Neue Synthesen des Chloramphenicols und deren stereochemischen Beziehungen

Summary Two new syntheses of Chloramphenicol are described starting from the diastereoisomers of -phenylserinmethyl ether and cinnamyl alcohol methyl ether respectively. The configurational correlation of the diastereoisomers of -phenylserin-methyl ether with -phenylserin and chloramphenicol is discussed. A new method for transforming erythro--phenylserinol into threo--phenylserinol is described. New examples of the Neighboring group effect were studied. The sterical course of the addition of methylhypobromite to the double bond is discussed.     

17β-Hydroxymethyl-Steroide: Darstellung von Derivaten des 17β-Hydroxymethyl-4-androsten-3-ons

Summary Starting from methyl 3-oxo-4-etienate, the authors prepared 17-hydroxymethyl-4-androsten-3-one and 11-hydroxy-17-hydroxymethyl-4-androsten-3-one. Chlorination of 17-acetoxymethyl-4-androsten-3-one yielded 4-chloro-17-acetoxymethyl-4-androsten-3-one. 17-Hydroxymethyl-1, 4-androstadien-3-one was obtained from 17-hydroxymethyl-4-androsten-3-one, both by chemical and biological methods.     

The distribution of some enzymes involved in the steroidogenesis of hen's ovary

Riassunto È stata studiata con metodi istochimici la distribuzione della ⁵-3-idrossisteroide deidrogenasi ( ⁵-3-HSDH) e delle 17-idrossisteroide deidrogenasi (17-HSDH), DPN- e TPN-dipendenti, nell'ovario di gallina ovulante. Mentre la ⁵-3-HSDH è presente in tutti i tessuti a secrezione steroide dell'ovario, la 17-HSDH è localizzata solo nelle cellule della granulosa.     

Isomeric homoallylic cations formed from 19-substituted steroids

Zusammenfassung Die Existenz von zwei verschiedenen isomeren Homoallylkationen in der Umlagerung von Steroid- ⁵-19-Methansulfonsäure-Estern zu 5, 19-cyclo-6-hydroxylierten Steroiden und deren Umlagerung zu ⁵(¹⁰)-B-homo-7-hydroxylierten Steroiden wurde bewiesen, und eine neue Art der Homoallylumlagerung eines ⁵(¹⁰)-B-homo-7-hydroxylierten Steroids zum 5, 6-Methano-9-en und zum 5, 6-Methano-10-ol wurde beobachtet.

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This material was presented at theSymposium on Steroids Made Through Intramolecular Functionalization on the C ₁₈-and C ₁₉-Methyl Groups, at the 149th meeting of the American Chemical Society in Detroit (Michigan), on April 7, 1965.     

The benzilic acid rearrangement of 3α,17β-Diacetoxy-11-hydroxy-12-oxo-5β-androst-9(11)-ene

Zusammenfassung Die Bildung von 11-Carboxy-3, 11, 17-trihydroxy-13-C-nor-5-androstan 11a,17-Lakton aus 3, 17-Diacetoxy-11-hydroxy-12-oxo-5-⁹(11)-androsten wird beschrieben. Der Mechanismus und die Stereochemie dieser Umwandlung (Retro-Aldolkondensation und Benzilsäureumlagerung) wird diskutiert.     

Resistance to β-lactam antibiotics

-lactams have a long history in the treatment of infectious diseases, though their use has been and continues to be confounded by the development of resistance in target organisms. -lactamases, particularly in Gram-negative pathogens, are a major determinant of this resistance, although alterations in the -lactam targets, the penicillin-binding proteins (PBPs), are also important, especially in Gram-positive pathogens. Mechanisms for the efflux and/or exclusion of these agents also contribute, though often in conjunction these other two. Approaches for overcoming these resistance mechanisms include the development of novel -lactamase-stable -lactams, -lactamase inhibitors to be employed with existing -lactams, -lactam compounds that bind strongly to low-affinity PBPs and agents that potentiate the activity of existing -lactams against low-affinity PBP-producing organisms.Received 9 February 2004; received after revision 30 March 2004; accepted 19 April 2004     

Carbohydrase and esterase activity in the gut of larvalCallosobruchus maculatus

Summary Carbohydrase activity has been demonstrated in homogenates of the alimentary tracts of late instar larvae ofC. maculatus:-D galactosidase, -D glucosidase and N-acetyl-D glucosaminidase activities were comparable and significantly greater than -D galactosidase,-D glucosidase and -D mannosidase. The effects of pH and substrate concentration are reported. The presence and changes in pattern of non-specific esterase activity in larval and adult gut homogenates is also described.     

11β-methyl-19-norsteroids: Novel progestational hormones

Zusammenfassung Die Synthese von 3, 17-Diacetoxy-17-Äthinyl-11-Methylestr-4-en (XII) wird beschrieben. Die Substanz besitzt besonders starke Antifertilitätseigenschaften, wie sie sonst nur Mischungen von Hormonen eigen sind, welche für die Humanfertilität benutzt werden, jedoch ohne deren Nebenwirkungen.     

Cardenolide glycosides from the adults and eggs ofChrysolina fuliginosa (Coleoptera: Chrysomelidae)

Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by¹H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.     

Zur Synthese des Batrachotoxinins: Synthese von 3β-Acetoxy-16β, 20β-dihydroxy-4′-methyl-18-nor-5β, 14β-pregnano[13,14-f]hexahydro-1′,4'-oxazepin-3′-on(20a)

Summary The synthesis of 3-acetoxy-16, 20-dihydroxy-4-methyl-18-nor-5, 14-pregnano[13,14-f]hexahydro-1, 4-oxazepin-3-one (20a) is described.     

Synthese von 5α- und 5β-Androstan-17β-ol-3-on-17-acetat aus Hyodesoxycholsäure

Summary 5- and 5-androstane-17-ol-3-one-17-acetate have been prepared from 5-androstane-6, 17-diol-3-one-17-acetate by a synthesis involving directedHuang-Minlon-reduction.Separation of 5-androstane-17-ol-3-one from its 5-isomer could readily be achieved by crystallisation of their 3-ethylenketals from acetone.     

Evidence for the extranuclear localization of thymosins in thymus

A new radioimmunoassay has been developed for thymosin ₄ by generating rabbit polyclonal antibodies against the synthetic N-terminal peptide fragment 1–15 coupled to KLH. The synthetic analogue [Tyr¹²]-thymosin ₄ (1–15) was used as tracer. This radioimmunoassay, with a useful range of 10–1000 pmoles, showed cross-reactivity with the second homologous -thymosin of man and rat (thymosin ₁₀) but not of calf (thymosin ₉). This radioimmunoassay, together with an improved radioimmunoassay for the N-terminus of parathymosin , was employed for the measurement of the levels of thymosin ₄ and parathymosin in nuclear and extranuclear extracts of calf thymus. The bulk of these polypeptides was found in the extranuclear material whereas only traces were observed in the nuclear environment, which indicates the extranuclear localisation of - and -thymosins.     

DNA synthesis and mitoses in atrial myocytes of rats with aortal stenosis

, . 2- , 1,60 ±0,59% , 0,96 ± 0,44% — . ë . , ³- .     

Metabolism in Porifera XII. Further informations on the biosynthesis of 3β-hydroxymethyl-A-nor-steranes in the spongeAxinella verrucosa

Summary Direct incorporation and cold trap experiments suggest that cholest-4-en-3-one is an intermediate in the conversion of cholesterol into 3-hydroxymethyl-A-nor-cholestane in the marine spongeAxinella verrucosa. Cholest-4-en-3-one is further transformed by the sponge into cholest-4-en-3-ol, 5-cholestan-3-one and 5-cholestan-3-ol; these compounds arise from side reactions, which are not part of the major metabolic route leading to 3-hydroxymethyl-A-norsteranes.     

Defensive steroids from a carrion beetle (Silpha americana)

Summary The defensive anal effluent discharged bySilpha americana in response to disturbance contains a mixture of steroids stemming from a glandular annex of the rectum. The compounds have been characterized as 15-hydroxyprogesterone (1, principal component), 5-pregnan-15-ol-3, 20-dione (2), 5-pregnan-3, 15-diol-20-one (3), 5-pregnan-7, 15-diol-3,20-dione (4), 5-pregnan-3, 7, 15-triol-20-one (5), 5-pregnan-16-ol-3,20-dione (6), and 5-pregnan-3, 16-diol-20-one (7), none previously found in insects. Bioassays with jumping spiders showed compounds1 and6 to be feeding deterrents at the 1 g level.Paper No. 78 of the series: Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908, AI-12020). We thank Maura Malarcher and Maria Eisner for excellent technical help, and the Squibb Institute of Medical Research for samples of authentic reference compounds.     

17β-Hydroxymethyl-Steroide: Darstellung von Derivaten des 17α-Hydroxy-17β-hydroxymethyl-4-androsten-3-ons

Summary Starting from 17-hydroxy-17-hydroxymethyl-4-androsten-3-one, we synthesized 4-chloro-17-hydroxy-17-hydroxymethyl-4-androsten-3-one-17, 20-acetonide and 17-hydroxy-17-hydroxymethyl-1, 4-androstadien-3-one. 11, 17-dihydroxy-17-hydroxymethyl-4-androsten-3-one was obtained from cortisone via methyl-17-hydroxy-3, 11-dioxo-4-etienate.     

Starfish saponins VII. Structure of luzonicoside,a further steroidal cyclic glycoside from the pacific starfishEchinaster luzonicus

Summary On the basis of comparative chemical and spectral data, the structure of the major saponin, luzonicoside, from the starfishEchinaster luzonicus has been elucidated as2. This is a further example of a novel class of steroidal cyclic glycoside from starfish of the genusEchinaster. Its structure includes a ⁷, 3,6-dioxygenated-23-oxosteroidal moiety, already found in the saponins ofEchinaster sepositus, and a trisaccharide moiety, -D-galactopyranosyl-(12) -L-arabinopyranosyl-(12)--D-glucuronopyranosyl, bridging C-3 and C-6 of the steroid.This contribution is part of the Progetto Finalizzato Oceanografia e Fondi Marini del C.N.R., Roma.Acknowledgments. We wish to thank Mrs M. Pusset, Laboratoire des Plantes Médicinales du C.N.R.S., Nouméa, for the extraction of starfish and the divers of the Centre Q.R.S.T.O.M. de Nouméa for collection.     

An epoxidation byCorynebacterium simplex

Zusammenfassung Während unserer Untersuchungen über die mikrobiologische Dehydrierung verschiedener 16-Methylsteroide durch Bakterienkulturen vonCorynebacterium simplex, wurde eine neue Art von Umwandlung beobachtet. Von 16-Methyl-9(11)-pregnen-17, 21-diol-3, 20-dion-21-acetat ausgehend, gelang es aus den Kulturfiltraten 16-Methyl-1, 4-pregnadien-9, 11-epoxy-17, 21-diol-3, 20-dion zu isolieren. In einigen Fällen wurde auch das4-Derivat dieser Verbindung als Nebenprodukt erhalten.     

Uptake of D-glucose anomers by rat retina

Summary Uptake ofd-glucose anomers by isolated rat retina was studied. After 3 min incubation at 37°C in the presence of or anomer (750 g/ml), a significantly greater uptake (1.32 mg/g wet tissue) of -anomer was observed compared with that of -d-glucose (1.11 mg/g wet tissue). This result and other data suggest that the carrier ford-glucose transport in the retina prefers the -anomer stereospecifically.Acknowledgment. The authors are grateful to Mr S. Suzuki for his technical assistance.