Formation, properties, and antimicrobial activity of a cotton xanthate-Cu(II)-metronidazole complex

To develop cotton derivatives with prolonged antibacterial activity, cotton is derivatized to cotton xanthate (CX) and coupled with metronidazole (Mz) by means of chelate bonding in the presence of Cu(II) using one- and two-b ath processes. The effects of coupling methods, concentration, [Mz]/[Cu(II) ] ratio, and reaction time on the formation of CX-Cu(II)-Mz are investigate d at 10 degrees C. In the one-bath process where CX is treated with a solut ion of the Cu(II)-Mz complex, binding of Mt takes place readily and rapidly and increases with a higher [Mz]/[Cu(II)] ratio. In the two-bath process, binding of Mz is much lower than in one bath. Release of Mz from CX-Cu(II)- Mz prepared from the one-bath process is investigated by the how method and takes place steadily during the first 3 hours. The extent of release reach es 65-99% in 20 hours, depending on the concentration of Cu(II) and Mt used to form CX-Cu(II)-Mz. Antibacterial activity of CX-Cu(II)-Mz is tested aga inst G(+) S. aureus, B. subtilis, and G(-) E. coli., and lasts longer than that of free Mz.