Microwave Synthesis, Characterization, and Antimicrobial Activity of Some Novel Isatin Derivatives

Table 1

The antimicrobial activities of the synthesized isatin derivatives expressed as inhibition zones of growth in mm against the tested pathogenic organisms.

Compound	Test organism
	B.s.	M.l.	M.p.	E.c.	P.v.	S.t.	C.a.	Ph.i.
1a	—	—	—	14 ± 0.33	14 ± 0.66	15 ± 0.33	—	—
1b	—	—	—	9 ± 0.33	9 ± 0.33	9 ± 0.33	—	—
1c	7 ± 0.33	—	—	—	—	—	—	—
1f	8 ± 0.66	—	—	10 ± 0.33	10 ± 0.66	—	8 ± 0.66	8 ± 0.33
3a	—	—	—	—	—	—	—	—
3b	—	—	—	—	—	—	—	—
3c	—	—	—	—	—	—	—	—
3d	9 ± 0.66	—	15 ± 0.33	—	—	—	—	—
3e	9 ± 0.33	—	15 ± 0.66	—	—	—	—	—
3f	7 ± 0.66	10 ± 0.33	15 ± 0.33	—	—	—	—	—
3g	—	—	—	—	—	—	—	—
3h	9 ± 0.66	—	10 ± 0.66	—	—	—	—	—
3i	7 ± 0.66	—	10 ± 0.33	—	—	—	—	—
3j	—	—	—	—	—	—	—	—
3k	—	—	—	—	—	—	—	—
3l	—	—	—	—	—	—	—	—
3m	—	—	—	—	—	—	—	—
3n	11 ± 0.33	13 ± 0.66	17 ± 0.33	—	—	—	—	—
5a	—	—	—	—	—	—	—	—
5b	—	—	—	17 ± 0.66	—	11 ± 0.33	—	—
5c	10 ± 0.66	—	—	—	—	—	10 ± 0.33	—
5d	18 ± 0.33	20 ± 0.66	23 ± 0.66	—	—	—	18 ± 0.33	15 ± 0.66
Erythromycin	28 ± 0.33	18 ± 0.33	16 ± 0.66	13 ± 0.33	14 ± 0.33	11 ± 0.66	—	—
Tetracycline	24 ± 0.66	20 ± 0.33	15 ± 0.66	22 ± 0.33	18 ± 0.66	20 ± 0.66	—	—

All the results were obtained in DMSO; “—”, no activity; B.s., Bacillus subtilis; M.l., Micrococcus luteus; M.p., Mycobacterium phlei; E.c., Escherichia coli; P.v., Proteus vulgaris; S.t., Salmonella Typhi; C.a., Candida albicans; and Ph.i., Phytophthora infestans. Zone of inhibition in mm (mean ± S.D., ). The concentration was 15 μg. The concentration was 30 μg.