scholarly journals Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 746
Author(s):  
Claudia Valverde Malaver ◽  
Ana Colmenares Dulcey ◽  
Carlos Rial ◽  
Rosa Varela ◽  
José Molinillo ◽  
...  

A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl β-xylopyranosyl-(1”-6’)-β-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known compounds reported for the first time in the Meriania genus. The structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry. The bioactivities of the compounds were determined by measuring the DPPH radical scavenging activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato). Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of 2.0 and 1.9 µM, respectively.

2018 ◽  
Vol 13 (9) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Hawraz Ibrahim M. Amin ◽  
Faiq H. S. Hussain ◽  
Marcello Maggiolini ◽  
Giovanni Vidari

In the first phytochemical investigation of non-volatile secondary metabolites from the Kurdish traditional plant Iris persica L, (-)-embinin was isolated from flowers and leaves, isovitexin from flowers, trans-resveratrol-3- O-β-D-glucopyranoside from rhizomes and tectorigenin from bulbs. The complete NMR spectra of embinin are reported for the first time. In an MTT assay, embinin showed an inhibition activity higher than the well-known antitumor drug cisplatin against five of the six tested human tumor cells. Moreover, embinin showed a significant DPPH radical scavenging activity (IC50 value of 112.16) comparable to the reference antioxidant ascorbic acid. The remarkable biological activities exhibited by the extracts of Iris persica and isolated compounds have validated the uses of I. persica in the traditional medicine of Kurdistan.


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.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2033
Author(s):  
Chuleeporn Bungthong ◽  
Sirithon Siriamornpun

Silk proteins have many advantageous components including proteins and pigments. The proteins—sericin and fibroin—have been widely studied for medical applications due to their good physiochemical properties and biological activities. Various strains of cocoon display different compositions such as amino-acid profiles and levels of antioxidant activity. Therefore, the objectives of this study were to find a suitable silk protein extraction method to obtain products with chemical and biological properties suitable as functional foods in two strains of Bombyx mori silk cocoon (Nangsew strains; yellow cocoon) and Samia ricini silk cocoon (Eri strains; white cocoon) extracted by water at 100 °C for 2, 4, 6 and 8 h. The results showed that Nangsew strains extracted for 6 h contained the highest amounts of protein, amino acids, total phenolics (TPC) and total flavonoids (TFC), plus DPPH radical-scavenging activity, ABTS radical scavenging capacity, and ferric reducing antioxidant power (FRAP), anti-glycation, α-amylase and α-glucosidase inhibition. The longer extraction time produced higher concentrations of amino acids, contributing to sweet and umami tastes in both silk strains. It seemed that the bitterness decreased as the extraction time increased, resulting in improvements in the sweetness and umami of silk-protein extracts.


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.


2020 ◽  
Vol 21 (9) ◽  
pp. 3087 ◽  
Author(s):  
Katarína Ražná ◽  
Zuzanna Sawinska ◽  
Eva Ivanišová ◽  
Nenad Vukovic ◽  
Margarita Terentjeva ◽  
...  

The aim of this study was to characterize extracts from the leaves of Ginkgo biloba L. from selected Slovakian localities in terms of the content of bioactive constituents, antioxidants and their antimicrobial properties. The results indicated that the content of antioxidants was sample-specific, and this specificity was statistically significant. Ginkgo biloba L. from the locality of Košice had the best activity determined by the free radical scavenging activity (DPPH) (1.545 mg Trolox equivalent antioxidant capacity (TEAC)/g fresh matter (FM)) as well as the molybdenum-reducing antioxidant power (35.485 mg TEAC/g FM) methods. The highest content of total polyphenols (2.803 mg gallic acid equivalent (GAE)/g FM) and flavonoids (4.649 μg quercetin equivalent (QE)/g FM) was also detected in this sample. All samples of G. biloba leaf extracts showed significant antimicrobial activity against one or more of the examined bacterial species, and Staphylococcus aureus subsp. aureus CCM 2461 was found to be the most susceptible (minimal inhibition concentration MIC50 and MIC90 values of 64.2 and 72.2 µg/mL, respectively). Based on the results it was concluded that Ginkgo biloba L. extracts can be used as antimicrobial and antioxidant additives. Selected miRNA-based molecular markers were used to examine the environmental adaptability of Ginkgo biloba L. An almost-complete genotype clustering pattern based on locality was determined in the analysis that involved a species-specific gb-miR5261 marker. Morphologically specific exemplar, cv. Ohatsuki, was excluded.


Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 632 ◽  
Author(s):  
Gabriele Rocchetti ◽  
Biancamaria Senizza ◽  
Gokhan Zengin ◽  
Murat Ali Okur ◽  
Domenico Montesano ◽  
...  

Like other members of the Colchicum genus, C. szovitsii subsp. szovitsii is also of medicinal importance in Turkish traditional medicine. However, its biological properties have not been fully investigated. Herein, we focused on the evaluation of the in vitro antioxidant and enzyme inhibitory effects of flower, root and leaf extracts, obtained using different extraction methods. In addition, a comprehensive (poly)-phenolic and alkaloid profiling of the different extracts was undertaken. In this regard, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) allowed us to putatively annotate 195 polyphenols and 87 alkaloids. The most abundant polyphenols were flavonoids (83 compounds), whilst colchicine and 2-demethylcolchicine were some of the most widespread alkaloids in each extract analyzed. However, our findings showed that C. szovitsii leaf extracts were a superior source of both total polyphenols and total alkaloids (being, on average 24.00 and 2.50 mg/g, respectively). Overall, methanolic leaf extracts showed the highest (p < 0.05) ferric reducing antioxidant power (FRAP) reducing power (on average 109.52 mgTE/g) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging (on average 90.98 mgTE/g). Interestingly, each C. szovitsii methanolic extract was more active than the water extracts when considering enzymatic inhibition such as against tyrosinase, glucosidase, and acetylcholinesterase (AChE). Strong correlations (p < 0.01) were also observed between polyphenols/alkaloids and the biological activities determined. Multivariate statistics based on supervised orthogonal projections to latent structures discriminant analysis (OPLS-DA) allowed for the detection of those compounds most affected by the different extraction methods. Therefore, this is the first detailed evidence showing that C. szovitsii subsp. szovitsii might provide beneficial effects against oxidative stress and the associated chronic diseases. Nevertheless, the detailed mechanisms of action need to be further investigated.


2018 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Riza Shabrina ◽  
Berna Elya ◽  
Arikadia Noviani

Objective: This study aimed to fractionate the antioxidant activity of the ethyl acetate leaf extract and to characterize the most active fractionsaccording to compound groups.Methods: The ethyl acetate extract was fractionated with column chromatography using a gradient elution system. Fractions were first screenedqualitatively for antioxidant activity before active fractions were quantified with respect to in vitro antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the ferric-reducing antioxidant power (FRAP) assay. The compound groups were identifiedfollowing separation by thin-layer chromatography.Results: Fraction 11 exhibited the greatest DPPH radical-scavenging activity, with an IC50 value of 6.58 μg/mL, while the fraction with the greatestantioxidant activity according to the FRAP assay was fraction 10, with a ferric ion equivalent antioxidant activity value of 1015.34 μmol/g.Conclusion: Compound group identification revealed that Fractions 10 and 11 contained flavonoids, with two common to both fractions, whilefraction 10 also contained one specific flavonoid.


Author(s):  
Ved Prakash ◽  
Shelly Rana ◽  
Anand Sagar

The current study was designed to investigate the leaf extracts of Vitex negundo Linn. for their antioxidant and enzyme inhibitory (α-amylae and urease) activity. The antioxidant capacity of the different extracts (methanol, acetone and aqueous) of this plant was evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl) and reducing power tests. The plant exhibited good DPPH radical scavenging activity and moderate reducing power potential Further, all the extracts of V. negundo were reported to possess good anti-alpha amylase and anti-urease activity of greater than 50% in all the solvents used at a concentration of 1 mg/mL. Thus the study provided scientific evidence to the traditional uses of this plant in the treatment of obesity, diabetes, ulcers, kidney stones etc. Therefore, the leaf extracts of this plant can be selected for further investigation to determine their therapeutic potential.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 457 ◽  
Author(s):  
Biancamaria Senizza ◽  
Gabriele Rocchetti ◽  
Murat Ali Okur ◽  
Gokhan Zengin ◽  
Evren Yıldıztugay ◽  
...  

In this work, the phytochemical profile and the biological properties of Colchicum triphyllum (an unexplored Turkish cultivar belonging to Colchicaceae) have been comprehensively investigated for the first time. Herein, we focused on the evaluation of the in vitro antioxidant and enzyme inhibitory effects of flower, tuber, and leaf extracts, obtained using different extraction methods, namely maceration (both aqueous and methanolic), infusion, and Soxhlet. Besides, the complete phenolic and alkaloid untargeted metabolomic profiling of the different extracts was investigated. In this regard, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) allowed us to putatively annotate 285 compounds when considering the different matrix extracts, including mainly alkaloids, flavonoids, lignans, phenolic acids, and tyrosol equivalents. The most abundant polyphenols were flavonoids (119 compounds), while colchicine, demecolcine, and lumicolchicine isomers were some of the most widespread alkaloids in each extract analyzed. In addition, our findings showed that C. triphyllum tuber extracts were a superior source of both total alkaloids and total polyphenols, being on average 2.89 and 10.41 mg/g, respectively. Multivariate statistics following metabolomics allowed for the detection of those compounds most affected by the different extraction methods. Overall, C. triphyllum leaf extracts showed a strong in vitro antioxidant capacity, in terms of cupric reducing antioxidant power (CUPRAC; on average 96.45 mg Trolox Equivalents (TE)/g) and ferric reducing antioxidant power (FRAP) reducing power (on average 66.86 mg TE/g). Interestingly, each C. triphyllum methanolic extract analyzed (i.e., from tuber, leaf, and flower) was active against the tyrosinase in terms of inhibition, recording the higher values for methanolic macerated leaves (i.e., 125.78 mg kojic acid equivalent (KAE)/g). On the other hand, moderate inhibitory activities were observed against AChE and α-amylase. Strong correlations (p < 0.01) were also observed between the phytochemical profiles and the biological activities determined. Therefore, our findings highlighted, for the first time, the potential of C. triphhyllum extracts in food and pharmaceutical applications.


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