scholarly journals Enhancement of the Antioxidant and Antimicrobial Activities of Porphyran through Chemical Modification with Tyrosine Derivatives

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2916
Author(s):  
Pedro Adão ◽  
João Reboleira ◽  
Marco Teles ◽  
Beatriz Santos ◽  
Nádia Ribeiro ◽  
...  

The chemical modification of porphyran hydrocolloid is attempted, with the objective of enhancing its antioxidant and antimicrobial activities. Sulfated galactan porphyran is obtained from commercial samples of the red algae Porphyra dioica using Soxhlet extraction with water at 100 °C and precipitation with isopropyl alcohol. The extracted porphyran is then treated with modified L-tyrosines in aqueous medium in the presence of NaOH, at ca. 70 °C. The modified tyrosines L1 and L2 are prepared through a Mannich reaction with either thymol or 2,4-di-tert-butylphenol, respectively. While the reaction with 2,4-di-tert-butylphenol yields the expected tyrosine derivative, a mixture of products is obtained with thymol. The resulting polysaccharides are structurally characterized and the respective antioxidant and antimicrobial activities are determined. Porphyran treated with the N-(2-hydroxy-3,5-di-tert-butyl-benzyl)-L-tyrosine derivative, POR-L2, presents a noticeable superior radical scavenging and antioxidant activity compared to native porphyran, POR. Furthermore, it exhibited some antimicrobial activity against S. aureus. The surface morphology of films prepared by casting with native and modified porphyrans is studied by SEM/EDS. Both POR and POR-L2 present potential applicability in the production of films and washable coatings for food packaging with improved protecting characteristics.

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2746
Author(s):  
Giuseppe Squillaci ◽  
Carla Zannella ◽  
Virginia Carbone ◽  
Paola Minasi ◽  
Veronica Folliero ◽  
...  

The purpose of the current study was to determine the phenolic composition, antioxidant, and antimicrobial activities in grape cane extracts from typical cultivars of Southern Italy. Aqueous extracts at different pHs (1–13) were prepared from “Aglianico”, “Fiano”, and “Greco” grape canes. The results demonstrated that an alkaline pH (13.00) produced the best polyphenol-rich extracts, as the total phenolic content was more than double when compared to the respective extracts prepared at pH 1.00. “Greco” grape canes gave the highest quantity of phenolic compounds at each pH, ranging from 42.7 ± 0.4 to 104.3 ± 3.0 mg Gallic Acid Equivalents (GAE)/g Dry Extract (DE) from pH 1.00 to 13.00. The Radical Scavenging Activity (RSA) and the Ferric Reducing Antioxidant Power (FRAP) were measured. The highest antioxidant activity was showed by “Greco” extract at pH 7.00. Seventy-five compounds were identified in the extracts by HPLC-MS with six of them described for the first time in grape canes. Procyanidins were highly abundant in extracts at pH 7.00, whereas stilbenoids were the most represented compounds at pH 13.00. Very strong antiviral activity against herpes simplex viruses was recorded for the extracts at pH 7.00 and 13.00 that were active in the early stages of infection by acting directly against the viral particles. The overall results suggest that grape canes, currently underutilized, can be usefully valorised by providing active extracts to use as antioxidant and antiviral agents.


2012 ◽  
Vol 7 (1) ◽  
pp. 1934578X1200700
Author(s):  
Chen-Lung Ho ◽  
Yu-Chang Su

The chemical composition, and antioxidant and antimicrobial activities of the essential oil isolated from the leaf of Machilus japonica from Taiwan have been investigated. The essential oil from the fresh leaves was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of 97 compounds were identified, representing 100% of the oil. The main components identified were α-phellandrene (14.5%), α-pinene (12.8%), thymol (12.6%), β-pinene (8.3%), α-terpineol (6.5%) and carvacrol (6.0%). The antioxidant activity of the oil was tested by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging capability test. The results showed that the IC50 was 51.8 μg/mL. The antimicrobial activity of the oil was tested by the disc diffusion and micro-broth dilution methods against ten microbial species. The oil exhibited strong growth suppression against Gram-positive bacteria and yeast, with inhibition zones of 48~54 mm and MIC values of 16.12~32.25 μg/mL, respectively. For the antioxidant and antimicrobial activities of the oil, the active source compounds were determined to be thymol and carvacrol.


2013 ◽  
Vol 8 (4) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Alper Gökbulut ◽  
Onural Özhana ◽  
Basri Satılmiş ◽  
Kadir Batçioğlu ◽  
Selami Günal ◽  
...  

Three Inula species, I. viscosa, I. helenium ssp. turcoracemosa and I. montbretiana, collected from different locations of Anatolia were investigated for their antioxidant and antimicrobial potential, and their total phenolic content and phenolic composition. Antioxidant activities of various extracts of the plant parts were measured using DPPH radical scavenging and ABTS assays. Antimicrobial potential of methanol extracts of the plant parts was determined by the agar dilution method against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Candida tropicalis. All the extracts were more active against Gram-positive bacteria and yeasts than Gram-negative bacteria. The extracts exhibited antioxidant and antimicrobial activities in different concentrations. Total phenolic concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard. The total phenolic content varied widely in different parts of the three tested Inula species, ranging from 21.1 ± 0.8 to 190.9 ± 6.1 mg GAE/g extract. Phenolic components, such as chlorogenic acid, caffeic acid, rutin, myricetin, quercetin, luteolin and kaempferol were quantified by HPLC-DAD in the methanol extracts of the Inula species. It was obvious that the antioxidant and antimicrobial properties of the plants were due to the phenolics.


2012 ◽  
Vol 67 (5-6) ◽  
pp. 282-290
Author(s):  
Liang Zhu ◽  
Si-ming Zhu ◽  
Ying-juan Tian

Antioxidant and antimicrobial activities of the essential oil and n-hexane (HEE), chloroform (CHE), ethyl acetate (EAE), and methanol (MEE) extracts, respectively, from the root of Saurauia lantsangensis Hu were investigated. The GC-MS analysis revealed 39 compounds representing 96.41% of the oil containing T-muurolol (13.85%), acetophenone (7.46%), α-cadinol (6.26%), methyl palmitate (5.36%), n-hexadecanoic acid (4.31%), torreyol (3.69%), and isospathulenol (3.48%) as major components. Antioxidant activities determined by three various testing systems, i. e. DPPH radical scavenging, superoxide anion radical scavenging, and reducing power assay, increased in the order: HEE < CHE < oil < MEE < EAE. CHE, EAE, MEE and oil exhibited a promising antimicrobial effect determined as the diameter of zones of inhibition (13.3 - 16.2, 16.5 - 20.4, 13.5 - 16.6, and 16.5 - 22.7 mm), respectively, along with their respective MIC values (500 - 1000, 125 - 500, 250 - 500, and 250 - 500 μg/ml) against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), and a yeast (Hansenula anomala).


2020 ◽  
Vol 36 (1) ◽  
pp. 19-30
Author(s):  
Josephine Ofeimun ◽  
James Afolabi ◽  
Ejiro Dowe ◽  
Osayemwenre Erhauyi ◽  
Enitome Bafor ◽  
...  

Afzelia bella Harms (Fabaceae), a plant widely distributed in Africa, is used in traditional medicine for varied disease conditions including the treatment of topical skin infections. The present study investigated the antimicrobial and antioxidant activities of the methanol extract and various solvent fractions of the leaves of the plant. The methanol leaf extract was partitioned to yield petroleum ether, chloroform, ethyl acetate and residual aqueous fractions. Total phenol and flavonoid contents, radical scavenging activity and ferric reduction antioxidant power (FRAP) were determined by spectrophotometry, while antimicrobial activity and minimum inhibitory concentration (MIC) of the extract and fractions were determined using agar-well diffusion and agar dilution methods, respectively against clinical bacterial isolates of Bacillus subtilis, Escherishia coli, Klebsiella pneumoniae, Staphylococcus aureus, and fungi, Aspergillus flavus, Candida parapsilosis, Microsporium audiounii. Bacillus subtilis was the most susceptible among the bacterial strains tested, while Microsporium audiounii was the most susceptible fungus. The alcoholic extract and all solvent fractions demonstrated a concentration dependent antimicrobial activity with inhibition zone diameter range of 7.5 to 35.0 mm. MIC ranged from 0.1 - 8 mg/ml and activity was highest in ethyl acetate fraction with MIC of 0.1 mg/ml. FRAP ranged from 0.161 - 0.319 mmol Fe2+/g extract and was highest in the ethyl acetate fraction. These results give an indication that A. bella leaf has high antioxidant and antimicrobial activities and support the folkloric claim of the therapeutic potential of the plant. Keywords: antioxidant, antimicrobial, ethnomedicine, Afzelia bella, Fabaceae 


2021 ◽  
Vol 45 (2) ◽  
pp. 223-231
Author(s):  
Kara Guzel ◽  
Mahmut Ulger ◽  
Ahmet Kahraman

The phytochemical contents of Salvia virgata mericarps and the antioxidant and antimicrobial activities of its ethanol extract were studied for the first time. S. virgata mericarps were collected in the province of Trabzon, Turkey. Chemical analyses were performed using chromatographic methods. The total phenolic and flavonoid contents and antioxidant potential were measured using Folin-Ciocalteu, Al(NO3)3, and DPPH radical scavenging activity methods, respectively. The antimicrobial activity was evaluated using the microdilution method for all the tested bacterial and fungal strains, with the exception of Mycobacterium tuberculosis for which the resazurin microtiter plate method was applied. The mericarps were rich in glutamic acid (3934 mg/100 g), potassium (12578.8 ?g/g), calcium (12092.0 ?g/g), and dietary fibers (35.565 g/100 g). The total phenolic and flavonoid contents were 2.50 ?g GAE/mg extract and 0.34 ?g QE/mg extract, respectively. The most effective DPPH free radical scavenging activity determined for the highest applied concentration was 92.44%. The ethanol extract obtained from the mericarps was found to be as effective as the reference drug ampicillin (MIC value = 125 ?g/mL) against the nosocomial pathogen Acinetobacter baumannii. In conclusion, S. virgata mericarps provide good nutritional value with low amounts of carbohydrates and high dietary fibers, amino acids, minerals and total phenolic and flavonoid contents and medicinal properties.


Author(s):  
SIRIKHWAN TINRAT

Objective: To screen phytochemical compounds and study antioxidant and antimicrobial activities of Pluchea indica (L.) Less (PI) leaves extracts for assessment the moisturizing lotion bar formulation containing it’s as a bioactive ingredient. Methods: PI leaves were extracted in different solvents. Crude extracts were screened phytochemical compounds and evaluated antioxidant and antimicrobial activities before formulating to antibacterial moisturizing lotion bar. Results: 95% ethanolic extract displayed high antioxidant activities. DPPH radical scavenging capacity with IC50 was 6.80±0.04 mg/ml (61.37±0.41%) and the ferric reducing ability power was 381.20±0.10 mg AAE/100 gDW. Additionally, 95% ethanolic extract served as a broad spectrum bacteriostatic agents against gram-positive and gram-negative species with an inhibition zone of 6.50±0.00-46.67±0.58 mm. It also was simultaneously as a broad spectrum bactericidal agents (MIC and MBC value of 25-200 mg/ml) by broth micro-dilution method. The screened phytochemical constituents (saponins, tannins, flavonoids, terpenoids, steroids, and alkaloids) in PI leaves extract may be responsible for high biological activities. Thus, 95% ethanolic extract was the most appropriate bioactive ingredient for formulated the product development. Conclusion: The developed moisturizing lotion bar with 0.0041% of 95% ethanolic extract was the most eligible formula that showed good appearance, odor, color, homogeneity, after feel and stability. This extract-containing lotion bar formulation achieved a high level of customer satisfaction by sensory evaluation and development of this specific formulation should be subject to further clinical investigation.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1565
Author(s):  
Kang Hyun Lee ◽  
Youngsang Chun ◽  
Ye Won Jang ◽  
Soo Kweon Lee ◽  
Hyeong Ryeol Kim ◽  
...  

Carbon-neutral and eco-friendly biomass-based processes are recognized as a frontier technology for sustainable development. In particular, biopolymers are expected to replace petrochemical-based films that are widely used in food packaging. In this study, the fabrication conditions of functional (antioxidant and antibacterial) bioelastomers were investigated using by-products from the juice processing (experimental group) and freeze-dried whole fruit (control group). Bioelastomer was fabricated by a casting method in which polydimethylsiloxane (PDMS) was mixed with 25 or 50 wt% aronia powder (juice processing by-products and freeze-dried whole fruit). The mechanical properties of the bioelastomers were measured based on tensile strength and Young’s modulus. When the mixture contained 50 wt% aronia powder, the strength was not appropriate for the intended purpose. Next, the surface and chemical properties of the bioelastomer were analyzed; the addition of aronia powder did not significantly change these properties when compared to PDMS film (no aronia powder). However, the addition of aronia powder had a significant effect on antioxidant and antimicrobial activities and showed higher activity with 50 wt% than with 25 wt%. In particular, bioelastomers fabricated from aronia juice processing by-products exhibited approximately 1.4-fold lower and 1.5-fold higher antioxidant and antimicrobial activities, respectively, than the control group (bioelastomers fabricated from freeze-dried aronia powder).


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jaiprakash Sharanappa Biradar ◽  
Parveen Rajesab ◽  
Naveen Jaiprakash Biradar ◽  
Sasidhar Balappa Somappa

A new series of novel triazolothiadiazepinylindole analogues were synthesized with an aim to examine possible antioxidant and antimicrobial activities. The titled compounds (3a–z) were obtained in good yield by reacting 5-(5-substituted-3-phenyl-1H-indol-2-yl)-4-amino-4H-1,2,4-triazole-3-thiols1a–cwith 3-(2,5-disubstituted-1H-indol-3-yl)-1(4-substituted phenyl)prop-2-en-1-ones2a–i. All the newly synthesized compounds were characterized by IR,1H NMR, mass spectroscopic and analytical data. The synthesized analogues were tested for antioxidant and antimicrobial potency. Among the tested compounds3a–cand3j–lhave shown very promising free radical scavenging activity and total antioxidant capacity. Compounds3d–f,3m–o, and3s–zhave shown excellent ferric reducing antioxidant activity. An outstanding antimicrobial activity is observed with compounds3a–cand3j–l.


Sign in / Sign up

Export Citation Format

Share Document