A preliminary study on the enzymatic biotransformation of ginsenosides is evaluated. β-Galactosidase from Aspergillus sp. displayed β-glucosidase activity, which was responsible for its ability to transform major ginsenoside Rb1 to rare ginsenoside F2 via ginsenoside Rd. The Rb1 conversion, Rd and F2 yields reached 100%, 80.7% and 14.3% after 60 h at 60 °C, respectively. Ginsenoside Rg3 can be selectively hydrolyzed and only Rh2 was obtained with this β-galactosidase as well. Before hydrolysis, an Rg3 inclusion complex was prepared with hydroxypropyl-β-cyclodextrin (HP-β-CD) to improve the aqueous solubility. The solubility of Rg3 increased 74.6 fold, and the phase solubility curve displayed a typical AL-type, which indicates the formation of a 1 : 1 inclusion complex. Using an enzyme loading of 500 U g−1 Rg3, the highest Rg3 conversion of 90.6% and Rh2 yield of 88.5% were obtained after 24 h at 60 °C. These results indicate that β-galactosidase from Aspergillus sp. could be useful for the mass production of rare ginsenosides.
In this study, a novel green-emitting fluorapatite phosphor Ca 9 Tb(PO 4 ) 5 (SiO 4 )F 2 :Ce 3+ (CTPSF:Ce 3+ ), which features excellent luminous efficiency and thermal stability, was first designed and prepared. High-concentration doping of Tb 3+ enables efficient green emission. Moreover, photoluminescence (PL) spectra and diffuse reflectance spectra reveal that the introduction of Ce 3+ extends the excitation spectrum to the range spanning 200 nm–380 nm, with a significant improvement in efficiency, which stem from the Ce 3+ → Tb 3+ energy transfer process. The introduction of Ce 3+ boosts the photoluminescence intensity of CTPSF by 2.315-fold, delivering a great internal quantum efficiency (IQE) of 73.95 % and an external quantum efficiency (EQE) of 57.86 %. Additionally, the thermal stability improved from retaining 66.3 % of the original intensity at 150 °C to 83.6 % retention of its original intensity at 150 °C. Finally, White-light-emitting diode (WLED) devices were fabricated by employing BaMgAl 10 O 17 :Eu 2+ (blue), CaAlSiN 3 :Eu 2+ (red), and the synthesized CTPSF:Ce 3+ (green) phosphors. Upon applying a forward bias current of 60 mA, the WLED device displayed a high color rendering index (Ra) of 92.7 and a low correlated color temperature (CCT) of 3973 K, validating the potential of this green-emitting phosphor for practical applications in WLED lighting systems.
Polyunsaturated fatty acids (PUFA), a group of nourishing and health-promoting nutrients, ameliorate age-related chronic diseases. However, how PUFA especially n-3 PUFA exert anti-aging functions remains poorly understood. Here we link fish oil, docosahexaenoic acid (DHA) and arachidonic acid (AA) to the aging etiology via a redox-telomere-antioncogene axis based on D-galactose-induced aging mice. Both fish oil and PUFA enhanced hepatic superoxide dismutase (SOD) and catalase activities and cardiac SOD activities within the range of 18%-46%, 26%-65% and 19%-58%, respectively, whereas reduced cerebral monoamine oxidase activity, plasma F 2 -isoprostane level and cerebral lipid peroxidation level by 56%-90%, 20%-79% and 16%-54%, respectively. Thus, PUFA improve the in vivo redox and oxidative stress induced aging process, which however does not exhibit a dose-dependent manner. Notably, both PUFA and fish oil effectively inactivated testicular telomerase and inhibited c-Myc -mediated telomerase reverse transcriptase expression, whereas n-3 PUFA rather than n-6 PUFA protected liver and testes against telomere shortening within the range of 13%-25% and 25%-27%, respectively. Therefore, n-3 PUFA may be better at inhibiting the DNA damage induced aging process. Surprisingly, only DHA significantly suppressed cellular senescence pathway evidenced by testicular antioncogene p16 and p53 expression. This work provides evident support for the crosstalk between PUFA especially n-3 PUFA and the aging process via maintaining the in vivo redox homeostasis, rescuing age-related telomere attrition and down-regulating the antioncogene expression.
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