Synthesis and Structural Characterization of Nonplanar Tetraphenylporphyrins and Their Metal Complexes with Graded Degrees of beta-Ethyl Substitution.

Different porphyrin conformations are believed to play a role in controlling the cofactor properties in natural tetrapyrrole-protein complexes. In order to study the correlation between macrocycle nonplanarity and physicochemical properties in detail, a series of six porphyrins with graded degrees of macrocycle distortion were synthesized via mixed condensation of pyrrole, diethylpyrrole, and benzaldehyde. The formal introduction of successively more beta-ethyl groups into the tetraphenylporphyrin parent macrocycle gave access to diethyltetraphenylporphyrin (H(2)DETPP), two regioisomers of tetraethyltetraphenylporphyrin (H(2)tTETPP, H(2)cTETPP), and hexaethyltetraphenylporphyrin (H(2)HETPP).

The reaction of porphyrins with organolithium reagents.

Porphyrins react readily with organolithium reagents, preferentially in the meso positions. The overall reaction is a nucleophilic substitution and proceeds via initial reaction of the organic nucleophile with a meso carbon yielding an anionic species which is hydrolyzed to a porphodimethene (5,15-dihydroporphyrin), formally constituting an addition reaction to two Cm positions. Subsequent oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) yields meso-substituted porphyrins.

Facile meso Functionalization of Porphyrins by Nucleophilic Substitution with Organolithium Reagents.

The ruffle of the porphyrin increases with the number of meso substituents. (Octaethylporphyrin)nickel(II) undergoes nucleophilic substitution reactions upon treatment with alkylating reagents such as butyllithium, hydrolysis with water, and oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone [DDQ; Eq. (a)].

Electron microscopic band-interband pattern of polytene chromosomes in Drosophila nasuta albomicans. 1. Salivary gland chromosome 2R.

The band-interband pattern of salivary gland chromosome 2R in Drosophila nasuta albomicans (division 53-83) was studied by light (LM) and electron microscopy (EM) using squash preparations and surface-spread polytene (SSP) chromosome preparations, respectively. LM and EM maps were compiled. Based on the digitized EM patterns of five homologous SSP chromosomes a computerized chromosome map was plotted.

Electron microscopic band-interband pattern of polytene chromosomes in Drosophila nasuta albomicans. 2. Salivary gland chromosome 2L.

The band-interband pattern (division 28-52) of salivary gland chromosome 2L in Drosophila nasuta albomicans was studied by light (LM) and electron microscopy (EM) using squash preparations and surface-spread polytene (SSP) chromosome preparations, respectively. LM and EM maps were complied. Based on the digitized EM patterns of five homologous SSP chromosomes a computerized EM chromosome map was plotted.

Comparative analysis of glue proteins in the Drosophila nasuta subgroup.

The patterns of protein fractions from total salivary glands and from glue plugs were compared in seven members of the Drosophila nasuta subgroup by the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The glue protein patterns are member specific concerning the numbers and the electrophoretic mobilities of major and minor glue protein fractions. However, the major fractions of all subgroup members could be grouped into five SDS-PAGE domains according to the homologies of their electrophoretic mobilities, prominence of Coomassie blue staining, and PAS reaction.

Glue proteins in Drosophila nasuta.

Larval glue protein fractions of Drosophila nasuta nasuta were analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Seven major and at least four minor glue protein fractions were recognized. Six of the major fractions are glycosylated.

Taxonomic identification of Drosophila nasuta subgroup strains by glue protein analysis.

Protein fractions of salivary glands were analyzed from 30 wildtype strains of eight species belonging to the Drosophila nasuta subgroup by SDS-polyacrylamide gel electrophoresis. The electrophoretic patterns indicated several prominent bands which could be shown to represent the major glue protein fractions. The glue protein fractions are species-specific as well as wildtype strain-specific.

The use of surface spread polytene chromosomes for high resolution fluorescence microscopic analyses.

The technique of surface spreading of polytene chromosomes is applied to fluorescence microscopy. With bisbenzimide Hoechst 33258 stained surface spread polytene chromosomes from the dipteran species Chironomus thummi piger, depiction of the band-interband structure is close to that of electron micrographs of the same enlargement.

Laser scanning microscopy of surface spread polytene chromosomes.

A new type of a Laser Scan Microscope (Zeiss) was used for the analysis of the band-interband pattern of polytene chromosomes in Chironomus. In contrast to the previously used techniques of transmission light and electron microscopy, we used differential interference contrast (DIC) in incident light to depict the pattern. Instead of using common squash preparations, we carried out this investigation with surface spread polytene (SSP) chromosome preparations of salivary glands.

Computerized EM maps of surface spread polytene chromosomes 1 digitizing and plotting of banding patterns.

A standard plotting program for the band-interband pattern of polytene chromosome maps was written in EXTENDED BASIC for a pocket computer coupled to a plotter (Sharp PC-1500 + CE-150). In this program, the individual polytene structure (i.e.

DNA replication of a polytene chromosome section in Drosophila prior to and during puffing.

Polytene chromosome sections 63E1-6 of 3L in Drosophila melanogaster were studied by 3H-uridine and 3H-thymidine autoradiography in late third instar larvae and prepupae. In late third instar larvae 63E does not incorporate 3H-uridine. In prepupae, however, a large puff is formed in 63E which is most active in RNA synthesis.

Correspondence of banding patterns to 3h-thymidine labeling patterns in polytene chromosomes.

3H-thymidine labeling frequencies over X chromosomal region 1A-4E of Drosophila melanogaster, were analysed with reference to chromosome sections with and without prominent bands. A correspondence was found between band sections and late start of silver grain labeling at the initial stage in combination with late labeling at the end stage of replication. A complementary situation is always to be found over puff/interband sections, where an early start of labeling at the initial stage is generally combined with early labeling completion at the end stage of replication.

Tandem duplications in Drosophila melanogaster II. Meiotic pairing and exchange in heterozygous tandem duplications.

In heterozygous females of tandem duplication Dp(1; 1) Gr, y(2) (w(-)spl sn(3)) (w(c) sn(3)) the frequency and distribution of exchange events were measured by the phenotypically different F1 recombinants. In comparison with wild type chromosomes the crossover values were strongly reduced within the heterozygous chromosome sections (between white and singed from 19.5 per cent to 2.