Identification and antimicrobial activity of most representative secondary metabolites from different plant species

Chemical and Biological Technologies in Agriculture

Table 3 Antimicrobial activity and MIC of pure compounds as components of S. nigrum

Bacteria	Solamargine		Solasonine		Solamargine/solasonine (1:1 v/v)
Bacteria	ZoI (mm)^a	MIC (mg L⁻¹)	ZoI (mm)^a	MIC (mg L⁻¹)	ZoI (mm)^a	MIC (mg L⁻¹)
Gram+
Bacillus cereus (A1I)	15.0 ± 1.0^A	5 ± 1^H	14.0 ± 0.9^A	5 ± 1^H	15.0 ± 1.0^A	5 ± 1^H
Bacillus thuringiensis (B7I2)	12.0 ± 0.9^B	20 ± 1^L	12.0 ± 0.8^B	40 ± 1^M	13.0 ± 1.0^B	40 ± 1^M
Bacillus amyloliquefaciens (A5TI)	12.0 ± 0.9^B	20 ± 1^L	12.0 ± 1.0^B	40 ± 1^M	14.5 ± 1.0^A	20 ± 1^L
Gram−
Pseudomonas orientalis (A14-1II)	13.0 ± 0.8^B	40 ± 1^M	13.0 ± 0.7^B	40 ± 1^M	13.5 ± 1.0^B	40 ± 1^M
Stenotrophomonas maltophilia (B9TIII)	15.0 ± 0.9^A	10 ± 1^K	14.0 ± 0.8^A	10 ± 1^K	15.0 ± 1.1^A	10 ± 1^H

Assays were performed in triplicate and results are the mean of three values ± standard deviation
Different letters in superscript to numerical data indicate significant differences (p value < 0.05)
^aZoI: diameter of inhibition zone obtained after 24 h of incubation in agar well diffusion assays. ZoI < 10 mm: low antimicrobial activity; 11 < ZoI < 15 mm: middle antimicrobial activity; ZoI > 16 mm: high antimicrobial activity