35 research outputs found
Matrix-free laser desorption ionization mass spectrometry as a functional tool for the analysis and differentiation of complex phenolic mixtures in propolis: a new approach to quality control
Matrix-free laser desorption ionization (LDI) is a rapid and versatile technique for the ionization of small, UV-light-absorbing molecules. Indeed, many natural products such as polyphenols exhibit inherent LDI properties, potentially facilitating their detection from highly complex samples such as crude extracts. With this in mind, the present work thoroughly evaluated the potential of LDI as an analytical tool for the chemical profiling and differentiation of propolis samples obtained from different global regions. Propolis is a complex bee product containing, among others, significant amounts of phenolic constituents that may show LDI effects. The present work will demonstrate that LDI not only provides reproducible and highly specific fingerprint spectra for each of the tested samples, it further allows their clear differentiation by principal compound analysis (PCA). Contrary to classical analytical approaches such as LC- or GC-MS, LDI does not require time-consuming sample preparation and method optimization procedures. Thus, the technique represents a most interesting analytical tool and potent supplement to classic LC-MS for quality control of herbal pharmaceuticals and dietary supplements. Present results clearly support this approach and further suggest the use of LDI as a versatile tool for the automated analysis of large sample batches on an industrial scale
A toolset of aequorin expression vectors for in planta studies of subcellular calcium concentrations in Arabidopsis thaliana.
Evaluation of new aequorin-based calcium probes for the monitoring of calcium dynamics and cross-talk between plastids and endoplasmic reticulum in plant cells
Integration of plastids in the plant calcium signalling network revealed by the targeting of aequorin chimeras to chloroplast subcompartments
Functional interaction in establishment of ribosomal integrity between small subunit protein rpS6 and translational regulator rpL10/Grc5p
Thylakoid-targeted aequorin probes reveal an integrated role for thylakoids in Ca2+ homeostasis and modulation of chloroplast Ca2+ signals
The screening for novel inhibitors of auxin-induced Ca2+ signaling
Ca2+-based second messenger signaling is used by many signal perception mechanisms to modulate specific cellular responses. The well-characterized phytohormone auxin elicits a very rapid Ca2+ signal, but the molecular players involved in auxin-induced Ca2+ signaling are still largely unknown. The complicated and often redundant nature of the plant Ca2+ signaling machinery makes the use of mutants and transgenic lines a painstaking process, which makes a pharmacological approach an attractive alternative to study these processes. Here, we describe the development and utilization of a screening assay that can be used to probe a compound library for inhibitors of auxin-induced Ca2+ entry in plant cell suspensions