Synthesis of perialkynylated tetrapyrazinoporphyrazines and its Optical Properties

2009 ◽  
Vol 2009 (5) ◽  
pp. 312-316 ◽  
Author(s):  
Chun Keun Jang ◽  
Jae Yun Jaung

Some phthalocyanines soluble in organic solvents have been developed by peripheral introduction of substituent groups. We report a new method for preparation of the polyphenyl-substituted dicyanopyrazines based on the [2 + 4] Diels-Alder cycloaddition of the tetraphenylcyclopentadienone to an ethynyl compound. The synthesised tetrapyrazinoporphyrazinato metal complexes were characterised by UV-visible spectroscopy, MALDI-TOF-Ms (matrix-assisted laser desorption ionisation time-of-flight mass) spectroscopy, and 1H NMR spectroscopy.

2009 ◽  
Vol 13 (07) ◽  
pp. 794-797 ◽  
Author(s):  
Chun Keun Jang ◽  
Seung Hwan Byun ◽  
Song Hak Kim ◽  
Do Kyung Lee ◽  
Jae Yun Jaung

2,3-dicyanopyrazine and metallophthalocyanines were synthesized with magnesium containing (±)camphorquinone substituent. 2,3-dicyanopyrazine was prepared by condensation reaction of diaminomaleonitrile (DAMN) with 1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-dione (1). The tetrapyrazinoporphyrazine was characterized by a combination of UV-visible spectroscopy, fluorescence spectroscopy, infrared radiation, elemental analysis, MALDI-TOF-MS and 1H NMR spectroscopy.


2020 ◽  
Vol 9 (1) ◽  
pp. 82
Author(s):  
Issa Sy ◽  
Lena Margardt ◽  
Emmanuel O. Ngbede ◽  
Mohammed I. Adah ◽  
Saheed T. Yusuf ◽  
...  

Fascioliasis is a neglected trematode infection caused by Fasciola gigantica and Fasciola hepatica. Routine diagnosis of fascioliasis relies on macroscopic identification of adult worms in liver tissue of slaughtered animals, and microscopic detection of eggs in fecal samples of animals and humans. However, the diagnostic accuracy of morphological techniques and stool microscopy is low. Molecular diagnostics (e.g., polymerase chain reaction (PCR)) are more reliable, but these techniques are not routinely available in clinical microbiology laboratories. Matrix-assisted laser/desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a widely-used technique for identification of bacteria and fungi; yet, standardized protocols and databases for parasite detection need to be developed. The purpose of this study was to develop and validate an in-house database for Fasciola species-specific identification. To achieve this goal, the posterior parts of seven adult F. gigantica and one adult F. hepatica were processed and subjected to MALDI-TOF MS to create main spectra profiles (MSPs). Repeatability and reproducibility tests were performed to develop the database. A principal component analysis revealed significant differences between the spectra of F. gigantica and F. hepatica. Subsequently, 78 Fasciola samples were analyzed by MALDI-TOF MS using the previously developed database, out of which 98.7% (n = 74) and 100% (n = 3) were correctly identified as F. gigantica and F. hepatica, respectively. Log score values ranged between 1.73 and 2.23, thus indicating a reliable identification. We conclude that MALDI-TOF MS can provide species-specific identification of medically relevant liver flukes.


2005 ◽  
Vol 51 (7) ◽  
pp. 1123-1131 ◽  
Author(s):  
Yoon Jun Kim ◽  
Soo-Ok Kim ◽  
Hyun Jae Chung ◽  
Mi Sun Jee ◽  
Byeong Gwan Kim ◽  
...  

Abstract Background: Identifying hepatitis C virus (HCV) genotypes has become increasingly important for determining clinical course and the outcome of antiviral therapy. Here we describe the development of restriction fragment mass polymorphism (RFMP) analysis, a novel matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay suitable for high-throughput, sensitive, specific genotyping of multiple HCV species. Methods: The assay is based on PCR amplification and mass measurement of oligonucleotides containing genotype-specific motifs in the 5′ untranslated region, into which a type IIS restriction endonuclease recognition was introduced by PCR amplification. Enzymatic cleavage of the products led to excision of multiple oligonucleotide fragments representing variable regions whose masses were determined by MALDI-TOF MS. Results: The RFMP assay identified viral genotypes present at concentrations as low as 0.5% and reliably determined their relative abundance. When sera from 318 patients were analyzed, the RFMP assay exhibited 100% concordance with results obtained by clonal sequencing and identified mixed-genotype infections in 22% of the samples, in addition to several subtype variants. Conclusions: The RFMP assay has practical advantages over existing methods, including better quantitative detection of mixed populations and detection of genotype variants without need for population-based cloning, enabling reliable viral genotyping in laboratories and efficient study of the relationship between viral genotypes and clinical outcome.


2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Joachim Spergser ◽  
Claudia Hess ◽  
Igor Loncaric ◽  
Ana S. Ramírez

ABSTRACTIn veterinary diagnostic laboratories, identification of mycoplasmas is achieved by demanding, cost-intensive, and time-consuming methods that rely on antigenic or genetic identification. Since matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) seems to represent a promising alternative to the currently practiced cumbersome diagnostics, we assessed its applicability for the identification of almost all mycoplasma species isolated from vertebrate animals so far. For generating main spectrum profiles (MSPs), the type strains of 98Mycoplasma, 11Acholeplasma, and 5Ureaplasmaspecies and, in the case of 69 species, 1 to 7 clinical isolates were used. To complete the database, 3 to 7 representatives of 23 undescribedMycoplasmaspecies isolated from livestock, companion animals, and wildlife were also analyzed. A large in-house library containing 530 MSPs was generated, and the diversity of spectra within a species was assessed by constructing dendrograms based on a similarity matrix. All strains of a given species formed cohesive clusters clearly distinct from all other species. In addition, phylogenetically closely related species also clustered closely but were separated accurately, indicating that the established database was highly robust, reproducible, and reliable. Further validation of the in-house mycoplasma library using 335 independent clinical isolates of 32 mycoplasma species confirmed the robustness of the established database by achieving reliable species identification with log scores of ≥1.80. In summary, MALDI-TOF MS proved to be an excellent method for the identification and differentiation of animal mycoplasmas, combining convenience, ease, speed, precision, and low running costs. Furthermore, this method is a powerful and supportive tool for the taxonomic resolution of animal mycoplasmas.


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