Bioassay-guided fractionation of a methanol extract of the seeds of Caesalpinia sappan led to the isolation of 12 new cassane-type diterpenes, caesalsappanins A-L (1-12). Their structures were elucidated on the basis of NMR and HRESIMS analysis, and the absolute configuration of compound 1 was determined by single-crystal X-ray crystallography. All isolated compounds were tested against a chloroquine-resistant Plasmodium falciparum strain for antiplasmodial activities and against a small panel of human cancer cell lines for antiproliferative activities. Compounds 7 and 8 displayed antimalarial activity against the chloroquine-resistant K1 strain of P. falciparum with IC50 values of 0.78 and 0.52 μM and selectivity indices of 17.6 and 16.4, respectively. Compound 10 showed antiproliferative activity against the KB cancer cell line with an IC50 value of 7.4 μM.
Abstract. The regional transport of air pollutants, controlled by emission
sources and meteorological factors, results in a complex source–receptor
relationship of air pollution change. Wuhan, a metropolis in the Yangtze
River middle basin (YRMB) of central China, experienced heavy air pollution
characterized by hourly PM2.5 concentrations reaching 471.1 µg m−3 in January 2016. To investigate the regional transport of
PM2.5 over central eastern China (CEC) and the meteorological impact on
wintertime air pollution in the YRMB area, observed meteorological and other
relevant environmental data from January 2016 were analyzed. Our analysis
presented noteworthy cases of heavy PM2.5 pollution in the YRMB area
with unique “non-stagnant” meteorological conditions of strong northerly
winds, no temperature inversion, and additional unstable structures in the
atmospheric boundary layer. This unique set of conditions differed from the
stagnant meteorological conditions characterized by near-surface weak winds,
air temperature inversion, and stable structure in the boundary layer that
are typically observed in heavy air pollution over most regions in China.
The regional transport of PM2.5 over CEC aggravated PM2.5 levels,
thus creating heavy air pollution in the YRMB area. This demonstrates a
source–receptor relationship between the originating air pollution regions
in CEC and the receiving YRMB region. Furthermore, a backward trajectory
simulation using a Flexible Particle dispersion (FLEXPART) Weather Research and
Forecasting (WRF) model to integrate the air pollutant
emission inventory over China was used to explore the patterns of regional
transport of PM2.5 governed by the strong northerly winds in the cold
air activity of the East Asian winter monsoon season. It was estimated that
the regional transport of PM2.5 from non-local air pollutant emissions
contributes more than 65 % of the PM2.5 concentrations to the heavy
air pollution in the YRMB region during the study period, revealing the
importance of the regional transport of air pollutants over China as a
causative factor of heavy air pollution over the YRMB area.
Eight new cassane-type diterpenes, caesalpins A-H (1-8), were isolated from the ethyl acetate extract of Caesalpinia minax. Compound 1 displayed significant antiproliferative activity against HepG-2 (IC50 4.7 μM) and MCF-7 (IC50 2.1 μM) cells, and compounds 2 and 4 exhibited selective cytotoxic activities against MCF-7 (IC50 7.9 μM) and AGS (IC50 6.5 μM) cells.
Natural daphnane diterpenoids, mainly distributed in plants of the Thymelaeaceae and Euphorbiaceae families, usually include a 5/7/6-tricyclic ring system with poly-hydroxyl groups located at C-3, C-4, C-5, C-9, C-13, C-14, or C-20, while some special types have a characteristic orthoester motif triaxially connectedat C-9, C-13, and C-14. The daphnane-type diterpenoids can be classified into five types: 6-epoxy daphnane diterpenoids, resiniferonoids, genkwanines, 1-alkyldaphnanes and rediocides, based on the oxygen-containing functions at rings B and C, as well as the substitution pattern of ring A. Up to now, nearly 200 daphnane-type diterpenoids have been isolated and elucidated from the Thymelaeaceae and Euphorbiaceae families. In-vitro and in-vivo experiments of these compounds have shown that they possess a wide range of biological activities, including anti-HIV, anti-cancer, anti-leukemic, neurotrophic, pesticidal and cytotoxic effects. A comprehensive account of the structural diversity is given in this review, along with the cytotoxic activities of daphnane-type diterpenoids, up to April 2019.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.