The total flavonoids in leaves of 12 varieties of Korean mulberry (Morus alba L.) were determined. Seventeen flavonoids were isolated and analyzed using ultra-performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC–DAD–QTOF/MS). To determine the flavonoid contents, HPLC analysis was performed on these 17 flavonoids. The total flavonoid contents of the 12 varieties of mulberry leaves ranged from 748.5 to 1297.9 mg, with the highest obtained from the Cheong Su variety (1297.9 ± 112.0 mg). Among the 17 flavonoids analyzed, quercetin 3-O-rutinoside (rutin) and quercetin 3-O-glucoside (isoquercitrin) had highest contents in the Cheong Su variety. Furthermore, the Dae Dang Sang variety gave the highest quercetin 3-O-rutinoside (rutin) content among the mulberry leaves investigated, at 425.5 ± 45.9 mg. Major flavonols from Dae Dang Sang were detected by UPLC–DAD–QTOF/MS. A total of 17 flavonoid compound peaks were identified in the analysis time range of 5–40 min, all of which were kaempferol and quercetin glycosides. Seven of the 17 compounds identified in mulberry leaves were unknown.

Zingiberaceae is the large diverse family comprised of rhizomatous plants with a higher concentration of phenolic compounds. The normal ginger (Zingiber officinale Rosc.) and black ginger (Kaempferia parviflora Wall.) belongs to this family and have similar morphological characteristics of rhizome, but their phenolic composition revealed differently. On this study, the phenolic composition of normal ginger (from Ethiopia and Korea) and black gingers (from Korea and Thailand) were profiled using ultra performance liquid chromatography coupled with diode array detector, quadrupole time-of-flight mass spectrometry (UPLC-DAD-QToF-MS). The result revealed that gingerol-related phenolic acid was detected only in normal gingers while, the methoxyflavones were identified exclusively in black gingers. 6-gingerol, 8-gingerol, 10-gingerol, 1-dehydro-6-gingerdione, and diacetoxy-8-gingerdiol were the major constituents among 18 phenolic acids detected from normal gingers, and 3,5,7,3′,4′-pentamethoxyflavone and 5,7,4′-trimethoxyflavone were confirmed as predominant constituents among 13 methoxyflavones from black gingers. The total phenolic content was 434.7 and 698.1 mg/100 g dry weight (DW) in Korean and Ethiopian sample, respectively. The total methoxyflavone concentration was 4388.0 mg/100 g DW and 3940.2 mg/100 g DW in Korean and Thai black ginger sample, respectively. The higher concentration of methoxyflavones is from advanced biosynthetic pathway related to accumulated color of black ginger. In addition, new possible structural fragmentation was proposed for gingerol homologous series as additional pathway under the positive ionization mode, and further rationalized that ferulic acid moiety is the biosynthetic precursor. The result suggested that despite the morphological similarity, normal and black ginger showed distinct biosynthetic difference to synthesis their major secondary metabolites.Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s0021 7-018-3188-z) contains supplementary material, which is available to authorized users. Graphical AbstractKeywords Kaempferia parviflora Wall. · Phenolic compounds · UPLC-DAD-QToF-MS · Zingiberaceae · Zingiber officinale Rosc.

Most previous studies have been focused on the variation of tea chemical composition by fermentative processes as well as different cultivars and regions. The detailed changes of flavonoid profiles were described for the first time by each processing step of green and black tea leaves in this study. A total of 24 flavonoid derivatives including catechins, theaflavins, and flavonols were separated and identified from the tea samples based on UPLC-DAD-QToF/MS data and constructed library. Among these, the fragmentation pathway of theaflavins was proposed specifically in positive ionization mode for structural interpretation. During leaf processing, the individual flavonols were changed as diverse patterns according to their aglycone types and glycosylated forms, but their total content showed a slight difference. EGCG and ECG were increased after roasting approximately twofold higher than that of fresh leaves (EGCG, 2709.5 →6085.6; ECG, 1548.0 →2318.2 mg/100 g dry weight, respectively) in green tea while considerably decreased their contents due to oxidation and conversion to theaflavins after fermentation during black tea processing. Especially, the drying steps also found to be factor to influence positively to increase the flavonoid contents in both tea processing. Therefore, this result indicated that detailed conditions of each processing step played important roles in changing the flavonoid profiles from tea leaves.

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