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Abstract 4 Novel aminophosphonates compounds were synthesized via one pot and threecomponent reaction. 4-aminoantipyrene was incorporated as a base amine and different aldehydes were used. The three precursors, aromatic diamines 1, carbonyl compounds 2 (aldehyde), and triphenylphosphite 3 in acetonitrile were reacted with the aid of Lewis acid catalyst (10 mol. %) of LiClO4. The reaction continued for 3 days with high separated yields. Schematic Illustration - Synthesis of α-aminophosphonates from 4-aminoantipyrene, different aldehydes and triphenylphosphite The molecular structures of α-aminophosphonates (4a-j) were affirmed by IR, 1H NMR, 13C-NMR and mass spectral analysis (for details cf. the experimental data). The antimicrobial activity of α–aminophosphonates was tested against Gramnegative bacteria, Escherichia coli; Gram-positive bacteria, Staphylococcus aureus; a fungus, Aspergillusniger; and a yeast, Candida albicans. Three of them (4f-h) exhibited high biological activity and were selected for drug delivery studies. Carrageenan (CAR) based cryogel system was established as a delivery vehicle. Physical and mechanical testing indicated that pure carrageenan cryogel is very brittle and inadequate for drug loading. With the aid of cellulose nanofibrills (CNF) as reinforcing material and glyoxal as a cross-linking agent, porous cryogels with improved mechanical properties were obtained. Among all, CAR-7 presents the optimum cryogel sample, which contained around 16% CNF and 0.2mL/15mL polymer blend. CAR-7 demonstrated highest mechanical compressive strength, porosity (80%), and (75%) swelling capacity. The release profiles of the aforementioned active compounds (4f-h) from carrageenan cryogels was investigated. Sustainable release behavior over 24 hours was observed for the samples that might be attributed to formation of interconnected network between CAR and CNF molecular chains. The antibacterial activity of loaded carrageenan cryogels was tested against Staphylococcus aureus and the results showed marginal differences between samples. CAR-9 (loaded with 4f) showed the highest reduction percentage in number of bacterial colonies (99.94%) followed by CAR-11 (loaded with 4h, 99.3%) and finally CAR-10 (loaded with 4g, 99.29%) when compared to the control. |