Somatic embryogenesis in cell suspension cultures of olive <Emphasis Type="Italic">Olea europaea</Emphasis> (L.) ‘Chetoui’

Somatic embryogenesis of olive Olea europaea (L.) ‘Chetoui’ was studied using cell suspension cultures initiated from mature leaf-derived calli. Calli were developed on half-strength MS medium supplemented with 10 μM NAA and 2.25 μM 2i-P in the dark. Different combinations of three plant growth regulators (2,4-D, NAA and zeatin) were tested to determine cell proliferation and somatic embryogenesis induction and differentiation. Embryogenic suspension cultures were established in olive-modified medium for embryogenesis (OMe) containing 2.5 μM 2,4-D and 2.5 μM zeatin. Pre-globular and globular embryos were induced from mature olive tissue in liquid medium. In addition, the nitrogen form as inorganic (reduced; (NH₄)₂SO₄ or oxidized; KNO₃) and organic (CH) was used separately or in combination to improve the cell growth and proliferation. The most effective growth rate and cell proliferation were obtained with the medium containing inorganic and organic nitrogen forms.     

New Thymine-Based Derivative of Nitrogen Mustards

This work deals with the synthesis of a new nitrogen mustard derivative based on thymine. To introduce the bis(2-chloroethyl)amine group to position 4 of the pyrimidine base, many strategies were explored and the desired compound was finally obtained, thanks to a synthetic pathway in five steps.     

Synthesis And Biological Evaluation Of Nitrogen Mustard Derivatives Of Purine Bases

This paper deals with the synthesis of nitrogen mustard analogs, derivatives of purine bases. Alkylation in position N-9 and diethanolamine fixation on position 6 were managed by microwave irradiations. Chlorination of these dihydroxylated intermediates led to a cyclization, giving tricyclic purine base analogs bearing a chloroethyl chain. Finally, MTT assays on obtained compounds do not show cytotoxicity on four different cancer cell lines.     

Pyrimidine-Purine and Pyrimidine Heterodinucleosides Synthesis Containing a Triazole Linkage

This article describes a synthetic route to generate two purine-pyrimidine and pyrimidine heterodinucleosides. Both microwave activated regioselective alkylation using hydride and copper-catalyzed-azide-alkyne-cycloaddition (CuAAC) were used in order to perform the synthesis.     

A contaminant trypsin-like activity from the timothy grass pollen is responsible for the conflicting enzymatic behavior of the major allergen Phl p 1

We intend to solve whether or not Phl p 1 can be regarded as a protease. A group reported that Phl p 1 has papain-like properties and later on, that this allergen resembles cathepsin B, while another one demonstrated that Phl p 1 lacks proteinase activity and suggested that the measured activity may rise either from a recombinant Phl p 1 contaminant or as a result of an incompletely purified natural allergen. A third group reported Phl p 1 to act by a non-proteolytic activity mechanism. We report the purification of the natural Phl p 1 by means of hydrophobic interaction, gel filtration and STI-Sepharose affinity chromatographies. The Phl p 1 purity was assessed by silver-stained SDS-PAGE and by ‘in-gel’ and ‘gel-free’ approaches associated to mass spectrometry analyses. The proteolytic activity was measured using Boc–Gln–Ala–Arg–AMC and Z-Phe–Arg–AMC as substrates. While amidolytic activity could be measured with Phl p 1 after rechromatography on gel filtration, it however completely disappeared after chromatography on STI-Sepharose. The contaminant activity co-eluting with Phl p 1 was not affected by cysteine proteases inhibitors and other thiol-blocking agents, by metalloproteases inhibitors and by aspartic proteases inhibitors. However, it was completely inhibited by low molecular weight and proteinaceous serine proteases inhibitors. TLCK, but not TPCK, inhibited the contaminant activity, showing a trypsin-like behavior. The pH and temperature optimum were 8.0 and 37 °C, respectively. These data indicated that Phl p 1 is not a protease. The contaminant trypsin-like activity should be considered when Phl p 1 allergenicity is emphasized.     

Occurrence of <Emphasis Type="Italic">Vibrio cholerae</Emphasis> non-O1 in three wastewater treatment plants in Agadir (Morocco)

A total of 21 isolates of Vibrio cholerae non-O1 strains were isolated from three wastewater treatment plants in Agadir, Morocco. The isolates were analyzed by biochemical analysis, antibiogram, pulsed-field gel electrophoresis and the MALDI-TOF patterns of their protein masses were compared. Over 67% of isolates were susceptible to antimicrobial agents tested and 14% proved resistant to both trimethoprim-sulfamethoxazole and nalidixic acid. Typing by pulsed-field gel electrophoresis with NotI digestion revealed that the V. cholerae non-O1 strains from Agadir (Morocco) have a lower level of genetic homogeneity, the restriction patterns of whole-chromosomal DNA grouped the V. cholerae O1 and V. alginolyticus strains into a separate cluster from V. metschnikovii and V. cholerae non-O1 isolates. Furthermore, to gain additional analytical accuracy and reliability in the analysis we used dendrogram based on MALDI-TOF spectral patterns generated by the BioTyper 1.1™ software. All m/z signatures of all strains tested indicate that the mass spectral data contained sufficient information to distinguish between strains of V. cholerae.     

Synthesis and Biological Evaluations of Click-Generated Nitrogen Mustards

This paper describes the synthesis of new click-generated nitrogen mustards and their biological evaluation. By using the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, we managed to synthesize eight new nitrogen mustards. This strategy paves the way for the synthesis of a new family of nitrogen mustard, with an important structural variability. Furthermore, we studied the biological activity of synthesized compounds by testing their cytotoxicity on four representative cancer cell lines A431, JURKAT, K562, and U266. One structure, 1-benzyl-4-(N,N-di-2-chloroethylaminomethyl)-1H-[1 Noll, D.M.; McG.Mason, T.; Miller, P.S. Formation and repair of interstrand cross-links in DNA. Chem. Rev. 2006, 106, 277–301.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar],2 Rink, S.M.; Hopkins, P.B. Direct evidence for DNA intrastrand cross-linking by the nitrogen mustard mechlorethamine in synthetic oligonucleotides. Bioorg. Med. Chem. Lett. 1995, 5(23), 2845–2850.[Crossref], [Web of Science ®] , [Google Scholar],3 Chabner, B.A.; Collins, J.M. Cancer Chemotherapy: Principles and Practices, PA, J.B. Lippincott Company, Philadelphia, 1990, pp. 276–313. [Google Scholar]]triazole, showed an interesting cytotoxic effect.     

Current production and metal oxide reduction by Shewanella oneidensis MR-1 wild type and mutants

Shewanella oneidensis MR-1 is a gram-negative facultative anaerobe capable of utilizing a broad range of electron acceptors, including several solid substrates. S. oneidensis MR-1 can reduce Mn(IV) and Fe(III) oxides and can produce current in microbial fuel cells. The mechanisms that are employed by S. oneidensis MR-1 to execute these processes have not yet been fully elucidated. Several different S. oneidensis MR-1 deletion mutants were generated and tested for current production and metal oxide reduction. The results showed that a few key cytochromes play a role in all of the processes but that their degrees of participation in each process are very different. Overall, these data suggest a very complex picture of electron transfer to solid and soluble substrates by S. oneidensis MR-1.     

Direct versus indirect effects of p-chloromercuribenzenesulphonic acid on sucrose uptake by plant tissues: The electrophysiological evidence

The short-term effects of p -chloromercuribenzenesulphonic acid (PCMBS) on the transmembrane potential difference (PD) of broad bean ( Vicia faba L. cv. Aguadulce) cotyledon cells and on sugar beet ( Beta vulgaris L. cv. Klein E.) leaf cells were studied by the electrophysiological method. These effects were compared with that of the permeant thiol reagents N-ethylmaleimide and HgCl₂. N-Ethylmaleimide and HgCl₂ markedly and rapidly depolarised the PD of all the material studied, while PCMBS caused either a slight depolarisation (cotyledon cells) or no depolarisation (leaf cells) during the first 30 min of treatment. In cotyledons, PCMBS markedly inhibited sucrose uptake (89%) and the sucrose-induced depolarisation associated with the proton-sucrose symport (67%), while it decreased the proton-motive force only marginally (7%). It is concluded that during short treatments (30 min or less). PCMBS inhibits sucrose uptake directly by blocking the sucrose carrier, and not the proton pump. For longer treatments, indirect effects cannot be excluded.     

Synthesis and biological evaluation of thioglycosylated porphyrins for an application in photodynamic therapy.

The aim of this work is the synthesis of a new family of glycosylated porphyrins in which the sugar moieties are linked to the tetrapyrrole ring by a thioglycosidic bond. Two series have been designed. The first one corresponds to meso-aryl porphyrin derivatives. The second one has been obtained from protoporphyrin IX derivatization. Aryl-porphyrins were prepared from tristolyl o- and p-hydroxyporphyrins followed by bromoallylation and thioglycosylation with peracetylated S-glucose, mannose and galactose and deprotection. The other series has been synthesized from protoporphyrin IX dimethylester with a regioselective glycosylation of terminal alkenyl carbon. The UV-visible, NMR and MALDI mass spectra are presented. Photocytotoxicities of the synthesized compounds against K562 chronic leukaemia cell line has been evaluated.