Kinetic and thermodynamic characteristic of Aspergillus awamori EM66 levansucrase.

This study is a new trial aimed to solve levansucrase high cost and levan associated problems during the purification process. Also, kinetic and thermodynamic study was done to compare between the partial pure (PP) and purified forms (PF). Within this context, Aspergillus awamori EM66 levansucrase was produced constitutively (5.44 U.mL-1) using rice straw as the sole medium component. The enzyme was partially purified and was eluted as single protein after two purification steps. Its molecular weight was determined to be 44.5 KDa. The optimum temperature recorded 40 °C for both enzyme forms. While, the purification process lowering the enzyme pH from 5.2 to 4.0. The NaCl concentrations (0.5-3.0 M) pointed to the halophilic nature of the enzyme. The PP form retained about 76% of its original activity after 1 h at 55 °C while the other retained about 57% after 45 min. at the same temperature. The kinetic parameters Km and Vmax concluded that the PF was more efficient than the PP. The thermodynamic parameters such as Ea, Ed, T1/2, D-value, also, ∆G*, ∆H* and ∆ S* for activation recorded that the PP had higher stability than the PF.

Computer-aided identification of novel anticancer compounds with a possible dual HER1/HER2 inhibition mechanism.

HER1 and HER2 are frequently overexpressed in human tumors where they drive cellular proliferation. For this reason they are considered important targets in anticancer therapy with dual HER1/HER2 inhibitors being recently approved and marketed. In this paper we report the identification of a series of compounds with anticancer activity by a combined virtual screening approach on the kinase domains of HER1 and HER2. 6 hit compounds that present a sub- or low-micromolar activity in two cell-based assays, were initially identified and a subsequent design cycle led to the synthesis of a compound with nanomolar activity in the cell-based assays.

Synthesis and antioxidant activity of new pyridines containing gallate moieties.

Pyridines containing the galloyl moiety have been prepared utilizing 4-acetyl pyrogallol. In addition, fused pyridines were synthesized from the obtained pyridines via further chemical transformations. The results indicated that compound 4a showed stronger DPPH scavenging activity than the other compounds, and the scavenging effect decreased in the following order 4a > t-BHQ > 2a > 2b > 3a > 3b > 4b. Accordingly, other antioxidant assays were conducted for 4a. The results suggested that compound 4a could be a good antioxidant candidate. The absence of mortality of rats receiving 5000 mg/kg body weight of 4a as single oral dose may indicate that it could be a safe antioxidant and may be used for further studies.

Synthesis, biological and medicinal significance of S-glycosido-thieno[2,3-d]-pyrimidines as new anti-inflammatory and analgesic agents.

Several 2-thioglycosides were prepared. Glycosylation of 2-thioxo-thieno[2,3-d]-pyrimidines 5a,b with 1-bromo-2,3,5-tri-O-acetyl-alpha-d-arabinofuranosyle 7, 2,3,4,6-tetra-O-acetyl-alpha-d-glucopyranosyl and galacto-pyranosyl bromide 8a,b gave the protected beta-d-nuclosides 10a,b and 13a-d in high yields, which were transformed to deacetylated derivatives 14a,b and 15a-d. The structures of the compounds were elucidated by spectral and elemental analysis. Anti-inflammatory and Analgesic activities screening of the new compounds (at a dose of 100 mg/kg body weight) utilizing in vivo acute carrageenan-induced paw oedema standard method exhibited that the deacetylated derivatives 14a,b and 15a-d possess highly promising activities.