4-Acylhydrazone-5-Pyrazolones and their Zinc(II) Metal Complexes: Synthesis, Characterization, Crystal Feature and Antimalarial Activity

Zinc(II) Complex with Pyrazolone-Based Hydrazones is Strongly Effective against Trypanosoma brucei Which Causes African Sleeping Sickness

“…In the far-IR region of 1–4, some medium absorptions in the range of 550–400 cm –1 were tentatively assigned to ν(M–N) and ν(M–O). 16 , 28 , 29 The 1 H and 13 C NMR spectra in CDCl 3 of Zn(II) complexes 1 and 2 are in accordance with the expected structures containing the N,O-chelating ( 1 ) and N,N,O-dichelating ( 2 ) ligands, confirming the existence of complexes in solution with the ligand signals downfield-shifted with respect to the corresponding signals in the free ligand spectrum. In principle, the geminal methylene protons of the benzyl moiety in proligand H 2 L 2 (H11 in Chart 1 ) should undergo diastereotopic splitting in complex 2 due to the stereochemistry of the zinc center.…”

“…It is known that pyrazolone also is a structural motif with a broad-spectrum of pharmacological features, including antimicrobial, antitumor, anti-inflammatory, antioxidant, antitubercular, antiviral, lipid-lowering, antihyperglycemic, and protein inhibitory activities . Previous studies of our research team underlined the wide biological activities of a series of Zn­(II) complexes with acylpyrazolones, displaying antiproliferative activity against human breast cancer cells, and of pyrazolone-based hydrazones and their ruthenium­(II) complexes as anticancer multitarget agents. , Moreover, some Cu­(II) and Zn­(II) complexes with acylpyrazolones and acylhydrazone-5-pyrazolones were recently reported and found to display in vitro antimalarial activity with considerable inhibitory effects against Plasmodium falciparum. − Based on these findings, two new pyrazolone-based hydrazones and their corresponding Zn­(II) and Cu­(II) complexes have been synthetized and screened against T. brucei and mammalian Balb/3T3 cells.…”

“… 12 , 13 Moreover, some Cu(II) and Zn(II) complexes with acylpyrazolones and acylhydrazone-5-pyrazolones were recently reported and found to display in vitro antimalarial activity with considerable inhibitory effects against Plasmodium falciparum . 14 − 16 Based on these findings, two new pyrazolone-based hydrazones and their corresponding Zn(II) and Cu(II) complexes have been synthetized and screened against T. brucei and mammalian Balb/3T3 cells. The most active and selective metal complex containing a Zn(II) center was further investigated to identify the mechanism of action and the possible target, focusing the study on the peculiar nucleotide metabolism of T. brucei .…”

Role of hydrazone substituents in determining the nuclearity and antibacterial activity of Zn(ii) complexes with pyrazolone-based hydrazones

“…In detail, they are the asymmetric and symmetric stretching modes at 1301 and 1165 cm −1 of the sulfonyl SO 2 in H 2 L 2 , 46,47 the asymmetric and symmetric stretching modes at 1490–1530 and 1325–1331 cm −1 of nitro NO 2 in H 2 L 3 and H 2 L 4 , 48,49 as well as bands at 1312, 1163, 1112 and 1065 cm −1 due to asymmetric and symmetric stretching vibrations of CF 3 group in H 2 L 5,50 while the typical ν (N–N) mode for all proligands is identified in the range 1040–1120 cm −1 . 44,51 1 H and 13 C chemical shifts were assigned based on the 1 H– 1 H, and one-bond and long-range 1 H– 13 C couplings, seen in the { 1 H, 1 H}-COSY, { 1 H, 13 C}-HSQC, and { 1 H, 13 C}-HMBC (see ESI†). Moreover, indirect 15 N NMR chemical shifts were assigned based on the { 1 H, 15 N}-HSQC and { 1 H, 15 N}-HMBC for both proligands and complexes 1–5 (see Table 1 and Fig.…”

Synthesis, Covalency Sequence, and Crystal Features of Pentagonal Uranyl Acylpyrazolone Complexes along with DFT Calculation and Hirshfeld Analysis

“…Ligands were synthesized and examined using the tools specified in previous studies published by our laboratory. , Uranyl nitrate was obtained from SULAB chemicals, Gujarat. Gravimetric techniques were used to determine the uranium concentration in U 3 O 8…”