“…The extract was concentrated using a freeze-drier. The pigment extract was purified by flash chromatography and preparative high-performance liquid chromatography . For the co-injection experiments, the extracts of Beta vulgaris L. roots, , Hylocereus polyrhizus fruits, and Iresine herbstii leaves from previous studies were processed by a similar procedure.…”
Betacyanins and betaxanthins were characterized and determined in an intensely pigmented red-colored callus culture of Celosia cristata L. (Amaranthaceae). A new malonyl derivative, 6'- O-malonyl-amaranthin (celoscristatin) was isolated and identified by spectroscopic and mass spectrometric techniques. Its stereoisomer, 4'- O-malonyl-amaranthin (celoscristatin acyl-migrated), as well as its 15 R diastereomer were also detected in the callus as a result of the malonyl group migration in celoscristatin/isoceloscristatin, respectively. Amaranthin occurs in the callus as the major betacyanin, followed by celoscristatin, betanin, phyllocactin, and other minor betacyanins. The effect of different carbon sources on the growth rates of the Celosia callus as well as on betalains profiles in the callus cultures was studied. High dopamine content in the callus culture was determined and compared with the content in C. cristata inflorescences. The dopamine-based betalain (miraxanthin V) was detected as the main betaxanthin in the callus, however, at a concentration level much lower than that of the identified betacyanins. The studied callus culture of C. cristata can accumulate betalains in amounts which approach the quantities produced by most known high-yielding plant species.
“…The extract was concentrated using a freeze-drier. The pigment extract was purified by flash chromatography and preparative high-performance liquid chromatography . For the co-injection experiments, the extracts of Beta vulgaris L. roots, , Hylocereus polyrhizus fruits, and Iresine herbstii leaves from previous studies were processed by a similar procedure.…”
Betacyanins and betaxanthins were characterized and determined in an intensely pigmented red-colored callus culture of Celosia cristata L. (Amaranthaceae). A new malonyl derivative, 6'- O-malonyl-amaranthin (celoscristatin) was isolated and identified by spectroscopic and mass spectrometric techniques. Its stereoisomer, 4'- O-malonyl-amaranthin (celoscristatin acyl-migrated), as well as its 15 R diastereomer were also detected in the callus as a result of the malonyl group migration in celoscristatin/isoceloscristatin, respectively. Amaranthin occurs in the callus as the major betacyanin, followed by celoscristatin, betanin, phyllocactin, and other minor betacyanins. The effect of different carbon sources on the growth rates of the Celosia callus as well as on betalains profiles in the callus cultures was studied. High dopamine content in the callus culture was determined and compared with the content in C. cristata inflorescences. The dopamine-based betalain (miraxanthin V) was detected as the main betaxanthin in the callus, however, at a concentration level much lower than that of the identified betacyanins. The studied callus culture of C. cristata can accumulate betalains in amounts which approach the quantities produced by most known high-yielding plant species.
“…Poor light absorption of betanin at 405 nm and its low fluorescence quantum yield 37 suggests that the direct excitation of surface betanin has little or no contribution to the emission observed during photocatalytic reaction. However, the molar attenuation coefficient of betalamic acid and neobetanin at 405 nm are higher than 20,000 L∙mol −1 ∙cm −1 and fluorescence of both compounds in solution is centered at around 500 nm 38 . Figure 6 Photoluminescence signal emanated from Ag NPs regenerating layer.…”
The efficient conversion of light energy into chemical energy is key for sustainable human development. Several photocatalytic systems based on photovoltaic electrolysis have been used to produce hydrogen via water reduction. However, in such devices, light harvesting and proton reduction are carried separately, showing quantum efficiency of about 10–12%. Here, we report a nano-hybrid photocatalytic assembly that enables concomitant reductive hydrogen production and pollutant oxidation with solar-to-fuel efficiencies up to 20%. The modular architecture of this plasmonic material allows the fine-tuning of its photocatalytic properties by simple manipulation of a reduced number of basic components.
“…An important modication of the transient absorption setup with respect to the standard commercial conguration was the use of a lter that suppresses the residual 800 nm white light continuum before the sample in order to avoid pump-and-dump artifacts. 14,32 Femtosecond transient absorption was performed under excitation at 600 nm in a 3 ns time window in the spectral range between 440 and 850 nm. Global analysis of the transient absorption data was performed using the Surface Explorer soware (Ultrafast Systems).…”
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