Metal complexes driven from Schiff bases and semicarbazones for biomedical and allied applications: a review

Abstract

Schiff bases are versatile organic compounds which are widely used and synthesized by condensation reaction of different amino compound with aldehydes or ketones known as imine. Schiff base ligands are considered as privileged ligands as they are simply synthesized by condensation. They show broad range of application in medicine, pharmacy, coordination chemistry, biological activities, industries, food packages, dyes, and polymer and also used as an O₂ detector. Semicarbazone is an imine derivative which is derived from condensation of semicarbazide and suitable aldehyde and ketone. Imine ligand-containing transition metal complexes such as copper, zinc, and cadmium have shown to be excellent precursors for synthesis of metal or metal chalcogenide nanoparticles. In recent years, the researchers have attracted enormous attention toward Schiff bases, semicarbazones, thiosemicarbazones, and their metal complexes owing to numerous applications in pharmacology such as antiviral, antifungal, antimicrobial, antimalarial, antituberculosis, anticancer, anti-HIV, catalytic application in oxidation of organic compounds, and nanotechnology. In this review, we summarize the synthesis, structural, biological, and catalytic application of Schiff bases as well as their metal complexes.

Keywords: 2,6-DAPBPTSC, 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone; 35-DTBP, 3,5-di-tert-butylphenol; 3CLpro, 3C-like protease; ATNR, Amine terminated liquid natural rubber; ATT, 2-acetylthiophene thiosemicarbazone; BBPT, Biacetyl bis(4-phenyl-3-thiosemicarbazone); BBTSC, Benzyloxybenzaldehyde thiosemicarbazone; BCG, Bacillus calmette-guérine; BDT, Benzyldithiosemicarbazone; BGPT, Bipyridyl glyoxal bis(4-phenyl-3-thiosemicarbazone); BMTS, Biacetyl monothiosemicarbazone; Biological/biomedical activities; Bipy, 2,2-bipyridine; CT DNA, Calf thymus deoxyribonucleic acid; DAPY, 2,3-diamino-pyridine; DTBP, 2,6-di-tert-butylphenol; DTBQ, 2,6-di-tert-butyl-4,4′-benzoquinone; EAC, Enrichlish Ascitices Cells; HEK-293, Human Embryonic Kidney cells; HL-60, Human leukemia-60 cell line; HeLa, immortal cell lines; HepG2, Hepatic cellular carcinoma cells (Human liver cancer cell line); IgG, Immunoglobin G; K B HCT-8, Human colon cancer cell line; M-IBDET, N-methylisatin-β-4′,4′-diethylthiosemicarbazone; MCF-7, Michigan Cancer Foundation-7; MCF7 cells, Michigan Cancer Foundation-7 (breast cancer cell line); MHV, Mouse hepatitis virus; MLV, Moloney leukemia virus; MSOPD, N,N-bis(3-methylsalicylidene)-ortho-phenylenediamine; Metal complexes; NQSC, Naphthoquinone semicarbazone; NQTS, ortho-Naphthoquinone thiosemicarbazone; OLED, Organic light emitting diode; PAS, p-amino salicylic acid; PPTS, Picolinealdehyde-4-phenyl-3-thiosemicarbazone; Phen, 1,10-phenanthroline; SARS CoV, Severe Acute Respiratory Syndrome coronavirus; SARS, Severe acute respiratory syndrome; SB-HAG, Schiff bases of hydroxyamino guanidines; SK-MEL-30, Human Melanoma Cell Line; SK-OV-3 cells, Ovarian cancer cell line; SSB-HAG, salicylaldehyde Schiff bases of HAG; Schiff base; Semicarbazone; TCIDw, Tissue culture Infective Dose; TTBDQ, 3,5,3′,5′-tetra-tert-butyl-4,4′-diphenoquinone; VSV, vesicular stomatitis virus; scCO2, Super-critical carbon dioxide.

Graphical abstract

Scheme 1

Typical aerobic oxidation of DTBP by Co(salen). DTBP, 2,6-di-tert-butylphenol.

Scheme 2

(A) Synthesis of derivatives of _D-2,3-bis(arylideneamino)-1,4-butanediol (3–6) and their manganese complexes (7–10), and (B) the epoxidation of indene by using the Mn (III) complexes of _D-2,3-bis(di-t-butyl-salicylideneamino)-1,4-butanediol.

Scheme 3

Schiff base ligands containing ONO, ONN, and NSO donor atoms.

Scheme 4

Schiff bases (16–18) from different chiral diamines.

Scheme 5

Synthesis of Ni (II) and Zn (II) salophen complexes.

Scheme 6

Synthesis of metal complexes of semicarbazones and their respective selenides.

Scheme 7

General reaction for synthesis of Schiff bases.

Scheme 8

General reaction mechanism of semicarbazone synthesis.

Fig. 1

Schematic presentation of application of complexes of imine derivatives.

Fig. 2

Biological applications of imine derivatives.

Scheme 9

The proposed structure of metal complexes with 27 and 28.

Scheme 10

Proposed structure of Isatin derivatives.

Scheme 11

Proposed structure of Cu (II), Ni (II), and Zn (II) Schiff base complexes.

Scheme 12

Schiff base ligands (46–51) of PAS.

Scheme 13

Schiff base obtained from glycylglycine.

Scheme 14

Proposed structure of Schiff base (54–58).

Scheme 15

(A) Schiff base of naptha[1,2-d]thiazol-2-amine, (B) it's Cu (II), Co (II), Ni (II) complexes.

Scheme 16

VO (IV) complexes (74–78).

Scheme 17

Structure of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone-4-ethyl-thiosemicarbazone.

Scheme 18

Structure of semicarbazones and thiosemicarbazones (86–89).

Scheme 19

Structure of complex (a) [M(L)X]X and (b) [M(L)SO₄], where L = ligand 90.

Scheme 20

Structure of ruthenium complexes.

Scheme 21

Structure of Isatin derivative 94 (A), some derivatives of 5-fluoroisatin (B).

Scheme 22

Structure of substituted 5-acyl-1,2,4-triazine (96a-c) and derivatives of 5-acyl-3-methylsulfamyl-1,2,4-triazine (97a-b).

Scheme 23

Structure of Pt (II) (98–102) and Pd (II) (103–107) complexes.

Scheme 24

Structure of Co (II), Ni (II) and Zn (II) complexes of oxoaporphine.

Scheme 25

Schematic representation of complexes Py₃CoL₁ (113) and Py₃CoL₂ (114).

Scheme 26

Typical structure of Ga (III) salicylaldehyde semicarbazone complexes.

Fig. 3

(a) UV-Visible/Photoluminescence and (b) X-ray diffraction as reproduced from ref (A. A. Jadhav, P. V. More, P. K. Khanna, New J. Chem., 2017, 41, 7438) and (c) reproduced from ref (A. A. Jadhav, P. K. Khanna, New J. Chem., 2017, 41, 14713).

Scheme 27

Structure of metal complex with 2,3-bis-[(3-ethoxy-2-hydroxybenzylidene) amino]but-2-enedinitrile (where, M = Cu (120), Ni (121)).

Scheme 28

Structure of [CuX₂(C₇H₁₄N₄O)₂·H₂O] where, X = ClO₄⁻(122), NO₃⁻(123).

Scheme 29

Sonogashira coupling reaction of phenylacetylene with aryl halides catalyzed by Cu(I) complexes (125–128).

Scheme 30

Structure of 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone (129).