ABSTRACT
In order to control the increasing ozone ï¼O3ï¼ pollution in Hebi, Henan Province, clarifying the pollution characteristics of ozone and its precursors is vital. Therefore, we conducted a comprehensive analysis of O3 pollution utilizing the OFP-PMF-EKMA method combined with online hourly resolution monitoring data of conventional pollutants and volatile organic compounds ï¼VOCsï¼ in the summer of 2022 ï¼June-Septemberï¼. Ozone formation potential ï¼OFPï¼ was used to identify the key VOCs species, and the PMF model was used to identify the VOCs emission sources, whereas EKMA curves and scenario analysis were used to identify the main ozone control area in Hebi and to determine the reduction ratio of VOCs and NOx in a scientifically refined way. In 2022, Hebi had persistent O3 pollution, with the highest concentration in June. Conditions of high temperature, low humidity, and low atmospheric pressure contributed to the O3 accumulation. Aromatic and oxygenated volatile organic compounds ï¼OVOCsï¼ contributed significantly to the OFP and VOCs fraction, which were the dominant active substance and concentration dominant species. The results of the VOCs source analysis indicated that vehicle exhaust sources ï¼25.3%ï¼ were the main source of atmospheric VOCs, followed by process sources ï¼17.7%ï¼ and biomass combustion sources ï¼17.6%ï¼. Thus, emission sources associated with the combustion of fossil fuels and industrial production emissions were the most urgent sources of atmospheric VOCs to be controlled in Hebi. The O3 generation in Hebi occurred in the VOCs-sensitive zones, and the emission reduction results showed that a synergistic emission reduction of VOCs and nitrogen oxide ï¼NOxï¼ could effectively control O3 pollution with a 75% reduction in VOCs and a 10% reduction in NOx.
ABSTRACT
OBJECTIVE: To study the chemical constituents from Anemone flaccida. METHOD: Chemical constituents were isolated by repeated column chromatography (silica gel, Toyopearl HW-40C and preparative HPLC). The structures were elucidated on the basis of spectral data analysis. RESULT: Twelve triterpenes were isolated and their structures were identified as follow: oleanolic acid (1), oleanolic acid 3-O-beta-D-glccopyranosyl-(1-->2)-beta-D-xylopyranoside (2), eleutheroside K (3), oleanolic acid 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranoside (4), oleanolic acid 3-O-beta-D-glccopyranosyl-(1-->2)-alpha-L-arabinofurnoside (5), oleanolic acid 3-O-beta-D-glccuronopyranose (6), oleanolic acid 3-O-beta-D-glccuronopyranose methyl ester (7), oleanolic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glccopyranosyl (1-->6)-beta-D-glccopyranosyl (8), oleanolic acid 3-O-beta-D-glccuronopyranose 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glccopyranosyl (1-->6)-beta-D-glccopyranoside (9), oleanolic acid 3-O-beta-D-glccopyranosyl methyl ester 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glccopyranosyl (1-->6)-beta-D-glccopyranoside (10), oleanolic acid 3-O-beta-D-glccopyranosyl-(1-->2)-beta-D-xylopyranosyl-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glccopyranosyl (1-->6)-beta-D-glccopyranoside (11), oleanolic acid 3-O-alpha-L-rh-amnopyranosyl-(1-->2)-alpha-L-arabinopyrnosyl-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glccopyranosyl (1-->6)-beta-D-glccopyranoside (12). CONCLUSION: compounds 5-8, 10, 12 were isolated from this plant for the first time. Compounds 2, 5 and 11 showed positive anti-tumor activities.
