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Herpes simplex virus (HSV) infections are highly widespread among humans, producing symptoms ranging from ulcerative lesions to severe diseases such as blindness and life-threatening encephalitis. At present, there are no vaccines available, and some existing antiviral treatments can be ineffective or lead to adverse effects. As a result, there is a need for new anti-HSV drugs. In this report, the in vitro anti-HSV effect of 9,9′-norharmane dimer (nHo-dimer), which belongs to the β-carboline (βC) alkaloid family, was evaluated. The dimer exhibited no virucidal properties and did not impede either the attachment or penetration steps of viral particles. The antiviral effect was only exerted under the constant presence of the dimer in the incubation media, and the mechanism of action was found to involve later events of virus infection. Analysis of fluorescence lifetime imaging data showed that the nHo-dimer internalized well into the cells when present in the extracellular incubation medium, with a preferential accumulation into perinuclear organelles including mitochondria. After washing the host cells with fresh medium free of nHo-dimer, the signal decreased, suggesting the partial release of the compound from the cells. This agrees with the observation that the antiviral effect is solely manifested when the alkaloid is consistently present in the incubation media. [ABSTRACT FROM AUTHOR]

This study reports valuable information regarding the presence and concentration of a series of photoactive β‐carboline (βCs) alkaloids (norharmane, harmane, harmine, harmol, harmaline, and harmalol) and their distribution across the floral age and organs of Passiflora caerulea. UHPLC–MS/MS data reported herein reveal that the βCs' content ranged from 1 to 110 μg kg−1, depending on the floral organ and age. In certain physiologically relevant organs, such as anthers, βCs' content was one order of magnitude higher than in other organs, suggesting a special role for βCs in this specific organ. βCs' content also varied in a structure‐dependent manner. Alkaloids bearing a hydroxyl group at position C(7) of the main βC ring were present at concentrations one order of magnitude higher than other βC derivatives investigated. UV–visible and fluorescence spectroscopy of the flower extracts provided complementary information regarding other biologically relevant groups of chromophores (phenolic/indolic derivatives, flavonoids/carotenes, and chlorophylls). Since flowers are constantly exposed to solar radiation, the presence of photoactive βCs in floral organs may have several (photo)biological implications that are further discussed. [ABSTRACT FROM AUTHOR]

Here, we provide mechanistic insight to the photocleavage of a compound in the folate family, namely pteroic acid. A bis‐decyl chain derivative of pteroic acid was synthesized, structurally characterized and photochemically investigated. We showed that, like folic acid, pteroic acid and the decylated derivative undergo a photocleavage reaction in the presence of H2O, while no reaction was observed in methanol solution. Furthermore, density functional theory calculations were carried out to predict relative stabilities of hypothetical mono‐, bis‐ and tris‐decylated pteroic acid derivatives to help rationalize the regioselectivity of the bis‐decyl pteroic acid product. Additionally, the lipophilicity of the bis‐decyl pteroic acid appears to confer a hydrophobic property enabling an interaction with biomembranes. [ABSTRACT FROM AUTHOR]

In this work, two Bacillus strains isolated from honey (Bacillus subtilis subsp. subtilis C4; access code HQ828992) and from a waste of an artisanal tannery (Bacillus amyloliquefaciens B31; access code KP893752) were evaluated in order to determine their antibacterial activity against five enteropathogenic Escherichia coli strains. The number of viable cultivable cells of the different strains of E. coli analyzed was determined by plate count. The crude cell‐free supernatants of both Bacillus strains exerted anti‐E. coli activities, whereas only the lipopeptide fraction of B31 had significant E. coli inhibition. The lipopeptides produced by the Bacillus were analyzed using matrix‐assisted laser desorption–ionization mass spectrometry (MALDI MS). The analysis was conducted combining the profiles (fingerprints) of the lipopeptides mixture and the individual lipopeptide fragmentation (tandem mass spectrometry [MS/MS] mode), both obtained from the same lipopeptides mixture sample, for higher output. Data obtained from C4 and B31 revealed that surfactin homologues were the most abundant lipopeptides produced by both strains studied. Additionally, kurstakin, iturin, and fengycin homologues were detected. Using the MS/MS mode, it was demonstrated that isobar compounds belonging to different families were produced by each Bacillus strain (e.g., C‐16 bacillomycin D was detected in B31 samples, meanwhile C‐15 iturin C was detected in C4). MS/MS analysis contributed with relevant information about the type of lipopeptides synthesized by Bacillus strains studied in this work. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) of diamond, titanium dioxide, titanium silicon oxide, barium strontium titanium oxide, and silver (Ag) were examined for their potential as MALDI matrixes for direct laser desorption/ionization of carbohydrates, especially fructans, from plant tissue. Two sample preparation methods including solvent-assisted and solvent-flee (dry) NPs deposition were performed and compared. All examined NPs except for Ag could desorb/ionize standard sucrose and fructans in positive and in negative ion mode. Ag NPs yielded good signals only for nonsalt-doped samples that were measured in file negative ion mode. In file case of in vivo studies, except for Ag, all NPs studied could desorb/ionize carbohydrates from tissue in both the positive and negative ion modes. Furthermore, compared to file results obtained with soluble sugars extracted from plant tissues, fructans with higher molecular weight intact molecular ions could be detected when the plant tissues were directly profiled. The limit of detection (LOD) of fructans and the ratios between signal intensities and fructan concentrations were analyzed. NPs had similar LODs for standard fructan triose (1-kestose) in the positive ion mode and better LODs in the negative ion mode when compared with the common crystalline organic MALDI matrixes used for carbohydrates (2,5-dihydroxybenzoic acid and nor-barmane) or carbon nanotubes. Solvent-free NP deposition on tissues partially improves the signal acquisition. Although lower signal-to-noise ratio sugar signals were acquired from the tissues when compared to file solvent-assisted method, the reproducibility averaged over all sample was more uniform. 10.1021/ac10012