CARACTÉRISATION DES CHAMPIGNONS MACROSCOPIQUES PAR SPECTROSCOPIE D’ABSORPTION UV-VISIBLE

2021 ◽  
Vol 3 (1) ◽  
pp. CA21A02-1-CA21A02-3
Author(s):  
Tongonmanegde Leonard Ouédraogo ◽  
◽  
Moussa Sougoti ◽  
Sié Zacharie Kam ◽  
Sidiki Zongo ◽  
...  
Keyword(s):  

Dans cet article, nous présentons une étude spectroscopique permettant de différentier les champignons macroscopiques : Russula Congoanan (Rc), Lactifluus gymnocarpoides (Lg) et Amanita amasasiensis (Aa). L’analysedes spectres, acquis par spectrophotométrie d’absorption dans le domaine des UV-visible des extraits obtenus par hydratation de fragment de champignons secs, montre qu’ils se distinguent par leurs pics d’absorption. Les caractéristiques telles que la position, l’intensité ainsi que la largeur à mihauteur changent en fonction de l’espèce de champignon étudié. Ainsi, les extraits des espèces Russula Congoanan (Rc), Lactifluus gymnocarpoides (Lg) et Amanita amasasiensis (Aa) présentent des pics aux longueurs d’ondes de 257nm, 222nm et 242nm respectivement, ou les propriétés électroniques sont attribués aux transitions des liaisons π-π<sup>*</sup> relatives aux polyphénols.

1979 ◽  
Vol 76 ◽  
pp. 273-276 ◽  
Author(s):  
R. Brouillard ◽  
B. Delaporte ◽  
J. M. EL Hage Chahine ◽  
J. E. Dubois
Keyword(s):  

1977 ◽  
Vol 38 (10) ◽  
pp. 1293-1299 ◽  
Author(s):  
U. Giorgianni ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta ◽  
G. Vermiglio
Keyword(s):  

2019 ◽  
Vol 29 (2) ◽  
pp. 189 ◽  
Author(s):  
Tho Truong Nguyen ◽  
Thi Minh Cao ◽  
Hieu Van Le ◽  
Viet Van Pham

The black TiO\(_2\) with substantial Ti\(^3+\) and oxygen vacancies exhibit an excellent photoelectrochemical water-splitting performance due to the improved charge transport the extended visible light response. In this study, black TiO\(_2\) nanotube arrays synthesized by the anodization method, and then, they have been investigated some characterizations by spectroscopic methods such as UV-visible reflectance (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and photoluminescence spectrum. The results showed that some highlighted properties of the black TiO2 nanotube arrays and they could apply for water-splitting effect.


Author(s):  
R. Preethi ◽  
P. Padma

The study focused on the green synthesis of silver nanobioconjugates (AgNPs) from phenolic-rich fruit source, Vitis vinifera seed extract and its major component phenolic, resveratrol respectively. Sunlight exposure for 20 minutes was the method of choice for the synthesis of AgNPs of the extract as well as the phenolic, resveratrol. The synthesized nanobioconjugates were characterized using UV-Visible spectroscopy, Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), Polydispersity index, Zeta potential and Fourier transform infrared spectroscopy (FTIR). The reduction of silver ions was confirmed by UV-visible spectroscopy with peaks at 440nm for both nanobioconjugates synthesized from seed extract and compound. The nanobioconjugates showed the spherical in shape with 14-35nm in size and crystalline in nature. The conjugates are well dispersed with 0.301 and 0.287 polydispersity index and the zeta potential range at -13.6 and -14.3mV for stability. The FTRI data proved that the components in grape seeds act as good reductants and stabilizers for the silver nanobioconjugate synthesis. All the synthesized nanobioconjugates exhibited steady and sustained release of the medicinal components conjugated, proving their druggability, and were biocompatible with human cells, demonstrating their safety. The findings of the study validate the anticancer properties of silver nanobioconjugates of Vitis vinifera and its active component resveratrol.


2020 ◽  
Author(s):  
Riccardo Mobili ◽  
Sonia La Cognata ◽  
Francesca Merlo ◽  
Andrea Speltini ◽  
Massimo Boiocchi ◽  
...  

<div> <p>The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous phase, buffered at pH 7 with HEPES, into dichloromethane. A 1:1 extractant:anion adduct is obtained. Extraction can be easily monitored by following changes in the UV-visible spectrum of the dicopper complex in dichloromethane, and by measuring the residual concentration of succinate in the aqueous phase by HPLC−UV. Considering i) the relevance of polycarboxylates in biochemistry, as e.g. normal intermediates of the TCA cycle, ii) the relevance of dicarboxylates in the environmental field, as e.g. waste products of industrial processes, and iii) the recently discovered role of succinate and other dicarboxylates in pathophysiological processes including cancer, our results open new perspectives for research in all contexts where selective recognition, trapping and extraction of polycarboxylates is required. </p> </div>


2020 ◽  
Vol 3 (1) ◽  
pp. 132-141
Author(s):  
Noverda Ayuchecaria ◽  
◽  
Mochammad Maulidie Alfiannor Saputera ◽  
Rakhmadhan Niah
Keyword(s):  

2016 ◽  
Vol 6 (2) ◽  
pp. 79
Author(s):  
Verawati Verawati ◽  
Afdhil Arel ◽  
Rucita Arfianisa

Metode ekstraksi dapat mempengaruhi komponen kimia dalam suatu ekstrak tanaman.Pada penelitian ini telah dilakukan uji penentuan kadar fenolat total dari daun piladang(Solenostemon scutellarioides (L.) Codd). yang diekstraksi dengan beberapa cara. Metodeekstraksi yang dilakukan antara lain cara tradisional (peremasan dan perebusan) dan ekstraksilaboratorium (sokletasi dan maserasi). Kadar fenolat total ekstrak daun piladang diperolehdengan metode Folin-Ciocalteu dengan menggunakan spektrofotometer UV-Visible. Asam galatdiukur pada panjang gelombang maksimum 758 nm. Kadar fenolat dinyatakan dalam mg setaraasam galat / gr ekstrak. Perolehan kadar fenolat tertinggi oleh sokletasi daun kering 376,5979mg/g, diikuti oleh maserasi daun kering 356,7619 mg/g, sokletasi daun segar 333,1509 mg/g,maserasi daun segar 293,3015 mg/g, rebusan daun segar 216,3534 mg/g, sari remasan 77,3158mg/g, rebusan daun kering 69,3957 mg/g.


Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.


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