scholarly journals Synthesis and Antioxidant Properties of Novel 2-(2,4-Dioxothiazolidin-5-ylidene)-Acetamides Containing 1,3,4-Thia/Oxadiazole Moieties

2021 ◽  
Vol 12 (5) ◽  
pp. 6710-6722

A series of novel 1,3,4-thia(oxa)diazole substituted 2-(2,4-dioxothiazolidine-5-ylidene)-acetamides 3a-c, 4 and 5a-k have been synthesized following the acylation reaction of 2-amino-5-aryl-1,3,4-oxadiazoles, 5-amino-1,3,4-thiadiazole-2-thiol and it’s S-alkylated derivatives with 2-(2,4-dioxothiazolidine-5-ylidene)acetyl chloride in dioxane medium. The functionalization of compounds 3b, 3c, 5d and 5e was carried out on their N3 position under N-alkylation conditions with N-aryl-2-chloroacetamides in DMF/ethanol medium yielded the corresponding 2,4-dioxothiazolidine-3,5-diacetic acid diamides 6a-e and 7a-b. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. The antioxidant activity evaluation in vitro of the synthesized compounds was performed by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the highly active compound 4, namely 2-(2,4-dioxothiazolidin-5-ylidene)-N-(5-mercapto-[1,3,4]thiadiazol-2-yl)acetamide was found to be the most efficient candidate among all compounds with a radical scavenging ability of 88.9%, which was comparable that for ascorbic acid (92.7%). The experimentally calculated IC50 value of 43.1 µM for compound 4 was lower than for ascorbic acid (50.5 µM).

2020 ◽  
Vol 11 (2) ◽  
pp. 1571-1577
Author(s):  
Lakshminarayanan B ◽  
Kannappan N ◽  
Subburaju T ◽  
Kalaichelvan V K

Pyrazolines are the most useful heterocyclic moiety in Pharmaceutical and Chemical fields and as the most potential molecules for the design of new chemical entities. Nitrogen-containing heterocyclic compounds, pyrazolines and their derivatives showed a variety of pharmacological activities, including antioxidant properties. In the present study, eleven novel ethoxylated pyrazoline derivatives were synthesized by condensing chalcones with electron releasingethoxy group at one end and different electron-donating, electron-withdrawing groups in another end with hydrazine hydrate andalcohol. The compounds synthesized were structural elucidated by their spectroscopic studies. All the compounds synthesized were evaluated for their in vitro antioxidant potential by 2,2’-diphenyl-1-picrylhydrazyl (DPPH)and hydrogen peroxide free radical scavenging assay methods.Some of these molecules possess moderate to good antioxidant activitywhen compared to standard ascorbic acid. The compound with methoxy group (EH2) exhibits potent antioxidant activity with IC50 value of 9.02 and 9.44µg/ml in DPPH and hydrogen peroxide assay method respectively and the compound with hydroxy group (EH9) also showed potent antioxidant activity with IC50 value of 12.41 and 14.56µg/ml in DPPH and hydrogen peroxide free radical scavengingassay method respectively when compared to standard. The compounds containing electron-donating substituents were found to be good antioxidantswhen compared to standard ascorbic acid.


2009 ◽  
Vol 6 (2) ◽  
pp. 227-231 ◽  
Author(s):  
S. A. Adesegun ◽  
A. Fajana ◽  
C. I. Orabueze ◽  
H. A. B. Coker

The antioxidant activities of crude extract ofPhaulopsis fascisepalaleaf were evaluated and compared with α-tocopherol and BHT as synthetic antioxidants and ascorbic acid as natural-based antioxidant.In vitro, we studied its antioxidative activities, radical-scavenging effects, Fe2+-chelating ability and reducing power. The total phenolic content was determined and expressed in gallic acid equivalent. The extract showed variable activities in all of thesein vitrotests. The antioxidant effect ofP. fascisepalawas strongly dose dependent, increased with increasing leaf extract dose and then leveled off with further increase in extract dose. Compared to other antioxidants used in the study, α-Tocopherol, ascorbic acid and BHT,P. fascisepalaleaf extract showed less scavenging effect on α,α,-diphenyl-β-picrylhydrazyl (DPPH) radical and less reducing power on Fe3+/ferricyanide complex but better Fe2+-chelating ability. These results revealed thein vitroantioxidant activity ofP.fascisepala.Further investigations are necessary to verify these activitiesin vivo.


2021 ◽  
Vol 33 (3) ◽  
pp. 677-685
Author(s):  
Abiodun Atinuke Adegborioye ◽  
Oyinlola Oluwunmi Olaokun ◽  
Benson Chuks Iweriebor ◽  
Larry Chikwulu Obi

Euryops brevipapposus (Asteraceae) is a medicinal plant of a local community utilized traditionally for its recognized effectiveness in managing non-communicable diseases, especially asthma. The traditional use of E. brevipapposus lacks scientific evidence and the increased burden of asthma makes confirming this claim paramount. The study characterized by GC-MS the bioactive compounds of E. brevipapposus essential oil (EbO) extracted with Clevenger apparatus. The antibacterial efficacy and antioxidant activity by free radical scavenging ability were investigated in vitro using standard methods. A strong antioxidant IC50 value of 6.71 × 10-7 mg/mL of oil was obtained for DPPH. The antibacterial activity against Escherichia coli and Vibrio spp. (MIC value of 0.055 mg/mL) was superior. GC-MS analysis of EbO showed α-phellandrene, α-pinene, germacrene D, β-pinene, β-mycrene, (E)-β-ocimene and bicyclogermacrene as the major compounds. The antioxidant and antibacterial potentials of E. brevipapposus may justify the therapeutic claims and local usage of this plant.


2021 ◽  
Vol 913 (1) ◽  
pp. 012093
Author(s):  
U Fitrotin ◽  
N Hilmiati ◽  
Mardiana ◽  
Y Triguna ◽  
A Surahman ◽  
...  

Abstract Preparation process for meniran (Phillantus urinaria) functional drink (MFD) influences its antioxidant activity. This research aims to understand the phenolic content, DPPH Radical Scavenging Activity (RSA), and LDL oxidation of MFD through various preparation processes. Those preparation processes included soaking fresh meniran (SFM), boiling fresh meniran for 5 minutes (BFM5’), boiling fresh meniran for 10 minutes (BFM10’), and soaking dried meniran (DM). The phenolic content was determined with Folin–Ciocalteu, antioxidant activity was assessed using DPPH and TBARS assay with LDL as the oxidation substrate. An antioxidant references in this research used ascorbic acid. The phenolic content in methods of SFM, BFM5’, BFM10’ and DM were 122±0.022, 182±0.043, 192 ±0.03, and 117 ±0.019 mg GAE/g of meniran respectively. Meanwhile, the DPPH RSA of SFM, BFM5’, BFM10’ and DM accounted for 82.18±0.35, 86.19±0.53, 86.75±0.64 and 69.96% respectively. As comparison, the DPPH RSA of ascorbic acid 50 ppm is 75.65±0.82%. At the same time the optimum inhibition of TBARS formation from BFM5’ and BFM10’ methods were 45.83 % and 48.66%, with MDA concentration in human LDL accounted for 38.30±2.39 and 36.30±1.82 nmol MDA/mg protein, respectively. As comparison, MDA concentration in human LDL added with ascorbic acid 25 ppm accounted for 41.35±2.41 nmol MDA/mg protein. In contrast, the control human LDL was 70.70±2.35 nmol MDA/mg protein. This study concludes that the BFM5’ and BFM10’ methods showed the highest antioxidant properties compared to other methods. All methods showed that MFD extract in concentration more than 25 ppm increased the concentration of MDA in human LDL. Therefore, to produce meniran functional drink in optimum antioxidant properties is best by using BFM5’ and BFM10’ preparation methods in meniran concentration of not more than 25 ppm.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Musbau Adewunmi Akanji ◽  
Samson Olasunkanmi Olukolu ◽  
Mutiu Idowu Kazeem

The leaves of Aerva lanata are one of the indigenous medicinal plants used in the management of diabetes mellitus and its associated complications in Africa. However, its effect on the activities of diabetes-related enzymes has not been investigated. This study evaluated the in vitro inhibitory effects of different extracts of the A. lanata leaf on the activities of diabetes-related enzymes (α-amylase and α-glucosidase) and chemically induced free radicals. Aqueous, ethanol, and hydroethanol extracts of A. lanata leaves were subjected to a standard enzyme inhibition assay followed by determination of modes of inhibition of the enzymes. The antioxidant activities of the extracts were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The results obtained showed that the hydroethanol extract of the A. lanata leaf optimally inhibited both α-amylase (IC50: 2.42 mg/mL) and α-glucosidase (IC50: 0.23 mg/mL). The Lineweaver-Burk plot revealed that the mode of inhibition of both enzymes by the hydroethanol extract was uncompetitive. However, the hydroethanol and aqueous extracts displayed the best DPPH and ABTS radical-scavenging ability, respectively. It can be concluded that the A. lanata extract inhibited the activities of both α-amylase and α-glucosidase uncompetitively, which may be attributed to its free radical-scavenging properties and rich phenolic composition.


2016 ◽  
Vol 2 (2) ◽  
pp. 77 ◽  
Author(s):  
Tomisin Happy Ogunwa ◽  
Tolulope Tosin Adeyelu ◽  
Rotimi Yemi Fasimoye ◽  
Mary Bose Oyewale ◽  
Taiwo Ademola Ademoye ◽  
...  

ABSTRACTClerodenrum volubile is an important locally used medicinal plant. It is one of the essential herbs nature has provided for mankind to be consumed as spices, vegetable and also used in the treatment of diseases. Qualitative phytoconstituent screening of the plant revealed the presence of steroids, flavonoids, tannins, saponins, and phenolic compound while chalcones, alkaloid and anthraquinone were absent. Quantitative phytochemical evaluation showed values of 8.29±1.26mg/g rutin equivalent for flavonoids, 3.53±0.05mg/g gallic acid equivalent for phenol, 3.97±0.03mg/g tannic acid equivalent for tannins and 13.67±1.27% for saponin per dry weight. As it is imperative to extend research work on therapeutic effects of the arsenal of plants nature has given to us in Africa so as to obtain a cure for various diseases attacking human’s health, antioxidant properties of the plant was evaluated. Antioxidant models used include iron chelating, DPPH radical, superoxide ion, hydrogen peroxide, ABTS radical, hydroxyl radical scavenging activities and ferric ion reducing properties. The obtained IC50 values against DPPH radical were 141.342 and 120.349µg/mL for Clerodendrum volubile and trolox respectively. The chelating effect of the plant extract at 50% inhibition was close to that of ascorbic acid (standard) with 134.34 and 131.19µg/mL concentration respectively. Overall, the aqueous extract of the plant showed antioxidant potential which was close to the effects exerted by known standard antioxidants (ascorbic acid, trolox and EDTA). The plant could hence provide natural antioxidants which are needed to combat numerous free radical-mediated diseases and complications such as aging, cancer, atherosclerosis, which are linked with oxidative stress. 


2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Sri Adi Sumiwi ◽  
Anas Subarnas ◽  
Supriyatna Supriyatna ◽  
Marline Abdassah Bratadiredja

Sintoc (Cinnamomum sintoc Bl.) is a plant which is used as medicine. This plant has been known to have an analgesic antiinflamatory activity, therefore it is predicted to have an antioxidant activity. An investigation on antioxidant activity of sintoc essential oils and ethanolic extract of its cortex using ascorbic acid as standard has been carried out. Essential oils and ethanol extract of sintoc cortex was tested using DPPH (1,1-diphenyl-2-pikril-hidrazil) by measuring absorbance using visible spectrophotometer at 518 nm. The methods of this research were distillation of essential oils and extraction of sintoc cortex, determination of the essential oil and extract concentrations required for 50% inhibition of DPPH radical scavenging effect (IC50) with ascorbic acid as the possitive control. The variation concentration  of essential oils are 15, 5, 1, 0.1, 0.5 ppm and 25, 20, 17, 15, 10 ppm for ethanolic extracts. The results showed that the essential oil showed antioxidant activity with IC50 value was 16.29 ppm (5 times lower than ascorbic acid) and then ethanolic extract showed IC50 value 38.89 ppm (11 times lower than ascorbic acid, IC50 of ascorbic acid was 3.35 ppm).


2019 ◽  
Vol 31 (8) ◽  
pp. 1724-1728
Author(s):  
P.M. Swami ◽  
P.K. Zubaidha ◽  
G.B. Tiwari

The present paper describes the synthesis of novel nitric oxide hybrids obtained by linking bioactive bicyclic amine to substituted furoxans. The antioxidant activities were studied in vitro based on the radical scavenging effect of stable DPPH free radical using ascorbic acid as a standard. The nitric oxide hybrids showed remarkable antioxidant properties and hence, can be employed as potential antioxidant agents.


2020 ◽  
Vol 10 (9) ◽  
pp. 3279 ◽  
Author(s):  
Shu-Ling Huang ◽  
Wei-Hsiung Wang ◽  
Xin-Yi Zhong ◽  
Chih-Ting Lin ◽  
Wen-Shin Lin ◽  
...  

The purpose of this study was to determine the antioxidant activity of the seed shells and kernels of Jatropha curcas L. The extracts obtained from five solutions (0%–95% ethanol) were tested and compared. Overall, the antioxidant capacity of seed shell extracts was higher than that of seed kernel extracts. The seed shell extract obtained using 95% ethanol exhibited the best antioxidant activity among the five solutions. The half-maximal inhibitory concentration (IC50) of 1,1-diphenyl-2-picrylhydrazyl and free radical scavenging ability of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) were 13.63 ± 0.15 and 6.75 ± 0.51 μg/mL, respectively. The reduction ability and total phenol content were 95.14 ± 27.04 μg ascorbic acid equivalents/mg of extract and 536.33 ± 8.62 μg gallic acid equivalents/mg of extract, respectively. In in vitro cytotoxicity assays, solutions with less than 250 μg/mL of seed shell extract had no major cytotoxicity. The seed shell of Jatropha curcas L. can be used as an antioxidant material and has potential for biomedical applications.


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