Ionic Sal-SG Schiff bases as new synergetic chemotherapeutic candidates: synthesis, metalation with Pd(ii) and in vitro pharmacological evaluation

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68260-68269 ◽  
Author(s):  
Reda F. M. Elshaarawy ◽  
Tahia B. Mostafa ◽  
Ayaat A. Refaee ◽  
Emtithal A. El-Sawi

A series of novelN-(salicylidene)-sulfaguanidines (Sal-SG) bearing ionic liquid (IL) terminals (ILSSGH,4a–f) have been synthesized by Schiff base condensation of IL-functionalized salicylaldehydes (ILSal,3a–g) and sulfaguanidine (SG).

2019 ◽  
Vol 48 (33) ◽  
pp. 12496-12511 ◽  
Author(s):  
G. Kalaiarasi ◽  
S. Dharani ◽  
V. M. Lynch ◽  
R. Prabhakaran

Three tetranuclear (1–3) complexes and a mononuclear (4) palladium(ii) complex were synthesized from 3-acetyl-chromen-2-one Schiff base ligands [H2-3MAC-Rtsc] (where R = H; CH3; C2H5[H2-3MAC-etsc] or C6H5) and potassium tetrachloropalladate.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New series of organotin(IV) complexes and Schiff bases derived from amino acids have been designed and synthesized from condensation of1H-indole-2,3-dione, 5-chloro-1H-indole-2,3-dione, andα-amino acids (phenylalanine, isoleucine, and glycine). All compounds are characterized by elemental analyses, molar conductance measurements, and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance (1H,13C, and119Sn NMR) spectral studies. The results suggest that Schiff bases behave as monobasic bidentate ligands and coordinate with dibutyltin(IV) in octahedral geometry according to the general formula [Bu2Sn(L)2]. Elemental analyses and NMR spectral data of the ligands with their dibutyltin(IV) complexes agree with their proposed distorted octahedral structures. Few representative compounds are tested for their in vitro antibacterial activity against Gram-positive (B. cereus,Staphylococcusspp.) and Gram-negative (E. coli,Klebsiellaspp.) bacteria. The results show that the dibutyltin complexes are more reactive with respect to their corresponding Schiff base ligands.


2006 ◽  
Vol 71 (7) ◽  
pp. 733-744 ◽  
Author(s):  
R. Nair ◽  
A. Shah ◽  
S. Baluja ◽  
S. Chanda

Two Schiff bases were synthesized from raceacetophenone: 1) ADS1 4-ethyl-6-{(E)-1-[(3-nitrophenyl)imino]ethyl}benzene-1,3-diol and 2) ADS3 4-ethyl-6-[(E)-1-{(2-nitrophenyl)imino]ethyl}benzene-1,3-diol. Then their metal complexes were formed. The metals selected for the preparation of complexes were copper, nickel, iron and zinc. Hence, in total 8 metal complexes were synthesized and screened for antibacterial activity against some clinically important bacteria, such as Pseudomonas aeruginosa, Proteus vulgaris, Proteus mirabilis, Klebsiella pneumoniae and Staphylococcus aureus. The in vitro antibacterial activity was determined by the Agar Ditch technique using DMF (polar) and 1,4-dioxane (non polar) as solvents. The Schiff bases showed greater activity than theirmetal complexes; themetal complexes showed differential effects on the bacterial strains investigated and the solvent used, suggesting that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. The Schiff base ADS3 in the polar solvent DMF showed better antibacterial activity towards the investigated bacterial strains. Amongst the four metals, Zn showed the best antibacterial activity followed by Fe in 1,4-dioxane while Ni followed by Zn and Fe showed the best antibacterial activity in DMF. P. vulgaris was the most resistant bacteria.


2020 ◽  
Vol 10 (5) ◽  
pp. 274-292
Author(s):  
Rohit Kumar ◽  
Sushil Kumar ◽  
Mohammad Asif Khan

Recently a series of Schiff bases of diphenylamine derivatives have been synthesized and evaluated in vitro for their antibacterial activity against pathogenic both Gram-positive bacteria B. subtitles and Gram-negative bacteria E. coli using ciprofloxacin as standard drug at conc. of 50 μg/ml and 100 μg/ml. Literature review revels that chalcones possesses various biological activities like antimicrobial, antiviral, anti-inflammatory, anticancer and sedative etc. Therefore the present study was designed on synthesis and pharmacological evaluation of 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides. Target compound was synthesized by reaction of chloroacetylchloride with diphenylamine to afford 2-chloro-N, N-diphenylacetamide which further by reaction with substituted Chalcones and characterized following recrystallization and evaluated for anti-microbial potential through cup-diffusion method. In results, the target compounds were tested for activity against B. Subtilis, E.Coli and C. albicans. The chalcones having the lipophilic 4-chloro group (RKCT2) showed the greatest antimicrobial activity (zone of inhibition 20 & 22 mm against. B. subtilis, E. Coli, C. Albicans respectively. It suggests further researchers to go through anti-microbial evaluations against a more varieties of bacteria and fungi. Keywords: Schiff bases of diphenylamine derivatives, antibacterial activity, Gram-positive bacteria, 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides


2021 ◽  
Vol 8 (1) ◽  
pp. 74-80
Author(s):  
Lamia S. Ashoor ◽  
Rawa’a Abass Majeed ◽  
Rehab K. R. Al-Shemary

"1998 onwards, a span reporting 1000s of studies depicts the ever-increasing Schiff bases and their complexes applicability; this study genetically tests the research of the last 20 years. The variety of these molecules structural has made them obtainable for a so broad ambit for implementations of biological. They are eminent and because of this unique feature they find their position in the quantitative and qualitative calculation of metals in the aqueous medium. It demonstrated to be prominent catalysts and showed an enjoyable effect of fluorescence. Definitively, Schiff base fissures gotten situation of a unique during bio-experiments and in vitro to develop drugs with a large number of biological structures containing parasites, fungi, viruses, cancer cells, bacteria, etc.


2010 ◽  
Vol 75 (8) ◽  
pp. 1075-1084 ◽  
Author(s):  
Muhammad Imran ◽  
Mitu Liviu ◽  
Shoomaila Latif ◽  
Zaid Mahmood ◽  
Imtiaz Naimat ◽  
...  

The condensation reactions of biacetyl with orthohydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2.2H2O] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 ?C. These compounds were also screened for their in-vitro antibacterial activity against four bacterial species, namely; Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtillis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.


Antioxidants ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 113
Author(s):  
Bamidele Okoli ◽  
Johannes Modise

The emphasis of previous studies has targeted the development of insulin mimic with little attention given to the development of metabolic enzyme inhibitors. Our focus is to synthesise nine o-hydroxy and p-nitro-azomethine analogues, investigate their digestive enzyme inhibitory capacity, as well as the antioxidant and antimicrobial activities. The substituted Schiff bases were analysed using thermal gravimetric analyser (TGA), X-ray diffractometer (XRD), nuclear magnetic resonance spectroscopy (NMR), elemental analyser, and Fourier-transform infrared spectroscopy (FT-IR). Determination of synthetic yield revealed that the o-hydroxy analogues produced the highest yield of ≥77.1% compared to p-nitro and unsubstituted analogues. Spectra study showed the presence of azomethine stretching vibration at 1698–1613 cm−1, proton signals at δ 8.46–9.81, and carbon signals at δ 145.95–159.53 ppm. Investigation into the thermal property indicated an elevated melting point for the o-hydroxy analogue, compared to the p-nitro derivative which showed high stability to heat. There are similarities in crystalline structure with few unique patterns suggesting different substituent group. The antioxidant activities of the substituted analogues registered low half maximal inhibitory concentration (IC50), with exception to the ferric reducing power; indicating that the Schiff bases are weak siderophores. All nine Schiff bases were bacteriostatic or fungistatic at the screened concentrations; however, the nitro-substituted analogues have an enhanced activity with Minimum Inhibitory Concentration (MIC) values of 0.03–2.54 µM. Both o-hydroxy and p-nitro-substitution does not improve the antifungal activity of the compounds against A. niger. The o-hydroxyl and p-nitro Schiff base derivatives showed enhanced activity towards the inhibition of α -amylase and α-glucosidase by hydroxylation and glycosylation, respectively. Although, hydroxy derivatives of sulphonic acid derived Schiff base slightly decreased the activities on α-glucosidase and α-amylase. Our findings suggest that p-nitro substitution enhances the in vitro nonenzymatic activity while the o-hydroxy derivatives are good hydrolase inhibitors. Therefore, substituent modification can be used as an enhancement technique in designing novel pharmacophore.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 359
Author(s):  
Alisa A. Nevskaya ◽  
Lada V. Anikina ◽  
Rosa Purgatorio ◽  
Marco Catto ◽  
Orazio Nicolotti ◽  
...  

Marine alkaloids belonging to the lamellarins family, which incorporate a 5,6-dihydro-1-phenylpyrrolo[2,1-a]isoquinoline (DHPPIQ) moiety, possess various biological activities, spanning from antiviral and antibiotic activities to cytotoxicity against tumor cells and the reversal of multidrug resistance. Expanding a series of previously reported imino adducts of DHPPIQ 2-carbaldehyde, novel aliphatic and aromatic Schiff bases were synthesized and evaluated herein for their cytotoxicity in five diverse tumor cell lines. Most of the newly synthesized compounds were found noncytotoxic in the low micromolar range (<30 μM). Based on a Multi-fingerprint Similarity Search aLgorithm (MuSSeL), mainly conceived for making protein drug target prediction, some DHPPIQ derivatives, especially bis-DHPPIQ Schiff bases linked by a phenylene bridge, were prioritized as potential hits addressing Alzheimer’s disease-related target proteins, such as cholinesterases (ChEs) and monoamine oxidases (MAOs). In agreement with MuSSeL predictions, homobivalent para-phenylene DHPPIQ Schiff base 14 exhibited a noncompetitive/mixed inhibition of human acetylcholinesterase (AChE) with Ki in the low micromolar range (4.69 μM). Interestingly, besides a certain inhibition of MAO A (50% inhibition of the cell population growth (IC50) = 12 μM), the bis-DHPPIQ 14 showed a good inhibitory activity on self-induced β-amyloid (Aβ)1–40 aggregation (IC50 = 13 μM), which resulted 3.5-fold stronger than the respective mono-DHPPIQ Schiff base 9.


2016 ◽  
Author(s):  
Elżbieta Hejchman ◽  
Barbara Sowirka ◽  
Magdalena Tomczyk ◽  
Dorota Maciejewska

Based on World Health Organization (WHO) report, it was estimated that one in five people before age 75 will suffer from cancer during their lifetime, and more than 13 million cancers death will happen in 2030. Chemotherapy is a basic approach for the treatment of cancer diseases. However, because of drug resistance and considerable side effects drug-induced toxicity, the discovery of new metal analogs with promising activity and high therapeutic index is an urgent need. The fundamental role of copper and the recognition of its complexes as important bioactive compounds in vitro and in vivo aroused an ever-increasing interest in these agents as potential drugs for therapeutic intervention in various diseases. Schiff bases are a critical class of compounds in medical chemistry that have demonstrated significant chemotherapeutic and antibacterial application. Schiff base Cu(II) complexes revealed great potential for antiproliferative, antibacterial, and gastroprotective activity. Coumarins are a wide class of natural and synthetic compounds that showed diverse pharmacological activities including anticancer activity. Among the wide variety of coumarins, 7-hydroxycoumarin derivatives have been shown to possess desirable antiproliferative activities. In particular, their antibacterial, antifungal and anticancer activities make the compounds attractive for further derivatization and screening as novel therapeutic agents. Taking these compounds as lead, we have designed and synthesized a series of new copper(II) complexes with coumarin-derived Schiff base ligands. Two series of Schiff bases were prepared by condensation of 8-formyl-7-hydroxy-4-methylcoumarin and 8-acetyl-7-hydroxy-4-methylcoumarin with p-substituted aniline derivatives. These compounds were used as ligands in the synthesis of copper(II) complexes. The obtained Schiff bases as well as copper complexes are mostly novel molecules. Only the products of condensation 8-formyl-7-hydroxy-4-methylcoumarin with p-toluidine and 8-acetyl-7-hydroxy-4-methylcoumarin with p-toluidine and its copper(II) complex were synthesized, but the anticancer activity of these compounds was not determined. The assay of their cytotoxic activity is in progress. Preliminary, we have identified two copper(II) coordination compounds of 7-hydroxy-8-[1-(4-methoxyphenyl imino)ethyl]-4-methyl-2H-chromen-2-one and 7-hydroxy-8-[1-(4-hydroxyphenyloimino)ethyl]-4-methyl-2H- chromen-2-one having dose-dependent antiproliferative activity on HeLa cancer cell line. Additionally, the Schiff bases – derivatives of substituted salicylaldehydes and 2-hydroxyacetophenones condensed with appropriate anilines were prepared. Such compounds have been reported in scientific papers, their copper complexes have not been assayed yet, and may serve as an useful tool in QSAR investigation.


2016 ◽  
Author(s):  
Elżbieta Hejchman ◽  
Barbara Sowirka ◽  
Magdalena Tomczyk ◽  
Dorota Maciejewska

Based on World Health Organization (WHO) report, it was estimated that one in five people before age 75 will suffer from cancer during their lifetime, and more than 13 million cancers death will happen in 2030. Chemotherapy is a basic approach for the treatment of cancer diseases. However, because of drug resistance and considerable side effects drug-induced toxicity, the discovery of new metal analogs with promising activity and high therapeutic index is an urgent need. The fundamental role of copper and the recognition of its complexes as important bioactive compounds in vitro and in vivo aroused an ever-increasing interest in these agents as potential drugs for therapeutic intervention in various diseases. Schiff bases are a critical class of compounds in medical chemistry that have demonstrated significant chemotherapeutic and antibacterial application. Schiff base Cu(II) complexes revealed great potential for antiproliferative, antibacterial, and gastroprotective activity. Coumarins are a wide class of natural and synthetic compounds that showed diverse pharmacological activities including anticancer activity. Among the wide variety of coumarins, 7-hydroxycoumarin derivatives have been shown to possess desirable antiproliferative activities. In particular, their antibacterial, antifungal and anticancer activities make the compounds attractive for further derivatization and screening as novel therapeutic agents. Taking these compounds as lead, we have designed and synthesized a series of new copper(II) complexes with coumarin-derived Schiff base ligands. Two series of Schiff bases were prepared by condensation of 8-formyl-7-hydroxy-4-methylcoumarin and 8-acetyl-7-hydroxy-4-methylcoumarin with p-substituted aniline derivatives. These compounds were used as ligands in the synthesis of copper(II) complexes. The obtained Schiff bases as well as copper complexes are mostly novel molecules. Only the products of condensation 8-formyl-7-hydroxy-4-methylcoumarin with p-toluidine and 8-acetyl-7-hydroxy-4-methylcoumarin with p-toluidine and its copper(II) complex were synthesized, but the anticancer activity of these compounds was not determined. The assay of their cytotoxic activity is in progress. Preliminary, we have identified two copper(II) coordination compounds of 7-hydroxy-8-[1-(4-methoxyphenyl imino)ethyl]-4-methyl-2H-chromen-2-one and 7-hydroxy-8-[1-(4-hydroxyphenyloimino)ethyl]-4-methyl-2H- chromen-2-one having dose-dependent antiproliferative activity on HeLa cancer cell line. Additionally, the Schiff bases – derivatives of substituted salicylaldehydes and 2-hydroxyacetophenones condensed with appropriate anilines were prepared. Such compounds have been reported in scientific papers, their copper complexes have not been assayed yet, and may serve as an useful tool in QSAR investigation.


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