Das Gynoeceum der Apiaceae — Modell und Ontogenie

Die früher entwickelte Modellvorstellung über den Aufbau und die vertikale Zonierung des unterständigen synkarpen Magnoliophytina-Gynoeceums trifft auch für den relativ hochentwickelten Formenkreis der Apiaceen zu: auf eine stark ausgeprägte synascidiate Zone folgt der extrem eingeschränkte symplikate Abschnitt, hierauf der asymplikate Bereich, der sich überwiegend aus den Styli aufbaut. Während bei den bisherigen Bearbeitungen vergleichbarer Fragestellungen meist das Konzept der congenitalen Verwachsung als typologischer Erklärungshintergrund angewandt worden ist, werden hier zusätzlich die ontogenetischen Entwicklungsabläufe aufgezeigt, die zum Aufbau des Hypanthialovars führen. Es handelt sich im wesentlichen um die Vorgänge der Meristeminkorporation und -fusion, sowie um das Wirken interkalarer Meristeme (Septum- und Hypanthialovarmeristem). Durch Interaktion dieser Prozesse kann unter Bezugnahme auf die Modellvorstellung die Morphologie des Apiaceen-Gynoece-ums vollständig erklärt werden.     

A MinION™‐based pipeline for fast and cost‐effective DNA barcoding

DNA barcodes are useful for species discovery and species identification, but obtaining barcodes currently requires a well‐equipped molecular laboratory and is time‐consuming, and/or expensive. We here address these issues by developing a barcoding pipeline for Oxford Nanopore MinION? and demonstrating that one flow cell can generate barcodes for ~500 specimens despite the high basecall error rates of MinION? reads. The pipeline overcomes these errors by first summarizing all reads for the same tagged amplicon as a consensus barcode. Consensus barcodes are overall mismatch‐free but retain indel errors that are concentrated in homopolymeric regions. They are addressed with an optional error correction pipeline that is based on conserved amino acid motifs from publicly available barcodes. The effectiveness of this pipeline is documented by analysing reads from three MinION? runs that represent three different stages of MinION? development. They generated data for (i) 511 specimens of a mixed Diptera sample, (ii) 575 specimens of ants and (iii) 50 specimens of Chironomidae. The run based on the latest chemistry yielded MinION? barcodes for 490 of the 511 specimens which were assessed against reference Sanger barcodes (N = 471). Overall, the MinION? barcodes have an accuracy of 99.3%–100% with the number of ambiguous bases after correction ranging from <0.01% to 1.5% depending on which correction pipeline is used. We demonstrate that it requires ~2 hr of sequencing to gather all information needed for obtaining reliable barcodes for most specimens (>90%). We estimate that up to 1,000 barcodes can be generated in one flow cell and that the cost per barcode can be 相似文献   

Synthesis of Neu5Ac- and Neu5Gc-α-(2→6′)-lactosamine 3-aminopropyl glycosides

In order to prepare 3-aminopropyl glycosides of Neu5Ac-α-(2→6′)-lactosamine trisaccharide 1, and its N-glycolyl containing analogue Neu5Gc-α-(2→6′)-lactosamine 2, a series of lactosamine acceptors with two, three, and four free OH groups in the galactose residue was studied in glycosylations with a conventional sialyl donor phenyl [methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (3) and a new donor phenyl [methyl 4,7,8,9-tetra-O-acetyl-5-(N-tert-butoxycarbonylacetamido)-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (4), respectively. The lactosamine 4′,6′-diol acceptor was found to be the most efficient in glycosylation with both 3 and 4, while imide-type donor 4 gave slightly higher yields with all acceptors, and isolation of the reaction products was more convenient. In the trisaccharides, obtained by glycosylation with donor 4, the 5-(N-tert-butoxycarbonylacetamido) moiety in the neuraminic acid could be efficiently transformed into the desired N-glycolyl fragment, indicating that such protected oligosaccharide derivatives are valuable precursors of sialo-oligosaccharides containing N-modified analogues of Neu5Ac.     

Characterization of the Frizzled10‐CreER™ transgenic mouse: An inducible Cre line for the study of Cajal‐Retzius cell development

Cajal‐Retzius cells are an enigmatic class of neurons located in the most superficial layer of the cerebral cortex, and they play an important role in cortical development. Although many studies have indicated that CR cells are involved in regulating cell migration and cortical maturation, the function of these cells is still not fully understood. Here we describe an inducible Cre mouse line in which CreER? is driven by the promoter for the Wnt receptor Frizzled10. Consistent with our previous studies on Frizzled10 expression and transgenic mouse lines using the Frizzled10 promoter, we found that in the developing telencephalon, Cre was mainly detected at the cortical hem, the largest source of CR cells. By crossing the Cre line to R26R reporter mice and injecting tamoxifen at different time points, we were able to detect via X‐gal staining CR cells produced from the cortical hem at distinct stages during development. Thus, this transgenic Cre mouse line is a valuable tool for studying the molecular and cellular mechanisms of CR cell development. genesis 47:210–216, 2009. © 2009 Wiley‐Liss, Inc.     

Antiproliferative Evaluation of Some 2‐[2‐(2‐Phenylethenyl)‐cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles: DFT and Molecular Docking Study

The 2‐[2‐(2‐phenylethenyl)cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles were synthesized from the reactions of 7‐benzylidenebicyclo[3.2.0]hept‐2‐en‐6‐ones with 2‐aminobenzenethiol. The antiproliferative activities of 2‐[2‐(2‐phenylethenyl)cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles were determined against C6 (rat brain tumor) and HeLa (human cervical carcinoma cells) cell lines using BrdU cell proliferation ELISA assay. Cisplatin and 5‐fluorouracil (5‐FU) were used as standards. The most active compound was 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against C6 cell lines with IC₅₀=5.89 μm value (cisplatin, IC₅₀=14.46 μm and 5‐FU, IC₅₀=76.74 μm ). Furthermore, the most active compound was 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against HeLa cell lines with IC₅₀=3.98 μm (cisplatin, IC₅₀=37.95 μm and 5‐FU, IC₅₀=46.32 μm ). Additionally, computational studies of related molecules were performed by using B3LYP/6‐31G+(d,p) level in the gas phase. Experimental IR and NMR data were compared with the calculated results and were found to be compatible with each other. Molecular electrostatic potential (MEP) maps of the most active 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against HeLa and the most active 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against C6 were investigated, aiming to determine the region that the molecule is biologically active. Biological activities of mentioned molecules were investigated with molecular docking analyses. The appropriate target protein (PDB codes: 1 M17 for the HeLa cells and 1JQH for the C6 cells) was used for 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole and 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole molecules exhibiting the highest biological activity against HeLa and C6 cells in the docking studies. As a result, it was determined that these molecules are the best candidates for the anticancer drug.     

Molecular tweezers for enantiodiscrimination in NMR: Di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl benzenedicarboxylates

A series of new chiral molecular tweezers, di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl phthalate (2), isophthalate (3) and terephthalate (4), were synthesized and their structure studied by NMR and molecular mechanics. Their effectiveness as chiral solvating agents for the determination of the enantiomeric purity of chiral compounds using NMR was demonstrated. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

DropArray™, a Wall‐Less 96‐Well Plate for Uptake and Immunofluorescence Microscopy,Confirms CD22 Recycles

CD22 is a cell surface glycoprotein restricted to normal and malignant B‐cells and is the target of several anti‐CD22 antibody‐based cancer therapies. For therapeutic antibody‐payload conjugates, it is important to understand the subcellular trafficking of anti‐CD22 antibodies to optimize antibody and/or linker–drug properties to maximize antitumor efficacy. It is agreed that anti‐CD22 antibodies rapidly internalize, but controversial whether they recycle or are degraded in lysosomes, and it is unclear if trafficking is antibody or cell‐type dependent. No studies examined anti‐CD22 trafficking to either pathway in B‐cells over time by dual immunofluorescence microscopy, likely partly because multiple samples of suspension cells are tedious to stain. We overcame this by using DropArray?, a novel wall‐less 96‐well plate technology allowing rapid simultaneous staining of suspension or adherent cells in small (10–20 μL) volumes. We examined the time‐course of trafficking of five different anti‐CD22 antibodies in eight B‐cell lines representing four B‐cell cancer types and show that in all cases antibodies internalize within 5 min and recycle, with only small amounts eventually trafficking to lysosomes. CD22 also localizes to recycling endosomes at steady state in the absence of antibody. Our data may help explain the differential efficacies of anti‐CD22 antibodies conjugated to different therapeutic payloads.      

6‐Methyl 3‐chromonyl 2,4‐thiazolidinedione/2,4‐imidazolidinedione/2‐thioxo‐imidazolidine‐4‐one compounds: novel scavengers of reactive oxygen species

The benefits of antioxidants on human health are usually ascribed to their potential ability to remove reactive oxygen species providing protection against oxidative stress. In this paper the free radicals scavenging activities of nine 6‐methyl 3‐chromonyl derivatives (CMs) were evaluated for the first time by the chemiluminescence, electron paramagnetic resonance, spin trapping and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^?) methods. The total antioxidant capacity was also measured using a ferric‐ferrozine reagent. Compounds having a hydrogen atom at the N3‐position of the β‐ring were effective in quenching CL resulted from the KO₂/18‐crown‐6‐ether system (a source of superoxide anion radical, ) in a dose‐dependent manner over the range of 0.05–1 mmol/L [IC₅₀ ranged from 0.353 (0.04) to 0.668 (0.05) mmol/L]. The examined compounds exhibited a significant scavenging effect towards hydroxyl radicals (HO^? HO^?), produced by the Fenton reaction, and this ranged from 24.0% to 61.0%, at the concentration of 2.5 mmol/L. Furthermore, the compounds examined were also found to inhibit DPPH^? and this ranged from 51.9% to 97.4% at the same concentration. In addition, the use of the total antioxidant capacity assay confirmed that CM compounds are able to act as reductants. According to the present study, CM compounds showed effective in vitro free radical scavenging activity and may be considered as potential therapeutics to control diseases of oxidative stress‐related etiology. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis and optical resolution of 1‐[(3‐carboxy‐1,1′‐biphenyl)‐2‐yl]‐1H‐pyrrole‐2‐carboxylic acid

Site selective mono‐ and dimetalation methods have been developed for the functionalization of 1‐[(1,1′‐biphenyl)‐2‐yl]‐1H‐pyrrole. Optical resolution of the prepared 1‐[(3‐carboxy‐1,1′‐biphenyl)‐2‐yl]pyrrole‐2‐carboxylic acid provided new atropisomeric 1‐arylpyrrole derivatives. The absolute configuration of the pure dicarboxylic acid enantiomers was determined by single crystal X‐ray diffraction and CD spectroscopy. Chirality 2009. © 2009 Wiley‐Liss, Inc.