Test methods Staphylococcus aureus showing

Newly synthesized compounds 22, 23, 25c-e, 26d and 29e were screened in vitro for their antimicrobial activities against Gram positive bacteria Staphylococcus aureus (NCTC-7447), Bacillus cereus (ATCC-14579) and Gram negative bacteria Serratia marcesens (IMRU-70) and Proteus merabitis (NTCC-289) using the paper disk diffusion method for the antibiotic sensitivity technique [60]. The tested compounds were dissolved in N,N-dimclhylformamidc (DMF) to obtain a 1 mg/mL solution. The inhibition zones of microbial growth produced by different compounds were measured in millimeters at the end of an incubation period of 48 h at 28 °C. DMF alone showed no inhibition zone. 

An antibacterial assay using the disc-diffusion method found that the stems and the roots of H. capitellata showed weak to moderate activities against the tested bacteria, Bacillus subtilis B28, Bacillus subtilis B29, Pseudomonas aeruginosa UI 60690 and methicillin resistant Staphylococcus aureus, (MRSA) while the leaves showed weak activity toward Bacillus subtilis B28, MRSA and P. aeruginosa only. However, the roots of H. dichotoma showed moderate antibacterial properties against all four bacteria. All other extracts did not exhibit any antibacterial properties. Table 10 shows the inhibition zones of the methanolic extracts of some Hedyotis species as measured by the disc-diffusion method. 

---