Cyclooctapyrroles such as 1–3 tend to form during the condensation of dipyrrolic units if cyclization to cyclotetrapyrroles is hindered for conformational reasons. These macrocycles are chiral and might afford interesting complexes with metal ions. Their most intriguing feature is their unusual figure‐eight conformation.
Die Cyclooctapyrrole 1‐3 sind eindrucksvolle Beispiele dafür, daß bei der Kondensation von dipyrrolischen Bausteinen die Bildung von Cyclooctapyrrolen gegenüber der entsprechender Cyclotetrapyrrole bevorzugt sein kann, wenn die Cyclisierung zu letzteren konformativ behindert ist. Die Makrocyclen sind chiral und könnten mit Metall‐Ionen interressante Komplexe bilden. Am faszinierendsten ist sicherlich ihre ungewöhnliche Konformation, die an das Aussehen der Zahl 8 erinnert.
Bilateral periventricular nodular heterotopia (BPNH) is a malformation of neuronal migration and is characterized by nodules of heterotopic gray matter lining the lateral ventricles of the brain. The majority of BPNH patients are female and have epilepsy as a sole clinical manifestation of their disease. Familial BPNH has been mapped to Xq28 by linkage analysis. A multiple congenital anomaly-mental retardation syndrome (BPNH/MR) was recently delineated in three unrelated boys with BPNH, cerebellar hypoplasia, severe mental retardation, epilepsy, and syndactyly. High-resolution chromosome analysis revealed a subtle abnormality of Xq28 in one of the boys with BPNH/MR syndrome. FISH with cosmids and YACs from Xq28 further characterized this abnormality as a 2.25-3.25-Mb inverted duplication. No abnormality of Xq28 was detected by G-banding or FISH in the other two boys. These data support the linkage assignment of BPNH to band Xq28 and narrow the critical region to the distal 2.25-3.25 Mb of Xq28.
We have constructed a restriction map for the genome of bacteriophage MX-8 from Myxococcus xanthus using the enzymes PvuII, MboI, and EcoRI. The phage genome size, as determined by restriction analysis, is 51.7 +/- 0.6 Kb. Double digestions, redigestions of isolated fragments, and crossed-contact hybridization of partial digestion products show that the restriction map is circular. Restriction analysis and Southern hybridization show that the phage DNA molecules are packaged sequentially from a concatemer starting from a specific site which we have mapped. The DNA molecules have an average terminal redundancy of approximately 8% and are circularly permuted over at least 40% of the genome.
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