scholarly journals Quinoline Functionalized Schiff Base Silver (I) Complexes: Interactions with Biomolecules and In Vitro Cytotoxicity, Antioxidant and Antimicrobial Activities

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1205
Author(s):  
Adesola A. Adeleke ◽  
Sizwe J. Zamisa ◽  
Md. Shahidul Islam ◽  
Kolawole Olofinsan ◽  
Veronica F. Salau ◽  
...  

A series of fifteen silver (I) quinoline complexes Q1–Q15 have been synthesized and studied for their biological activities. Q1–Q15 were synthesized from the reactions of quinolinyl Schiff base derivatives L1–L5 (obtained by condensing 2-quinolinecarboxaldehyde with various aniline derivatives) with AgNO3, AgClO4 and AgCF3SO3. Q1–Q15 were characterized by various spectroscopic techniques and the structures of [Ag(L1)2]NO3Q1, [Ag(L1)2]ClO4Q6, [Ag(L2)2]ClO4Q7, [Ag(L2)2]CF3SO3Q12 and [Ag(L4)2]CF3SO3Q14 were unequivocally determined by single crystal X-ray diffraction analysis. In vitro antimicrobial tests against Gram-positive and Gram-negative bacteria revealed the influence of structure and anion on the complexes′ moderate to excellent antibacterial activity. In vitro antioxidant activities of the complexes showed their good radical scavenging activity in ferric reducing antioxidant power (FRAP). Complexes with the fluorine substituent or the thiophene or benzothiazole moieties are more potent with IC50 between 0.95 and 2.22 mg/mL than the standard used, ascorbic acid (2.68 mg/mL). The compounds showed a strong binding affinity with calf thymus-DNA via an intercalation mode and protein through a static quenching mechanism. Cytotoxicity activity was examined against three carcinoma cell lines (HELA, MDA-MB231, and SHSY5Y). [Ag(L2)2]ClO4Q7 with a benzothiazole moiety and [Ag(L4)2]ClO4Q9 with a methyl substituent had excellent cytotoxicity against HELA cells.

2020 ◽  
Vol 10 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Imane Rihab Mami ◽  
Rania Belabbes ◽  
Mohammed El Amine Dib ◽  
Boufeldja Tabti ◽  
Jean Costa ◽  
...  

Background: Carthamus caeruleus belongs to the Asteraceae family. The roots are traditionally used as healing agents. They help to heal burns and treat skin diseases. They are also used against joint inflammation and are very effective against diseases such as irritable bowel syndrome for cancer patients. Objectives: The purpose of this work was i) to study the chemical composition of i) the essential oil and hydrosol extract of Carthamus caeruleus, ii) to isolate the major component of both extracts and iii) to evaluate their antioxidant, antifungal and insecticidal activities. Methods: The essential oil and hydrosol extract obtained from the roots were studied by GC and GC/MS. The antioxidant activities were performed using two different methods i) Radical scavenging activity (DPPH) and ii) the Ferric-Reducing Antioxidant Power (FRAP), using BHT as a positive control. Whereas, the antifungal activity of the essential oil and Carlina oxide was investigated against plant fungi. The fumigation toxicity of C. caeruleus essential oil besides Carlina oxide was evaluated against adults of Bactrocera oleae better known as the olive fly. Results: The essential oil and hydrosol extract were mainly represented by acetylenic compounds such as carline oxide and 13-methoxy carline oxide. Carlina oxide was isolated and identified by 1H and 13C NMR spectroscopic means. The results showed that Carlina oxide presented interesting antioxidant and antifungal properties, while C. caeruleus root essential oil had better insecticidal activity. Furthermore, Carlina oxide has demonstrated promising in vivo antifungal activity to control infection of apples by Penicillium expansum. Conclusion: Carlina oxide can be used as a natural food preservative and alternative to chemical fungicides to protect stored apple against Penicillium expansum.


2020 ◽  
Vol 42 (1) ◽  
pp. 109-109
Author(s):  
Hao Zang Hao Zang ◽  
Qian Xu Qian Xu ◽  
Luyun Zhang Luyun Zhang ◽  
Guangqing Xia Guangqing Xia ◽  
Jiaming Sun and Junyi Zhu Jiaming Sun and Junyi Zhu

A series of hydroxytyrosol (HT) derivatives were synthesized by modification of alcohol hydroxyl group of HT, twenty-five target compounds were obtained and characterized by NMR and HRMS. The antioxidant activities of those compounds were evaluated in three different assays. Except 3e and 3y, all other compounds demonstrated significant 2,2and#39;-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical cation scavenging activity ranging from IC50 3.4 to 24.4 μM, which were more potent than L-ascorbic acid (IC50=24.8 μM). Compounds 3b-3d, 3f-3k, 3m-3x were better than Trolox (18.3 M). Moreover, the ferric reducing antioxidant power (FRAP) of all compounds were discovered to be more potent than L-ascorbic acid (40.7 mmol/g), except 3e, all other compounds (141.5-202.1 mmol/g) were better than Trolox (94.7 mmol/g). Compounds 3a-3d, 3f-3j, 3l-3m, 3o, 3q, 3t, 3v-3y exhibited more potent hydroxyl radical scavenging activity (IC50=245.1-475.1 M) than L-ascorbic acid (554.4 M) and Trolox (500.4 M). Compounds 3q, 3t and 3y exhibited more potent -Glucosidase inhibition activity (39.1-52.4 M) than Acarbose (60.9 M). Compounds 3a, 3d, 3f-3m, 3s-3t, 3v-3y showed some acetylcholinesterase inhibition activities, compounds 3a, 3d, 3f-3j, 3l-3m, 3o-3p, 3s-3t, 3w showed some butyrylcholinesterase inhibition activities.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5295
Author(s):  
Xinyu Zhao ◽  
Ruyi Chen ◽  
Yueyue Shi ◽  
Xiaoxi Zhang ◽  
Chongmei Tian ◽  
...  

This study aimed to isolate, prepare and identify the main flavonoids from a standardized Smilax glabra flavonoids extract (SGF) using preparative HPLC, MS, 1H NMR and 13C NMR, determine the contents of these flavonoids using UPLC, then compare their pharmacological activities in vitro. We obtained six flavonoids from SGF: astilbin (18.10%), neoastilbin (11.04%), isoastilbin (5.03%), neoisoastilbin (4.09%), engeletin (2.58%) and (−)-epicatechin (1.77%). The antioxidant activity of six flavonoids were evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS+) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the anti-inflammatory activity of six flavonoids were evaluated by determining the production of cytokines (IL-1β, IL-6), nitric oxide (NO) using enzyme linked immunosorbent assay and the NF-κB p65 expression using Western blotting in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results showed that (−)-epicatechin, astilbin, neoastilbin, isoastilbin and neoisoastilbin had strong antioxidant activities, not only in DPPH and ABTS+ radicals scavenging capacities, but in FRAP system. Furthermore, all the six flavonoids could significantly inhibit the secretion of IL-1β, IL-6, NO (p < 0.01) and the protein expression of NF-κB p-p65 (p < 0.01) in LPS-stimulated RAW264.7 cells. This study preliminarily verified the antioxidant and anti-inflammatory activities of six flavonoids in S. glabra.


2014 ◽  
Vol 31 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jovana Veljković ◽  
Jelena Brcanović ◽  
Aleksandra Pavlović ◽  
Snežana Mitić ◽  
Biljana Kaličanin ◽  
...  

Summary While there is a large number of scientific papers reporting chemical composition and biological activities of Aronia melanocarpa, there is a lack information regarding the commercially available bagged tea. In order to supply new information on the antioxidant activity of the Aronia melanocarpa tea infusions, the aim of this study was to evaluate individual phenolic compounds which could be responsible for antioxidant activities of these beverages. Selected anthocyanins (cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin- 3-O-arabinoside, and cyanidin-3-O-xyloside), gallic acid, caffeic acid, rutin, morin, and protocatechuic acid were simultaneously detected from commercially available tea infusions using a High Performance Liquid Chromatographic (HPLC) method. The antioxidant activity was measured using five in vitro spectrophotometric methods: 1,1-diphenyl- 2-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline- 6-sulphonic acid) radical cation scavenging activity (ABTS), ferric reducing-antioxidant power (FRAP) and reduction power (RP)Fe(III) to Fe(II). Obtained results showed that anthocyanins, predominantly of cyanidin-3-O-galactoside, are the major class of polyphenolic compounds in tea infusions. Among phenolic acids the most abundant is caffeic acid. A significant correlation between DPPH and ABTS and FRAP and RP suggested that antioxidant components in these beverages were capable scavenging free radicals and reducing oxidants. Generally, these beverages had relatively high antioxidant capacities and could be important dietary sources of antioxidant phenolics for the prevention of diseases caused by oxidative stress.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 314
Author(s):  
Jed Jebali ◽  
Hanene Ghazghazi ◽  
Chedia Aouadhi ◽  
Ines ELBini-Dhouib ◽  
Ridha Ben Salem ◽  
...  

Mint species (Lamiaceae family) have been used as traditional remedies for the treatment of several diseases. In this work, we aimed to characterize the biological activities of the total phenolic and flavonoid contents of Mentha pulegium L. extracts collected from two different regions of Tunisia. The highest amounts of total phenols (74.45 ± 0.01 mg GAE/g DW), flavonoids (28.87 ± 0.02 mg RE/g DW), and condensed tannins (4.35 ± 0.02 mg CE/g DW) were found in the Bizerte locality. Methanolic leaf extracts were subjected to HPLC-UV analysis in order to identify and quantify the phenolic composition. This technique allowed us to identify seven phenolic compounds: two phenolic acids and five flavonoid compounds, such as eriocitrin, hesperidin, narirutin, luteolin, and isorhoifolin, which were found in both extracts with significant differences between samples collected from the different regions (p < 0.05). Furthermore, our results showed that the methanolic extract from leaves collected from Bizerte had the highest antioxidant activities (DPPH IC50 value of 16.31 μg/mL and 570.08 μmol Fe2+/g, respectively). Both extracts showed high radical-scavenging activity as well as significant antimicrobial activity against eight tested bacteria. The highest antimicrobial activities were observed against Gram-positive bacteria with inhibition zone diameters and MIC values ranging between 19 and 32 mm and 40 and 160 µg/mL, respectively. Interestingly, at 10 μg/mL, the extract had a significant effect on cell proliferation of U87 human glioblastoma cells. These findings open perspectives for the use of Mentha pulegium L. extract in green pharmacy, alternative/complementary medicine, and natural preventive therapies for the development of effective antioxidant, antibacterial, and/or antitumoral drugs.


Author(s):  
Nabil Q. M. Al-Hajj

This study aimed to investigate the phytochemical, antimicrobial, and antioxidant activities of Carica papaya L. seeds extracts collected from Al Hudaydah city, Yemen (Latitude: 14°47′52″ N Longitude: 42°57′16″ E) during the months of January and February 2021. The seed was extracted with different solvents by the cold percolation method. The disk diffusion method was employed to assess the antibacterial activity of the seed extract against six bacterial and four fungal strains. Spectrometric methods were employed to calculate the total alkaloids, anthocyanin, flavonoid, phenolic, quinones, saponin, steroids, terpenoid, tannin, and phenols contents, as well as the antioxidant activities. Antibacterial and antifungal activity tests exhibited that the selected microorganisms are highly sensitive to the ethanolic and methanolic extracts of C. papaya L. seeds, followed by chloroform, water, and n-hexane extracts. The samples also demonstrated a significant DPPH, FRAP, and APTS radical scavenging activity. Additionally, the preliminary phytochemical analysis revealed the presence of flavonoid, terpenoid, saponin, alkaloids, steroids, quinones, anthocyanin, tannin, and phenols, all of which potentially contribute to the antimicrobial activities of C. papaya L. seeds.


2011 ◽  
Vol 6 (3) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Ilkay Erdogan Orhan ◽  
Osman Üstün ◽  
Bilge Şener

Ficus carica var. domestica Tsch. & Rav. (common fig) is widely grown in Turkey and exported for its edible fruits. In this study, the n-hexane, chloroform, acetone, methanol, n-butanol, and water extracts of the leaves of F. carica var. domestica were screened for their cholinesterase inhibitory and antioxidant activities. Cholinesterase inhibition against acetyl- (AChE) and butyrylcholinesterase (BChE) was measured by the spectrophotometric method of Ellman at concentrations of 25, 50, and 100 μg/mL., while antioxidant activity was tested using three in vitro methods; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, metal-chelation capacity, and ferric-reducing antioxidant power (FRAP). Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. Our results revealed that the n-hexane and acetone extracts exerted a notable inhibition against both AChE (62.9±0.9% and 50.8±2.1%, respectively) and BChE (76.9±2.2% and 45.6±1.3%, respectively). However, they had low activity in the antioxidant tests. The chloroform extract was found to be the richest in total flavonoid content (252.5±1.1 mg/g quercetin equivalent), while the n-butanol extract had the highest total phenol amount (85.9±3.2 mg/g extract gallic acid equivalent).


2021 ◽  
Vol 33 (4) ◽  
pp. 741-746
Author(s):  
V. PRABHU ◽  
K. ARUNKUMAR ◽  
B. MONIKA ◽  
V. LATHA ◽  
G. SIBI

Physalis minima Linn. was investigated for its antioxidant and acetylcholine esterase inhibition activities. The methanolic extract of the whole plant was evaluated for radical scavenging and in vitro hydrolysis of acetylthiocholine iodide. Inhibitory concentration (IC50) of the extract exhibited IC50 values of 78.6, 46.2, 76.7 and 296 μg/mL under 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS (2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid)), hydroxyl radical scavenging and acetylcholine esterase inhibition assays. GC-MS analysis revealed the presence of 11 compounds of which most of the compounds were reported with biological activities. The study suggests further investigations of P. minima for isolation, purification and characterization of valuable bioactive compounds related to their radical scavenging activity and for the treatment of neurodegenerative disease.


1970 ◽  
Vol 8 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Md Afzal Azam ◽  
BRP Kumar ◽  
R Mazumdar ◽  
B Suresh

A series of copper(II) and cobalt(II) coordination compounds with 2-substituted benzimidazole derived monodentate and bidentate ligands have been prepared and characterized by microanalysis, IR and UV-Vis spectroscopy. Synthesized metal complexes have been screened for their in vitro antioxidant and antitumor activity. The complex 4a showed significant nitric oxide free radical scavenging activity (IC50 65μg/ml), while 3i and 3g showed potent superoxide dismutase activity with IC50 of 0.26 and 0.28 μM respectively. In vitro cytotoxicity study with human breast MCF-7 and CNS SF 268 cancer cell lines showed that the most active 2-benzyl-1H-benzimidazole Cu(II) complex 3a inhibited the growth of cancer cells at 20 μM concentration. Keywords: Cu(II) complexes; Co(II) complexes; Benzimidazoles; Antitumor activity. DOI: 10.3329/dujps.v8i2.6027 Dhaka Univ. J. Pharm. Sci. 8(2): 131-140, 2009 (December)


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1632
Author(s):  
Maram Al-Tamimi ◽  
Shaza M. Al-Massarani ◽  
Ali A. El-Gamal ◽  
Omer A. Basudan ◽  
Maged S. Abdel-Kader ◽  
...  

A new dihydroisocoumarin glucoside, vacillanoside (3), and two new anthrone C-glycosides microdantin derivatives; vacillantin A (10) and B (11), together with nine known compounds belonging to the anthraquinone, anthrone and isocoumarin groups were isolated from the leaves of Aloe vacillans. The structures were determined based on spectroscopic evidence including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRESIMS) data, along with comparisons to reported data. The leaves were used to extract compounds with different solvents. The extracts were tested for antioxidant activity with a variety of in vitro tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS•+), ferric reducing antioxidant power assay (FRAP), superoxide, and nitric oxide radical scavenging assays. The dichloromethane fraction was most active, displaying significant free radical scavenging activity. The n-butanol fraction also showed notable activity in all assays. Therefore, these findings support the potential use of A. vacillans leaves as an antioxidant medication due to the presence of polyphenolic compounds.


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