Microwave-Assisted Synthesis and Antimicrobial Activity of Some Novel Isatin Schiff Bases Linked to Nicotinic Acid via Certain Amino Acid Bridge

Table 1

Antimicrobial activity of the synthesized compounds at 10 mg/mL.

Comp. number	Bacteria			Fungi
	Gram-positive		Gram-negative	Unicellular	Filamentous
	B. subtilis	S. aureus	E. coli	C. albicans	Aspergillus niger
4b	15.13 ± 0.1768	00.00 ± 0.0000	00.00 ± 0.0000	11.125 ± 0.1768	00.00 ± 0.0000
6a	30.18 ± 0.2475	22.12 ± 0.1626	25.125 ± 0.1768	30.125 ± 0.1768	00.00 ± 0.0000
6b	18.17 ± 0.2404	15.10 ± 0.1414	15.125 ± 0.1768	15.10 ± 0.1414	15.16 ± 0.2263
6c	23.18 ± 0.2475	23.18 ± 0.2475	20.175 ± 0.2475	20.115 ± 0.1626	00.00 ± 0.1768
6d	20.10 ± 0.1414	24.08 ± 0.1060	20.175 ± 0.2475	20.17 ± 0.2404	00.00 ± 0.0000
6e	25.20 ± 0.2828	30.13 ± 0.1768	30.15 ± 0.2121	25.175 ± 0.2475	00.00 ± 0.0000
6f	27.18 ± 0.2475	32.10 ± 0.1410	32.13 ± 0.1768	25.10 ± 0.1414	00.00 ± 0.0000
6g	15.13 ± 0.176	15.00 ± 0.0000	15.10 ± 0.1414	00.00 ± 0.0000	14.10 ± 0.1414
S^* = 10 g	14.00 ± 0.0000	00.00 ± 0.0000	12.00 ± 0.0000	00.00 ± 0.0000	00.00 ± 0.0000
TE^* = 30 g	18.00 ± 0.0000	00.00 ± 0.0000	23.5 ± 2.1213	00.00 ± 0.0000	00.00 ± 0.0000
N^* = 30 g	00.00 ± 0.0000	00.00 ± 0.0000	00.00 ± 0.0000	16.00 ± 1.4142	15.00 ± 0.0000
NS^* = 100 g	00.00 ± 0.0000	00.00 ± 0.0000	00.00 ± 0.0000	00.00 ± 0.0000	15.00 ± 0.0000

S: streptomycin; TE: tetracycline; N: neomycin, and NS: nystatin.