scholarly journals Antifungal Activity and Fourier Transform Infrared Spectrometric Characterization of Aqueous Extracts of Acacia senegal and Acacia tortilis on Phytopathogenic Fungi

2019 ◽  
pp. 1-11
Author(s):  
Al-Otibi Fatimah
Keyword(s):  
Fourier Transform ◽  
Antifungal Activity ◽  
Functional Groups ◽  
Aqueous Extract ◽  
Phytopathogenic Fungi ◽  
Aqueous Extracts ◽  
Acacia Tortilis ◽  
Acacia Senegal ◽  
High Concentrations ◽  
Scanning Electron

Objective: To evaluate the in vitro antifungal activity of aqueous extracts of Acacia senegal (A. senegal) and Acacia tortilis (A. tortilis) against three phytopathogenic fungi (viz., Alternaria alternata [A. alternata], Helminthosporium rostratum [H. rostratum] and Fusarium solani [F. solani]). Methods: Crude aqueous extracts of A. senegal and A. tortilis at 1%, 2.5% and 5% concentrations were used for screening. Antifungal activities of the extracts were evaluated against three phytopathogenic fungal strains (A. alternata, H. rostratum and F. solani) by poisoned food technique. Scanning electron microscopy (SEM) of the treated and untreated mycelia was employed to analyze the ultrastructural changes and Fourier-transform infrared (FTIR) spectrometry analysis was performed to identify important functional groups. Results: Aqueous extract of A. tortilis at high concentrations exhibited moderate inhibitory activity against the selected fungal strains. The aqueous extract of A. senegal showed no effect on A. alternata, while exhibited very mild activity against H. rostratum and F. solani at high concentrations (2.5% and 5%). Scanning electron microphotographs of the untreated fungal cells showed no structural changes (well‒defined mycelium and conidia without any distortion), whereas the treated cells showed structural distortions, twisted and wrecked mycelia and showed the presence of vesicles on the surface. FTIR analysis showed the presence of important functional groups such as alcohols, carboxylic acids and aromatic compounds. Conclusion: Results from this study indicate that the aqueous extracts of both A. senegal and A. tortilis have the potential to be used as natural fungicidal agents in the management of diseases caused by plant pathogenic fungi.

scholarly journals Underlying Mechanisms of Anti-spasmodic, Antidiarrheal, Antioxidant and Acute Toxicity Assessments of Aqueous Extract of Mentha Suaveolens Ehrh and its Fourier Transform Infra-red Spectroscopy Analysis

2020 ◽  
pp. 37-54
Author(s):  
EL-Akhal Jamila ◽  
Chda Alae ◽  
Tazi Abdelali ◽  
Boukir Abdelatif ◽  
Bencheikh Rachid
Keyword(s):  
Fourier Transform ◽  
Animal Models ◽  
Functional Groups ◽  
Aqueous Extract ◽  
Castor Oil ◽  
Butylated Hydroxytoluene ◽  
Calcium Antagonism ◽  
Small Intestinal Transit ◽  
Infra Red ◽  
Underlying Mechanisms

Objective: The aim of this present study is to investigate the antidiarrheal, spasmolytic and antioxidant activities of aqueous extract of Mentha suaveolens Ehrh (AEMS), to study their underlying mechanisms in animal models and to reveal its main functional groups using Fourier Transform Infra-Red Spectroscopy (FTIR). Methods: Mentha suaveolens Ehrh was studied for antidiarrheal activity on Wistar rats of both sexes at the doses of 200 and 800 mg/kg body weight using castor oil-induced diarrhea, castor oil-induced enteropooling and small intestinal transit models. The extract was studied for antispasmodic property in isolated rabbit jejunum using various spasmogenic agents including Ach (10-5M), KCl (100 mM) and in the absence and in the presence of L-NAME (10-4 M) and the methylene blue (10-5 M).The antioxidant capacity of AEMS was carried out using DPPH radical scavenging activity and the ferric reducing antioxidant potential (FRAP). Ascorbic acid and Butylated HydroxyToluene (BHT) were used as references. The functional chemical groups were determined by FTIR. Results: The great antidiarrheal potential of AEMS seems to be mediated through calcium antagonism. The marked and concentration-dependent induced spasmolytic effect of AEMS appears to involve Ca2+ voltage channel blockade and the NO/cGMP pathway activation. AEMS possessed strong and concentration-dependent antioxidant potency using DPPH and FRAP. Polyphenols, carboxyl and carbohydrates were found to be the main functional groups in the AEMS analyzed by FTIR. Conclusion: Overall, our current findings provide scientific proves in animal models for the traditional use of AEMS in folk medicine for the prevention or the treatment of gastrointestinal diseases in Morocco.

scholarly journals Comparative Study of Carbon Nanosphere and Carbon Nanopowder on Viscosity and Thermal Conductivity of Nanofluids

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 608
Author(s):  
Thong Le Ba ◽  
Marcell Bohus ◽  
István Endre Lukács ◽  
Somchai Wongwises ◽  
Gyula Gróf ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Fourier Transform ◽  
Photoelectron Spectroscopy ◽  
Comparative Research ◽  
Base Fluid ◽  
X Ray ◽  
Ft Ir ◽  
High Concentrations ◽  
Scanning Electron

A comparative research on stability, viscosity (µ), and thermal conductivity (k) of carbon nanosphere (CNS) and carbon nanopowder (CNP) nanofluids was performed. CNS was synthesized by the hydrothermal method, while CNP was provided by the manufacturer. Stable nanofluids at high concentrations 0.5, 1.0, and 1.5 vol% were prepared successfully. The properties of CNS and CNP nanoparticles were analyzed with Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area (SBET), X-ray powder diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), and energy dispersive X-ray analysis (EDX). The CNP nanofluids have the highest k enhancement of 10.61% for 1.5 vol% concentration compared to the base fluid, while the CNS does not make the thermal conductivity of nanofluids (knf) significantly higher. The studied nanofluids were Newtonian. The relative µ of CNS and CNP nanofluids was 1.04 and 1.07 at 0.5 vol% concentration and 30 °C. These results can be explained by the different sizes and crystallinity of the used nanoparticles.

scholarly journals Étude botanique, tri phytochimique et évaluation in vitro de l’activité antifongique des extraits de feuilles de Mallotus oppositifolius (Geisel.) Müll. Arg (Euphorbiaceae) sur Fusarium sp. et Phytophthora sp. deux champignons phytopathogènes

2019 ◽  
Vol 41.2 ◽  
pp. 6903-6915
Author(s):  
SARAKA Allou Isidore ◽  
ABO Kouabenan ◽  
OUATTARA Katinan Etienne ◽  
ZIRIHI Guédé Noël
Keyword(s):  
Antifungal Activity ◽  
Skin Diseases ◽  
Phytopathogenic Fungi ◽  
Dilution Method ◽  
Aqueous Extracts ◽  
Phytochemical Screening ◽  
Ethanolic Extracts ◽  
Fusarium Sp ◽  
Extraits Aqueux

L’objectif de ce travail est d’évaluer le pouvoir fongicide des feuilles de Mallotus oppositifolius sur Phytophthora sp. et Fusarium sp. deux champignons phytopathogènes dans le cadre de la recherche de substances naturelles d’origine végétale comme alternative aux pesticides chimiques en agriculture. Une enquête ethnobotanique réalisée auprès de quarante tradipraticiens de santé du District de Yamoussoukro sur les Euphorbiaceae médicinales a permis d’identifier treize espèces. L’étude a montré que les maladies de la peau (36%) étaient majoritairement traitées par ces Euphorbiaceae dont Mallotus oppositifolius. Au vue de ces données et celles de la littérature, Mallotus oppositifolius a été retenu pour l’évaluation du potentiel antifongique contre Fusarium sp. et Phytophthora sp. L'activité antifongique a été évaluée par la méthode de double dilution sur milieu PDA avec des extraits éthanoliques et aqueux dérivés des feuilles de cette plante. Les résultats ont montré que les extraits aqueux et éthanoliques 70% de Mallotus oppositifolius possèdent des propriétés antifongiques à la fois sur Fusarium sp. et Phytophthora sp. Les activités antifongiques ont été plus importantes avec les extraits éthanoliques qu’avec les extraits aqueux. Avec une concentration minimal inhibitrice CMI = 25±0,0 mg/mL, une CI50 = 6,5±0,05 mg/mL et une concentration minimal fongicide CMF = 200±0,0 mg/mL Fusarium sp. semble être le plus sensible. Phytophthora sp. est moins sensible avec une CMI = 50±0,0 mg/mL, une CI50 = 12±0,05 mg/mL et une CMF = 200±0,0 mg/mL. Le screening phytochimique a mis en évidence la présence de sept groupes de composés parmi lesquels les alcaloïdes, les polyterpènes et stérols, les tanins galliques et les catéchines sont les plus abondants dans les extraits éthanoliques. En plus de ces composés, les flavonoïdes, les polyphénols ainsi que les saponines sont aussi bien présents dans les extraits aqueux que dans les extraits alcooliques de Mallotus oppositifolius. Ces composés pourraient justifier l’activité des extraits éthanoliques de Mallotus oppositifolius. Ces résultats peuvent servir pour les recherches agronomiques dans le cadre de la lutte contre les deux champignons phytopathogènes étudiés. Botanical study, phytochemical screening and in vitro evaluation of the antifungal activity of Mallotus oppositifolius (Geisel.) Müll. Arg. (Euphorbiaceae) leaf extracts on Fusarium sp. and Phytophthora sp., two phytopathogenic fungi. ABSTRACT The purpose of this work is to evaluate the fungicidal power of the leaves of Mallotus oppositifolius on Phytophthora sp. and Fusarium sp. two phytopathogenic fungi in the research of natural substances of plant origin as an alternative to chemical pesticides in agriculture. An ethnobotanical survey of forty traditional healers in the Yamoussoukro District on medicinal Euphorbiaceae identified thirteen species.The study showed that skin diseases (36%) were mainly treated by these Euphorbiaceae including Mallotus oppositifolius. In view of these data and those in the literature, Mallotus oppositifolius was selected for the evaluation of the antifungal potential against Fusarium sp. and Phytophthora sp. The antifungal activity was evaluated by the double dilution method on PDA medium with ethanolic and aqueous extracts derived from the leaves of this plant. The results showed that aqueous and ethanolic extracts 70% of Mallotus oppositifolius have antifungal properties on both Fusarium sp. and Phytophthora sp. Antifungal activities were more important with ethanolic extracts than with aqueous extracts. With a minimum inhibitory concentration MIC = 25±0.0 mg/mL, a minimal concentration for 50 % of inhibition IC50 = 6.5±0.05 mg/mL and a minimum fungicide concentration MFC = 200±0.0 mg/mL Fusarium sp. appears to be the most sensitive. Phytophthora sp. is less sensitive with an MIC = 50±0.0 mg/mL, an IC50 = 12±0.05 mg/mL and a MFC = 200±0.0 mg/mL. Phytochemical screening revealed the presence of seven groups of compounds among which alkaloids, polyterpenes and sterols, gallic tannins and catechins are the most abundant in ethanol extracts. In addition to these compounds, flavonoids, polyphenols and saponins are present in both aqueous and alcoholic extracts of Mallotus oppositifolius. These compounds could justify the activity of the ethanolic extracts of Mallotus oppositifolius. These results can be used for agronomic research to control the two phytopathogenic fungi studied.

scholarly journals Corrosion Inhibition of Pipeline Steel in 0.5 M HCL Using Cotyledon of Chrysophyllum cainito

2020 ◽  
pp. 38-45
Author(s):  
E. P. Othaki ◽  
N. C. Ngobiri
Keyword(s):  
Fourier Transform ◽  
Surface Morphology ◽  
Corrosion Inhibition ◽  
Aqueous Extract ◽  
Pipeline Steel ◽  
Surface Film ◽  
Steel Corrosion ◽  
Fourier Transform Infrared ◽  
Inhibition Mechanism ◽  
Scanning Electron

The corrosion inhibition characteristics of Chrysophyllum cainto cotyledon aqueous extract was studied for the corrosion of pipeline steel in 0.5 M HCl using gravimetric technique. The corrosion surface morphology and corrosion surface film were studied using Scanning electron microscope and Fourier transform infrared spectroscopy respectively. The results obtained showed Chrysophyllum cainto aqueous extract as a good corrosion inhibitors of pipeline steel corrosion in acidic environment, recording an average corrosion inhibition efficiency above 90% at 303 K. The Scanning electron micrograph showed a smoother corrosion surface morphology in the presence of the extract while the Fourier transform infrared spectroscopic data showed the corrosion inhibition mechanism to be through adsorption.

scholarly journals Comparative Analysis on the Antimycotic Effect of Azadiracta indica and Jatropha curcas on Curvularia Species

2021 ◽  
pp. 50-57
Author(s):  
E. E. Ameh ◽  
A. A. Orukotan ◽  
A. J. Dadah ◽  
A. A. Abdullahi
Keyword(s):  
Antifungal Activity ◽  
Aqueous Extract ◽  
Jatropha Curcas ◽  
Ethanol Extract ◽  
Diffusion Method ◽  
Aqueous Extracts ◽  
Isolation And Identification ◽  
Extract Concentration ◽  
Significant Difference ◽  
Curvularia Species

This study was carried out to determine the phytochemical properties and the antimycotic effect of Jatropha curcas and Azadiracta indica leaves on Curvularia species. Isolation and identification of the fungal isolates were carried out using standard conventional method. Maceration technique was employed for crude extraction from the plant. The phytochemical tests were carried out using standard conventional methods. Agar well diffusion method was used to determine the susceptibility of the isolates.  Phytochemical tests of A. indica revealed the presence of flavonoids, phenols, saponins, tannins, phenols, and glycosides.  Jatropha curcas showed the presence of glycoside, tannins, saponin steroids and phenols. The antifungal activity of Azadiracta indica and Jatropha curcas on Curvularia species, the ethanol extract of Azadiracta indica showed more antifungal activity with highest percentage inhibition of 50.56±0.84c at 20% extract concentration, and Aqueous extract was 40.00±0.55b at 20%. The aqueous extract of Jatropha curcas showed more antifungal activity of 50.55±0.05c at 20% while that of ethanol extract was 35.55±0.54a at 20% extract concentration. The synergestic antifungal activity of the plants revealed that ethanolic extract had more antifungal effect of 57.54±0.56c at 20% concentration and that of the aqeous extract showed more activity of 45.89±0.50b at 20%. There was significant difference (P<0.05) between the ethanoic and aqueous extracts of the plants. The Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of Jatropha curcas on Curvularia Species showed the MIC at 250 mg/ml extract concentration for both ethanol and aqueous extracts against Curvularia Species. The ethanol and aqueous extract of Jatropha curcas occurred has no fungicidal effect against Curvularia Species.

Therapeutic efficacy of some extracts of hot pepper fruits (Capsicum annuum) and Sumac seeds (Rhus coriaria) on the growth of some isolated dermatophytes species

2018 ◽  
Vol 1 (3) ◽  
pp. 52-62
Author(s):  
Sara Omran ◽  
Abdulghani Alsamarai ◽  
Firas Razzzaq
Keyword(s):  
Antifungal Activity ◽  
Fungal Infection ◽  
Aqueous Extract ◽  
Plant Extracts ◽  
Therapeutic Efficacy ◽  
Diffusion Method ◽  
Quantitative Detection ◽  
Hot Pepper ◽  
Alcoholic Extract ◽  
Dermatology Clinic

Background: Fungal infections are one of the common skin diseases with difficulty in their treatment approach. The present efficient drugs for fungal infection are limited. Aim: To determine the therapeutic efficacy of plant extracts as alternative antifungal agents. Materials and methods: 100 clinical samples [68 from female and 32 from male] were collected during the period from March to July 2017 from subjects attending Dermatology Clinic in Salah Uldean General Hospital. Fungal infection was diagnosed with using KOH wet preparation. Fungal species identified by using conventional approach. The active ingredients existing in the plant extracts were detected and analyzed through qualitative and quantitative detection technique of chemical compounds using a high performance liquid chromatographic device (HPLC). Agar diffusion method was used to determine antifungal activity of plant extracts. Results: Direct microscopic examination showed that there were (75%) positive samples, while culture shows (67%) positive samples. The isolated dermatophytes belong to Epidermophyoton, Microsporum, and Trichophyton genus. The predominant dermatophytes were T. rubrum (25%) species. The highest frequency of infection was in the age group of 11-20 years. The sensitivity of the tested fungi to the aqueous and alcoholic plant extracts varies. Alcoholic extract of the hot pepper plant was more effective as antifungal than the aqueous extract of the same plant. However, aqueous hot pepper extracts was more effective against T. mentagrophyte than that of alcoholic extract. Additionally, alcoholic Sumac extract shows higher efficacy that aqueous extract. Conclusion: Hot pepper and Sumac extracts show antifungal activity against Microsporum canis, Trichophyton rubrum and T. mentagrophyte.

PENGGUNAAN TiO2 PARTIKEL NANO HASIL SINTESIS BERBASIS AIR MENGGUNAKAN METODA SOL-GEL PADA BAHAN KAPAS SEBAGAI APLIKASI UNTUK TEKSTIL ANTI UV

Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sol Gel ◽  
Crosslinking Agent ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Infra Red ◽  
Scanning Electron

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

The Role of Temperature and Heterotrophism in Determining Crude Oil Toxicity

1975 ◽  
Vol 10 (1) ◽  
pp. 73-83
Author(s):  
J.E.S. Graham ◽  
T.C. Hutchinson
Keyword(s):  
Crude Oil ◽  
Aqueous Extract ◽  
Chlorella Vulgaris ◽  
Nutrient Medium ◽  
General Pattern ◽  
Growth Stimulation ◽  
Aqueous Extracts ◽  
Chlamydomonas Eugametos ◽  
Wide Range ◽  
Oil Toxicity

Abstract Crude oil spills are increasingly likely to occur from drilling, pumping and transportation activities as oil development proceeds at a rapid pace. These spills may occur over the wide range of climatic conditions which obtain in Canada. Little is known of oil toxicity at different temperatures; consequently, laboratory studies were made of the variability of the toxicity of aqueous extracts of a Norman Wells crude oil to freshwater algae over the temperature range 5°C to 35°C. Two unicellular green algae were studied: Chlamydomonas eugametos and Chlorella vulgaris. Their response (measured by cell numbers) varied with temperature and species. Whereas Chlamydomonas eugametos showed a general pattern of growth inhibition by oil at all temperatures with maximum inhibition at 25°C, Chlorella vulgaris showed general growth stimulation by oil with maximum stimulation at 25°C, this temperature was chosen for all further experimentation. All experiments were done using unialgal cultures and sterile technique. Cells were grown in 50 ml of nutrient medium (BBM) in 125 ml Erlenmeyer flasks. Such flasks allow gas exchange and permit loss of volatile hydrocarbons. Aqueous extracts were made by slowly stirring 5% crude oil with the nutrient medium for six hours using a magnetic mixer. The extract was then allowed to sit for two to four hours before the lower fraction was drawn off for use. Experiments were carried out in controlled environment chambers (±2°C) with a twelve hour light-dark cycle. All further experiments used a similar methodology. (Note: Chlamydomonas eugametos experiments were carried out on a rotary shaker at 125 rpm.) An attempt was made to determine the reason for the remarkable stimulation in growth of Chlorella vulgaris #29 at 25°C. This organism has been described in the literature as heterotrophic. Thus three reasons for stimulation seemed possible: 1. heterotrophic uptake of hydrocarbons directly from solution; 2. heterotrophic uptake of organic compounds formed or released by microbial breakdown of hydrocarbons (the aqueous extract of crude was not sterile); or 3. the use of CO2 released to solution by microbial respiration. The original experiment was repeated in the dark at 20°C to determine if stimulation still occurred. It did not, since cells exposed to the aqueous extract decreased in numbers. However, after two weeks the cells were illuminated and even though experimental flasks started off with depleted populations, they outgrew the control cells within two weeks. This suggested that if stimulation was related to heterotrophism, it must, at least in this case, have been the unusual case of photoheterotrophism. The reasons for this stimulation of growth are currently under investigation. Several methods are being employed to investigate the suspected heterotrophism. Experiments will be done to determine whether light energy is essential to the stimulation. Two varieties of Chlorella vulgaris, i.e. #29 and #260 are heterotrophic and autotrophic respectively, are to be used in experiments. Sterile aqueous extracts made by pressure ultrafiltration will be used. These experiments should determine whether algal growth stimulation is related to heterotrophism or whether microbial degradation of hydrocarbons is the real source of stimulation. Although the toxicity of crude oil may be rapidly ameliorated by physical and/or biological phenomena, one must still be aware of the possibility of a large input of organic carbon causing extensive eutrophication. Thus both toxicity and eutrophication will cause a selection, in terms of survival, in a natural environment. It is evident that although an oil spill may not totally destroy an ecosystem, it will certainly alter its natural composition considerably.

Antifungal Activity Directed Toward the Cell Wall by 2-Cyclohexylidenhydrazo- 4-Phenyl-Thiazole Against Candida albicans

2019 ◽  
Vol 19 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Nívea P. de Sá ◽  
Ana P. Pôssa ◽  
Pilar Perez ◽  
Jaqueline M.S. Ferreira ◽  
Nayara C. Fonseca ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Mammalian Cells ◽  
C Elegans ◽  
Buccal Epithelial Cells ◽  
Mutant Strains ◽  
Low Toxicity ◽  
High Concentrations ◽  
Mic Value

<p>Background: The increasing incidence of invasive forms of candidiasis and resistance to antifungal therapy leads us to seek new and more effective antifungal compounds. </P><P> Objective: To investigate the antifungal activity and toxicity as well as to evaluate the potential targets of 2- cyclohexylidenhydrazo-4-phenyl-thiazole (CPT) in Candida albicans. </P><P> Methods: The antifungal activity of CPT against the survival of C. albicans was investigated in Caenorhabditis elegans. Additionally, we determined the effect of CPT on the inhibition of C. albicans adhesion capacity to buccal epithelial cells (BECs), the toxicity of CPT in mammalian cells, and the potential targets of CPT in C. albicans. </P><P> Results: CPT exhibited a minimum inhibitory concentration (MIC) value of 0.4-1.9 µg/mL. Furthermore, CPT at high concentrations (>60 x MIC) showed no or low toxicity in HepG2 cells and <1% haemolysis in human erythrocytes. In addition, CPT decreased the adhesion capacity of yeasts to the BECs and prolonged the survival of C. elegans infected with C. albicans. Analysis of CPT-treated cells showed that their cell wall was thinner than that of untreated cells, especially the glucan layer. We found that there was a significantly lower quantity of 1,3-β-D-glucan present in CPT-treated cells than that in untreated cells. Assays performed on several mutant strains showed that the MIC value of CPT was high for its antifungal activity on yeasts with defective 1,3-β-glucan synthase. </P><P> Conclusion: In conclusion, CPT appears to target the cell wall of C. albicans, exhibits low toxicity in mammalian cells, and prolongs the survival of C. elegans infected with C. albicans.</p>

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