stage contained the highest carthamin content with the strongest antioxidant capacity with ...

Background and objectives: Safflower (Carthamus tinctorious L.) florets contain valuable red and yellow pigments and are used in food, textile dying, and pharmaceutical industries. Red carthamine pigment is formed from a yellow precursor, precarthamine, through an oxidation reaction at the end of flowers' maturation stage. The present study was conducted to find out the most effective ...

background and objectives: safflower (carthamus tinctorious l.) florets contain valuable red and yellow pigments and are used in food, textile dying, and pharmaceutical industries. red carthamine pigment is formed from a yellow precursor, precarthamine, through an oxidation reaction at the end of flowers' maturation stage. the present study was conducted to find out the most effective procedure...

Effect of manganese with three different valence states on carthamin formation was studied by using freshly collected flowers from dyer’s saffron ( C. tinctorius) capitula. At 1 10 hm con­ centration, these cations accelerated markedly the carthamin formation induced by endoge­ nous enzyme(s) in the detached floral tissues. The acceleration was obviously dependent on the valence state of the te...

Glucose was found to be a potential stimulator o f carthamin formation in triturated florets o f C. tinctorius. At a 10 m M glucose level, carthamin-producing activity was raised from 3.2fold (upper) to 2.0-fold (lower) level compared with the control having no sugar. Glucose oxi­ dase (ß-D-glucose: oxygen 1-oxidoreductase, EC 1.1.3.4) from Aspergillus niger could catalyze the conversion of pre...

Catalytic activity o f the enzyme which mediates the synthesis o f carthamin was examined in the etiolated hypocotyl tissues o f Carthamus tinctorius L. The enzyme was optim ally active at pH 5.2 in citrate buffer. The activity o f the enzyme was highest in the extract from 2-day-old seedlings after sowing and it declined sharply with tissue ageing. The enzyme activity was localized in the apic...

Precarthamin, a yellow precursor of carthamin, was efficiently isolated from the yellow petals of safflower (Carthamus tinctorius L. ) with Sephadex LH-20 column chromatography and preparative HPLC, and identified with UV-vis and NMR spectrometry. The UV-vis spectrum of precarthamin showed lambda(max) of 238 and 406 nm in MeOH. The molar extinction coefficients of precarthamin at 406 nm in MeOH...

Carthamin from safflower petals has been used for centuries in Asia as a red colorant for dyes and cosmetics. Carthamin is unstable, however, both in hot, aqueous solutions, which causes difficulties in its analysis in textiles, and to light, which results in fading of dyed textiles. We have found, using HPLC and mass spectrometric analysis, that carthamin undergoes a reverse aldol condensation...