MEDICINAL CHEMISTRY/COMPUTATIONAL CHEMISTRY438 doi:10.2533/chimia.2007.438 CHIMIA 2007, 61,No. 7/8 Medicinal Chemistry 85 Medicinal Chemistry 86 NewC-glucosylxanthones from theleaves of Arrabidaea patellifera Analyses andbioactivitiesofwildpopulations of Rhodiola rosea L. (Bignoniaceae) (Crassulaceae) from Switzerland F. Martina ,A.E.Haya ,S.Vargas a ,L.Vivasb ,M.P.Guptac and D. van Diermen, A. Marston, K. Ndjoko and K. Hostettmann K. Hostettmanna,* LaboratoryofPharmacognosyand Phytochemistry, School of Pharmaceuti- a LaboratoryofPharmacognosyand Phytochemistry, School of Pharmaceuti- cal Sciences,University of Geneva, University of Lausanne, Quai Ernest- cal Sciences,University of Geneva, University of Lausanne, Quai Ernest- Ansermet30, CH-1211 Geneva 4, Switzerland Ansermet30, CH-1211 Geneva 4, Switzerland. b London School of Hygiene and Tropical Medicine, Department of Infec- tious and Tropical Diseases,Keppel Street, LondonWC1E7HT,UK Rhodiola rosea L.,alsoknown as Golden root, hasbeen used forcenturies c Center forPharmacognostic Research on Panamanian Flora in the traditionalmedicine of EasternEurope and Asia. It has been classed (CIFLORPAN), College of Pharmacy,University of Panama,Panama as an adaptogenbyRussian researchersdue to its ability to increaseresis- tance in humans to avariety of stressors. As apartofour ongoing investigations on Panamanian Bignoniaceae [1], According to the Soviet Pharmacopoeia(RFMHMI 1983),extracts of sevenmethanolic extractsfrom sixplantsweresubmittedtoa -hematin Rhodiola rosea L. arenow standardized in both rosavin (min. 3%)and sa- polymerization inhibition test[2].This reaction is one of the possible targets lidroside(min.1%) content [1]. in the fight againstparasites of the genus Plasmodium,responsible forma- Theefficacy observed in clinical studies is due to thesynergistic activity of laria. Theextract fromthe leaves of Arrabidaeapatellifera (Schlecht) these two metabolitesand otheractive ingredients. Sandw.,aliana which grows fromlowlands to mountainforest, wasselected An efficient analytical method by HPLC-UV/DADwas developedtoquan- becauseofits good activity, corroborated by an in vitro test against Plasmo- tifyrosavin and salidrosideinthe roots of four wild populations of R. rosea dium falciparum.Moreover,this plant has never been investigated before. L. comingfromthe same area in Switzerland. Theanalyses wereperformed Theextract was firstfractionated by vacuumliquidchromatography (VLC) in order to observe the variability in the populations,and to establishthe and then by medium pressure liquid chromatography (MPLC).Itafforded dynamicsoftheir rosavin and salidroside content over aone year period. directly mangiferin and four of its derivatives,new C-glucosylxanthones, all Theresults obtainedafter the analysis of 20 sampleswill be useful in the active in vitro against P. falciparum.Further chromatographic separations selection of the mostappropriate population forlarge scale cultivation. gave other compounds,ofwhich theidentificationisunderway. Acetylcholinesterase-inhibitory activity was observed due to the presence in Thestructures were determined by meansofspectrometric methods,includ- theplant of linoleic acidand cinnamic alcohol. ing 1D and 2D NMRexperiments and MS analysis. Further investigations on R. rosea areunderwayinorder to discover new biological activities, especially in the area of depression (inhibition of [1] F. Martin, A.E. Hay, L. Corno, M. P. Gupta,K.Hostettmann, Phyto- monoamine-oxidase). chemistry. 2007,inpress [2]K.K.Ncokazi, T. J. Egan, Anal.Biochem. 2005, 338 ,306-319 [1]Khanum F.,BawaA.S., Singh B ., Comp RevFood Sci Food Safety, 2005, 4 ,55-62. Medicinal Chemistry 87 Computational Chemistry 88 ANew Protocol to theSyntheses of , -Diamino Acids DFT Study of Jahn-Teller Effect in Cobaltocene Y. Liu 1 ,P.Schmutz1 ,M.Bauwens2 ,J.Mertens2 ,R.Alberto1 Matija Zlatar1 , 2 ,Emmanuel PenkaFowe1 ,Carl-Wilhelm Schlapfer1 , Claude Daul1 1 Institute of Inorganic Chemistry, University of Zurich Winterthurerstr. 190, 1 CH-8057 Zurich,Switzerland 2 Radiopharmaceutical Chemistry, DepartmentofChemistry,UniversityofFribourg, Chemin de Mus´e e9, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussel, Belgium CH-1700, Fribourg, Switzerland 2 Center for Chemistry,IHTM, UniversityofBelgrade, Njegoˇs eva12, P.O. Box815, 11001 Belgrade, Serbia , -Diamino Acids have attracted the interests from both organic chemists and biochemists through years,becauseofits unique structural and ubiqui- The detailed analysis of Jahn-Teller (JT) effect in bis -cyclopentadyenyl- tous role playing in biologically active compounds.Moreover,ithas been cobalt(II) -cobaltocene (CoCp2 ), is given. Descentinsymmetry goes from demonstratedthatthe , -diamino acid can be used as efficient tripodal D 5 h (eclipsed conformation of the two rings) to C 2 v .The electronic ground ligand forthe labelling of Re(I)/Tc(I) tricarbonyl,the corresponding hydro- 2 2 2 state, E 1 ,splits into A 2 and B 1 .Wehave used the methoddeveloped by philic compound of which is stable to air and competition fromcysteine or Daul et al. [1] for the calculation of the ground-state JT stabilization energy histidine. However,inthe radiopharmaceutical context, only after being ( E JT)and the resulting properties of aJT-activemolecules by DFT. The adi- coupled to otherbiomolecules,could , -diaminoacids be feasible for the abatic potential energy surface is described by three parameters ( E JT,Δand further application[1]. R JT)whichare related to the Bersuker’s description [2] of E ⊗ e problem ( K E , Herewereportanew method forthe preparation of , -diamino acid, F E , G E -force constant, first and second order vibronic coupling constants − 1 which entails alsothe convenientsynthesesof , -diamino acids derivat- respectively). We obtained E JT =750 − 850 cm (depending on the basis ized at -position. Thedeprotected 2 formedstableRe(I)/Tc(I)tricarbonyl set and functional used) whichisinagreementwith experimentally estimated complex, whichcan be recognized and transported into acell by LAT1 [2]. value of 1010 cm− 1 [3]. There is no second order JT effect. The geometry changed mainly in the Cp rings. The results are interpreted by group theory, NHCbz NHCbz in both, the high, D ,and the low, C 2 v ,symmetry.In D ,the problem NHBoc 5 h 5 h a) CN MsO COOEt a) wasconsidered as amultimode E ⊗ ( e )and in a C as amultimode BocHN COOEt i i 2 v b) 2 2 AcHN COOEt AcHN COOEt AcHN COOEt ( A 2 + B 1 ) ⊗ ( i a i )vibronic interactions. The contribution of the totally 1 2 symmetrical vibrations in C to the E wasanalysed. o 2 v JT a) NaBH4 ,NiCl 2 ,Boc2 O, MeOH,0C; b) NaOEt, EtOH,reflux [1] R. Bruyndockx, C. Daul, P. T. Manoharan, E. Deiss, Inorg. Chem., [1]R.Alberto, Top. Curr. Chem., 2005, 252,1-44. 1997, 36,4251-4256. [2]Y.Liu,J.K.Pak,P.Schmutz,M.Bauwens, J. Mertens, H. Knight,R. [2] I. B. Bersuker, The Jahn-Teller Effect,Cambridge University Alberto, J. Am.Chem. Soc., 2006, 128, 15996-15997. Press, 2006. [3] R. Bucher, ESR-Untersuchungen an Jahn-Teller-Aktiven Sand- witchkomplexen,PhD Thesis, ETH Zuerich, 1977. COMPUTATIONAL CHEMISTRY439 CHIMIA 2007, 61,No. 7/8 Computational Chemistry 89 Computational Chemistry 90 Equilibrium geometries of non-covalently bound intermolecular Electronic Structureofthe Ni/-Al 2 O 3 Catalyst: DFTCluster ModelStudy complexes derived from subsystem formulation of density functional theory IzabelaCzekaj,JörgWambach, Alexander Wokaun Marcin Dulaka ,Jakub W. Kami´n skia,b and Tomasz A. Wesolowskia Paul ScherrerInstitute, CH-5232 Villigen PSI, Switzerland a Universit´e de Gen`e ve,D´e partementdeChimie Physique 30, quai Ernest-Ansermet, CH-1211 Gen`e ve 4, Switzerland Themolecular structureofNi/ -Al O catalystusedduring methanation of 2 3 b Institute of Physical and Theoretical Chemistry,WroclawUniversityof synthesis gaswas investigated using DFTmethod with anon-local func- Technologym, Wyb. Wyspia´n skiego 27, 50-370 Wrocl aw,Poland tional [1]. Theseveral Ni-compounds such as Ni, NiO and Ni3 Caswellas -Al 2 O 3 surfaces wereconsidered. Furthermore,the geometricand theelec- The equilibrium geometries of the noncovalently bound molecular complexes tronic structures of Ni deposited on -Al 2 O 3 system were studiedindetails. have been obtained using subsystem formulation of densityfunctional[1] the- Thetheoretical studies arepresently used to help with understanding more ory applying proposed efficientoptimization algorithm. The representativeset detailedsurface modifications duringmethanation and reasons of anickel of molecules is chosen and divided into hydrogen-, dipole- and weakly-bounded particles detachment together withacarbon whiskersformation in specific spices as proposed by Truhlar[2] for acomparisions standart, where accurate fixed bed conditions.TheNi/ -Al 2 O 3 catalystindifferent stateofmethana- ab-initio benchmark data are available. We have also tested performance tion consists of several Ni-compounds such as Ni, NiO and Ni3 C, which was of two differentwaysofapproximating the exchange-correlation- and non- suggestedbyprevious experimental studies [2,3]. Our findings about elec- additivekinetic energy parts of total energy.The non-empirical local density tronic structuresuggestthat the nickel carbide is supposed to be less reac- approximation (LDA) leads to excellentequilibrium geometries and interac- tivethenpurenickel or nickel oxide. Thenickel adsorbsatAl 2 O 3 (100) sur- tion energies with accordance to reference data in all of the studied three sets. face in the hole position between surface