Unpalatable Weed Stellera chamaejasme L. Provides Biotic Refuge for Neighboring Species and Conserves Plant Diversity in Overgrazing Alpine Meadows on the Tibetan Plateau in China

Steller chamaejasme L. （S. chamaejasme for short） is one of the most noxious unpalatable weeds in China, which has been frequently reported its negative interaction （i.e. competition and allelopathy） with other herbaceous species in grasslands. This study compared species diversity, biomass and sexual reproduction of herbaceous plants in meadows with S. chamaejasme and in open meadows without S. ehamaejasme in overgrazing meadows on the Tibetan Plateau in China to determine whether positive facilitation exist between S. chamaejasme and other herbaceous species under livestock＇s overgrazing. The results showed that there are more herbaceous species in meadows with S. chamaejasme than those in open meadows （35s and30s, respectively）. Diversity index and above-ground biomass were also significantly higher in meadows with S. charnaejasme. There were 39% （11/28） of all species with sexual reproduction found in meadows with S. charnaejasme, which was 7 times more than those in open meadows. Our study showed that S. charnaejasme could provide biotic refuge for neighboring plants and preserve plant diversity from livestock＇s overgrazing in alpine meadows on the Tibetan Plateau. It also suggested that inter-specific facilitation between S. charnaejasme and other herbaceous species may play a key role in overgrazing alpine meadows.

ANTITUMOR PRINCIPLES OF STELLERA CHAMAEJASME L.

Methanol extract of Stellera chamaejasme L wasassessed for antitumor activity by an antitumor activebioassay against murine leukemia P388 in vivo. Thebioassay-directed separation of the extract furnishedseven diterpene compounds (stellerarin, stelleramacrin,gnidimacrin, pimelea factor P2, subtoxin, huratoxin,simplexin ) and two biflavanone compounds (neochemae-jasmin A and B). Among them, gnidimacrin, stellerarinand stelleramacrin (a novel compound) were found tohave high antitumor and cytotoxic activities against P388,L1210 and K562 in vivo and in vitro. The results suggestedthat the diterpene compounds were the potent anti-tumor principles of Stellera chamaejame L

A New Biflavonoid from Stellera chamaejasme L.

A new biflavonoid, stelleranol, was isolated from the roots of Stellera chamaejasme L.. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.

A New Chromone Derivative from Stellera chamaejasme L

A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.

In vitro inhibitory and pro-apoptotic effect of Stellera Chamaejasme LExtract on human lung cancer cell line NCI-H157

OBJECTIVE:To investigate the inhibitory and pro-apoptotic effect of Stellera Chamaejasme L extract(ESC) in vitro.METHODS:ESC was first extracted with ethanol,and then washed using a polyamide column with 60% ethanol.ESC was then decompressively recycled and vacuum dried at room temperature to obtain active fractions.Subsequently,the cytotoxic and apoptotic effects of ESC on NCI-H157 human lung cancer cells were determined.RESULTS:The results showed that ESC was rich in isomers of Chamaejasminor,neochamaejasmine and Sikokianin.ESC had significant cytotoxicity against NCI-H157 cells,with an IC 50 of approximately 18.50 μg.mL-1.ESC caused significant increase in total apoptotic rate,the activity of caspase 3 and 8,and Fas protein expression(P<0.05).CONCLUSION:The inhibitory effect of ESC on NCI-H157 tumor cells might partly be attributed to its apoptotic induction through activation of the Fas death receptor pathway.

THE ANTITUMOR ACTIVITIES OF GNIDIMACRIN ISOLATED FROM STELLERA CHAMAEJASMEL．

Gnidimacrin, a diterpene compound, isolated from the methanol extract of Stellera, chamaejasme L., showed significant antitumor activities against mouse leukemia P-388 and L-1210 in vivo, such as Lewis lung carcinoma, B-16 melanoma and Colon cancer 26. It showed ILSs of 40%.49% and 41% at the dosages of 0.01-0.02 mg/kg ip,respectively. Gnidimacrin strongly inhibited cell Proliferation of human cancer cell lines such as leukemia K562, stomach cancers Kato-III, MKN-28, MKN-45, and mouse leukemia L-1210 by the MTT assay and colony forming assay in vitro. The IC50 of gnidimacrin was 0.007-0.00012 μg/ml. It is concluded that gnidimacrin is the principal antitumor element in Stellera chemaejasme L. with strong antitumor activities.

Design, Synthesis, and Insecticidal Activity of 1,5-Diphenyl-l-pentanone Analogues

Three series of novel 1,5-diphenyl-l-pentanone derivatives were designed and synthesized. Their structures were characterized by IR, IH NMR techniques, and elemental analysis. The insecticidal activities of the new compounds were preliminarily evaluated. The bioassay results indicated that the compounds Xll--X30 displayed better aphicidal activity against Aphis gossypii than compounds X1--X10 and the lead compound （E）-l,5-diphenyl-1- penten-1-one （A）. The inhibitory rates of compounds X6 and X29 were 100% against Plutella xylostella （L.） at 600 mgoL 1. Compounds X12, X13, X19, X24, X25, X26 and X27 showed higher insecticidal activity against Tetranychus cinnabarinus （Boisduval） at 600 mgoL 1 than the lead compound （A）. Keywords Stellera chamaejasme L, （E）-l,5-diphenyl-l-penten-l-one, analogue, synthesis, design, insecticidal activity

Isochamaejasmin induces apoptosis in leukemia cells through inhibiting Bcl-2 family proteins

The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L.(Thymelaeaceae) that is used in traditional Chinese medicine(TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand(–)-gossypol through 3D similarity search. It selectively bound to Bcl-xL and Mcl-1 with Ki values being 1.93 ± 0.13 μmol·L-1 and 9.98 ± 0.21 μmol·L-1, respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 μmol·L-1 and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 μmol·L-1. Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L..

Synthesis and fungicidal activity study of novel daphneolone analogs with 2,6-dimethylmorpholine

A series of novel daphneolone analogs was designed and synthesized on the basis of natural product 1,5-diphenyl-2-penten-1-one（I） from Stellera chamaejasme L. as lead compound, whereby 2,6-dimethylmorpholine moiety was introduced to replace 1-phenyl group. Their structures were confirmed by IR,1H NMR, and HRMS（ESI） or elemental analysis,13 C NMR for some representative compounds. The two isomers of target compounds were separated and identified by NOESY technique and chemical method.All of the synthesized compounds have been evaluated for anti-plant pathogenic fungi activities. The results showed that some compounds exhibited moderate to good antifungal activities against tested fungi at the concentration of 50 mg/L. Among them, compound 7d, with a 4-bromine-substituted phenyl group and cis-2,6-dimethylmorpholine moiety, displayed best activity with an EC50 of 23.87 mmol/L against Valsa mali, superior to lead compound I. In addition, preliminary structure–activity relationship analysis indicated that, between two isomers of target compounds, the antifungal activities of the isomer with cis-2,6-dimethylmorpholine were better than the trans-isomer.