Phenolic constituents in dried flowers of aloe vera (Aloe barbadensis) and their in vitro antioxidative capacity.

The dried flowers from ALOE VERA (L.) Burm. f. ( ALOE BARBADENSIS Mill .) (Asphodelaceae) were analysed by means of HPLC-DAD and HPLC-MS/MS, verifying chlorogenic, caffeic, 5- P-coumaroylquinic, caffeoylshikimic, 5-feruloylquinic, 5- P- CIS-coumaroylquinic, P-coumaric and ferulic acid as well as luteolin, apigenin, quercetin, kaempferol, isoorientin, isovitexin and their 7- O-glucosides, saponarin and lutonarin. On searching for anthranoids in the flower extract, aloe-emodin as well as the glycosylchromone aloeresin B could be identified. Aloin A and B, the laxative principle of the drug Curacao-Aloes, are not accumulated in the dried flowers. The polyphenol content of three different batches was 0.73 - 1.01 % (± 0.05 %) and the flavonoid content 0.24 - 0.34 % (± 0.01 %). The hydrophilic antioxidative capacity amounted to 85.7 - 94.9 (± 0.5) μmol TEAC/g dried ALOE VERA flower and was directly correlated with the polyphenol and flavonoid contents.