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Flavonoid‐C‐glycosides with various pharmacological actions were abundant in corn silk, and fragmentation in mass spectra of flavonoid‐C‐glycosides compounds was particularly important. This paper aimed to supervise the fragmentation patterns of flavonoid‐C‐glycosides in the enriched flavonoids from corn silk by high‐efficiency ultra‐high‐performance liquid chromatography combined with a quadrupole time‐of‐flight mass spectrometry approach. Therefore, the flavonoids were extracted by heating reflux and then purified based on D101 macroporous resin. Thirty‐five flavonoids were triumphantly identified in the purified product. Among them, 14 were flavonoid‐C‐glycosides, seven of them owned luteolin mother nuclei (luteolin‐C‐glycosides) and seven of them owned apigenin mother nuclei (apigenin‐C‐glycosides). Importantly, the diagnostic product ions of luteolin‐C‐glycosides including m/z (431, 413, 395, 369, 367, 313, and 299) and m/z (429, 411, 393, 367, 365, 311, and 297), and the characteristic product ions of apigenin‐C‐glycosides covered m/z (353, 339, and 299) and m/z (339, 327, and 309). In addition, diagnostic H2O neutral loss and glycosyl craking were familiar, and the difference values among product ions mainly contained 40, 60, 70, 80, 90, 100, and 120 Da. Thus, the fragmentations of luteolin‐C‐glycosides and apigenin‐C‐glycosides identified in corn silk were with proper regularity. The obtained fragmentation patterns provided rapid recognition and meaningful guidance for the purification study of flavonoid‐C‐glycosides. [ABSTRACT FROM AUTHOR]

Background and Purpose: This study explores the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and mortality among Parkinson's disease (PD) patients, providing evidence for the potential benefits of vitamin D (VD) supplementation., Methods: PD patients were collected from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2020. These patients were categorized based on their serum 25(OH)D levels: deficiency, insufficiency, and sufficiency. We compared demographic information and analyzed mortality data from the National Death Index. A restricted cubic spline model assessed the nonlinear association between 25(OH)D levels and mortality, complemented by multivariable Cox regression analysis. Consistency of results was checked through subgroup analysis., Results: The study included 364 PD patients: 87 (23.9%) with VD deficiency, 121 (33.2%) with insufficiency, and 156 (42.9%) with sufficiency. Demographically, 46.4% were male, and 56% were over 65 years. The deficiency group predominantly consisted of Mexican Americans (53.1%), had lower income levels, a higher unmarried rate, and increased liver disease incidence. The analysis showed a U-shaped curve between 25(OH)D levels and mortality risk, with the lowest risk at 78.68 nmol/L ( p -non-linear = 0.007, p -overall = 0.008). Kaplan-Meier analysis found the highest survival rates in patients with 25(OH)D levels between 75-100 nmol/L ( p  = 0.039). Compared to this group, patients with levels below 50 nmol/L had a 3.52-fold increased mortality risk (95% CI = 1.58-7.86, p  = 0.002), and those above 100 nmol/L had a 2.92-fold increase (95% CI = 1.06-8.05, p  = 0.038). Age-specific subgroup analysis ( p  = 0.009) revealed that both very low (<50 nmol/L) and high (>100 nmol/L) levels increased mortality risk in patients under 65, while levels below 75 nmol/L raised mortality risk in older patients., Conclusion: Serum 25(OH)D levels are nonlinearly linked to mortality in PD patients, with optimal survival rates occurring at 75-100 nmol/L. Deviations from this range increase the risk of death., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yong, Dong, Zhou, Zhu, Gu and Li.)