Antibacterial activity constituents

Hydrox5rpyranonate and hydroxypyridinonate complexes have been patented for the treatment of zinc deficiency (451) and are used in zinc supplements. Maltolate and ethylmaltolate complexes of zinc, copper, and tin have been included as essential constituents in patents for formulations for oral care (96). The arylmercury(II) complexes RHgL, where R = 4-XCgH4, X — Me, OMe, NO2, and L — malt, koj, have been tested for antibacterial activity (101). 

Cephalosporins, a common class in the )0-lactam family of antibiotics, are therapeutically important/advantageous for their broad antibacterial activity. Out of a total worldwide production of around 5x10 kg/annum, the /i-lactam group constitutes an amount of the order of 3 X 10 kg/annum. Penicillins and cephalosporins are the main constituents of commercially important /i-lactams and they are mainly produced by biosynthetic routes, the mechanism of which is now fairly well understood [ 1 ]. 

Chang, S.T., Chen, P.F. and Chang, S.C. (2001) Antibacterial activity of leaf essential oils and their constituents from Cinnamomum osmophloem. Journal of Ethnopharmacology 77(1), 123-127. 

Another interesting antibiotic constmct is a peptide-conjugated form of j8-KDO. jS-KDO is an inhibitor of the CMP-KDO synthetase that is involved in lipopolysaccharide (LPS) synthesis, a major constituent of the bacterial cell wall. Antibacterial activity is thus accomplished by interference with cell wall construction. /3-KDO is incapable of membrane permeation, and therefore is not useful as an antibiotic in its native form. Hammond et al. have shown that conjugation of a /3-KDO analog to certain dipeptides resolves this problem [184] (O Fig. 14). Attachment of the /3-KDO analog to a dipeptide allows the glycopeptide constmct to permeate the bacterial membrane. Inside the cell, proteases hydrolyze the peptide and release the inhibitor, resulting ultimately in bacterial cell death. 

Among cyclic diarylheptanoids garuganins and garugamblins isolated from Garuga pinnata and G. gamblei (88-95) exhibited antibacterial activity (57, 58). Activity and mechanism of action of the pure isolated constituents is unknown. 

A novel acetophenone-4-O-glucoside named nauplathizine was isolated as an active constituent from the antibacterial acetone extract of the aerial parts of Nauplius aquaticus (L.) [245]. The dichloromethane extract of underground parts of Calea uniflora Less, exhibited antifungal activities [246]. Four />-hydroxyacetophenone derivatives were isolated as the main compounds. Some of them showed antifungal activity, with MIC values between 500 and 1000 pg/ml against pathogenic Candida spp. and dermatophytes. 

Antibacterial activity of extracts and isolated constituents of P. sidoides was evaluated against three gram-positive and five gram-negative bacteria (707). Most compounds exhibited antibacterial activities. Further investigations complement these findings 108). 

Alkyl-dimethyl-benzylammonium chlorides are constituents of many disinfectants because of their antibacterial activity. 

Particular attention has been paid to the antibacterial, antiviral, antiinflammatory and antifertility effects of Wikstroemia indica that contains abrmdant active constituents, including flavonoids, biflavonoids, coumarins, lignans, volatile oils, polysaccharides, etc. [66]... 

As mentioned before, of the constituents of thyme oil, thymol (91) was the most active, followed by carvacrol (92), borneol (93),/7-cymene (37), a-pinene (13) and camphene (94). When mixtures of these 6 materials were made and the antibacterial activity evaluated, the results were quite unexpected. The antibacterial activity of the mixtures was less than that of the essential oil of thyme. This suggests that the minor compounds play a significant role in the biological activity [121]. 

Phenolic constituents of M grandiflora L., namely magnolol (6), honokiol (7), and 3, 5 -diallyl-2 -hydroxy-4-methoxy-biphenyl (46) were found to have good antibacterial activity against Bacillus subtilis. Staphylococcus aureus, and Mycobacterium smegatis when compared to streptomycin sulfate [67]. Additionally, magnolol and honokiol were found to be... 

Inouye, S., Takizawa, T., and Yamaguchi, H., Antibacterial activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact, J. Antimicrob. Chemother., 47, 565, 2001. 

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