摘要:

AbstractCurrent methodology for the chemical synthesis of short chains (up to about twenty nucleotide units) of deoxyribopolynucleotides is reviewed.

ISSN:0570-0833    

DOI:10.1002/anie.197204511

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractAmong numerous nonsteroidal anti‐imflammatory agents synthesized in the past few years, various analogs of indomethacin, phenylacetic acid and heteroarylacetic acid have reached the stage of clinical evaluation. Their biochemical mechanisms of action are exemplified by the broad activity profile of indomethacin which includes inhibition of mediators and enzymes, effects on cell membranes, and, most recently, inhibition of prostaglandin biosynthesis. The importance of pharmacodynamic properties to clinical efficacy was clearly demonstrated in some cases. Several candidates were eliminated because of their side‐effects. A group of α‐methylarylacetic acids showed a high degree of stereospecificity in their potency and metabolismsin vivo, as well as inhibition of prostaglandin synthetase and albumin bindingin vitro. Extrinsic Cotton effect provides a sensitive technique in the study of interactions of these drugs with biopolymers. Competitive binding and antagonistic interactions between nonsteroidal drugs, particularly salicylate, were observedin vitroandin vivo. Progress in salicylate research was marked by the synthesis of flufenisal as a new derivative with enhanced potency and longer duration of action. Several fenamate analogs and new chemical types have shown promise in preliminary clinical trials. Various immunological approaches are under investigation for the treatment of rheumatoid arthritis. Newer concepts are still needed to achieve more effective control of arthritic dis

ISSN:0570-0833    

DOI:10.1002/anie.197204601

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractOrganolithium compounds are thermally quite stable, despite their extremely high reactivity. Thermolability,i.e.the property of undergoing irreversible changes at low temperatures without the participation of molecules of a different kind, is associated with additional functional groups, which may be readily eliminated together with the metal cation, may cause intramolecular rearrangements, or may lead to intermolecular additions and substitutions involving several molecules of the same type. Thermolabile organolithium compounds have frequently been postulated or detected as intermediates of important reactions, and are therefore of theoretical and practical interest. If certain precautions are taken, it is occasionally possible (mainly at low temperatures) to prepare them intact, and hence to release them from the constraint of the fate assigned to them as short‐lived intermediates. Investigations with this aim have for some time occupied a place of considerable importance in the chemistry of organometallic compound

ISSN:0570-0833    

DOI:10.1002/anie.197204731

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractRecent experiments using electron diffraction techniques, optical and infrared spectroscopy and mass spectroscopy have provided convincing evidence for the existence of bound states of gaseous Ar2, (H2)2, (O2)2, (NO)2and other simple dimers. The bond strength of these van der Waals molecules is hundreds of times weaker than ordinary chemical bonds. These experimental studies yield information on the structure and stability of van der Waals molecules and can provide new insight into weak intermolecular interactions.

ISSN:0570-0833    

DOI:10.1002/anie.197204861

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe progress made in molecular biology has provided definite evidence that DNA is the genetic material of all cellular organisms. It is mainly localized within the cell nuclei and, in association with histones and acidic proteins, forms the fundamental structure of the chromosomes. The DNA‐protein complex, called nucleohistone or chromatin, represents the sum of all existing genes of one cell type and can be considered as a functional genetic unit. All genetic structures contain this fundamental element and only their steric arrangement or multiplicity determine the species‐specific differences in chromosomal morphology. The preservation of the three‐dimensional structure seems to be the function of histones which, in general, are associated with densely packed and metabolically inactive DNA sequences. The lysine‐rich histone I probably has a specific regulatory function since it inhibits the transcription of certain genes. Acidic proteins are mainly to be found in stretched chromosomal structures of high metabolic activity which accentuate the correlation between structure and function of nucleohistones. Approximately 50% of the DNA of the nucleohistone complex is not masked by proteins though only a small percentage of the free nucleotide sequences can be transcribed by RNA polymerase. The “open” structure of nucleohistones finds a plausible explanation in the fact that amino acid sequence analysis of several histones revealed an asymmetric distribution of charged groups and that therefore only these protein fractions can interact with DNA. InCrick's recently published model of the chromosomal organization the unique structure of histones is taken into account and it is assumed that the histone‐rich heterochromatin contains multiple but untranscribable control elements. Functional genes are represented by a single stranded DNA duplex within the interbands which utilize a special protein to preserve this unique

ISSN:0570-0833    

DOI:10.1002/anie.197204961

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197205061

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197205071

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197205081

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197205101

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197205111

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY