Study on Betalains in Celosia cristata Linn. Callus Culture and Identification of New Malonylated Amaranthins

Abstract

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.

Separation of betacyanins from flowers of Amaranthus cruentus L. in a polar solvent system by high‐speed counter‐current chromatography

“…The NMR signals of the aglycone and glucose moieties in pigment 1 confirmed the presence of a betanin derived compound (Table 4) [9,41,43]. The individual coupled 1 H-spin systems of the aglycone (H-2 and H3a/b, indicating the lack of decarboxylation at C-2; H-11 and H-12 distinguished by the low-and high-field position; as well as H-14a/b and H-15) were readily assigned in the COSY spectra and the H-18 proton was indicated by its position and width [41,43]. The HSQC correlations were established for H-2, H-3ab, and H-7 in the dihydroindolic system.…”

“…The presence of the carboxyl in the glucuronosyl ring was finally indicated by the HMBC detection of the carboxyl carbon C‐6′′ at δ 175.3 ppm correlating with the protons H‐5′′ and H‐4′′ (Table , Figure ). A definitive evidence of the lack of acylation at C‐6′ carbon was provided by the position of the H‐6′ab protons signal . As a result of the data analysis, compound 1 was confirmed as amaranthin betanidin 5‐ O ‐(2′‐ O ‐ β ‐ d ‐glucuronosyl)‐ β ‐ d ‐glucopyranoside).…”

“…Further HRMS determination of the molecular formula in combination with the HRMS fragmentation pattern of the precursor ion [M+H] + matching the predicted m/z values (Table 3, Figure 2) supported the identification of malonylated amaranthin. This pigment has never been identified in betacyanin sources except for C. cristata callus culture in the recent study and NMR structure elucidation [41]. Therefore, co-elution chromatographic experiments with 4/4 ′ and standards obtained in the previous study [41] indicated the identity of 4/4 ′ as betanidin/isobetanidin 6 ′ -Omalonyl-5-O-(2 ′ -O--D-glucuronosyl)--D-glucopyranoside abbreviated as 6 ′ -O-malonyl-amaranthin/isoamaranthin (celoscristatin/isoceloscristatin).…”

“…Reference betacyanins as well as their C-15 diastereomers which were completely structurally elucidated were derived from the flowers of red G. globosa [33] and Celosia cristata Linn. callus culture from a recent study [41].…”

Study of influence of ascorbic acid, reducing sugars and methyldopa on betalains content in Celosia cristata callus

“…Production of significant amounts of betalains was noted in this culture. These pigments was investigated recently and new onesceloscristatin and its isomerswere isolated and characterized [6]. Moreover, a large amount of dopamine was discovered in this culture [6].…”