6.1.3 Glycosylated flavones

Glycosylated flavones (isolated from cottonseed flour) promote topoisomerase IV-dependent cleavage of DNA in E. coli. Rutin is the most potent glycosylated isoflavone in exciting topoisomerase IV-dependent cleavage of DNA (CC50 = 1 μg/ml). It blocks the catalytic activity of type II topoisomerase in addition to alleviate the cleavable complex. At CC50 = 64 μg/ml, rutin inhibited the decantation action of topoisomerase IV.

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

Protein synthesis was also significantly inhibited by genistein but was delayed a

The outer bacterial membranes safeguard the bacterial cells from harsh environment, causing them to survive in extreme conditions. The inner membrane or the so-called cytoplasmic membrane regulates the uptake of solutes and minerals into the cell as well as the transport of proteins and other macromolecules. The alteration in membranes causes many adverse effects on functions of bacterial cells that might be very important for bacterial integrity, like uptake of mineral ions and nutrients. To study the membrane effects of antioxidants, fluorescence polarization methods using model membranes (consisting of two component: DPPC and POPC) are used. Fluorescence polarization increasingly alters in correspondence with

The antioxidants like polyhydroxyl flavans and catechin of green tea hinder the development of certain bacteria and affect Gram-positive and Gram-negative bacteria by damaging the structure of membranes of the bacterial cells (see Table 1).

Sophoraflavanone G, a phytochemical with intensive antibacterial activity, shows very low MICs (1.56—12.5 μg/ml) against Gram-positive bacteria than Gramnegative bacteria by altering membrane functions. Increased polarization in DPPC and POPC liposomes implies that sophoraflavanone G decreases membrane fluidity

The pathogenicity of Gram-negative bacteria is linked to the lipopolysaccharide

Catechins intermingle and target bacterial membrane protein, fatty acid synthase, beta lactamase, and such other bacterial enzymes. Antibacterial catechins were reported to alter membrane fluidity [16]. Tea catechins impart specific agitation in

layer (reduce the sensitivity against antibacterial agents). That is why, the antibacterial agents demonstrate more activity for Gram-positive bacteria.

little, suggesting that repression of translation by genistein is secondary effect.

reduction in membrane fluidity. MIC values are given in Table 3.

listed in Table 3.

6.2 Disruption of membranes

Antioxidants: Natural Antibiotics

DOI: http://dx.doi.org/10.5772/intechopen.84864

6.2.1 Sophoraflavanone G

6.2.2 Catechins

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(for MIC value see Table 4) [15].
