Characterization of alginate extracted from Sargassum latifolium and its use in Chlorella vulgaris growth promotion and riboflavin drug delivery.

Alginates derived from macroalgae have been widely used in a variety of applications due to their stability, biodegradability and biocompatibility. Alginate was extracted from Egyptian Sargassum latifolium thallus yielding 17.5% w/w. The chemical composition of S. latifolium is rich in total sugars (41.08%) and uronic acids (47.4%); while, proteins, lipids and sulfates contents are 4.61, 1.13 and 0.09%, respectively. NMR, FTIR and TGA analyses were also performed. Crystallinity index (0.334) indicates alginate semicrystalline nature. Sodium alginate hydrolysate was evaluated as Chlorella vulgaris growth promoter. The highest stimulation (0.7 g/L biomass) was achieved by using 0.3 g/L alginate hydrolysate supplementation. The highest total soluble proteins and total carbohydrates were 179.22 mg/g dry wt and 620.33 mg/g dry wt, respectively. The highest total phenolics content (27.697 mg/g dry wt.), guaiacol peroxidase activity (2.899 µmol min-1 g-1) were recorded also to 0.3 g/L alginate hydrolysate supplementation. Riboflavin-entrapped barium alginate-Arabic gum polymeric matrix (beads) was formulated to achieve 89.15% optimum drug entrapment efficiency (EE%). All formulations exhibited prolonged riboflavin release over 120 min in simulated gastric fluid, followed Higuchi model (R2 = 0.962-0.887) and Korsmeyer-Peppas model with Fickian release (n ranges from 0.204 to 0.3885).

Development of New Potential Anticancer Metal Complexes Derived from 2-Hydrazinobenzothiazole.

BACKGROUND: Due to the side effects of clinically approved anticancer drugs there is a great need to explore and develop new metal-based anticancer drug molecules of high efficiency with less or no side effects. OBJECTIVE: To synthesize new metal complexes of 2-hydrazinobenzothiazole (hbt) and to investigate their potential anticancer characteristics. METHODS: New five complexes; [VO(hbt)2SO4].4H2O (1), [Ru(hbt)2Cl3(H2O)] (2), [M(hbt)2Cl2] [M(II) = Pd (3), Pt (4)] and [Ag(hbt)2].NO3 (5) were prepared and their structure was investigated by means of FTIR, 1H NMR, ESI-MS and UV-Vis spectra, elemental and thermal analysis, magnetic and molar conductance measurements. The ligand and its complexes were examined as anticancer agents against Ehrlich ascites carcinoma (EAC) and human cancer cells (hepatocellular carcinoma Hep-G2, mammary gland breast cancer MCF-7 and colorectal carcinoma HCT-116). This feature is further supported by the DNAmetal complexes binding ability. In addition, anti-oxidation activity of the complexes was investigated. RESULTS: Complex (5) shows the highest anticancer activity with IC50 of 5.15, 9.9, 13.1 and 17.7 µg/mL for EAC, HePG-2, MCF-7 and HCT-116, respectively. Complexes (2) and (3) show promising cytotoxicity against EAC and HePG-2 cells with IC50 5.49 and 16.2 µg/mL, respectively. While, complexes (1) and (4) show optimistic cytotoxicity against EAC with IC50 of 9.63 and 11.25 µg/mL, respectively. The order of DNA binding ability of the complexes is (5) > (3) > (2) > (1) > (4). Among the five complexes, complex (5) shows the best anti-oxidation activity. CONCLUSION: Complex (5) showed the highest DNA binding ability, anti-oxidation and anticancer activities.

Cellulose derivatives modified by sodium tellurate and a chromium(III) tellurate complex.

A novel cellulose (Cell) derivative, sodium-tellurato (Cell-TeO(OH)4(ONa)/Cell-Cl), has been synthesized from the reaction of 6-chloro-6-deoxycellulose (Cell-Cl) with telluric acid in the presence of sodium hydroxide. The subsequent reaction of this polymeric material with chromium(III) in aqueous solution yields the [Cr(Cell-TeO3(OH)3/Cell-Cl)(Cell-TeO2(OH)4/Cell-Cl)(H2O)3] complex. The molecular structures and morphology of the new polymer and the Cr(III) complex have been examined using elemental analysis, solid-state (13)C NMR, UV-vis, XRD and FTIR spectroscopy, and SEM-EDX, TGA and magnetic measurements. The results are considered to be consistent with the formulations proposed. The deprotonation constants of the modified cellulose and the stability constant of the Cr(III) complex have been determined by pH-metric measurements.

Preparation, characterization and pH-metric measurements of 4-hydroxysalicylidenechitosan Schiff-base complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ru(III), Rh(III), Pd(II) and Au(III).

The 4-hydroxysalicylidenechitosan Schiff-base (2CS-Hdhba) was prepared by the condensation of 2,4-dihydroxybenzaldehyde with chitosan, and its metal complexes, [M(2CS-dhba)Cl(2)(H(2)O)(2)] (M(III)=Fe, Ru, Rh), [M'(2CS-dhba)(AcO)(H(2)O)(2)] (M'(II)=Co, Ni, Cu, Zn), [Pd(2CS-dhba)Cl(H(2)O)] and [Au(2CS-dhba)Cl(2)], are reported. These complexes were characterized by elemental analysis, by spectral data (FTIR, solid-phase (13)C NMR, UV-vis and ESR spectroscopy), by morphological observations (SEM and XRD), and by magnetic and thermal measurements. The Schiff base (2CS-Hdhba) behaves as a bidentate chelate with a single negative charge. The azomethine nitrogen and the deprotonated 2-hydroxy centres with the pendant glucosamine hydroxy functionality play no role in coordination. The dissociation constants of 2CS-Hdhba and the stability constants of some of its metal complexes have been determined pH-metrically.

Antineoplastic Activity of New Transition Metal Complexes of 6-Methylpyridine-2-carbaldehyde-N(4)-ethylthiosemicarbazone: X-Ray Crystal Structures of [VO(2)(mpETSC)] and [Pt(mpETSC)Cl].

New complexes of dioxovanadium(V), zinc(II), ruthenium(II), palladium(II), and platinum(II) with 6-methylpyridine-2-carbaldehyde-N(4)-ethylthiosemicarbazone (HmpETSC) have been synthesized. The composition of these complexes is discussed on the basis of elemental analyses, IR, Raman, NMR ((1)H, (13)C, and (31)P), and electronic spectral data. The X-ray crystal structures of [VO(2)(mpETSC)] and [Pt(mpETSC)Cl] are also reported. The HmpETSC and its [Zn(HmpETSC)Cl(2)] and [Pd(mpETSC)Cl] complexes exhibit antineoplastic activity against colon cancer human cell lines (HCT 116).

Synthesis, Spectroscopic, and Anticancerous Properties of Mixed Ligand Palladium(II) and Silver(I) Complexes with 4,6-Diamino-5-hydroxy-2-mercaptopyrimidine and 2,2'-Bipyridyl.

Synthesis of two new water-soluble mixed ligand [Pd(bpy)(dahmp)]Cl and [Ag(bpy)(Hdahmp)]NO(3) complexes (dahmp and Hdahmp are the deprotonated monoanion and the protonated neutral 4,6-diamino-5-hydroxy-2-mercaptopyrimidine, resp.) is reported. The composition of the reported complexes was discussed on the bases of IR, (1)H NMR, and mass spectra, as well as conductivity and thermal measurements. The reported complexes display a significant anticancer activity against Ehrlich ascites tumor cells (EACs). The higher activity of these complexes with their higher conductivity values corresponds to their complete ionization in aqueous solution.

The first metal complexes of 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione: preparation, physical and spectroscopic studies, and preliminary antimicrobial properties.

The new complexes [M(2)O(5)L(2)(H(2)O)(2)] . H(2)O (M = Mo, 1; M = W, 2), [RuL(2)(H(2)O)(2)] . H(2)O (3), [ML(3)] . xH(2)O (M = Rh, x = 2, 4; M = Ir, x = 1, 5), [RhL(2)(PPh(3))(2)](ClO(4)) . 2H(2)O (6), [PdL(2)] . 2H(2)O (7), [PdL(phen)]Cl . H(2)O (8), [Re OL(2)(PPh(3))]Cl (9) and [UO(2)L(2)] (10) are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L(-) is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino group as donor atoms. Oxobridged dinuclear (1, 2) and various mononuclear (3-10) structures are assigned for the complexes in the solid state. The metal ion coordination geometries are octahedral (1-6, 9, 10) or square planar (7, 8). The free ligand LH and complexes 1, 4, 7, and 8 were assayed in vitro for antimicrobial activity against two bacterial and two fungal cultures.