We have developed the first selective fluorescent chemosensor (PyDPA) for (p)ppGpp, a bacterial and plant alarmone. By using pyrene-excimer fluorescence, PyDPA shows very good selectivity for (p)ppGpp from among other nucleotides in water. PyDPA was used for the real-time detection of in vitro ppGpp synthesis by bacterial ribosomal complexes.
"In the future it is therefore desirable to be able to generate specific small peptides with the desired activity. Targeted isolation of the desired peptides can in the future be facilitated by means of, for example, utilizing selective molecular tweezers, an isolation strategy that has been used with great success for other compounds     , attached to solid support such as magnetic beads. The beads can then be isolated by a magnet and the selectively bound peptides removed upon washing. "
[Show abstract][Hide abstract] ABSTRACT: Recent research has shown that fish residual materials contain a range of components with interesting biological activity. Therefore, there is a great potential in the marine bioprocess industry to utilize these by-products as starting material for generating more valuable products. The aim of the present study was to search for bioactive peptides (in particular small natural bioactive peptides with molecular weight lower than 10 kDa) in Atlantic herring (Clupea harengus L.) by-products such as skin and more general residual materials. By such means a range of peptides with claimed interesting biological activities was found. Herein the activity of the detected bioactive peptides and strategies for isolating peptide fragments containing the bioactive motif is discussed. Identification of bioactive peptides in crude peptide/protein sources (skin and residual materials) was performed directly using a combination of mass spectrometry (Orbitrap), bioinformatics and database search. This method was a good angle of approach in order to map the potential in new species and species that have been very little studied.
[Show abstract][Hide abstract] ABSTRACT: We have synthesized a novel class of dendrimers, consisting of a polysulfurated pyrene core with appended poly(thiophenylene) dendrons (PyG0, PyG1, and PyG2, see Scheme 1), which exhibit remarkable photophysical and redox properties. In dichloromethane or cyclohexane solution they show a strong, dendron-localized absorption band with a maximum at around 260 nm and a band in the visible region with a maximum at 435 nm, which can be assigned to the pyrene core strongly perturbed by the four sulfur substituents. The dendrimers exhibit a strong (Phi=0.6), short-lived (tau=2.5 ns) core-localized fluorescence band with maximum at approximately 460 nm in cyclohexane solution at 293 K. A strong fluorescence is also observed in dichloromethane solution at 293 K, in dichloromethane/chloroform rigid matrix at 77 K, and in the solid state (powder) at room temperature. The dendrimers undergo reversible chemical and electrochemical one-electron oxidation with formation of a strongly colored deep blue radical cation. A second, reversible one-electron oxidation is observed at more positive potential values. The photophysical and redox properties of the three dendrimers are finely tuned by the length of their branches. The strong blue fluorescence and the yellow to deep blue color change upon reversible one-electron oxidation can be exploited for optoelectronic devices.
Chemistry - A European Journal 11/2008; 14(33):10357 - 10363. DOI:10.1002/chem.200801198 · 5.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chlorophyll and bacteriochlorophyll derivatives possessing a trifluoroacetyl group at the 3-position were synthesized as new colorimetric sensors for amine detection. α-Amino alcohol formation of the free-base ehlorin and metallochlorins showed visual color changes from brown to purple and from green to blue, respectively. On the other hand, bacteriochlorin derivative showed large blue-shifts of the Q y peak in the near-infrared region (775 → 724 nm) and the Q x peak in the visible region (549 → 520 nm), which are advantageous points for amine sensing. Clear color change was observed from pink to turquoise by the formation of α-amino alcohol adduct.
Bulletin of the Chemical Society of Japan 01/2009; 82(2):267-271. DOI:10.1246/bcsj.82.267 · 2.21 Impact Factor
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