Home About us Contact
|
Home About us Contact | ||
|
|
||
Strong Activity (strong + activity)
Selected AbstractsIn-vitro antiproliferative effects on human tumour cell lines of extracts and jacaranone from Senecio leucanthemifolius PoiretJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2005M. R. Loizzo We have studied the cytotoxic activity of extracts and jacaranone from Senecio leucanthemifolius Poiret. Extracts from S. leucanthemifolius were able to inhibit the in-vitro proliferation of a series of human tumour cell lines. The dichloromethane extract demonstrated effective cytotoxic activity with an IC50 of 20.1 ,g mL,1 on the large cell carcinoma cell line COR-L23. The ethyl acetate extract showed an IC50 value of 5.0 ,g mL,1 and the butanol extract an IC50 value of 6.4 ,g mL,1 on the same cell line. A major active constituent of the dichloromethane extract was shown to be jacaranone, which was demonstrated to have a very strong activity against all of the tumour cell lines with IC50 values between 2.86 and 3.85 ,g mL,1, although it did not account for all the activity observed. Constituents of S. leucanthemifolius extracts were identified by GC/MS analysis and NMR. [source] In vitro fungitoxic activity of Larrea divaricata cav. extractsLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2004E.N. Quiroga Abstract Aims:, To evaluate the fungitoxic activity of Larrea divaricata Cav. extract and one of its components against yeasts and fungi. This activity was compared with the action of ketoconazole, a known synthetic antimycotic. Methods and Results:, Antifungal activity of Larrea divaricata extract and of a fraction (Fr. B) purified by thin layer chromatography, was investigated using different methodologies. Both exhibited strong activity against the majority of the assayed fungi. Only Fusarium oxysporum and Schizophyllum commune growth was not affected with the assayed conditions. The fungitoxic and cytotoxic activity of the ethanolic extract and ketoconazole were compared. Conclusions:, Ethanolic extracts of L. divaricata Cav. produce growth inhibition of several fungi. One of its constituents with the same activity was purified and identified as a glycoside of a flavanone. A comparison with the action of ketoconazole, which is currently used as antimycotic and can cause adverse health effects was made. Significance and Impact of the Study:, Our data suggest that L. divaricata extract contains, at least, one compound of phenolic nature, with fungitoxic potency against yeasts and fungi. [source] The relationship between the chemical composition of three essential oils and their insecticidal activity against Acanthoscelides obtectus (Say)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2004Dimitrios P Papachristos Abstract The chemical composition of the essential oils isolated from various parts of three Greek aromatic plants (Lavandula hybrida Rev, Rosmarinus officinalis L and Eucalyptus globulus Labill) collected at different seasons was determined by GC/MS analysis. The insecticidal action of these oils and of their main constituents on Acanthoscelides obtectus (Say) adults was evaluated and their LC50 values were estimated. All essential oils tested exhibited strong activity against A obtectus adults, with varying LC50 values depending on insect sex and the composition of the essential oils. A correlation between total oxygenated monoterpenoid content and activity was observed, with oxygenated compounds exhibiting higher activity than hydrocarbons. Among the main constituents, only linalyl and terpinyl acetate were not active against A obtectus, while all the others exhibited insecticidal activity against both male and female adults, with LC50 values ranging from 0.8 to 47.1 mg litre,1 air. An attempt to correlate the insecticidal activity to the monoterpenoid's structure is presented, and the difference in sensitivity between male and female individuals is also explored. Copyright © 2004 Society of Chemical Industry [source] The diurnal cycle of shallow cumulus clouds over land: A single-column model intercomparison studyTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 604 2004Geert Lenderink Abstract An intercomparison study for single-column models (SCMs) of the diurnal cycle of shallow cumulus convection is reported. The case, based on measurements at the Atmospheric Radiation Measurement program Southern Great Plains site on 21 June 1997, has been used in a large-eddy simulation intercomparison study before. Results of the SCMs reveal the following general deficiencies: too large values of cloud cover and cloud liquid water, unrealistic thermodynamic profiles, and high amounts of numerical noise. Results are also strongly dependent on vertical resolution. These results are analysed in terms of the behaviour of the different parametrization schemes involved: the convection scheme, the turbulence scheme, and the cloud scheme. In general the behaviour of the SCMs can be grouped in two different classes: one class with too strong mixing by the turbulence scheme, the other class with too strong activity by the convection scheme. The coupling between (subcloud) turbulence and the convection scheme plays a crucial role. Finally, (in part) motivated by these results several models have been successfully updated with new parametrization schemes and/or their present schemes have been successfully modified. © Royal Meteorological Society, 2004. S. Irons's contribution is Crown copyright [source] Effect of CaO on NH3 + NO + O2 reaction system in the absence and presence of high concentration CO2ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010Tianjin Li Abstract The effect of CaO on the NH3 + NO + O2 reaction system at 650,850 °C was investigated. High CO2 concentration was added to investigate the effect of CaCO3 on this reaction system also. Experimental results showed that CaO had a strong catalytic effect on NH3 decomposition, NH3 oxidation by O2 to NO, and NO reduction by NH3 in the absence of O2. The overall effect of CaO on the NO + NH3 + O2 reaction was to enhance NH3 oxidation by O2 to produce more NO. A small amount of NO2 and no N2O was detected in the outlet gas stream over CaO in the NH3 + NO + O2 reaction. NO2 formation decreased with temperature increase. NO2 formation in the NH3 + NO + O2 reaction over CaO was attributed to the oxidization of NH3 and NO by O2. The performance of CaCO3 was different from CaO. NH3 decomposition was promoted, but NH3 oxidation to NO was inhibited after CaO was converted to CaCO3. No catalytic activity for NO reduction was detected in NO + NH3 reaction over CaCO3, but strong activity for NH3 decomposition was observed. NO and NH3 outlet concentration over CaCO3 in the NH3 + NO + O2 reaction was lower and higher, respectively, than that of CaO, which was mainly due to the difference of CaO and CaCO3 for NH3 oxidation. NO2 formation was inhibited, but N2O was observed over CaCO3. N2O formation increased with temperature increase at 650,750 °C, and then decreased at 750,850 °C. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Structure of the ligand-binding domain of rat VDR in complex with the nonsecosteroidal vitamin D3 analogue YR301ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2008Shinji Kakuda Vitamin D receptor (VDR) is a ligand-inducible hormone receptor that mediates 1,,25(OH)2D3 action, regulating calcium and phosphate metabolism, induces potent cell differentiation activity and has immunosuppressive effects. Analogues of 1,,25(OH)2D3 have been used clinically for some years. However, the risk of potential side effects limits the use of these substances. LG190178 is a novel nonsecosteroidal ligand for VDR. (2S)-3-[4-(3-{4-[(2R)-2-hydroxy-3,3-dimethylbutoxy]-3-methylphenyl}pentan-3-yl)-2-methylphenoxy] propane-1,2-diol (YR301) is the only one of the four evaluated stereoisomers of LG190178 to have strong activity. To understand the strong activity of YR301, the crystal structure of YR301 complexed with the rat VDR ligand-binding domain (VDR LBD) was solved at 2.0,Å resolution and compared with the structure of the VDR LBD,1,,25(OH)2D3 complex. YR301 and 1,,25(OH)2D3 share the same position and the diethylmethyl group occupies a similar space to the C and D rings of 1,,25(OH)2D3. YR301 has two characteristic hydroxyl groups which contribute to its potent activity. The first is 2,-OH, which forms hydrogen bonds to the NE2 atoms of both His301 and His393. The other is 2-OH, which interacts with Ser233,OG and Arg270,NH1. These two hydroxyl groups of YR301 correspond exactly to 25-OH and 1-OH, respectively, of 1,,25(OH)2D3. The terminal hydroxyl group (3-OH) of YR301 is directly hydrogen bonded to Arg270 and also interacts indirectly with Tyr232,OH and the backbone NH of Asp144 via water molecules. Additional derivatization of the terminal hydroxyl group using the positions of the water molecules might be useful for the design of more potent compounds. [source] | ||||||||||