, an endophytic fungus associated with the herbal medicine , produced four new polyketides, aspeversins A-D (1-2 and 5-6) and four known compounds, -methylaverufin (2), aversin (3), varilactone A (7) and spirosorbicillinol A (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by calculated electronic circular dichroism (ECD) and Mo(AcO)-induced CD data. Compound 5 was found to exhibit α-glucosidase inhibitory activity with an IC value of 25.
View Article and Find Full Text PDFNigrograna sp. LY66, an endophytic fungus associated with the herbal medicinal plant Clematis shensiensis, produced four undescribed steroids, nigergostanes A-D (1-4), including an unusual ketal-containing nigergostane (1), and four undescribed sesquiterpenoids decorated with cyclohexanone motifs, nigbisabolanes A-D (7-10), along with three known compounds, 23R-hydroxy-(20Z,24R)-ergosta-4,6,8(14),20(22)-tetraen-3-one (5), ergosta-5,7,22-trien-3β-ol (6), and curculonone A (11). The structures and absolute configurations of these undescribed compounds were confirmed using spectroscopic data (NMR and HRESIMS), modified Mosher's method, and ECD experiments.
View Article and Find Full Text PDFThis paper takes the 2014 pilot project of accelerated depreciation of fixed assets as a quasi-natural experiment, and builds a Propensity Score Matching-Difference in Differences (PSM-DID) model based on the data of Chinese listed companies from 2000 to 2019 to test the impact of tax preference on enterprise investment efficiency and its mechanism. The results show that the policy inhibits supported enterprises investment efficiency significantly. Heterogeneity analysis shows that the policy causes greater investment efficiency losses for small and medium-sized enterprises, non-state-owned enterprises and asset-heavy enterprises.
View Article and Find Full Text PDFA correct use of food nutrition la bels benefits consumers in pursuing balanced diets. As a result, we conducted interviews in Nanjing, China and randomly sampled 427 respondents. Further, we used both descriptive statistics and binary logistic regression to assess their perception of food nutrition label use.
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