ABSTRACT
The chemical composition, security and bioactivity of pigments from Penicillium purpurogenum Li-3 strain screened by our group were firstly studied in this work. DPPH and the filter disc diffusion method were used to determine the biological activities of the red pigments. The pigment was characterized by UV/VIS, FT-IR, NMR and UPLC-Q-TOF-MS. HPLC/MS was used to detect mycotoxins (citrinin) in fermentation broth. An acute toxicity was detected in the embryos of zebrafish. As a consequence, the crude red pigment from the AcOEt fraction showed better DPPH scavenge capacity and antibacterial activity. Spectroscopic (UV, FT-IR, 13 C-NMR) and UPLC-Q-TOF-MS analysis revealed that the Penicillium purpurogenum Li-3 red pigment (RPs) was monascus-like pigment and its molecular weight was 439.1997. Moreover, the red pigment was shown to be weak cytotoxic against the zebrafish embryos. The yield of the red pigment increased 69 % under optimized culture conditions. These outstanding properties will enlarge the application of RPs for natural food additives, new antioxidant and antibacterial drug development.
Subject(s)
Penicillium/metabolism , Pigments, Biological/chemistry , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antioxidants/chemistry , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Citrinin/analysis , Citrinin/isolation & purification , Citrinin/pharmacology , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/metabolism , Escherichia coli/drug effects , Mass Spectrometry , Molecular Weight , Penicillium/chemistry , Pigments, Biological/pharmacology , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus/drug effects , Zebrafish/growth & developmentABSTRACT
A calibration method for Raman spectroscopic quantitative analysis of binary alkaline silicate glasses is proposed. By applying ab initio quantum chemistry simulation, Raman optical activities (ROA) of various cluster units consisting of silicon-oxygen tetrahedra (SiOT) with different number of non-bridging oxygen (NBO) can be obtained. Thus, experimental results could be calibrated in order to reflect and represent directly the true relative density of various silicon-oxygen tetrahedra existing inside the silicate glasses. Cation effect on the intensity of Raman bands was also observed and discussed.
ABSTRACT
Cuspidine plays an important role in conventional metallurgical continuous casting mould flux. An UV laser source was used to record its ambient and high temperature Raman spectra (temperature range: 298-1 723 K) combined with a charge coupled device (CCD) detector. Both increasing and decreasing processes as well as characteristic spectra and shifts in wavenumber were observed. Micro-structure of cuspidine in liquid state is not unitary and different from that in solid state, suggesting multi clusters coexisting. Density functional theory (DFT) simulation method was applied to calculate its wavenumbers of Raman active vibrations by introducing the crystal spatial configuration model of cuspidine. Thus the experimental vibrational wavenumbers of the characteristic peaks could be assigned. This will help study physical and chemical behavior of cuspidine in continuous casting mould flux and provide an unique in-situ method under varying temperature with Raman spectroscopic technique.
