Antimicrobial lexitropsins containing amide, amidine, and alkene linking groups.

The synthesis and properties of 80 short minor groove binders related to distamycin and the thiazotropsins are described. The design of the compounds was principally predicated upon increased affinity arising from hydrophobic interactions between minor groove binders and DNA. The introduction of hydrophobic aromatic head groups, including quinolyl and benzoyl derivatives, and of alkenes as linkers led to several strongly active antibacterial compounds with MIC for Staphylococcus aureus, both methicillin-sensitive and -resistant strains, in the range of 0.

Screening methods used to determine the anti-microbial properties of Aloe vera inner gel.

The emergence of antibiotic resistant bacterial strains is a growing problem and is an important concern for patients, physicians, healthcare managers, and policymakers as it results in poorer health and economic outcomes. This has led to an urgent global call for new antimicrobial drugs, particularly from natural resources. We have been studying the antimicrobial properties of the inner leaf gel component of Aloe barbadensis Miller and have used a number of different, simple in vitro assays to establish a scientific basis for the potential use of Aloe vera on a range of clinically relevant bacteria.

Synthesis and antimicrobial activity of some netropsin analogues.

Nine novel lexitropsins were synthesized by linking two netropsin-like moieties through three different dicarboxylic acids; 9,10-dihydro-2,7-phenanthrenedicarboxylic acid; [(3-[[(carboxymethyl)amino]carbonyl]benzoyl)amino]acetic acid and indole-2,5-dicarboxylic acid. The netropsin residues were modified by the use of N-isopentylpyrrole, 5-methylthiophene or 5-isopropylthiazole heterocyclic building blocks in place of the usual N-methylpyrrole. The compounds were tested against five gram-positive bacteria: Staphylococcus aureus, Streptomyces faecalis, methicillin resistant Staphylococcus aureus, Enterobacter cloacae, Mycobacterium fortuitum, three gram-negative bacteria: Klebsiella aerogenes, Proteus vulgaris, Escherichia coli and three fungi: Aspergillus niger, Candida albicans and Aspergillus nidulans.

Distamycin analogues with enhanced lipophilicity: synthesis and antimicrobial activity.

Forty-eight heterocyclic amino acid trimers, analogues of distamycin, with a number of features that enhance lipophilicity are described. They contain alkyl or cycloalkyl groups larger than methyl; some are N-terminated by acetamide or methoxybenzamide and are C-terminated by dimethylaminopropyl or aliphatic heterocylic aminopropyl substituents. The ability of these compounds to bind principally to AT tracts of DNA has been evaluated using capillary zone electrophoresis.