Microbial L-asparaginase (ASNase) is an important anticancer agent that is used extensively worldwide. In this study, 40 bacterial isolates were obtained from the Red Sea of Saudi Arabia and screened for ASNase production using a qualitative rapid plate assay, 28 of which were producing large L-asparagine hydrolysis zones. The ASNase production of the immobilized bacterial cells was more favorable than that of freely suspended cells. A promising isolate, KKU-KH14, was identified by 16S rRNA gene sequencing as Bacillus licheniformis . Maximal ASNase production was achieved using an incubation period of 72 h, with an optimum of pH 6.5, an incubation temperature of 37 °C, an agitation rate 250 rpm, and with glucose and (NH 4 ) 2 SO 4 used as the carbon and nitrogen sources, respectively. The glutaminase activity was not detected in the ASNase preparations. The purified ASNase showed a final specific activity of 36.08 U/mg, and the molecular weight was found to be 37 kDa by SDS-PAGE analysis. The maximum activity and stability of the purified enzyme occurred at pH values of 7.5 and 8.5, respectively, with maximum activity at 37 °C and complete thermal stability at 70 °C for 1 h. The K m and V max values of the purified enzyme were 0.049995 M and of 45.45 μmol/ml/min, respectively. The anticancer activity of the purified ASNase showed significant toxic activity toward HepG-2 cells (IC 50 11.66 µg/mL), which was greater than that observed against MCF-7 (IC 50 14.55 µg/mL) and HCT-116 cells (IC 50 17.02 µg/mL). The results demonstrated that the Red Sea is a promising biological reservoir, as shown by the isolation of B. licheniformis , which produces a glutaminase free ASNase and may be a potential candidate for further pharmaceutical use as an anticancer drug.

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A new series of pyrazole 4–7 and pyrazolo[1,5-a]pyrimidine 8–13 were synthesized by using a simple, efficient procedure, and screened for their in-vitro antimicrobial and antitumor activities. Symmetrical and asymmetrical 3,6-diarylazo-2,5,7-triaminopyrazolo[1,5-a]pyrimidine were synthesized by the conventional method and also subjected to microwave irradiation and under ultrasound conditions. The biological results revealed that most of the tested compounds proved to be active as antibacterial and antifungal agents. The antitumor activity of the synthesized compounds was evaluated against human cancer cell lines, MCF-7, HCT-116, and HepG-2, as compared with Doxorubicin as a control.

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