scholarly journals Physicochemical Characterization and Antimicrobial Activity against Erwinia amylovora, Erwinia vitivora, and Diplodia seriata of a Light Purple Hibiscus syriacus L. Cultivar

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1876
Author(s):  
Eva Sánchez-Hernández ◽  
Laura Buzón-Durán ◽  
Belén Lorenzo-Vidal ◽  
Jesús Martín-Gil ◽  
Pablo Martín-Ramos

Phytochemicals are essential raw materials for the production of formulations that can be helpful in crop protection. In particular, Hibiscus spp., which are often used in traditional medicine, are rich in potential bioactive molecules. This study presents an analysis of the thermal, vibrational, and phytochemical characteristics of a light purple variety of Hibiscus syriacus, using thermal gravimetric and differential scanning calorimetry, Fourier-transform infrared spectroscopy, and gas chromatography-mass spectroscopy techniques. Further, with a view to its valorization, the antimicrobial activity of its extracts has been investigated in vitro against Erwinia amylovora (the phytopathogen responsible for fire blight in apples, pears, and some other members of the family Rosaceae), Erwinia vitivora (the causal agent of the “maladie d’Oléron” in grapevines), and Diplodia seriata (responsible for “Bot canker”). Higher heating values and thermal features showed similarities with kenaf biomass. The main compounds identified in the hydro-methanolic extracts were: in flowers, 1-heptacosanol, heptacosane, 1-tetracosanol, hexadecenoic acid, 9,12,15-octadecatrienoic acid, and 9,12-octadecadienoic acid; and in leaves, the coumarin derivative 4,4,6,8-tetramethyl-2-chromanone, vitamin E, phytol, and sitosterol. MIC values of 500 and 375 μg·mL−1 were obtained against E. amylovora for flower and leaf extracts, respectively, upon conjugation with chitosan oligomers (to improve solubility and bioavailability). In the case of E. vitivora, MIC values of 250 and 500 μg·mL−1, respectively, were registered. Regarding the antifungal activity, EC90 values of 975.8 and 603.5 μg·mL−1, respectively, were found. These findings suggest that H. syriacus (cv. ‘Mathilde’) may be a promising source of antimicrobials for agriculture.

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1852
Author(s):  
Eva Sánchez-Hernández ◽  
Laura Buzón-Durán ◽  
Natalia Langa-Lomba ◽  
José Casanova-Gascón ◽  
Belén Lorenzo-Vidal ◽  
...  

The work presented herein deals with the characterization and valorization of a halophyte from the cliffs of the Asturian coast: Limonium binervosum (G.E.Sm.) C.E.Salmon (rock sea-lavender). Its biomass and hydromethanolic extracts were studied by elemental and thermal analysis, infrared spectroscopy and gas chromatography–mass spectroscopy. Tetradecanoic acid/esters and 1,2-tetradecanediol were identified in its flower extract, while the leaf extract was rich in linolenic and linoleic acids and their esters, hexadecanoic acid and its esters, and phytol. Both flower and leaf hydromethanolic extracts contained eicosane, sitosterol and tocopherols in significant amounts. With a view to its valorization, the antimicrobial activity of these extracts was investigated against three apple tree and grapevine phytopathogens. Both the hydroalcoholic extracts and their main constituents, alone or in combination with chitosan oligomers (COS), were tested in vitro. A remarkable antibacterial activity was observed for the conjugated complexes of the flower extract with COS, both against Xylophilus ampelinus (MIC = 250 μg·mL−1) and Erwinia amylovora (MIC = 500 μg·mL−1), and complete inhibition of the mycelial growth of Diplodia seriata was found at concentrations <1000 μg·mL−1. In view of these results, this extremophile plant can be put forward as a promising source of bioactive metabolites.


Author(s):  
Meka Lingam ◽  
Vobalaboina Venkateswarlu

The low aqueous solubility of celecoxib (CB) and thus its low bioavailability is a problem.    Thus, it is suggested to improve the solubility using cosolvency and solid dispersions techniques. Pure CB has solubility of 6.26±0.23µg/ml in water but increased solubility of CB was observed with increasing concentration of cosolvents like PEG 400, ethanol and propylene glycol. Highest solubility (791.06±15.57mg/ml) was observed with cosolvency technique containing the mixture of composition 10:80:10%v/v of water: PEG 400: ethanol. SDs with different polymers like PVP, PEG were prepared and subjected to physicochemical characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), solubility and dissolution studies. These studies reveals that CB exists mainly in amorphous form in prepared solid dispersions of PVP, PEG4000 and PEG6000 further it can also be confirmed by solubility and dissolution rate studies. Solid dispersions of PV5 and PV9 have shown highest saturation solubility and dissolution rate


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1643
Author(s):  
Ricardo Donate ◽  
María Elena Alemán-Domínguez ◽  
Mario Monzón

Surface modification of 3D-printed PLA structures is a major issue in terms of increasing the biofunctionality and expanding the tissue engineering applications of these parts. In this paper, different exposure times were used for low-pressure oxygen plasma applied to PLA 3D-printed scaffolds. Alkali surface treatments were also evaluated, aiming to compare the modifications introduced on the surface properties by each strategy. Surface-treated samples were characterized through the quantification of carboxyl groups, energy-dispersive X-ray spectroscopy, water contact angle measurements, and differential scanning calorimetry analysis. The change in the surface properties was studied over a two-week period. In addition, an enzymatic degradation analysis was carried out to evaluate the effect of the surface treatments on the degradation profile of the 3D structures. The physicochemical characterization results suggest different mechanism pathways for each type of treatment. Alkali-treated scaffolds showed a higher concentration of carboxyl groups on their surface, which enhanced the enzymatic degradation rate, but were also proven to be more aggressive towards 3D-printed structures. In contrast, the application of the plasma treatments led to an increased hydrophilicity of the PLA surface without affecting the bulk properties. However, the changes on the properties were less steady over time.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2930
Author(s):  
Jelena Šuran ◽  
Ivica Cepanec ◽  
Tomislav Mašek ◽  
Božo Radić ◽  
Saša Radić ◽  
...  

Propolis is a honeybee product known for its antioxidant, anti-inflammatory, anticancer, and antimicrobial effects. It is rich in bioactive molecules whose content varies depending on the botanical and geographical origin of propolis. These bioactive molecules have been studied individually and as a part of propolis extracts, as they can be used as representative markers for propolis standardization. Here, we compare the pharmacological effects of representative polyphenols and whole propolis extracts. Based on the literature data, polyphenols and extracts act by suppressing similar targets, from pro-inflammatory TNF/NF-κB to the pro-proliferative MAPK/ERK pathway. In addition, they activate similar antioxidant mechanisms of action, like Nrf2-ARE intracellular antioxidant pathway, and they all have antimicrobial activity. These similarities do not imply that we should attribute the action of propolis solely to the most representative compounds. Moreover, its pharmacological effects will depend on the efficacy of these compounds’ extraction. Thus, we also give an overview of different propolis extraction technologies, from traditional to modern ones, which are environmentally friendlier. These technologies belong to an open research area that needs further effective solutions in terms of well-standardized liquid and solid extracts, which would be reliable in their pharmacological effects, environmentally friendly, and sustainable for production.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.


Author(s):  
Annie A. Cerón ◽  
Lorrane Nascife ◽  
Samuel Norte ◽  
Silgia A. Costa ◽  
José Heriberto Oliveira do Nascimento ◽  
...  

2018 ◽  
Vol 7 (3) ◽  
pp. 122-129
Author(s):  
Fatma Youcefi ◽  
Ali Riazi ◽  
Meriem Mokhtar ◽  
Tefiani Choukri ◽  
Khaouani Naima

Chitosan is the most abundant natural organic polymer in nature. Its positive charge and its molecular arrangement confer interesting properties on the plane food, pharmaceutical, medical, cosmetic, water treatment. The present study was undertaken to study the physiochemical parameters and the in vitro antimicrobial activity of chitosan extracted from shrimp shells waste. The molecular weight of chitosan is 1414.33±16.99 kDa with, the percent of Ash 0,345±0,040 %, moisture is 2,98 ±0,13 % , and protein is 0.3 ±0,041 %.Chitosan produced (5 %) was also characterized with Fourier Transform Infrared Spectroscopy (FTIR) the spectrum of the chitosan sample from the shell recorded 16 peaks in the range of 689.40/cm and 3430.02 /cm. The antibacterial and antifungul activities of chitosan were examined against Escherichia coli ATCC10536, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC7644, Staphylococcus aureus ATCC29213, Aspergillus niger ATCC 16888 and Candida albicans ATCC 10231 by agar wells diffusion the tests inhibitions zones diameters were 49,74± 0,75 , 54,35±0,93 , 42,27±1,07 , 32,95±0,28 and 53,73±0,64mm respectively. The minimum inhibitory concentration (MIC) using a broth microdilution method against tested microorganisms was ranging from 008% to 1.22%. These results open interesting perspectives of the chitosan. It can be used as new biomaterial with utility in many industrial areas.


2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.


2008 ◽  
Vol 33 (1) ◽  
pp. 1-3
Author(s):  
Shinkichi Tawata ◽  
Yoshihisa Ozoe ◽  
Hisashi Miyagawa

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 241 ◽  
Author(s):  
Walter Ferreira da Silva Júnior ◽  
Danielle Lima Bezerra de Menezes ◽  
Luana Carvalho de Oliveira ◽  
Letícia Scherer Koester ◽  
Patrícia Danielle Oliveira de Almeida ◽  
...  

α, β amyrin (ABAM) is a natural mixture of pentacyclic triterpenes that has a wide range of biological activities. ABAM is isolated from the species of the Burseraceae family, in which the species Protium is commonly found in the Amazon region of Brazil. The aim of this work was to develop inclusion complexes (ICs) of ABAM and β-cyclodextrin (βCD) and hydroxypropyl-β-cyclodextrin (HPβCD) by physical mixing (PM) and kneading (KN) methods. Interactions between ABAM and the CD’s as well as the formation of ICs were confirmed by physicochemical characterization in the solid state by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). Physicochemical characterization indicated the formation of ICs with both βCD and HPβCD. Such ICs were able to induce changes in the physicochemical properties of ABAM. In addition, the formation of ICs with cyclodextrins showed to be an effective and promising alternative to enhance the anti-inflammatory activity and safety of ABAM.


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