No abstract

The 1 titljor constituent of the alkaloid fraction of the leaves of Puraei~lluras wiu[rophyllu I'IERRE has found to be the new paravallarine-type steroidal alkaloid 20-epi-kibataline. The structure of this steroidal alkaloid has been determined by X-ray analysis. The corilpouncl crystallizes in the inonoclinic space group 1'21 with the lattice parameters

The title compound crystallizes in tho monoclinic space group P 2, with 2 formula units

A new solanocapsine-type alkaloid named aculeamine has been isolated from roots of Solanum aculeatum and its structure has been established by X-ray analysis as 22,26-cpimino-23~-methoxy-16a,23-epoxy-5a,22aH,25~H-cholestane-~~~-ol. The compound crystallizes in the hexagonal space group P6, with the lattice parameters a = b = 16.706, c = 17.056 A, a = ,9 = go", y = 120". The final residual value was R = 0.079. Ein neues Alkaloid vom

Crystal and Molecular Structure of (20R)-19-nor-5P,14~-pregnane-3P,14,20-triol 3,20-diacetate Dedicated to Professor Ernst HOHNE on the occasion of his 60th birtlitlaj The title compound (20R)-19-nor-5,8,14,8-pregnane-3P, 14,2O-triol 3,20-diacetatc crystallizes in the monoclinic space group P2, with 4 formula imits C,,H,,O, in the unit cell. Thc latticv paratneters are a = 14.324, b = 12.569, c = 12.685 $, ,8 = 90.21'. Tlre c q s t a l structure was tleterniinetl by direct methods and rcfinctl by the least-squares procwlurt* t o the discrepancy factor R = 0.042. Bond leiigth, bond angles, ring c.onforlnations, as well as t h e absolute configmation at C20 were detertriinetl. In the crystal the tnolecules a] c' linked to infinite chains by two hydrogen bonds. Div Titelvc.ihintlring (20R)-19-Nor-5~,14~-pr.egnan-3,8,14,20-trio1-3,20-diac~~tat hlistallisiei t in der tiiotioklinen Raurngruppe P2, rnit 4 Fornieleinheiten C,,H,,O, in tler Elellirntar-/elk. Die Gitterkonstanten sind a = 14,324, b = 12,569, c = 12,685 A, ,8 = 90,211". Dic.Kristallstiuktur wurde init direktcn Methoden gelbst untl iiiit tlcr Methotle tlrr kleitisten Quatlrate his zu eirieni R-Wert von 0,042 verfcinert. Es wurtlen Biiitlungsabsthtidc, Bintliuigswinkel, Kingkonforinationt.n und die absolute Konforination an C20 bestilnliit. 1111 Kiistall sind (lie Molekulc durch zwei ~~asserstoffbriickeii zii nuentlliclicn Kt.1 t <,ti 1 erb l t n~l~n .