6.1.4 Catechins

Catechins like epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (structure is shown below) inhibit ATPase action because the ATP-binding site of B subunit of gyrase shares the structural similarity with these catechins. So, owing to this similarity with ATP-binding site, the catechins occupy these sites and as a result inhibits of ATPase activity. Catechins inhibit the ATPase activity in the following order, EGC < ECG < EGCG, while EC had no affect at all (for MIC values see Table 4) [12]. ATP hydrolysis provides vigorous force for DNA supercoiling. The inhibition of ATPase activity by catechins prevents ATP hydrolysis. In this way the DNA supercoiling is affected and so the bacterial growth.

#### Catechin based antioxidants

#### 6.1.5 Soybean isoflavone

SI (soybean isoflavone) could alter the supercoiling of double-stranded DNA could be altered by affecting DNA topoisomerase. By increasing the concentration of soybean isoflavone, the supercoiling activity increases and the quantity of linear and open circular DNA decreases.

At 6.4 mg/ml concentration, SI significantly inhibited the activity of both topoisomerase I and II so stops the bacterial growth by affecting nucleic acid synthesis. Topoisomerase inhibitors form a drug-gyrase-DNA cleavable complex or disrupt the topoisomerase binding to DNA [13].

#### 6.1.6 Genistein

Genistein is an isoflavone (shown in structure below) and characteristic of other flavonoids, apigenin, daidzein, and kaempferol for common use on the laboratory strains bacterial species like B. subtilis, E. coli, and V. harveyi. Addition of this flavonoid to bacterial cultures imposes drastic effects on the synthesis of DNA and RNA in almost 15 min [14].

stabilizes DNA topoisomerase II complex causing DNA to cleave [11]. MIC values

Glycosylated flavones (isolated from cottonseed flour) promote topoisomerase IV-dependent cleavage of DNA in E. coli. Rutin is the most potent glycosylated

addition to alleviate the cleavable complex. At CC50 = 64 μg/ml, rutin inhibited the

Catechins like epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (structure is shown below) inhibit ATPase action because the ATP-binding site of B subunit of gyrase shares the structural similarity with these catechins. So, owing to this similarity with ATP-binding site, the catechins occupy these sites and as a result inhibits of ATPase activity. Catechins inhibit the ATPase activity in the following order, EGC < ECG < EGCG, while EC had no affect at all (for MIC values see Table 4) [12]. ATP hydrolysis provides vigorous force for DNA supercoiling. The inhibition of ATPase activity by catechins prevents ATP hydrolysis. In this way the DNA supercoiling is affected and so the bacterial

Catechin based antioxidants

SI (soybean isoflavone) could alter the supercoiling of double-stranded DNA could be altered by affecting DNA topoisomerase. By increasing the concentration of soybean isoflavone, the supercoiling activity increases and the quantity of linear

At 6.4 mg/ml concentration, SI significantly inhibited the activity of both topoisomerase I and II so stops the bacterial growth by affecting nucleic acid synthesis. Topoisomerase inhibitors form a drug-gyrase-DNA cleavable complex or disrupt

Genistein is an isoflavone (shown in structure below) and characteristic of other flavonoids, apigenin, daidzein, and kaempferol for common use on the laboratory strains bacterial species like B. subtilis, E. coli, and V. harveyi. Addition of this flavonoid to bacterial cultures imposes drastic effects on the synthesis of DNA and

isoflavone in exciting topoisomerase IV-dependent cleavage of DNA (CC50 = 1 μg/ml). It blocks the catalytic activity of type II topoisomerase in

for different bacterial strains are listed in Table 3.

decantation action of topoisomerase IV.

6.1.3 Glycosylated flavones

6.1.4 Catechins

Antioxidants

growth.

6.1.5 Soybean isoflavone

6.1.6 Genistein

360

and open circular DNA decreases.

RNA in almost 15 min [14].

the topoisomerase binding to DNA [13].

Three hours after addition, genistein caused the bacterial cells to become elongate that cause troubled cell division and chromosome replication. MIC values are listed in Table 3.

Protein synthesis was also significantly inhibited by genistein but was delayed a little, suggesting that repression of translation by genistein is secondary effect.
