## 2 Results and Discussion
### Antimicrobial Screening
In the first screening phase against _Staphylococcus aureus_ ATCC 25923, **5a** was noted to be the most sensitive derivative, with an inhibition zone of 31 mm, the MIC being 3.9 \(\upmu\)g/mL and the MBC being 31.5 \(\upmu\)g/mL, respectively (Tables 4-6). Then, against the same pathogenic bacteria, four compounds **5d**, **5e**, **5h** and **5l** showed an excellent activity with MIC values in the range of 31.5-62.5 \(\upmu\)g/mL as MBC with an inhibition zone between 11 and 20 mm, compared to standard antibiotic Tetracycline. When testing against _Microococcus luteus_ NCIMB 8166, compounds **5f**, **5g**, **5n** and **5o** were equipotent as Tetracycline. Thus, **5h** and **5p** were found to be the most active, with  
Figure 6: Antibacterial activity of some derivatives via determination of the inhibition zone (mm) around discs impregnated with **5a** (M1V),**5b** (M2V), **5c** (M3V), **5d** (M4V), **5e** (M7V), **5f** (H1V), **5g**(H2V), **5h** (H3V), **5i** (M1 VF), **5j** (M2 VF), **5k** (M3 VF), **5l** (M4 VF), **5m** (M7 VF), **5n** (H1 VF), **5o** (H2 VF), **5p** (H3 VF), and **5q** (M3 VI) concentration (10 mg/disk).Tetracycline (10 mg/mL) or Amphotericin B (10 mg/mL) expressed as mean \(\pm\)SD (n = 3). Figure 7: Antimicrobial activity of some samples determined via the inhibition zone (mm) around discs impregnated with **5a** (M1V),**5b** (M2V), **5c**(M3V), **5d**(M4V), **5e**(M7V),**5f**(H1V), **5g**(H2V), **5h** (H3V), **5i** (M1 VF), **5j** (M2 VF), **5k**(M3 VF), **5l**(M4 VF), **5m**(M7 VF), **5n**(H1 VF), **5o**(H2 VF), **5p**(H3 VF), and **5q**(M3 VI) compounds (10 mg/disk); Tetracycline (10 mg/mL) or Amphotericin B (10 mg/mL) expressed as mean \(\pm\) SD (n = 3). MIC values of 31.5 and 62.5 \(\upmu\)g/mL, respectively (Table 4). Concerning the evaluation of the inhibition zone, the compounds **5d**, **5o** and **5p** were found to be the most sensitive, with 17 mm to 14 mm. Additionally, the different compounds were evaluated against two gram-negative bacteria (_Escherichia coli_ ATCC 25,922 and _Pseudomonas aeroginosa_ ATCC 27853). In this case, **5e** was found to be the most sensitive, with an inhibition zone of 15 mm. All compounds were found to be equal or less active (125- >1000 \(\upmu\)g/mL) concerning the MIC or MBC compared to standard antibiotic Tetracycline. On the other hand, the in vitro antifungal activity data reveal that **5a**, **5f** and **5i** display the highest activity with MIC 7.812 \(\upmu\)g/mL against Amphotericin B. Compounds **5d**, **5k** and **5q** showed a somewhat less efficient activity, when compared to compounds **5i** and **5p** with MIC 31.5 \(\upmu\)g/mL relating to _Candida albicans_ ATCC 90028. Additionally, regarding the results of antifungal screening, the MRC is noted to have good antifungal activity on **5a**, **5i** and **5c** with 7.81, 31.5 and 62.5 \(\upmu\)g/mL, respectively. Furthermore, **5b** appeared to be the most sensitive heterocycle (14 mm). In contrast, as indicated in Table 5, **5n** was revealed to be the least sensitive heterocycle, with an inhibition zone of 6 mm. Finally, we discuss the last yeast strains is _Candida krusei_ ATCC 6258. In fact, **5g**, **5i** and **5p** showed a superior sensitivity with an inhibition zone of 14-12 mm. It is also worth mentioning the excellent antifungal activity of compounds **5a**, displaying both a MIC and MFC of 31.5 \(\upmu\)g/mL (Table 6).