been cooled down to room temperature the mixture is neutralized with 0 1 n hcl and then dialyzed and freeze dried the yield is 95 based on the ds achieved elemental analysis n 5 11 mean degree of substitution ds n 1 32 the antibacterial activity of the compounds as directed against staphylococcus aureus sg 511 s aureus 134 93 multiresistant and mycobacterium vaccae imet 10670 was tested by means of determining the minimum inhibitory concentrations mhcs in a microbroth dilution test in m u00fcller hinton broth difco in accordance with the nccls guidelines national committee for clinical laboratory standards methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically 4th ed villanova ed approved standard document m7 a4 nccls 1997 the results are shown in table 6 prior to the antiviral investigations the 50 cytotoxic concentration cc 50 in green monkey kidney gmk cells was determined in order to be able to exclude nonspecific substance effects to do this continuous gmk cell lawns in microtiter plates are inoculated with the appropriate substance dilution series factor 2 sclmidtke et al j virol meth 95 2001 133 after a 72 hour incubation the cells are stained with crystal violet methanol after the dye has been leached out the optical densities of the individual wells are measured 550 630 nm in a dynatech plate photometer and compared with the mean value for 6 untreated cell controls which value is taken to be 100 the cc 50 is the substance concentration at the point where the extinction curve of the dilution series intersects with the 50 line of the mean value for the control the antiviral effect of the compounds in regard to.