RESUMEN
Balticidins A-D (1-4), four new antifungal lipopeptides, were isolated from the laboratory-cultivated cyanobacterium Anabaena cylindrica strain Bio33 isolated from a water sample collected from the Baltic Sea, Rügen Island, Germany. Fractionation of the 50% aqueous MeOH extract was performed by bioassay-guided silica gel column chromatography followed by SPE and repeated reversed-phase HPLC. The main fraction containing the compounds exhibited a strong and specific antifungal activity with inhibition zones in an agar-diffusion assay from 21 to 32 mm against Candida albicans, Candida krusei, Candida maltosa, Aspergillus fumigatus, Microsporum gypseum, Mucor sp., and Microsporum canis. The structures were elucidated by multidimensional (1)H and (13)C NMR spectroscopy, HRESIMS, amino acid analysis, and sugar analysis. Spectroscopic data analysis afforded an unambiguous sequence of R.CHO(S1).CHOH.CONH-Thr(1)-Thr(2)-Thr(3)-HOTyr(4)-Dhb(5)-D-Gln(6)-Gly(7)-NMeThr(8)(S2)-L-Gln COOH(9), in which Dhb is dehydroaminobutyric acid, S1 is d(-)-arabinose-(3-1)-D-(+)-galacturonic acid, S2 is D-(+)-mannose, and R is the aliphatic residue -C13H26Cl or -C13H27. Besides NMeThr, D-allo-Thr, D-Thr, and L-Thr were identified, but the position of the enantiomers in the sequence is not clear. The four balticidins differ in their cyclic (2, 4)/linear (1, 3) core and the presence (1, 2)/absence (3, 4) of chlorine in the aliphatic unit.
Asunto(s)
Anabaena cylindrica/química , Antifúngicos/aislamiento & purificación , Lipopéptidos/aislamiento & purificación , Péptidos Cíclicos/aislamiento & purificación , Antifúngicos/química , Antifúngicos/farmacología , Aspergillus fumigatus/efectos de los fármacos , Candida albicans/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Cianobacterias/química , Alemania , Lipopéptidos/química , Lipopéptidos/farmacología , Pruebas de Sensibilidad Microbiana , Microsporum/efectos de los fármacos , Estructura Molecular , Mucor/efectos de los fármacos , Resonancia Magnética Nuclear Biomolecular , Océanos y Mares , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacologíaRESUMEN
The sorption of 4-octylphenol (4-OP) by two freshwater algae was investigated. Results showed that the sorption of 4-octylphenol by algae was obvious and quick, where 20% of initial 4-OP (2 mg/L) was accumulated by Chlorella vulgaris (CV) and 46% initial 4-OP (2 mg/L) was accumulated by Anabaena cylindrical (AC) after 5 min incubation. The sorption got equilibrium at 1 h after incubation. Langmuir sorption model was good appropriate type for this sorption. The effect of pH value on CV sorption was obvious than that on AC sorption. The sorption capacity of the biomass of two algae increased with the decrease of pH value. The analyzing of interaction between algae and 4-octylphenol was performed by fluorescence spectrum. Results showed that the algae could weaker the fluorescence spectrum intensity of 4-octylphenol and result in red shift of the maximum absorbance wavelength of mixture solution. Based on the results, it was speculated that algae bound with the contamination could use the near UV region of solar radiation and induced the contamination degradation.
Asunto(s)
Anabaena cylindrica/química , Chlorella/química , Agua Dulce/análisis , Fenoles/aislamiento & purificación , Purificación del Agua/métodos , Adsorción , Anabaena cylindrica/metabolismo , Biodegradación Ambiental , Chlorella/metabolismo , Fenoles/metabolismoRESUMEN
The first biomimetic total synthesis of the iron chelator anachelin H isolated from the cyanobacterium Anabaena cylindrica is reported. A first generation approach delivered one enantiomeric series of the polyketide fragment. Comparison of the 1H NMR data suggested the relative configuration of this anachelin fragment. The relative and absolute configuration of anachelin H was then established by total synthesis. A second generation approach involved the enzymatic conversion of N,N-dimethyltyramine to the anachelin chromophore. It was demonstrated that the enzyme tyrosinase is activated by the product during this reaction, the anachelin chromophore can serve as a tyrosinase activator. Anachelin H was evaluated against a panel of eleven bacterial and fungal pathogens, and moderate antibiotic activity (32 microg/mL) against Moraxella catarrhalis was found.
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Antifúngicos/síntesis química , Antifúngicos/farmacología , Moraxella catarrhalis/efectos de los fármacos , Oligopéptidos/síntesis química , Oligopéptidos/farmacología , Compuestos de Quinolinio/síntesis química , Compuestos de Quinolinio/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Anabaena cylindrica/química , Antibacterianos/química , Antifúngicos/química , Biomimética , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Oligopéptidos/química , Compuestos de Quinolinio/química , EstereoisomerismoRESUMEN
Growth, morphological variation, and liquid chromatography-photodiode array detection-mass spectrometric analysis of pigments have been studied in a diazotrophic cyanobacterium Anabaena cylindrica in response to NaCl stress. The chlorophyll and cellular protein contents increased initially in response to 50 mM: NaCl. Further increment in NaCl concentration, however, resulted in a significant decrease in both chlorophyll and cellular protein. A. cylindrica cells subjected to NaCl stress also showed morphological variations by having alteration in their size and volume. A. cylindrica cells subjected to NaCl stress also exhibited altered plastoquinone and chlorophyll-a (chl a) levels in comparison to its NaCl-untreated counterpart. Furthermore, a relative increase in plastoquinone level and a subsequent decrease in chl a level were recorded in NaCl adapted cells of A. cylindrica in response to NaCl stress. These results suggest that owing to adaptation various morphological, physiological, and biochemical changes occur in the cyanobacterium A. cylindrica in response to NaCl stress.