In vitro α-glucosidase inhibitory activity of isolated fractions from water extract of Qingzhuan dark tea

Table 2 The main constituent of Qingzhuan tea extracts (%)

Extracts	Polyphenol	Carbohydrate	Caffeine	Theaflavin	Thearubigin	Theabrownin
The crude water extract	18.25 ± 0.21 cC	14.74 ± 1.02 bA	5.82 ± 0.06 bB	0.15 ± 0.01 cC	5.51 ± 0.14 bB	21.17 ± 0.21 bcC
Chloroform fraction	0.98 ± 0.06 fF	1.28 ± 0.33 dC	70.55 ± 0.01 aA	0.62 ± 0.00 bB	0.74 ± 0.00 cC	0.21 ± 0.00 eE
Ethyl acetate fraction	62.72 ± 2.63 aA	5.85 ± 1.16 cB	0.50 ± 0.01 cC	1.70 ± 0.23 aA	24.21 ± 3.18 aA	4.17 ± 0.17 dD
n-Butanol fraction	31.09 ± 0.73 bB	15.56 ± 0.07 abA	0.30 ± 0.002 dD	0.24 ± 0.03 cC	28.00 ± 1.68 aA	24.82 ± 1.25 abB
Sediment fraction	9.16 ± 0.35 eE	16.65 ± 0.04 aA	ND	0.02 ± 0.01 dD	ND	27.18 ± 0.80 aA
Residual aqua fraction	11.15 ± 0.31 dD	17.19 ± 0.20 aA	0.13 ± 0.02 eE	0.03 ± 0.03 dD	0.14 ± 0.19 cC	19.56 ± 0.05 cC

Note: At the same column, different capital letters mean a significant difference at p < 0.01 level and small letters at p < 0.05 level compare to each other, ND means not detected

ISSN: 2662-7671