Showing: 10 from total: 357 publications
1. Structural, optical and photocatalytic properties under UV-A and visible lights of Co-, Ni- and Cu-doped ZnO nanomaterials. Comparative study
Aadnan, I ; Zegaoui, O ; El Mragui, A ; Moussout, H ; da Silva, JCGE
in ARABIAN JOURNAL OF CHEMISTRY, 2024, ISSN: 1878-5352,  Volume: 17, 
Article,  Indexed in: scopus, wos 
Abstract In this investigation, Co-, Ni- and Cu-doped ZnO nanoparticles were prepared using precipitation methods. The characterization of the as-prepared nanomaterials was carried out using XRD, FT-IR, DRS, XPS and SEM. The XRD analysis showed that the insertion of foreign metal ions into the matrix of ZnO caused a slight shift of the positions of (100), (002) and (101) diffraction peaks of ZnO towards the lower 2 theta, by comparison with pure ZnO. The DRS results showed that Co-doped ZnO nanoparticles absorb wavelengths higher than 400 nm. The estimated band gaps (eV) were 2.48, 3.17 and 3.14 for 10 %Co-ZnO, 10 %Ni-ZnO and 10 %Cu-ZnO respectively. The XPS results showed the existence of two valence states for Co and Ni (Co2+/Co3+ and Ni2+/Ni3+) while Cu exists in the form of Cu2+. The photocatalytic efficiency was evaluated under UV and visible irradiations in aqueous solution using methyl orange (MO) as an organic pollutant probe molecule. The results showed that, under visible light, the MO degradation increased significantly by doping ZnO (10 %Co-ZnO: 33.2 %; 10 %NiZnO: 19.8 % and 10 %Cu-ZnO: 52.5 %) by comparison with undoped ZnO (9.3 %). The important increase in photocatalytic activity observed for the doped ZnO by comparison with pure ZnO, particularly for 10 %Cu-ZnO, has been linked to a synergistic effect of both the band gap narrowing and the increase in the lifetime of photogenerated charge carriers.

2. Comparative investigation into the anticancer activity of analogs of marine coelenterazine and coelenteramine
Magalhaes, CM ; Pereira, RB ; Erbiai, E ; González Berdullas, P ; da Silva, JCGE ; Pereira, DM ; da Silva, LP
in BIOORGANIC CHEMISTRY, 2024, ISSN: 0045-2068,  Volume: 144, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Cancer is still one of the most challenging diseases to treat, making the pursuit for novel molecules with potential anticancer activity an important research topic. Herein, we have performed a comparative investigation into the anticancer activity of analogs of marine coelenterazine and coelenteramine. The former is a well-known bioluminescent substrate, while the latter is a metabolic product of the resulting bioluminescent reaction. While both types of analogs showed anticancer activity toward lung and gastric cancer cell lines, we have obtained data that highlight relevant differences between the activity of these two types of compounds. More specifically, we observed relevant differences in structure-activity relationships between these types of compounds. Also, coelenteramine analogs showed time-dependent activity, while coelenterazine-based compounds usually present time-independent activity. Coelenterazine analogs also appear to be relatively safer toward noncancer cells than coelenteramine analogs. There was also seen a correlation between the activity of the coelenterazine-based compounds and their light-emission properties. Thus, these results further indicate the potential of the marine coelenterazine chemi-/bioluminescent system as a source of new molecules with anticancer activity, while providing more insight into their modes of action.

3. Nanomaterial-Based Advanced Oxidation/Reduction Processes for the Degradation of PFAS
Cardoso, IMF ; da Silva, LP ; da Silva, JCGE
in NANOMATERIALS, 2023, ISSN: 2079-4991,  Volume: 13, 
Review,  Indexed in: scopus, wos 
Abstract This review focuses on a critical analysis of nanocatalysts for advanced reductive processes (ARPs) and oxidation processes (AOPs) designed for the degradation of poly/perfluoroalkyl substances (PFAS) in water. Ozone, ultraviolet and photocatalyzed ARPs and/or AOPs are the basic treatment technologies. Besides the review of the nanomaterials with greater potential as catalysts for advanced processes of PFAS in water, the perspectives for their future development, considering sustainability, are discussed. Moreover, a brief analysis of the current state of the art of ARPs and AOPs for the treatment of PFAS in water is presented.

4. SPR studies in PVA composite films of SiO2@NaYF4:Er3+/Yb3+ UCNPs via AuNPs concentration variation and their temperature sensing applications
Kumar, A ; da Silva, JCGE ; Tiwari, SK
in JOURNAL OF ALLOYS AND COMPOUNDS, 2023, ISSN: 0925-8388,  Volume: 967, 
Article,  Indexed in: crossref, scopus, wos 
Abstract The composite film of mesoporous silica coated NaYF4:Er3+/Yb3+ upconversion nanoparticles and gold nanoparticles (AuNPs) in Poly vinyl alcohol (PVA) medium were prepared. The effect of the concentrations of AuNPs with 0 mu l, 50 mu l, 100 mu l and 150 mu l on the structure and upconversion luminescence intensity were studied. The phenomenon of enhancement in upconversion luminescence intensity due to AuNPs were explained via surface plasmon resonance (SPR) phenomenon. Apart from this the XRD, FE-SEM and AFM studies were done for estimation of structure and surface morphology etc. The impurities were estimated through FTIR analysis. The optical properties of these polymer composite films were studied via UV-vis absorption spectra and upconversion luminescence spectra analysis. A low temperature sensing ability of these films have been demonstrated for the suitability of these films in bio-medical applications.

5. Assessment of Surface Water Quality Using the Water Quality Index (IWQ), Multivariate Statistical Analysis (MSA) and Geographic Information System (GIS) in Oued Laou Mediterranean Watershed, Morocco
Azhari, HE ; Cherif, E ; Sarti, O ; Azzirgue, E ; Dakak, H ; Yachou, H ; da Silva, JCGE ; Salmoun, F
in WATER, 2023, ISSN: 2073-4441,  Volume: 15, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities' impact on surface water quality in the Oued Laou watershed, Northern Morocco. Thirteen surface water samples were characterized for 26 physicochemical and biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), water quality indices (WQI), irrigation water quality (IWQI), and Geographic Information System (GIS) were employed to identify the sources of surface water pollution, their suitability for consumption, and the distribution of surface water quality. The results showed that the major ion concentrations were reported in the following order: Ca2+, Na+, Mg2+, and K+; and HCO3- > CO32- > Cl- > SO42- > NO3- > F- > PO43- > NO2-. It was also demonstrated that almost all parameters had concentrations lower than World Health Organization (WHO) limits, except for bicarbonate ions (HCO3-) and the biochemical oxygen demand for five days (BOD5), which exceeded the WHO limits at 120 mg/L and 3 mg/L, respectively. Furthermore, the types of Ca2+-HCO3- (Calcium-Bicarbonate) and Ca2+-Mg2+-HCO3- (Calcium-Magnesium-Bicarbonate) predominated in surface water. The Principal Component Analysis (PCA) indicates that the Oued Laou river was exposed to two forms of contamination, the first being attributed to anthropogenic activities such as agriculture, while the second reflects the water-sediment interaction. The Hierarchical Cluster Analysis (HCA), reflecting the mineralization in the study area, has classified the samples into four clusters. The Inverse Distance Weighting (IDW) of the WQI indicates that 7.69% and 38.46% of the surface water represent, respectively, excellent and good quality for drinking. At the same time, the IWQI revealed that 92.30% of the water surface is good for irrigation. As a result, the combination of WQIs, PCA, IWQI, and GIS techniques is effective in providing clear information for assessing the suitability of surface water for drinking and its controlling factors and can also support decision-making in susceptible locations such as the Oued Laou river in northern Morocco.

6. Phytochemical Compounds and Anticancer Activity of Cladanthus mixtus Extracts from Northern Morocco
El Mihyaoui, A ; Charfi, S ; Erbiai, E ; Pereira, M ; Duarte, D ; Vale, N ; Castillo, MEC ; Badoc, A ; Lamarti, A ; da Silva, JCGE ; Arnao, MB
in CANCERS, 2023, ISSN: 2072-6694,  Volume: 15, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Simple Summary Cancer is a dramatic illness that ranks among the most pressing health concerns facing humanity and necessitates a proactive approach to treatment. Phytochemicals are regarded as interesting molecules for the development of anticancer drugs due to their pleiotropic effects on broad targets. The actions of phytochemicals are focused on tumor cells alone, with no negative effects on normal cells. The intricate process of carcinogenesis involves numerous signaling cascades. This study examined the effects of four organ extracts from a Mediterranean endemic plant, Cladanthus mixtus, on human tumor cells. To the best of our knowledge, this is the first study on this plant from northern Morocco showing relevant antiproliferative activity against two cancer cell lines and one non-tumoral cell line. Many of the chemotherapeutic drugs for the treatment of cancer are molecules identified and isolated from plants or their synthetic derivatives. This work aimed to identify the bioactive compounds using LC-MS and GC-MS and to evaluate the anticancer activity of the methanolic extracts of roots, stems, leaves, and flowers from Cladanthus mixtus. The anticancer activity was evaluated in vitro against two cancer cell lines: human breast carcinoma (MCF-7) and human prostate carcinoma (PC-3), using the MTT assay and microscopic observation. A human normal lung fibroblast (MRC-5) was included to determine the extract's safety for non-tumoral cells. The chemical composition results by LC-MS analysis revealed the presence of 24 phenolic compounds. Furthermore, GC-MS analysis allowed the identification of many biomolecules belonging to terpenoids, esters, alcohols, alkanes, fatty acids, organic acids, benzenes, phenols, ketones, carbonyls, amines, sterols, and other groups. The findings suggest that the majority of C. mixtus extracts have antiproliferative activity against two cancer cell lines, MCF-7 and PC-3, and one non-tumoral cell line, MRC-5. The activity was dose-dependent, and the highest effect was obtained with leaf extract in the two cancer cell lines. Moreover, these extracts demonstrated an acceptable toxicological profile against normal cells. Overall, C. mixtus extracts revealed promising antitumor properties provided by their phytochemical composition.

7. Antimicrobial Activity of Some Medicinal Herbs to the Treatment of Cutaneous and Mucocutaneous Infections: Preliminary Research
Noites, A ; Borges, I ; Araujo, B ; da Silva, JCGE ; de Oliveira, NM ; Machado, J ; Pinto, E
in MICROORGANISMS, 2023, ISSN: 2076-2607,  Volume: 11, 
Article,  Indexed in: crossref, scopus, wos 
Abstract (1) Background: Superficial, including cutaneous and mucocutaneous infections are a current public health problem with universal distribution. One of the main concerns, in the present/future, is fungal/bacterial infections by resistant microorganisms. This study aimed to verify if decoctions of coptidis (Coptis chinensis, Ranunculaceae family), neem (Azadirachta indica, Meliaceae family), and their essential oils (EOs), as well as the EO of manuka (Leptospermum scoparium, Myrtaceae family) have antimicrobial activity against prevalent species of microorganisms responsible for superficial infections. (2) Methods: The antimicrobial activity was determined by the minimum inhibitory concentration (MIC), using broth microdilution method, and minimum lethal concentration (MLC) was determined from subculture of MIC plates. (3) Results: C. chinensis EO and decoction demonstrated some antifungal action against the yeasts and dermatophytes tested. Greatest bactericidal effect against Propionibacterium acnes and some action against Staphylococcus aureus was observed. For A. indica only EO proved activity against dermatophytes and P. acnes. L. scoparium EO showed the broadest antimicrobial spectrum with activity against bacteria, yeasts, and dermatophytes showing greater activity against P. acnes and S. aureus. (4) Conclusions: C. chinensis (EO/decoction), EOs of L. scoparium and A. indica proved in vitro efficacy against fungal, bacterial, or mixed agents of superficial infections, either by sensitive or resistant strains.

8. Chemical Characterization and Several Bioactivities of Cladanthus mixtus from Morocco
El Mihyaoui, A ; Erbiai, E ; Charfi, S ; Pinto, E ; Castillo, MEC ; Hernandez Ruiz, J ; Cano, A ; Badoc, A ; Lamarti, A ; da Silva, JCG ; Arnao, MB
in MOLECULES, 2023, Volume: 28, 
Article,  Indexed in: crossref, wos 
Abstract The purpose of this work was to investigate, for the first time to our knowledge, the chemical composition and bioactivity of methanolic extracts (roots, stems, leaves, and flowers) from Cladanthus mixtus (L.) Chevall. that grows wild in northern Morocco (the Tangier-Tetouan-Al Hoceima region). The phenolic and flavonoid contents were determined by spectrophotometer methods, and the composition of derivatized methanolic extracts from C. mixtus using N-O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was carried out by applying the 2,2 '-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. The micro-dilution technique was chosen to investigate the antimicrobial activity of methanolic extracts against two bacterial strains and three fungal species. The results showed that the values of total phenolic and flavonoid contents were found to be higher in flower extracts (30.55 +/- 0.85 mg of gallic acid equivalents (GAE)/g of dried weight (DW) and 26.00 +/- 1.34 mg of quercetin equivalents (QE)/g DW, respectively). Other groups of chemical compounds were revealed by GC-MS, such as carbohydrates (27.25-64.87%), fatty acids (1.58-9.08%), organic acids (11.81-18.82%), and amino acids (1.26-7.10%). Root and flower methanolic extracts showed the highest antioxidant activity using ABTS (39.49 mg of Trolox equivalents (TE)/g DW) and DPPH (36.23 mg TE/g DW), respectively. A positive correlation between antioxidant activity and polyphenol and flavonoid amounts was found. Antibacterial tests showed that the best activity was presented by the leaf extract against Staphylococcus aureus (minimum inhibitory concentration (MIC) = minimum bactericidal concentration (MBC) = 20 mg/mL) and Escherichia coli (MIC of 30 mg/mL and MBC of 35 mg/mL). S. aureus was more sensitive to the extracts compared to E. coli. All extracts showed antifungal activity against Trichophyton rubrum, with the best efficacy reported by the flower and leaf extracts (MIC = 1.25 mg/mL and minimum fungicidal concentration (MFC) = 2.5 mg/mL). In general, extracts of C. mixtus appeared less effective against Candida albicans and Aspergillus fumigatus.

9. Interactions Evaluation between the Jouamaa Hakama Groundwater and Ouljat Echatt River in the North of Morocco, Using Hydrochemical Modeling, Multivariate Statistics and GIS
Azzirgue, E ; Cherif, E ; El Azhari, H ; Dakak, H ; Yachou, H ; Ghanimi, A ; Nouayti, N ; da Silva, JE ; Salmoun, F
in WATER, 2023, ISSN: 2073-4441,  Volume: 15, 
Article,  Indexed in: crossref, scopus, wos 
Abstract The processed discharges from Tangier Automotive City's (TAC) Chrafate Wastewater Treatment Plant (WWTP) contaminate the Jouamaa Hakama groundwater and the Ouljat Echatt river. We aimed to study the unknown interactions between surface water (SW) and groundwater (GW). A total of nine Jouamaa Hakama GW samples and eleven Ouljat Echatt SW samples were taken and analyzed in 2021 and 2022 to determine 16 physical and chemical parameters (pH, temperature (T), electrical conductivity (EC), dissolved oxygen (DO), total hardness (TH), turbidity (TURB), and total dissolved solids (TDS), cations: Na+, K+, Mg2+ and Ca2+, anions: Cl-, CO32-, HCO3-, NO3-, and SO42-). For exploitation of the data, we used a methodology based on hydrochemical modeling (HM), principal component analysis (PCA), Water Quality Index (WQI), Irrigation Water Quality Index (IWQI), inverse distance weighted interpolation (IDW) using Geographic Information Systems (GIS), and regression analysis (RA). We studied the interaction of the surface water of the river (contaminated by discharges from the WWTP) with the shallow groundwater on a strip of 100 m on either side of the river to understand the transverse and longitudinal dispersion of this pollution The investigations indicated that the major ions found in GW and SW were characterized in a different order in the anion list order Cl- > CO32- > NO3- > HCO3- > SO42- and Cl- > SO42- > CO32- > NO3- > HCO3-, respectively, while the concentrations of cations showed the same order for both: Na+ > Ca2+ > Mg2+ > K+. As a result, GW showed in the Piper diagram the type of sodium chloride to magnesium carbonate, while SW belongs to the sodium chloride to magnesium sulfate type. The WQI showed that the river waters are all unsuitable for use (WQI > 100), while the GW is of poor quality (WQI > 76). Moreover, the results of the GW-SW interaction along the river revealed a significant relationship (R-2 = 0.85), which means that strong circulation and the infiltration of contaminated SW into shallow GW occur in this area. The approaches followed have been proven effective in evaluating water quality for human and animal uses. These results can help decision-makers in the region take suitable management measures to mitigate this environmental problem.

10. Chemical Characterization and Antifungal Activity of Blue Tansy (Tanacetum annuum) Essential Oil and Crude Extracts against Fusarium oxysporum f. sp. albedinis, an Agent Causing Bayoud Disease of Date Palm
Ettakifi, H ; Abbassi, K ; Maouni, S ; Erbiai, E ; Rahmouni, A ; Legssyer, M ; Saidi, R ; Lamrani, Z ; da Silva, JCGE ; Pinto, E ; Maouni, A
in ANTIBIOTICS-BASEL, 2023, ISSN: 2079-6382,  Volume: 12, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Tanacetum annuum L. is a Mediterranean plant, commonly known as Blue Tansy due to its blue colour as an essential oil, which is widely used for medicinal purposes. However, there are no studies on the bioactive compounds (especially, phenolic compounds) and the biological properties of their organic extracts. Herein, the purpose of the present work was to investigate the chemical composition of the essential oil and crude extracts of the T. annuum aerial parts collected from northern Morocco and to evaluate their antioxidant and antifungal activity against Fusarium oxysporum f. sp. albedinis, an agent causing Bayoud disease of the date palm, an important food source and commercial perennial crop in the Sahara and North Africa. Chemically, Folin-Ciocalteu and aluminium chloride colourimetric methods were used to determine the total phenolic (TPC) and total flavonoid (TFC) contents, respectively; polyphenols were characterized using HPLC-MS, while GC-MS was used to analyse the essential oil composition. Moreover, the evaluation of antioxidant and antifungal activities was carried out using the DPPH test and microdilution method, respectively. The results showed that the three T. annuum parts (stems, leaves and flowers) extracts contained important TPC and TFC with values varied between 51.32 and 116.32 mg/g of dry crude extract (DCE). HPLC-MS analysis revealed the identification and quantification of 19 phenolic acids and flavonoids with an emphasis on apigenin 7-glucoside (4540 mu g/g of dry weight (DW)), luteolin 7-glucoside (2804 mu g/g DW) and salicylic acid (1878 mu g/g DW). Additionally, 39 biomolecules were identified in the essential oil using GC-MS, which were predominated by camphor (16.69%), a-pinene (12.37%), bornyl acetate (11.97%) and limonene (11.10%). The methanolic and hydro-methanolic extracts of T. annuum parts demonstrated a strong antioxidant property with IC50 values ranging between 0.22 and 0.65 mg/mL. Concerning antifungal activity, the essential oil and crude extracts of the Moroccan Blue Tansy exhibited a potent capacity against F. oxysporum f. sp. albedinis at low concentrations, with MIC and MFC values of 3.33 and 4.58 mu L/mL for the essential oil and values of 3.33 and 9.17 mg/mL for crude extracts, respectively. Overall, these results demonstrated T. annuum as an important source of bioactive compounds and contribute significantly to the potential of using essential oils and extracts for controlling the Bayoud disease of date palms. Moreover, the finding suggests that T. annuum can be highly useful for phytosanitary and pharmaceutical industries.