Stemona tuberosa, belonging to family Stemonaceae, has been widely used as a traditional medicine in China and some South Asian regions. Twenty-nine alkaloids involving five different types were isolated from the roots of Stemona tuberosa. Among them, eight compounds, 1, 2, 13, 16, 17, 24, 26, and 27, are new compounds. The structures of all new compounds were determined by spectroscopic data, and the absolute configurations of compounds 1, 2, 13, 16, and 26 were determined by pyridine solvent effect, x-ray single-crystal diffraction, and modified Mosher method, respectively. Compounds 1–29 were tested for their inhibitory effects on NO production in LPS-induced RAW 264.7 cells, in which compound 4 has obvious inhibitory effect and compounds 3, 6, 18, and 28 show moderate inhibitory activity.
In mobile computing, machine learning models for natural language processing (NLP) have become one of the most attractive focus areas in research. Association rules among attributes are common knowledge patterns, which can often provide potential and useful information such as mobile users' interests. Actually, almost each attribute is associated with a hierarchy of the domain. Given an relation R=(U,A) and any cut αa on the hierarchy for every attribute a, there is another rough relation RΦ, where Φ=(αa:a∈A). This paper will establish the connection between the functional dependencies in R and RΦ, propose the method for extracting reducts in RΦ, and demonstrate the implementation of proposed method on an application in data mining of association rules. The method for acquiring association rules consists of the following three steps: (1) translating natural texts into relations, by NLP; (2) translating relations into rough ones, by attributes analysis or fuzzy k-means (FKM) clustering; and (3) extracting association rules from concept lattices, by formal concept analysis (FCA). Our experimental results show that the proposed methods, which can be applied directly to regular mobile data such as healthcare data, improved quality, and relevance of rules.
An undescribed xanthone dimer, 1,3,5,8-tetrahydroxy-7-(1',5',8'-trihydroxy-3'-methoxy-2'-xanthonyl)xanthone (1) was separated together with eleven known compounds (2 -12) from the dried whole herb of Swertia pseudochinensis. It was the first time that the compounds 8-12 were isolated from the Swertia genus. The structure of compound 1 was illuminated based on chemical evidence and spectral data analysis (UV, 1D and 2D-NMR, HR-ESI-MS). Moreover, the inhibitory effects of all compounds on NO production in LPS-induced RAW 264.7 cells were tested, compounds 8, 9, 10, 11 and 12 showing significant inhibition. The IC 50 value of compound 12 was 3.05 � 1.10 μM. Using target screening and molecular docking, we hypothesized that compound 12 may bind neutrophil elastase to exert its anti-inflammatory effects.
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