The main subgroups of flavonoids are flavanols, flavanones
, flavonols, flavones, anthocyanidins and isoflavones (Figure 1) (3, 10).
They have been classified into six subgroups: flavones, flavonols, flavanones
, flavan-3-ols, isoflavones, and anthocyanidins .
ANR: anthocyanidin reductase; CER: ECERIFERUM; CHI: chalcone flavanone
isomerase; CYP: cytochrome P450; DFR: dihydroflavonol 4-reductase, (transcript_61515 was chosen for DFR); GPAT: glycerol-3-phosphate acyltransferases.
(2012, 2013) found that the inhibition of Pro-Ca on enzyme activities of 2-ODDs flavanone
3-hydroxylase gene (F3H), flavonol synthase gene (FLS) and anthocyanidin synthase gene (ANS) in flavonoid biosynthesis pathway in the skin of apples might lead to a decrease in anthocyanin content.
compounds are antioxidant substances which are widely used.
Naringenin-oxime (NOX) is a new derivative compound of naringenin (4,5,7-trihydroxyflavanone) which is a predominant flavanone
in citrus fruits including oranges and grapefruit .
Too high temperature was confirmed to be harmful to preserve flavanone
glycosides [35, 36].
In the standard juicing process, high pressure is applied to the flavedo and/or albedo of the yuzu fruit, resulting in the extraction of ascorbic acid, flavanone
glycosides, and odorants present in the juice.
 reported that the content of flavanone
in all parts of Gethyllis multifolia decreased when this plant were subjected to photo-stress treatment, while the contents of polyphenols and flavone increased in the roots when subjected to drought stress and the antioxidant activity was also significantly higher.
HPLC-PDA-ESI/MSn Analysis of Flavanones
glycosides, expressed as hesperidin (Hd) equivalents (g/100g of extract), were determined by HPLC  using the HPLC-PDA-ESI/MSn equipment described above.
Studies have found that the total flavonoids from Oxytropis falcata Bunge are mainly composed of flavonoid glycoside, flavanone
, flavonols, chalcone, dihydrochalcone, flavanones
, and isoflavane and have strong anti-inflammatory and antioxidant effects .
Pro-Ca also blocks flavanone
3-hydroxylase, thereby inducing a completely new spectrum of flavonoids and other phenolic plant constituents (Rademacher, 2000).