scholarly journals Steric Effect of Antioxidant Diels-Alder-Type Adducts: A Comparison of Sanggenon C with Sanggenon D

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2610 ◽  
Author(s):  
Xican Li ◽  
Zhenxing Ren ◽  
Zimei Wu ◽  
Zhen Fu ◽  
Hong Xie ◽  
...  

Sanggenons C and D are two Diels-Alder-type adducts from Chinese crude drug Sang-bai-pi. Structurally, both sanggenons construct stereoisomers. In the study, they were comparatively determined using four antioxidant assays, including ferric ion reducing antioxidant power (FRAP) assay, Cu2+-reducing assay, 1,1-diphenyl-2-picryl-hydrazl (DPPH•)-scavenging assay, and 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid radical (ABTS•+)-scavenging assay. Their Fe2+-binding reactions were explored using UV-Vis spectra. Finally, their cytoprotective effects were evaluated using flow cytometry. In electron transfer (ET)-based FRAP and Cu2+-reducing assays, sanggenon D was found to have lower IC50 values than sanggenon C; however, in multi-pathway-based DPPH•-scavenging and ABTS•+-scavenging assays, sanggenon C possessed lower IC50 values than sanggenon D. UV-Vis spectra suggested that sanggenon C generated a bathochromic-shift (286 nm → 302 nm) and displayed stronger UV absorption than sanggenon D. In flow cytometry, sanggenon C and sanggenon D, respectively, exhibited 31.1% and 42.0% early apoptosis-percentages towards oxidative-stressed mesenchymal stem cells (MSCs). In conclusion, both sanggenons may undergo multiple pathways (e.g., ET and Fe2+-binding) to protect MSCs against oxidative stress. In the mere ET aspect, sanggenon D possesses a higher level than sanggenon C, while in multi-pathway-based radical-scavenging, Fe2+-binding, and cytoprotection aspects, sanggenon C is more active than sanggenon D. These discrepancies can conclusively be attributed to the steric effect.

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7099
Author(s):  
Leyla Polat Kose ◽  
İlhami Gulcin

In this study, the antioxidant and antiradical properties of some phyto lignans (nordihydroguaiaretic acid, secoisolariciresinol, secoisolariciresinol diglycoside, and α-(-)-conidendrin) and mammalian lignans (enterodiol and enterolactone) were examined by different antioxidant assays. For this purpose, radical scavenging activities of phyto and mammalian lignans were realized by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS•+) scavenging assay and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging assay. Additionally, the reducing ability of phyto and mammalian lignans were evaluated by cupric ions (Cu2+) reducing (CUPRAC) ability, and ferric ions (Fe3+) and [Fe3+-(TPTZ)2]3+ complex reducing (FRAP) abilities. Also, half maximal inhibitory concentration (IC50) values were determined and reported for DPPH• and ABTS•+ scavenging influences of all of the lignan molecules. The absorbances of the lignans were found in the range of 0.150–2.320 for Fe3+ reducing, in the range of 0.040–2.090 for Cu2+ reducing, and in the range of 0.360–1.810 for the FRAP assay. On the other hand, the IC50 values of phyto and mammalian lignans were determined in the ranges of 6.601–932.167 µg/mL for DPPH• scavenging and 13.007–27.829 µg/mL for ABTS•+ scavenging. In all of the used bioanalytical methods, phyto lignans, as secondary metabolites in plants, demonstrated considerably higher antioxidant activity compared to that of mammalian lignans. In addition, it was observed that enterodiol and enterolactone exhibited relatively weaker antioxidant activities when compared to phyto lignans or standard antioxidants, including butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), Trolox, and α-tocopherol.


2021 ◽  
Vol 17 ◽  
Author(s):  
Tooba Naz Shamsi ◽  
Sumbul Afreen ◽  
Romana Parveen ◽  
Manish Kumar ◽  
Tasneem Fatma ◽  
...  

Background: Garlic, being a well-known medicinal plant is the most commonly used culinary spice worldwide. Investigation of protease inhibitor isolated from garlic leads to a promising contender in pharmacognostic and pharmacological studies. Objective/Introduction: Protease Inhibitor (PI) from 'garlic' (Allium sativum) was analyzed for its biological role as an antioxidant, antimicrobial, and anti-inflammatory agent. Methods: Antioxidant activity was evaluated using ferric ion reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. The anti-inflammatory activity was assessed using trypsin inhibitory assay and heat-induced albumin denaturation method. The antimicrobial activity was examined in broth against E. coli and B. Subtilis. The crystallization was setup using the hanging drop method. Results: ASPI showed DPPH radical scavenging with IC50 values 561±0.337 µg/ml. Also, ASPI showed the highest value of 0.699±0.009 mM at 1000 μg/ml and the lowest i.e. 0.181±0.006 mM at 100 μg/ml in FRAP assay. Ascorbic acid was taken as standard in both cases. ASPI showed IC50 values of 651±0.532 μg/ml and ~657±1.802 μg/ml respectively. The antibacterial role of ASPI was testified and results showed maximum inhibition against E. coli (ATCC 25922) i.e., 87.8 ±0.602% but no inhibition against B. subtilis (MTCC 736). Cuboidal shaped crystals of the ASPI were obtained in 4-6 weeks using 0.2M calcium chloride dihydrate, 0.1M sodium acetate trihydrate, 20 % isopropanol. Conclusion: ASPI has tremendous potential for the development of suitable drugs in pharmaceutical industries against diseases due to the generation of reactive oxygen species and cancer. The cuboidal crystals were obtained which is the first study in the context of crystallization of ASPI to date.


Author(s):  
Raj Kumar Tiwari ◽  
Udayabanu Malairaman ◽  
Silpi Chanda

Objective: The intent  of this report  was to investigate the effect of aqueous root extract of Clerodendrum serratum L. for antioxidant activity using divergent models viz. DPPH scavenging assay, Superoxide scavenging assay and Ferric Reducing Antioxidant Power (FRAP) assay.Materials and Methods: The root of C. serratum was extracted using water. The yield of aqueous extract was 10%w/w. The outcome was examined statistically by the regression method.Results and discussions: The IC50 values are 85.43 µg/ml and 107.59 µg/ml for DPPH radical scavenging and Superoxide scavenging assay respectively whereas  FRAP showed significant reducing power activity with increased concentration of sample. The pilot study showed, a significant correlation existed between concentrations of the extract and percentage engrossment of free radicals.Conclusion: The antioxidant property may be corresponding to the polyphenols and flavonoids adjacent in the extract. These results clearly revealed that C. serratum might be effective against diseases analogous with free radical mediated. Keywords Clerodendrum serratum, DPPH, Superoxide, FRAP, Rutin, Antioxidant


Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 205 ◽  
Author(s):  
Xican Li ◽  
Jingyuan Zeng ◽  
Yangping Liu ◽  
Minshi Liang ◽  
Qianru Liu ◽  
...  

In this study, the anti-ferroptosis effects of catecholic flavonol quercetin and its metabolite quercetin Diels-Alder anti-dimer (QDAD) were studied using an erastin-treated bone marrow-derived mesenchymal stem cell (bmMSCs) model. Quercetin exhibited higher anti-ferroptosis levels than QDAD, as indicated by 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid (C11-BODIPY), 2′,7′-dichlorodihydrofluoroscein diacetate (H2DCFDA), lactate dehydrogenase (LDH) release, cell counting kit-8 (CCK-8), and flow cytometric assays. To understand the possible pathways involved, the reaction product of quercetin with the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH●) was measured using ultra-performance liquid-chromatography coupled with electrospray-ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-Q-TOF-MS). Quercetin was found to produce the same clusters of molecular ion peaks and fragments as standard QDAD. Furthermore, the antioxidant effects of quercetin and QDAD were compared by determining their 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical-scavenging, Cu2+-reducing, Fe3+-reducing, lipid peroxidation-scavenging, and DPPH●-scavenging activities. Quercetin consistently showed lower IC50 values than QDAD. These findings indicate that quercetin and QDAD can protect bmMSCs from erastin-induced ferroptosis, possibly through the antioxidant pathway. The antioxidant pathway can convert quercetin into QDAD—an inferior ferroptosis-inhibitor and antioxidant. The weakening has highlighted a rule for predicting the relative anti-ferroptosis and antioxidant effects of catecholic flavonols and their Diels-Alder dimer metabolites.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1144
Author(s):  
Aliyu Dantani Abdullahi ◽  
Pratthana Kodchasee ◽  
Kridsada Unban ◽  
Thanawat Pattananandecha ◽  
Chalermpong Saenjum ◽  
...  

The study investigated the impact of the fermentation process on the phenolic contents and antioxidant and anti-inflammatory activities in extracts of Miang, an ethnic fermented tea product of northern Thailand. The acetone (80%) extraction of Miang samples fermented by a non-filamentous fungi-based process (NFP) and filamentous fungi-based process (FFP) had elevated levels of total polyphenols, total tannins, and condensed tannins compared to young and mature tea leaves. The antioxidant studies also showed better the half-maximal inhibitory concentration (IC50) values for fermented leaves in both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays as well as improved ferric reducing antioxidant power (FRAP) compared to young and mature tea leaves. Extracts of NFP and FFP samples at concentrations of 50 and 100 ppm showed better protective effects against hydrogen peroxide (H2O2)-induced intracellular reactive oxygen species (ROS) production in HT-29 colorectal cells without exerting cytotoxicity. Additionally, lipopolysaccharide (LPS)-induced production of nitric oxide (a proinflammatory mediator as well as a reactive nitrogen species) was also inhibited by these fermented Miang extracts with an IC50 values of 17.15 μg/mL (NFP), 20.17 μg/mL (FFP), 33.96 μg/mL (young tea leaves), and 31.33 μg/mL (mature tea leaves). Therefore, both NFP-Miang and FFP-Miang showed the potential to be targeted as natural bioactive functional ingredients with preventive properties against free radical and inflammatory-mediated diseases.


Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
Pattamaporn Aksornchu ◽  
Netima Chamnansilpa ◽  
Sirichai Adisakwattana ◽  
Thavaree Thilavech ◽  
Charoonsri Choosak ◽  
...  

Antidesma bunius (L.) spreng (Mamao) is widely distributed in Northeastern Thailand. Antidesma bunius has been reported to contain anthocyanins, which possess antioxidant and antihypertensive actions. However, the antidiabetic and antiglycation activity of Antidesma bunius fruit extract has not yet been reported. In this study, we investigated the inhibitory activity of anthocyanin-enriched fraction of Antidesma bunius fruit extract (ABE) against pancreatic α-amylase, intestinal α-glucosidase (maltase and sucrase), protein glycation, as well as antioxidant activity. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) chromatogram revealed that ABE contained phytochemical compounds such as cyanidin-3-glucoside, delphinidin-3-glucoside, ellagic acid, and myricetin-3-galactoside. ABE inhibited intestinal maltase and sucrase activity with the IC50 values of 0.76 ± 0.02 mg/mL and 1.33 ± 0.03 mg/mL, respectively. Furthermore, ABE (0.25 mg/mL) reduced the formation of fluorescent AGEs and the level of Nε-carboxymethyllysine (Nε-CML) in fructose and glucose-induced protein glycation during four weeks of incubation. During the glycation process, the protein carbonyl and β-amyloid cross structure were decreased by ABE (0.25 mg/mL). In addition, ABE exhibited antioxidant activity through DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) with the IC50 values 15.84 ± 0.06 µg/mL and 166.1 ± 2.40 µg/mL, respectively. Meanwhile, ferric reducing antioxidant power (FRAP) showed an EC50 value of 182.22 ± 0.64 µg/mL. The findings suggest that ABE may be a promising agent for inhibiting carbohydrate digestive enzyme activity, reducing monosaccharide-induced protein glycation, and antioxidant activity.


2015 ◽  
Vol 3 (1) ◽  
pp. 60-65
Author(s):  
Meena Kusi ◽  
Kanti Shrestha ◽  
Rajani Malla

This study focuses on antibacterial, antioxidant and toxic potentials of Viscum album Linn, commonly known as European mistletoe associated with Acacia catechu (Khayer in Nepali). Methanol extract of the aerial parts of the Mistletoe was prepared by cold percolation method. The resulting extract was simultaneously subjected to phytochemical screening; anti-microbial activity; anti-oxidant potential and Brine shrimp toxicity test. The major biologically active phyto-constituents observed were alkaloids, glycosides, saponins, polyphenols, flavonoids, tannins, terpenoids and cardiac glycosides. Upon antibacterial activity screening, the plant extract was found to be highly effective against Pseudomonas aeruginosa with the zone of inhibition 16±1mm compared to 17±1mm of chloramphenicol (50 mcg). The antioxidant activity as EC50 value by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity was found to be 1.58 mg/ml while the ferric reducing capacity was measured to be 282.83±19.55 mg FeSO4.7H2O eqvt/g dry wt. of the extract during Ferric Ion Reducing Antioxidant Power (FRAP) Assay. The LC50 value for Brine Shrimp Toxicity Assay was found to be 31.62 ppm. This study shows the medicinal value of the mistletoe associated with Acacia catechu. Further meticulous analysis of this plant might lead to identification of active biomolecules effective as drugs for various ailmentsNepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 60-65


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Marieta Hristozkova ◽  
Liliana Gigova ◽  
Maria Geneva ◽  
Ira Stancheva ◽  
Ivanina Vasileva ◽  
...  

Abstract Mycorrhizal fungi, algae and cyanobacteria are some of the most important soil microorganisms and major components of a sustainable soil-plant system. This study presents for the first time evidence of the impact of green alga and cyanobacterium solely and in combination with arbuscular mycorrhizal fungi (AMF) on plant-antioxidant capacity. In order to provide a better understanding of the impact of AMF and soil microalgae on Ocimum basilicum L. performance, changes in the pattern and activity of the main antioxidant enzymes (AOEs), esterases and non-enzymatic antioxidants including phenols, flavonoids, ascorbate, and α-tocopherols were evaluated. The targeted inoculation of O. basilicum with AMF or algae (alone and in combination) enhanced the antioxidant capacity of the plants and the degree of stimulation varied depending on the treatment. Plants in symbiosis with AMF exhibited the highest antioxidant potential as was indicated by the enhanced functions of all studied leaf AOEs: 1.5-, 2- and more than 10-fold rises of superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GR), respectively. The greatest increase in the total esterase activity and concentration of phenols, flavonoids and ascorbate was marked in the plants with simultaneous inoculation of mycorrhizal fungi and the green algae. 2,2-diphenyl-1-pycril-hydrazyl (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay proved the increased plant antioxidant capacity after co-colonization of green algae and mycorrhizae.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Nichcha Nitthikan ◽  
Pimporn Leelapornpisid ◽  
Surapol Natakankitkul ◽  
Wantida Chaiyana ◽  
Monika Mueller ◽  
...  

The aim of this study was to develop green robusta coffee beans extract loaded nanostructured lipid carriers (NLCs) for enhancing dermal application and its efficiency. The green robusta coffee beans extract cultivated in Chumphon (CP) exhibited the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay with IC50 of 34.1 ± 0.9 µg/ml, lipid peroxidation inhibition with percentage inhibition of 38.8 ± 1.7, and ferric reducing antioxidant power (FRAP) assay with a FRAP value of 234.5 ± 12.3 mM FeSO4/g. The extract contained caffeine, chlorogenic acid, and caffeic acid as major compounds. The anti-inflammatory test indicated that CP could decrease the secretion of IL-6 in macrophage cells and caused no irritation to blood vessels on the irritation test by hen’s egg test chorioallantoic membrane (HET-CAM) assay. The particle size of CP-loaded NLCs was 158.1 ± 0.2 nm with a narrow polydispersity index and showed no noticeable difference after the stability test. Entrapment efficacy of CP-loaded NLCs was found to be over 60%. Caffeine and chlorogenic acid in CP-loaded NLCs were released sustainably and penetrated deeper into the skin than the extract in a conventional emulsion. In conclusion, the CP-loaded NLCs can be further used in cosmetics for dermal applications due to good efficacy and safety.


2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Gordana Zdunic ◽  
Dejan Godjevac ◽  
Katarina Savikin ◽  
Silvana Petrovic

A comparative analysis of the phenolic compounds in the 70% EtOH extracts of Hypericum acutum, H. androsaemum, H. barbatum, H. hirsutum, H. maculatum, and H. richeri has been carried out using high-performance liquid chromatography coupled with photodiode array UV detection and high resolution TOF mass spectrometry. Quercetin, astilbin, I3, II8-biapigenin, orientin, 2”- O-acetylorientin, three phenolcarboxylic acids, and eight flavonols 3- O-glycosides were identified in the extracts on the basis of their on-line UV spectra, accurate mass spectral data, and in comparison of retention times with those from the standards. Fingerprint analysis of the extracts revealed significant differences in the qualitative and quantitative chemical composition of the studied species. Antioxidant assays with various reaction mechanisms were used including ferric reducing antioxidant power (FRAP) assay, DPPH, ABTS, superoxide anion radical scavenging capacity and inhibition of liposome peroxidation induced by Fe2+. The most potent were extracts of H. acutum and H. maculatum indicating this Hypericum species interesting for further research aimed as a potentially new source of biologically active compounds.


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