Donald J. Abraham

Proposed detailed structural model for tRNA and its geometric relationship to a messenger.

Abstract A new model for transfer ribonucleic acid which is different in concept from those published to date and a relationship of transfer RNA to messenger RNA is postulated. The above new concepts are combined to provide a molecular theory for protein biosynthesis.

Stereochemistry and absolute configuration of the antibiotic spectinomycin: an X-ray diffraction study

A single crystal X-ray diffraction study of spectinomycin dihydrobromide pentahydrate has shown that the molecule has a B/Ccis ring juncture and exists as a stable ketone hydrate; the absolute configuration of the molecule was determined by anomalous dispersion.

Notizen: Silydianin und Silychristin, zwei isomere Silymarine aus Silybum marianum L. Gaertn. (Mariendistel) / Silydianin and Silychristin, two Isomeric Silymarins from Silybum marianum L. Gaertn. (milk thistle)

Two isomeric flavonolignans (Silymarins) have been isolated from the fruits of Silybum marianum L. Gaertn. and structurally elucidated mainly by means of NMR/mass spectroscopy and X-ray analysis respectively.

Isolation of hörhammericine fromC. lanceus (Apocynaceae) roots

was d u t c h karzere Hg-S-Abs t i inde inne rha lb der P y r a m i d e n , vor al lem aber du rch eine d ichtere A n o r d n u n g der P y r a m i d e n selbs t zu erklgren ist. lEine i so type Verb indung HgaS%F u m i t a = 8,38v/k konn t e auf g le ichem W e g aus H gSe a n d (CsH~NH)~HgF 4 e rha l t en werden, j edoch n u t im Gemisch mi t e ther weiteren, o f fenbar rhombi s chen Modif ikat ion.

Methylphenylmercury: a novel heavy atom reagent for protein crystallography

Methylphenylmercury reacts with two normally inaccessible cysteine residues in crystals of carbonmonoxyhaemoglobin, but not with the third, normally reactive one. It may, therefore, be useful in the preparation of new heavy atom derivatives for protein crystallography.

Structural Analogs of AF64A: Synthesis and their Effects on High Affinity Choline Transport and QNB Binding

A chronic deficiency in central cholinergic function has been demonstrated in a number of neuropsychiatrie diseases, including Alzheimer’s disease.1–6 Until recently, animal models that simulate the neurochemical conditions which appear to cause these diseases in humans, as a result of a direct manipulation of the central cholinergic system, were not available. Over the past few years, however, we have been successful in developing a compound, ethylcholine mustard aziridinium ion (AF64A), which has the potential to serve as a novel toxin in developing animal models of human brain disorders in which a cholinergic hypofunction has been implicated.