Objective:To design the synthesis of high epigallocatechin gallate (EGCG) alkylated derivatives

analyze the structure-activity relationship and the pharmacological activity in inhibiting human hepatocellular carcinoma cell proliferation

in order to select the more stable and effective EGCG derivatives. Method:With EGCG and (CH3 CH2 O)2 SO2 as raw materials

a series of EGCG derivatives were ethylated. The effect of ethylated EGCG on the proliferation of human hepatocellular carcinoma cell SMMC-7721 and HepG2 were determined by 3-(4

5 dimethylthiazol-2-yl)-2

5 dimethyl-2H-tetrazolium bromide (MTT) method. With the cell density at 1×108/mL

the 3/4 of EGCG derivatives were diluted into four concentrations

with 60

80

100

150 mg·L-1

and 30

40

50

60 mg·L-1 for SMMC-7721 cells

and 60

80

100

150 mg·L-1

and 20

30

40

50 mg·L-1 for HepG2 cells

both were drug groups. A cell control group was also set up. Each concentration group has four complex wells

and the cells were continuously cultured for 24 h after addition of drugs. Result:We synthesized four EGCG derivatives. Their structures were identified by 1H-NMR

13C-NMR

2DNMR

mass spectrometry and other methods

all of them were novel compounds. Ethylated EGCG product 3 and 4 can inhibit proliferation of hepatocellular carcinoma cell SMMC-7721 and HepG2. Conclusion:Ethylated EGCG product 3 and 4 have inhibition effect on hepatocellular carcinoma cell SMMC-7721 and HepG2

and 4 has a much stronger effect than EGCG.