Synthesis, Antioxidant Activity and Theoretical Investigation of Isoxazolines Derivatives of Monoterpenoids

2019 ◽  
Vol 16 (6) ◽  
pp. 501-510
Author(s):  
Melek Gul ◽  
Serpil Eryılmaz

The 3+2 cycloaddition reactions are important to generate five-membered heterocyclic compounds as well as altering biological activity effects based on structure. In the study, we synthesized new isoxazoline derivatives of different monoterpenoids and examined the structure analysis using spectroscopical analysis methods, reveal changes in the theoretical analysis related to the biological activity. These new compounds exhibit antioxidant activities; DPPH radical scavenging, ferric reducing, metal chelating activities which are significantly higher than the related commercial monoterpenoids. Theoretical approaches on the compounds containing isoxazole moiety have been performed by the DFT/B3LYP/method, 6-31G(d,p) basis set in the ground state. The global and local chemical reactivity properties of the compounds were investigated by considering the values of electronegativity, global hardness-softness, electronic chemical potential, electrophilicity index and condensed Fukui functions, local softness and local electrophilicity index. Furthermore, total energy, FMOs energy values and the dipole moment (µ), mean polarizability (α), and first order hyperpolarizability (β) values were analysed at the theoretical level to examine the polarizability characteristics of the compounds. The antioxidant activity values of the newly synthesized compounds were compared with a finding of the computational study. The results obtained exhibited good correlation on some parameters.

Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 189 ◽  
Author(s):  
Choon Young Lee ◽  
Ajit Sharma ◽  
Julius Semenya ◽  
Charles Anamoah ◽  
Kelli N. Chapman ◽  
...  

Antioxidants are an important component of our ability to combat free radicals, an excess of which leads to oxidative stress that is related to aging and numerous human diseases. Oxidative damage also shortens the shelf-life of foods and other commodities. Understanding the structure–activity relationship of antioxidants and their mechanisms of action is important for designing more potent antioxidants for potential use as therapeutic agents as well as preservatives. We report the first computational study on the electronic effects of ortho-substituents in dendritic tri-phenolic antioxidants, comprising a common phenol moiety and two other phenol units with electron-donating or electron-withdrawing substituents. Among the three proposed antioxidant mechanisms, sequential proton loss electron transfer (SPLET) was found to be the preferred mechanism in methanol for the dendritic antioxidants based on calculations using Gaussian 16. We then computed the total enthalpy values by cumulatively running SPLET for all three rings to estimate electronic effects of substituents on overall antioxidant activity of each dendritic antioxidant and establish their structure–activity relationships. Our results show that the electron-donating o-OCH3 group has a beneficial effect while the electron-withdrawing o-NO2 group has a negative effect on the antioxidant activity of the dendritic antioxidant. The o-Br and o-Cl groups did not show any appreciable effects. These results indicate that electron-donating groups such as o-methoxy are useful for designing potent dendritic antioxidants while the nitro and halogens do not add value to the radical scavenging antioxidant activity. We also found that the half-maximal inhibitory concentration (IC50) values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) better correlate with the second step (electron transfer enthalpy, ETE) than the first step (proton affinity, PA) of the SPLET mechanism, implying that ETE is the better measure for estimating overall radical scavenging antioxidant activities.


Author(s):  
HAYUN HAYUN ◽  
BAITHA PALANGGATAN MAGGADANI ◽  
ARINI KURNIA ◽  
AULIA HANIFAH ◽  
MEIDI YULIANDI ◽  
...  

Objective: To further understand this compound, we synthesized and evaluated the antioxidant and anti-inflammatory activity of a series of itsMannich base derivatives.Methods: We synthesized the compounds via the previously reported Mannich reaction method. Their structures were elucidated by Fouriertransforminfrared,1H-NMR,13C-NMR, and high-resolution mass spectra. The derivatives’ anti-inflammatory and antioxidant activities were testedusing the inhibition of protein denaturation method and the 2,2-diphenyl-2-picrylhydrazyl free radical scavenging assay.Results: The IC50 values for the anti-inflammatory activity of the 2,6-dimethylmorpholine, pyrrolidine, 1-methylpiperazine, and dimethylamineMannich base derivatives 2a–d were 10.67, 10.72, 37.75, and 1.93 μM, respectively; for (2E,6E)-2-({4-hydroxy-3-methoxyphenyl}methylidene)-6-(phenylmethylidene)cyclohexan-1-one (1), diclofenac sodium, and curcumin, the IC50 values were 56.29, 1.52, and 8.43 μM, respectively. The IC50values for the antioxidant activity of compounds 2a–2d were 229.62, 57.29, 280.43, and 219.22 μM, respectively; for compound 1, quercetin, andcurcumin, the IC50 values were 144.22, 27.28, and 26.45 μM, respectively.Conclusion: Substituting Mannich bases into (2E,6E)-2-[(4-hydroxy-3-methoxyphenyl) methylidene]-6-(phenylmethylidene)cyclohexan-1-oneenhanced its anti-inflammatory activity, but lowered its antioxidant activity. Compound 2d, (2E,6E)-2-({3-[(dimethylamino)methyl]-4-hydroxy-5-methoxyphenyl}methylidene)-6-(phenyl methylidene)cyclohexan-1-one, exhibited potent anti-inflammatory activity comparable to diclofenacsodium and four times higher than curcumin. However, further investigation of this compound’s mechanism of action and toxicity is warranted.


2011 ◽  
pp. 151-157 ◽  
Author(s):  
Marijana B. Saka ◽  
Julianna F. Gyura ◽  
Aleksandra Mišan ◽  
Zita I. Šereš ◽  
Biljana S. Pajin ◽  
...  

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 °C at pH = 5.7during 60 min) and treatment with hydrogen peroxide (20 g/LH2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 °C), ground and sieved. TF was investigated in comparison with commercially available Fibrex®. The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 ± 1 ºC). The obtained results indicated that substitution of wheat flour with Fibrex® in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex®-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex®-enriched cookies could be attributed to the presence of ferulic acid.


2020 ◽  
Vol 10 (3) ◽  
pp. 312-321
Author(s):  
Idin Sahidin ◽  
Carla W. Sabandar ◽  
Wahyuni ◽  
Rini Hamsidi ◽  
Sandra Aulia Mardikasari ◽  
...  

Background: Marine sponges provided a great source of natural products with promising biological activity. This study was aimed to investigate the chemical constituents of methanol extracts of selected Indonesian marine sponges (Callyspongia sp., Clathria sp., Melophlus sarasinorum, and Xestospongia sp.), collected from the Saponda Islands, Southeast Sulawesi, Indonesia as well as to evaluate their antimicrobial and antioxidant activities. Methods: LCMS/MS analysis used to identify the compounds. Agar well diffusion and DPPH assays were used to evaluate the antimicrobial and antioxidant activities. Results: Chemical screening reported alkaloids, terpenoids, steroids, and saponins from all investigated sponges. The LC-MS/MS analysis identified various compounds which mainly contained steroids. Antimicrobial activity (against Bacillus subtilis, Escherichia coli, Salmonella enterica, and Candida albicans) was only shown by the Xestospongia sp. extract. Meanwhile, extracts of M. sarasinorum, Xestospongia sp., and Callyspongia sp. exhibited potent radical scavenging activity. Conclusion: The study concluded that the selected sponges could provide various groups of compounds. Methanol extracts of these sponges could be used as sources of antimicrobial and antioxidant agents.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1325
Author(s):  
Mohamed Z. M. Salem ◽  
Abeer A. Mohamed ◽  
Hayssam M. Ali ◽  
Dunia A. Al Al Farraj

Background: Trees are good sources of bioactive compounds as antifungal and antioxidant activities. Methods: Management of six molecularly identified Fusarium oxysporum isolates (F. oxy 1, F. oxy 2, F. oxy 3, F. oxy 4, F. oxy 5 and F. oxy 6, under the accession numbers MW854648, MW854649, MW854650, MW854651, and MW854652, respectively) was assayed using four extracts from Conium maculatum leaves, Acacia saligna bark, Schinus terebinthifolius wood and Ficus eriobotryoides leaves. All the extracts were analyzed using HPLC-VWD for phenolic and flavonoid compounds and the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene-linoleic acid (BCB) bleaching assays. Results: In mg/kg extract, the highest amounts of polyphenolic compounds p-hydroxy benzoic, benzoic, gallic, and rosmarinic acids, with 444.37, 342.16, 311.32 and 117.87, respectively, were observed in C. maculatum leaf extract; gallic and benzoic acids with 2551.02, 1580.32, respectively, in A. saligna bark extract; quinol, naringenin, rutin, catechol, and benzoic acid with 2530.22, 1224.904, 798.29, 732.28, and 697.73, respectively, in S. terebinthifolius wood extract; and rutin, o-coumaric acid, p-hydroxy benzoic acid, resveratrol, and rosmarinic acid with 9168.03, 2016.93, 1009.20, 1156.99, and 574.907, respectively, in F. eriobotryoides leaf extract. At the extract concentration of 1250 mg/L, the antifungal activity against the growth of F. oxysporum strains showed that A. saligna bark followed by C. maculatum leaf extracts had the highest inhibition percentage of fungal growth (IPFG%) against F. oxy 1 with 80% and 79.5%, F. oxy 2 with 86.44% and 78.9%, F. oxy 3 with 86.4% and 84.2%, F. oxy 4 with 84.2, and 82.1%, F. oxy 5 with 88.4% and 86.9%, and F. oxy 6 with 88.9, and 87.1%, respectively. For the antioxidant activity, ethanolic extract from C. maculatum leaves showed the lowest concentration that inhibited 50% of DPPH free radical (3.4 μg/mL). Additionally, the same extract observed the lowest concentration (4.5 μg/mL) that inhibited BCB bleaching. Conclusions: Extracts from A. saligna bark and C. maculatum leaves are considered potential candidates against the growth of F. oxysporum isolates—a wilt pathogen—and C. maculatum leaf as a potent antioxidant agent.


2014 ◽  
Vol 955-959 ◽  
pp. 387-389 ◽  
Author(s):  
Bao Qing Wang

Antioxidant activities of acetone and ethyl acetate extracts from Metaplexis japonica Makino, one of famous medicine plants in the eastnorth region of China, named luomo in Chinese, were examined by a DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical-scavenging assay and a β-carotene-linoleic acid test. In DPPH, the antioxidant activity of the acetone extracts, ethyl acetate extracts and derivative were IC50 were 313.21, 266.92 and 118.78μg/mL, respectively. In the β-carotene-linoleic acid test, IC50 were 285.09, 351.57 and 123.89μg/mL. It was concluded that Metaplexis japonica Makino and its derivatives might be a potential natural source of antioxidants .


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
K. Nagendra Prasad ◽  
Jing Hao ◽  
Chun Yi ◽  
Dandan Zhang ◽  
Shengxiang Qiu ◽  
...  

Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (10) ◽  
pp. 34-41
Author(s):  
Kanthlal S. K. ◽  
Jipnomon Joseph ◽  
Bindhu P. Paul ◽  
Vijayakumar M ◽  
Rema Shree A. B. ◽  
...  

Amomum subulatum, commonly known as large or black cardamom, is a commonly used spice in Indian kitchens and is traditionally used to treat various ailments. To add more knowledge about the medicinal values of the fruit, this study was conducted to evaluate the in vitro antioxidant activities of aqueous, methanol, ethanol, hydro alcohol, ethyl acetate, acetone and chloroform extracts of the fruit. Preliminary assessment was done to detect the presence of phytoconstituents using identification tests. The antioxidant activity was measured by employing methods such as diphenylpicrylhydrazyl (DPPH) radical scavenging assay, total antioxidant activity equivalent to ascorbic acid, reducing power assay and superoxide anion scavenging assay. The antioxidant activities were compared with their respective phenol and flavonoid contents. Preliminary assessment revealed that large cardamom fruit is a good source of all the bioactive constituents as well as phenol and flavonoid essential for medicinal values. The extract obtained by polar solvents showed the highest antioxidant efficacy in relation to its phenol content. Also, all the solvent-soluble fractions showed a concentration-dependent antioxidant effect. Results from our study prove that large cardamom can alleviate oxidative stress, suggesting the potential of large cardamom as a functional food


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sushil Kumar Middha ◽  
Talambedu Usha ◽  
Veena Pande

This study revealed polyphenolic content, nutritive content, antioxidant activity, and phenolic profile of methanol and aqueous extracts ofPunica granatumpeel extract. For this, extracts were screened for possible antioxidant activities by free radical scavenging activity (DPPH), hydrogen peroxide scavenging activity and ferric-reducing antioxidant power (FRAP) assays. The total phenolics and flavonoid recovered by methanolic (MPE) and the water extract (AQPE) were ranged from 185 ± 12.45 to 298.00 ± 24.86 mg GAE (gallic acid equivalents)/gm and 23.05 ± 1.54 to 49.8 ± 2.14 quercetin (QE) mg/g, respectively. The EC50of herbal extracts ranged from 100 µg/ml (0.38 quercetin equivalents), for AQPE, 168 µg/ml (0.80 quercetin equivalents), for MPE. The phenolic profile in the methanolic extracts was investigated by chromatographic (HPLC) method. About 5 different flavonoids, phenolic acids, and their derivatives including quercetin (1), rutin (2), gallic acid (3), ellagic acid (4), and punicalagin as a major ellagitannin (5) have been identified. Among both extracts, methanolic extract was the most effective. This report may be the first to show nutritive content and correlation analysis to suggest that phenols and flavonoids might contribute the high antioxidant activity of this fruit peel and establish it as a valuable natural antioxidant source applicable in the health food industry.


2020 ◽  
Vol 38 ◽  
Author(s):  
M. AKBAR ◽  
I.N. SHERAZI ◽  
M.S. IQBAL ◽  
T. KHALIL ◽  
H.M. WAQAS

ABSTRACT: In the present study, antibacterial and antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity] activities of a weed, slender amaranth (Amaranthus viridis L.) were investigated. Extracts of different plant parts were prepared in n-hexane, chloroform and ethyl acetate. Antibacterial activity was measured by using 100 mg mL-1 concentration extracts against 4 deadly phytopathogenic bacterial species viz. Pseudomonas syringae Van Hall, Ralstonia solanacearum Smith, Erwinia carotovora (Jones), Holland and Xanthomonas axonopodis Hasse. In antioxidants assays, 10, 20 and 30 mg mL-1 extracts were used keeping DPPH as control. In these bioassays, ethyl acetate fraction of A. viridis leaf exhibited the best antibacterial and antioxidants activity. Ethyl acetate leaf fraction showed the highest inhibition zone diameter (IZD) where it caused 21 mm IZD against P. syringae and 19 mm IZD against E. carotovora. This extract also showed 22, 52 and 84% antioxidant activity at 10, 20 and 30 mg mL-1 concentrations, respectively. Previously there is no report available that describes antibacterial activity of root extract of A. viridis against P. syringae. Moreover, antioxidant activity of stem and root extracts in n-hexane, chloroform and ethyl acetate was investigated first time in the world. It was concluded that the biological activities observed during the present investigation may be due to the presence of bioactive constituents that can be harnessed as natural antibacterials and antioxidants.


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