In this study, a titanium ion (Ti 4+ ) functionalized polydopamine coated ferroferric oxide (Fe 3 O 4 @PDA@Ti 4+ ) core-shell magnetic particle was prepared for the selective extraction of nucleotides. Firstly, different metal ions including Ti 4+ , Zr 4+ , Fe 3+ , Al 3+ , Cu 2+ , Zn 2+ , Ni 2+ and Mg 2+ were respectively immobilized onto Fe 3 O 4 @PDA particles and their extraction efficiency for five nucleotides [cytidine-5′-monophosphate (CMP), uridine-5′-monophosphate (UMP), guanosine-5′-monophosphate (GMP), thymidine-5′-monophosphate (TMP) and adenosine-5′-monophosphate (AMP)] were compared. Among these prepared materials, Fe 3 O 4 @PDA@Ti 4+ , which exhibited the highest extraction efficiency for nucleotides, was further characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. After being optimized of the extraction parameters including adsorbent amounts, extraction time, extraction temperature, type and concentration of the eluent, the prepared Fe 3 O 4 @PDA@Ti 4+ magnetic particles were successfully applied for the selective extraction and determination of CMP, UMP, GMP, TMP and AMP in Cordyceps and Lentinus edodes . Good linearity (varying from 0.063 to 19.000 μg/mL, R 2 > 0.999) and low limit of detection (LODs) (ranging between 0.0047 and 0.0141 μg/mL) for target analytes were achieved. These results demonstrated that the synthesized material in this study had potential for selective extraction of phosphorylated small molecular compounds in complicated matrix.
Daihua Hu,Wang Chen,Xinsheng Li,Tianli Yue,Zhijian Zhang,Zili Feng,Cuili Li,Xing Bu,Qing X. Li,Ching Y. Hu,LiuDi Li
Vitamin D deficiency is a serious global health problem. Edible mushrooms are a good source of vitamin D for human health. The objective of this experiment was to investigate the efficiency of converting its precursor ergosterol to vitamin D2 in shiitake mushroom (Lentinus edodes) and oyster mushroom (Pleurotus ostreatus) powder in ethanol suspension under ultraviolet (UV) irradiation. UV irradiation conditions were optimized for several parameters, such as material form, wavelength, wavelength combination, and exposure time. Under the optimal conditions, UV irradiation increased the concentrations of vitamin D2 from undetectable to 40.59 ± 1.16 μg/g (dw) in dry shiitake mushroom powder and to 677.28 ± 40.42 μg/g (dw) (an approximately 16.69-fold increase) in ethanol suspension. The concentration of vitamin D2 increased from undetectable to 23.71 ± 5.72 μg/g (dw) in the dry oyster mushroom powder upon UV irradiation, whereas UV irradiation increased the concentration to 275.32 ± 48.45 μg/g (dw) (an approximately 11.61-fold increase) in the ethanol suspension. Comparing the effects of varying combinations of wavelengths showed that irradiation with UV-A, UV-C, or a combination of both is more effective than UV-B irradiation. In addition, the increase in vitamin D2 in shiitake mushrooms irradiated by UV-C was time-dependent, that is, dose-dependent. Nevertheless, the increase rates decreased with time. The concentration of ergosterol decreased with the increase in vitamin D2, but ergosterol was only partially converted to vitamin D2, whereas most of the ergosterol was probably UV-degraded. Exposure to ultraviolet light in ethanol suspension offers an effective way to increase the concentration of vitamin D2 and thus improve the nutritional value of edible mushrooms, as well as make them more functional as a source of vitamin D to improve the consumer health.
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