Abstract The current project deals with designing and synthesizing of colorimetric chemosensors to detect the cations in the aqueous medium and biological sample. To achieve this goal a new series of quinazolinone derivatives were synthesized via reaction of the novel 6-nitro-2-propyl-4H- benzo[d][1,3]oxazin-4-one (3) with selected nitrogen nucleophiles, namely, formamide, hydrazine hydrate, hydroxylamine hydrochloride, O-phenylendiamine, O-aminophenol and O-aminothiophenol, urea and/or thiourea. Structures of the new compounds have been investigated depending on their spectral data (IR, 1H NMR, 13C NMR and MS) and elemental analyses. Some of the newly synthesized products exhibited a significant response as chemosensors for some cations detection. The synthesized chemosensors 11a and 11b showed high-selectivity and specificity towards cooper (CuII) and mercury (HgII) cations detection through exhibiting colormetric responses. Chemosensors 7 and 10 b showed high selectivity toward cadmium (CdII) cation, whilst other examined compounds (9b, c, 10a, 12, 13, and 14) did not exhibit colorimetric response in all cation's samples.

Resumen En el presente proyecto se diseñan y sintetizan quimiosensores colorimétricos para detectar los cationes en el medio acuoso y en la muestra biológica. Para lograr este objetivo se sintetizó una nueva serie de derivados de quinazolinona mediante la reacción de la 6-nitro-2-propil-4H-benzo[d][1,3]oxazin-4-ona (3) con nucleófilos nitrogenados seleccionados, a saber, formamida, hidrato de hidracina, clorhidrato de hidroxilamina, O- fenilendiamina, O -aminofenol y O-aminotiofenol, urea y/o tiourea. Las estructuras de los nuevos compuestos se han comprobado en función de sus datos espectrales (IR, 1H NMR, 13C NMR y MS) y de los análisis elementales. Algunos de los nuevos productos sintetizados mostraron una respuesta significativa como quimiosensores para la detección de algunos cationes. Los quimiosensores sintetizados 11a y 11b mostraron una alta selectividad y especificidad hacia la detección de los cationes cobre (Cu II) y mercurio (Hg II) al mostrar respuestas colormétricas. Los quimiosensores 7 y 10b mostraron una alta selectividad hacia el catión cadmio (Cd II), mientras que otros compuestos examinados (9b, c, 10a, 12, 13 y 14) no mostraron respuesta colorimétrica con los cationes investigados.

Physiological studies were conducted to determine the optimum cultural conditions for maximal carboxymethyl cellulase (CMCase) formation by Aspergillus terreus DSM 826. Shaking condition at 150 rpm is favorable for the production of CMCase from rice straw and sugar cane bagasse. The highest enzyme yield was obtained at the third day of incubation at 30ºC for both cases; however CMCase formation occurred at a broad range of pH values, with maximal formation of A. terreus DSM 826 CMCase at pH 4.5 and 5.0 when rice straw and sugar cane bagasse were used as sole carbon source, respectively. Carboxymethyl cellulose (CMC) was found to be a good inducer for CMCase formation in both agricultural wastes with CMC concentrations of 0.5 and 1.0 % (w/v) in case of rice straw and sugar cane bagasse, respectively. High level of enzyme formation was obtained with the addition of ammonium chloride as nitrogen source in both cases and at a concentration of 0.4 % (v/v Tween-80) as an addition to medium containing rice straw. However this addition did not influence the production of CMCase in case of using sugar cane bagasse as carbon source.