One of the gamones (gamone II) which are effective for the induction of conjugation in Blepharisma intermedium has been isolated in a crystalline form and designated as blepharismin. From the result of chemical and spectroscopic investigations, in which x-ray crystallographic analysis was used as a definitive tool, blepharismin has been found to have the structure of calcium 3-(2′-formylamino-5′-hydroxybenzoyl)lactate.

No abstract

The crystal structure of showdcmycin, C9H1,N06, has been determined by a thres-dimensional X-ray analysis.The crystals are monoclinic, a = 1 5.454, b = 6-547, c = 11.425, p = 121 "1 6'. Z = 4, space group C2. The intensities were measured with a Hilger and Watts automatic four-circle diffractometer using Mo-K, radiation. The structure was solved by the symbolic addition procedure for phase determination as applied to noncentrosymmetric crystals, and refined by full-matrix least-squares calculations to a final R of 0-050 for 1092 independent observed reflexions. Atom C(2') of the sugar residue is displaced by ca. 0.58 a from the least-squares plane through the other four ring atoms and lies on the same side of the plane a t C(5'). This plane also makes an angle of ca. 46" with the least-squares plane through the five atoms of the pyrroline ring. The torsion angle with respect to the glycosidic bond, according to the Sundaralingam and Jensen definition, is 129.5". and the conformation therefore is syn. Osaka, Japan3-(P-~-ribofuranosyl)-3-pyrroline-2,5-di-No absorption corrections were applied since the specimen one, an antibiotic,"C,H,1N06, was first isolated from Streptowzyces showdoensis. A number of studies of showdomycin (I) 2-4 and its derivative (11) 5 have been reported, but no details of the stereochemistry of showdomycin have yet been given. The present X-ray study was therefore undertaken to obtain molecular conformational information on the structure of showdomycin.

No abstract

The crystal structure of oestradiol 3-p-bromobenzoate, C,,H,,O,Br, has been determined by three-dimensional X-ray diffraction methods. The crystals are orthorhombic, a = 20.51, b = 9.54, c = 10.94 A, Z = 4, space-group P2,2,2,.

The crystal structure of 3-methoxy-8@-methyioestradiol 17-rnonobromoacetate, Cz2HzpO3Br, has been determined by a three-dimensional X-ray analysis. The crystals are monoclinic with a = 11.84, b = 8.08, c = 10.47 8, and @ = 96" 39', in space group P2,. The crystal structure was solved by the heavy-atom method and refined by the least-squares method. The final value of R over the 715 independent reflexions was 0.094. The ring c of the steroid skeleton has a normal chair form, and ring D is represented by the slightly deformed P-envelope conformation.

No abstract

No abstract