scholarly journals Synthesis, Antiproliferative Activity and Radical Scavenging Ability of 5-O-Acyl Derivatives of Quercetin

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1608
Author(s):  
Stephen Lo ◽  
Euphemia Leung ◽  
Bruno Fedrizzi ◽  
David Barker

Quercetin is a flavonoid that is found in many plant materials, including commonly eaten fruits and vegetables. The compound is well known for its wide range of biological activities. In this study, 5-O-acyl derivatives of quercetin were synthesised and assessed for their antiproliferative activity against the HCT116 colon cancer and MDA-MB-231 breast cancer cell lines; and their radical scavenging activity against the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical species. Four derivatives were found to have improved the antiproliferative activity compared to quercetin whilst retaining radical scavenging activity.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephen Lo ◽  
Euphemia Leung ◽  
Bruno Fedrizzi ◽  
David Barker

AbstractLuteolin is a flavonoid found in a wide range of plant materials, including commonly eaten fruits and vegetables. It displays a wide range of biological activities but is known to have poor bioavailability. In this study, ten different mono-acyl (nine 5-O-acyl and one 7-O-acyl) derivatives of luteolin were synthesised for the purpose of improving bioactivity and bioavailability, and therefore enhance their therapeutic potential. The antiproliferative activity of these derivatives was assessed against the HCT116 colon cancer and MDA-MB-231 breast cancer cell lines using a 3[H] thymidine incorporation assay. The radical scavenging activity of these derivatives against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical using Trolox as a standard, was also assessed. Some of these derivatives were found to have improved antiproliferative activity with comparable radical scavenging activity compared to luteolin. Increased lipophilicity has been shown to increase the bioavailability of flavonoids implying these analogues will also have increased bioavailability.


2021 ◽  
Vol 19 (4) ◽  
pp. 329-343
Author(s):  
Yaaser Q. Almulaiky ◽  
Ammar AL-Farga

Commiphora gileadensis is commonly used in Saudi Arabia for oral hygiene. A lack of data about its biological activity encouraged us to evaluate the antioxidant and antibacterial activities of its leaf and stem extracts. Ethanol, methanol, acetone and deionized water were tested as extraction solvents. 80% methanol gave the highest extracted concentrations of phenolic and flavonoid substances. The leaf and stem extracts were respectively evaluated for their radical scavenging activity with DPPH (EC50 = 3.39, and 1.06), ABTS (EC50 = 0.690, and 0.55), and peroxide scavenging activity (EC50 = 2.43, and 1.28). GC-MS identified a wide range of compounds that may be responsible for these activities of the results observed. The highest levels of chlorophyll, carotenoids, and lycopene were found in the leaf extract while level of proanthocyanidins was found in the stem peels extract. The peroxidase and catalase activities of stem peel extract were higher than those of the leaf extract. The findings showed that the leaf and stem peel extracts of C. gileadensis exhibited significant antibacterial activity against the test organisms. The minimum inhibitory concentrations for the plant extracts were compared with the standard reference drug Augmentin but the time–kill curves for the C. gileadensis extracts showed that they were less effective than Augmentin. Moreover, the stem peel extract exhibited stronger antibacterial activity than the leaf extract. In conclusion, C. gileadensis can be an important source of natural antioxidants, used as a healthy chewing stick for teeth brushing and oral hygiene purposes.


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.


2018 ◽  
Vol 46 (2) ◽  
pp. 517-524
Author(s):  
Kandhan KARTHISHWARAN ◽  
Subban KAMALRAJ ◽  
Chelliah JAYABASKARAN ◽  
Shyam S. KURUP ◽  
Sabitha SAKKIR ◽  
...  

Aerva javanica (Burm. f) Juss. ex Schult. (Family: Amaranthaceae) family is one of the traditional medicinal plant growing in the United Arab Emirates. Apart from studies related to some medicinal properties, phytochemical, GC MS compound characterization and biological activities still to be investigated. An experiment was conducted to determine the possible bioactive components with their chemical structures and elucidation of phytochemicals from the aerial parts of the plant. The macro and micro-mineral constituents and antioxidant activities were also evaluated. Aerial parts of A. javanica were extracted sequentially with hexane, chloroform, ethyl acetate, acetone, methanol by cold percolation method. Free radical scavenging and antioxidant properties of methanolic extract were evaluated by using in vitro antioxidant assays such as hydroxyl radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radical scavenging activity and ABTS radical scavenging activity. Primary phytochemical and micro-macro element was tested using standard protocol. The chemical characterization was done with the help of Gas Chromatography-Mass Spectrometry (GC–MS), and the mass spectra of the total compounds in the extract were matched with the National Institute of Standard and Technology (NIST) library. Mineral constituents were identified and estimated by ICP-OES. Ninety-nine metabolites were obtained by GC-MS anslysis; indole was found to be major components followed by 2-Chlorallyl diethyldithiocarbamate (CDEC), Carbaril, Bis(2-ethylhexyl) phthalate, Quinoline, 4H-Cyclopenta[def]phenanthrene,2-[Bis(2-chloroethylamino)]-tetrahydro-2H-1,3,2-oxazaphosphorine-2-oxide, Phenobarbital, 1H-Indole, 2-methyl-, 2,3,7,8-Tetrachlorodibenzo-p-dioxin Disulfide, diphenyl. The presence of various bioactive compounds in the extract validates the traditional medicinal uses of this plant.


2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Aneta Wojdyłto ◽  
Jan Oszmiański

Fruits are one of the most important sources of phenolic compounds in our diet. Many of these compounds exhibit a wide range of biological activities, especially antioxidant activity. The objective of this study was to determine the composition and antioxidant activity of phenolic compounds found in fruit juice obtained from buckthorn, flowering quince, rowanberry and hawthorn. Hydroxycinnamic acids (neochlorogenic and chlorogenic acid) and procyanidins were the main phenolics in rowanberry juice. The highest level of flavonols (quercetin derivatives) was found in sea buckthorn. All juices showed strong free-radical scavenging activity against ABTS•+ radicals and ferric reducing ability measured by the FRAP method. The strongest antioxidant activity was found in rowanberry juice, but the lowest was measured in hawthorn and sea buckthorn juices.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Trung Dung Tran ◽  
Anh Dzung Nguyen ◽  
...  

Chitosan oligosaccharide (COS) has become of great interest in recent years because of its worthy biological activities. This study aims to produce COS using the enzymatic method, and investigates Paenibacillus sp. TKU047, a chitinolytic-producing strain, in terms of its chitosanase productivity on several chitinous material-containing mediums from fishery process wastes. The highest amount of chitosanase was produced on the medium using 2% (w/v) squid pens powder (0.60 U/mL) as the single carbon and nitrogen (C/N) source. The molecular mass of TKU047 chitosanase, which could be the smallest one among chitinases/chitosanases from the Paenibacillus genus, was approximately 23 kDa according to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. TKU047 chitosanase possessed the highest activity at 60 °C, pH 7, and toward chitosan solution with a higher degree of deacetylation (DDA) value. Additionally, the hydrolysis products of 98% DDA chitosan catalyzed by TKU047 chitosanase showed the degree of polymerization (DP) ranging from 2 to 9, suggesting that it was an endo-type activity chitosanase. The free radical scavenging activity of the obtained chitosan oligosaccharide (COS) was determined. The result showed that COS produced with Paenibacillus sp. TKU047 chitosanase expressed a higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than that from the commercial COSs with maximum activity and IC50 values of 81.20% and 1.02 mg/mL; 18.63% and 15.37 mg/mL; and 15.96% and 15.16 mg/mL, respectively. As such, Paenibacillus sp. TKU047 may have potential use in converting squid pens waste to produce chitosanase as an enzyme for bio-activity COS preparation.


Author(s):  
Saira Tabassum ◽  
Muhammad Zia ◽  
Esperanza J. Carcahe de Blanco ◽  
Riffat Batool ◽  
Roohi Aslam ◽  
...  

Abstract Background Arisaema jacquemontii is traditionally used in treatment of different diseases. In this study, phytochemical, in vitro biological and chemo-preventive screening of A. jacquemontii was carried out to explore its pharmacological potential. Methods The dried tuber of A. jacquemontii was extracted in 11 organic solvent mixture of different polarity. The extracts were screened for phytochemical assays (phenolics and flavonoids), antioxidants potential (free radical scavenging activity, total antioxidant activity, reducing power), biological activities (antibacterial, antifungal, cytotoxic, antileishmanial, protein kinase inhibition), and chemopreventive activities using different cell lines through standard protocols. Results Significant amount phenolic contents were determined in EtOH and MeOH extracts (210.3 ± 3.05 and 193.2 ± 3.15 μg GAE/mg, respectively). Maximum flavonoid content was determined in MeOH extract (22.4 ± 4.04 μg QE/mg). Noteworthy, DPPH scavenging activity was also recorded for MeOH extract (87.66%) followed by MeOH+EtOAc extract (85.11%). Considerable antioxidant capacity (7.8 ± 0.12 μg AAE/mg) and reducing power (3.1 ± 0.15 μg AAE/mg) was observed in extract of MeOH. The LC50 against brine shrimp and leishmanial parasite was found 9.01 and 12.87 μg/mL for n-Hex and CHCl3 extracts, respectively. The highest zone of inhibition against Streptomyces hyphae formation (12.5 ± 1.77 mm) by n-Hex extract. Growth zone of inhibition 13.8 ± 1.08 mm was recorded for EtOAc and MeOH extracts, respectively against Micrococcus luteus while 10.0 ± 0.11 mm for MeOH extract against Aspergillus flavus. In-vitro cytotoxic assay showed that n-Hex extract had higher cytotoxicity against DU-145 prostate cancer and HL-60 cancer cell lines. NF-kB and MTP potential showed 34.01 and 44.87 μg/mL for n-Hex and CHCl3 extracts, respectively in chemo-preventive potential. Conclusion The study concludes that Arisaema jacquemontii bears significant phytochemical activity and pharmacological activities, this plant can be further explored for isolation of active component against a number of aliments.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2460
Author(s):  
Yingqi Mi ◽  
Wenqiang Tan ◽  
Jingjing Zhang ◽  
Zhanyong Guo

A novel and green method for the preparation of chitosan derivatives bearing organic acids was reported in this paper. In order to improve the antioxidant activity of chitosan, eight different hydroxypropyltrimethyl ammonium chitosan derivatives were successfully designed and synthesized via introducing of organic acids onto chitosan by mild and non-toxic ion exchange. The data of Fourier Transform Infrared (FTIR), 13C Nuclear Magnetic Resonance (NMR), 1H NMR, and elemental analysis for chitosan derivatives indicated the successful conjugation of organic acid salt with hydroxypropyltrimethyl ammonium chloride chitosan (HACC). Meanwhile, the antioxidant activity of the chitosan derivatives was evaluated in vitro. The results indicated that the chitosan derivatives possessed dramatic enhancements in DPPH-radical scavenging activity, superoxide-radical scavenging activity, hydroxyl radical scavenging ability, and reducing power. Furthermore, the cytotoxicity of the synthesized compounds was investigated in vitro on L929 cells and showed low cytotoxicity. Thus, the enhanced antioxidant property of all novel chitosan products might be a great advantage, while applied in a wide range of applications in the form of antioxidant in biomedical, food, and cosmetic industry.


2017 ◽  
Vol 41 (15) ◽  
pp. 7531-7543 ◽  
Author(s):  
A. Bistrović ◽  
N. Stipaničev ◽  
T. Opačak-Bernardi ◽  
M. Jukić ◽  
S. Martinez ◽  
...  

Diverse natural coumarin-based compounds linked to aryl via a 1,2,3-triazole spacer with antiproliferative activity against K562 cells, radical scavenging activity and a decrease of ROS production were provided.


Author(s):  
Farediah Ahmad ◽  
Adiana Mohamed Adib ◽  
Muhammad Sum Idris

Natural flavonoids, 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone were synthesised via their respective chalcone. The initial step wasto synthesise derivatives of 2-hydroxyacetophenone and benzaldehyde by protecting the phenolic hydroxyl groups. The chalcone was synthesised byClaisen-Schmidt condensation. Acid hydrolysis and subsequent treatment with sodium acetate of 2’-hydroxy-4,4’-6’-tris(methoxymethyloxy)chalconeand 2’-hydroxy-3,4,4’,6’-tetrakis(methoxymethyloxy)chalcone, gave 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone, respectively.3’,4’,5,7-Tetrahydroxyflavanone was found to be more potent as an antioxidant agent than 4’,5,7-trihydroxyflavanone with 83.11% inhibition and SC508.57 μg/mL in the radical scavenging activity by ESR method.


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