A new series of thiazolo[3,2-a]pyrimidine bromide salt derivatives 7a–d were synthesized from 3,4-dihydropyrimidinethione precursors. The target compounds were fully characterized by 1D- and 2D-NMR, high resolution ESI-MS/MS and single crystal X-ray diffraction analysis, which confirmed a regioselective 5H cyclization of the dihydropyrimidinethiones. All target compounds were evaluated in vitro as human acetylcholinesterase (hAChE) inhibitors via an Ellman-based colorimetric assay and showed good inhibition activities (better than 70% at 10 µM and IC₅₀ values in the 1 µM range). Molecular docking simulations for all target products into hAChE were performed and confirmed strong binding to the enzyme. These results provide a promising and new starting point to improve acetylcholinesterase inhibitors and explore novel treatment options against Alzheimer’s disease.

The combination of hydrogel and fertilizer as slow release fertilizer hydrogel (SRFH) has become one of the most promising materials to overcome the shortcomings of conventional fertilizer by decreasing fertilizer loss rate, supplying nutrients sustainably, and lowering the frequency of irrigation. The hydrogel based on carboxymethyl cellulose (CMC) and polyacrylic acid (PAA) (CMC/PAA) was synthesized. All materials, Vinasse, hydrogel (CMC/PAA) and (Vinasse/CMC-PAA) were characterized by FTIR, XRD, and SEM. The formed hydrogel was applied to control the salinity of Vinasse to use it as a cheap and economical fertilizer. The results showed that using the prepared hydrogel with Vinasse (V/CMC-PAA) as a slow-release organic fertilizer decreased the EC value through the first six hours from 1.77 to 0.35 mmohs/cm. Also, using V/CMC-PAA can control and keep the potassium as fertilizer for 50 days. The productivity per feddan from the sugar cane crop increased by about 15%, and the number of irrigations decreased from 5 to 4 times.

Three biopolymer composites (1), (2) and (3) based on chitosan and carboxymethyl cellulose were synthesized, characterized and applied as nontoxic cationic color precipitant and flocculating agents for mixed cane juice (MCJ) and raw syrup refining process. The chemical structure of the obtained composites was elucidated by different techniques, FT-IR, XRD and SEM. They were investigated as a decolorizing agent of colorant matters of MCJ and raw syrup. The composite (1) was chosen and tested for further procedures due to its stability and economically purposes. Composite (1) showed a color removal efficiency of MCJ and raw syrup by 15.8 and 40.7%, respectively, at 200 ppm dosages, compared to the traditional clarification method. All the analyses of MCJ and raw syrup were conducted in the pilot plant to compare between the obtained clarification efficiency in presence of bioclarifying agent and that with the currently used phosphatation process. Also, the obtained results showed that the composite (1) can act as flocculating agent where 50% reduction is in the dosage of anionic flocculant. Moreover, the total cost of chemical aids and maintenance will be decreased by about 2.4 million LE in case of incorporating composite (1) in the clarification process of sugar cane juice.

Aryl-3,4-dihydropyrimidinones (DHPM), thiazolopyrimidines and related heteroaromatic compounds are important classes of N-containing fused heterocycles widely used as key building blocks for pharmaceutical agents due to a wide range of biological activities that include antimicrobial and antitumor properties^[1-6]. As part of a program aimed at preparing new bioactive heterocycles, we designed and synthesized a series of thiazolopyrimidines and their 2-arylidene derivatives. The compounds were fully characterized by 1D- and 2D-NMR, high resolution ESI-MS/MS and single crystal X-ray diffraction analysis, which indicated a consistent Z configuration at the arylidene double bond. In addition, the ESI-MS fragmentation mechanisms for representatives of the DHPM, thiazolopyrimidine, and 2-arylidene-thiazolopyrimidine classes were elucidated. Studies are underway to assess the biological activities of the new compounds.  References. B. Kuppast, H. Fahmy, Eur. J. Med. Chem. 113 (2016) 198-213. P. Selvam, V. Karthick, P. V. Kumar, M. A. Ali, Drug Disc. Ther. 6 (2012) 198-204. B. Pan, R. Huang, L. Zheng, C. Chen, S. Han, D. Qu, M. Zhu, P. Wei, Eur. J. Med. Chem. 46 (2011) 819-824. A. Nehad, M. S.Nermien, M. M. Ashraf, M. M. Abdulla, Monatsh Chem. 138 (2007) 715-724. O. Kappe, W.M.F. Fabian, M.A. Semones, Tetrahedron 53 (1997) 2803-2816. S. Atwal, B.N. Swanson, S.E. Unger, D.M. Floyd, S. Moreland, A. Hedberg, B.C. O'Reilly, J. Med. Chem. 34 (1991) 806-811.

Acetylcholinesterase (AChE) is the enzyme that catalyzes the hydrolysis of the neurotransmitter acetylcholine (ACh) into acetic acid and choline, a crucial mechanism for regulation of neurotransmission at synapses in all nervous systems. According to the cholinergic hypothesis, depleted levels of ACh are associated with Alzheimer's disease. As part of a program aimed at preparing new bioactive heterocycles with kinase and AChE inhibition properties, we designed and synthesized a series of (Z)-2-arylidene- and 2-aminomethylene derivatives of thiazolo[3,2-a]pyrimidine by a convenient multicomponent method. The products were fully characterized by 1D- and 2D-NMR, high resolution ESI-MS/MS and single crystal X-ray diffraction analysis, which indicated a consistent Z configuration at the arylidene and amino methylene double bond. Additionally, molecular docking simulations of the series of 2-arylidene/aminomethylene-thiazolo[3,2-a]pyrimidine derivatives to human AChE (PDB ID: 4m0f, chain A) were conducted to investigate the binding mode of those compounds in comparison to Territrem B, used as positive control. The results indicate that some of the test compounds have binding energies to AChE that are comparable, or better, than the positive control, Territrem B. Biological activity studies are underway to assess the activities of the new compounds [1-4]. References: Francis, P.; Palmer, A.; Snape, M.; Wilcock, G. Neurol. Neurosurg. Psychiatry 1999, 66, 137-147. Zhi, H.; Chen, L.; Zhang, L.; Liu, S.-j.; Wan, D. C. C.; Lin, H.; Hu, C. Arkivoc 2008, 13, 266-277. Jin, C.H.; Jun, K.Y.; Lee, E.; Kim, S.; Kwon, Y.; Kim, K.; Na, Y. Med. Chem. 2014, 22, 4553-4565. Cheung, J.; Gary, E. N.; Shiomi, K.; Rosenberry, T. L. ACS Med. Chem. Lett. 2013, 4, 1091-1096.