The ability of nitrobenzoxadiazoles to induce the SOX-operon from a genetically engineered biosensor based on E. coli MG 1655 (pSoxS-lux) was confirmed by the fact of producing nitric oxide. The NO-donating properties of three nitrobenzoxadiazole derivatives bearing pi-excessive carbo- and heterocycles were found by the ESR method using spin trapping. The yield of nitrogen(II) oxide was 17, 0.3, and 1.6%. Sodium sulfide accelerates the thiol-dependent transformation and increases the yield of nitric oxide to 27, 16, and 12%, respectively.