The complete amino acid sequences of two potassium channel proteins from NGlOE-15 neuroblastoma-glioma hybrid cells have been deduced by cloning and sequencing the cDNAs. One of these proteins (NGKZ) is structurally more closely related to the Drosophila Show gene product than to the Shaker and Shah gene products, whereas the other (NGKl) is identical with a rat brain potassium channel protein (BK2) which is more closely related to the Drosophila Shaker gene product. mRNAs derived from both the cloned cDNAs, when injected into Xenopus oocytes, direct the formation of functional potassium channels with properties of delayed rectifiers.

Two series of dehydroannulenes fused with bicyclo[2.2.2]octene (BCO) units were synthesized either by an oxidative coupling with copper(I) under air or by a palladium−copper-catalyzed coupling. The first series of dehydroannulenes consisted of tetradehydro[12]annulene (12), hexadehydro[18]annulene (13), octadehydro[24]annulene (14), and decadehydro[30]annulene (15), which all have the BCO units connected by the butadiyne linkage. The second consisted of tridehydro[12]annulene (16) and tetradehydro[16]annulene (17), which have the BCO units connected by the acetylene bond. The molecular structures of the relatively stable annulenes 13 and 17 were determined by X-ray crystallography, which showed that 13 has a planar π-system, whereas 17 has a tub structure like cyclooctatetraene. The 1H NMR signal for the bridgehead proton of the BCO units is a good measure for the ring current effect. This signal clearly indicated the presence of diatropicity in [18]annulene 13 and paratropicity in [12]annulenes 12 and 16. The redox properties of these annulenes were examined by cyclic voltammetry. The antiaromatic [12]- and [16]annulenes 16 and 17 having only one acetylene bond between the BCO units were found to be more readily oxidized than the other annulenes as expected from the energy level of HOMOs calculated by the PM3 semiempirical MO method.

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