α-Tocopherolquinone

The chemical constituents in the ethanol extract of Viburnum utile were isolated by column chromatography with D101 macroporous resin, silica gel, and Sephadex LH-20. Their structures were identified by spectroscopic techniques such as NMR and MS. All the compounds were evaluated for the inhibitory activities against α-glucosidase. Sixteen compounds were obtained and identified as viburnumide A(1), vitamin E(2), α-amyrin(3), α-tocoquinone(4), narjatamanin B(5), ethyl caffeate(6), naringenin(7), apigenin(8), ethyl β-D-ribo-hex-3-ulopyranoside(9), trans-p-hydroxycinnamic acid(10), amentoflavone(11), apigenin-7-O-β-D-glucoside(12), luteolin-7-O-β-D-glucoside(13), henryoside(14), ursolic acid(15), and 2α-hydroxy-oleanolic acid(16). Among them, compound 1 was a new compound, and compounds 2-16 were isolated from V. utile for the first time. The inhibitory activity(IC_(50) of 4.0 μmol·L~(-1)) of compound 11 against α-glucosidase was comparable to that of the positive control acarbose(IC_(50) of 2.3 μmol·L~(-1)).

Atmospheric polycyclic aromatic hydrocarbons (PAHs) and their derivatives are a global problem that influences the environment and threatens human health. To investigate the characteristics, sources, and health risk assessment of PM_2.5-bound PAHs and their derivatives, PM_2.5 were collected at an urban site in Zibo from November 5 to December 26, 2020, and the concentrations of 16 conventional PAHs, nine NPAHs, and five OPAHs in PM_2.5 were analyzed using gas chromatography-mass spectrometry. Source apportionment of PAHs and their derivatives was conducted using diagnostic ratios and a PMF model, and the health risks of PAHs and their derivatives to adult men and women were evaluated using the source-dependent incremental lifetime cancer risk (ILCR) model. The results showed that the average concentrations of ∑₁₆pPAHs, ∑₉NPAHs, and ∑₅OPAHs in PM_2.5 of Zibo City during the sampling period were (41.61 ± 13.40), (6.38 ± 5.70), and (53.20 ± 53.47) ng·m^-3, respectively. The concentrations of the three PAHs increased significantly after heating, which were 1.31, 2.04, and 5.24 times larger than those before heating. During the sampling period, Chr, BaP, and BaA were the dominant components of pPAHs; 9N-Ant and 2N-Flt + 3N-Flt were the dominant components of NPAHs; and ATQ and BZO were the dominant components of OPAHs. Source apportionment results showed that motor vehicles were the main source of PAHs and their derivatives in PM_2.5 before heating, whereas after heating, the main sources were the mixed source of coal and biomass combustion and secondary formation. The total BaP equivalent (TEQ) was 14.5 ng·m^-3 during the sampling period, and the TEQ increased significantly after heating, which was approximately 1.2 times of that before heating. Assisted by the individual PAH source apportionment results, the ILCR of PM_2.5-boundPAHs and NPAHs in Zibo City had a certain potential carcinogenic risk for adult males (1.06 × 10^-5) and females (9.32 × 10^-6). Among them, the health risks of PAHs from gasoline vehicles, diesel vehicles, and coal/biomass combustion were significantly higher than those from other emission sources.