Antibacterial activity patterns

Racemosol and demethylracemosols, together with their possible biogenetic precursors, preracemosols A and B (175 and 176) exhibited moderate antimalarial activity with ECso values of 0.9, 2.0, 18.0 and 3.0 / g/ml, respectively [101]. The antibacterial activity pattern of the two photosensitizers, dehydroeffusol and juncusol, against methicillin-resistant and -sensitive S. aureus and B. subtilis was similar to that of their antifungal activity [456]. 

As such, the magainins provide a useful initial target for peptoid-based peptido-mimetic efforts. Since the helical structure and sequence patterning of these peptides seem primarily responsible for their antibacterial activity and specificity, it is conceivable that an appropriately designed, non-peptide helix should be capable of these same activities. As previously described (Section 1.6.2), peptoids have been shown to form remarkably stable hehces, with physical characterishcs similar to those of peptide polyprohne type-I hehces (e.g. cis-amide bonds, three residues per helical turn, and 6A pitch). A faciaUy amphipathic peptoid helix design, based on the magainin structural motif, would therefore incorporate cationic residues, hydrophobic aromatic residues, and hydrophobic aliphathic residues with threefold sequence periodicity. 

Neocarzinostatin, isolated from Streptomyces carzinostaticus, consists of a mixture of chro-mophore (32) and a protein [43]. This compound having potent antitumor and antibacterial activities induces single strand and double strand scissions in a ration 5 1, respectively, with a preference for T and A residues. The sequence specificity differs from other enedyines partly because of the different glycosylation pattern of the molecule. 

Figure 1. Different species of flies have different patterns of antibacterial activity after isoelectric focusing. Dro, Drosophila melanogaster Med, Ceratitis capitata Mel, Dacus cucurbitae Dor, Dacus dorsalis. Antibacterial proteins (ABs) are labeled according to their isoelectric points.

Tilmicosin, Figure 1, is a new semisynthetic antibiotic derived from the macrolide antibiotic tylosin. The synthesis and antibacterial activity of tilmicosin have been described by Debono, et al. and Kirst, et al. (/-4). Tilmicosin has in vitro activity against a variety of Gram positive and Gram negative bacteria, as well as mycoplasma species. It is effective for treatment of bovine respiratory disease caused by Pasteurella haemolytica when administered as a single subcutaneous injection (5, 6). This paper describes the excretion, tissue residue pattern, and metabolism of tilmicosin when injected into cattle, and also gives comparative metabolism data from rats which were dosed orally. 

Relationship between structure, antibacterial activity S.W, Fesik et al, Mol Pharmacol. 25, 275 (1984). Effect on resistance patterns in chickens J. R, Walton,... 

In summary, the pattern recognition studies indicate that the reactivity of the p-lactam ring is a crucial determinant of the in vitro antibacterial activity of a related series of cephalosporins. Physicochemical properties that do not reflect reactivity appear to be less useful indicators of activity. 

The cell distribution of 3-amino-4-hydroxymethyl acridine derivatives 70 (Scheme 25), which has the N3—C4—16 substitution pattern, was studied by real-time fluorescence microscopy and SIMS structured illumination microscopy). The latter method required the introduction of an iodine atom at position 6 of the acridine which influences the Upophihcity but does not modify significantly the biological properties such as IC50 and subcellular localization (2009EJMC4758). A co-polymer 71 consisting of water-soluble maleic anhydride-containing poly[maleic anhydride-u/i-acrylic acid] (poly(MA-alt-AA) or MAAA) copolymer was modified with acriflavine (AF) which displayed antibacterial activity on EHEC and Staphylococcus aureus (2014MI2903). 

Kusche BR, Sntith AE, McGuirl MA, Priestley ND. The alternating pattern of stereochemistry in the nonactin macrocycle is required for antibacterial activity and efficient ion binding. J. Am. Chem. Soc. 2009 131 (47) 17155-17165. 

Pyrrolidines are structural subunits found in many natural and unnatural products, which have important biological activity.102 Depending on the substitution pattern and functionalization, pyrrolidines have been shown to be effective antibacterials,103 neuroexcitatory agents,104 potent venom,105 and glyosidase inhibitors.106... 

Antimicrobial effect. The in vitro antibacterial, antifungal and antiviral activities of LF are well demonstrated and have been reviewed in many excellent articles (Reiter, 1985 Hutchens et al., 1994 Naidu and Arnold, 1997 Vorland, 1999). LF exerts its antimicrobial effects by various mechanisms, which can be divided into two main patterns ... 

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