Sequencing-based Molecular Typing of Treponema pallidum Strains in the Czech Republic: All Identified Genotypes are Related to the Sequence of the SS14 Strain

A set of 415 clinical samples isolated from 294 patients suspected of having syphilis collected in the Czech Republic between 2004 and 2010 was tested for the presence of treponemal DNA. Standard serological tests showed that 197 patients were syphilis-seropositive and 97 patients were syphilis-seronegative. In each sample, PCR tests for polA (TP0105), tmpC (TP0319), TP0136, TP0548 and 23S rRNA genes were performed. Samples taken from 91 patients were PCR-positive. Molecular typing of treponemal DNA was based on the sequencing of TP0136, TP0548 and 23S rRNA genes. Treponemal DNA was typeable in samples taken from 64 PCR-positive patients and 9 different genotypes were found. The proportion of treponemal strains resistant to macrolide antibiotics was 37.3%. In the DNA samples taken from 39 patients, a parallel treponemal typing approved by Centers for Disease Control and Prevention was performed. The variants of arp and tpr genes appear to combine independently with sequence variants of TP0136, TP0548 and 23S rRNA genes

Two squares in a barrel: An axially disubstituted conformationally rigid aliphatic binding motif for cucurbit[6]uril

Novel binding motifs suitable for the construction of multitopic guest-based molecular devices (e.g., switches, sensors, data storage, and catalysts) are needed in supramolecular chemistry. No rigid, aliphatic binding motif that allows for axial disubstitution has been described for cucurbit[6]uril (CB6) so far. We prepared three model guests combining spiro[3.3]heptane and bicyclo[1.1.1]pentane centerpieces with imidazolium and ammonium termini. We described their binding properties toward CB6/7 and α-/β-CD using NMR, titration calorimetry, mass spectrometry, and single-crystal X-ray diffraction. We found that a bisimidazolio spiro[3.3]heptane guest forms inclusion complexes with CB6, CB7, and β-CD with respective association constants of 4.0 × 104, 1.2 × 1012, and 1.4 × 102. Due to less hindering terminal groups, the diammonio analogue forms more stable complexes with CB6 (K = 1.4 × 106) and CB7 (K = 3.8 × 1012). The bisimidazolio bicyclo[1.1.1]pentane guest forms a highly stable complex only with CB7 with a K value of 1.1 × 1011. The high selectivity of the new binding motifs implies promising potential in the construction of multitopic supramolecular components.Internal Funding Agency of Tomas Bata University, (IGA/FT/2023/001); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (LM2023042, LUAUS23144); Ústav organické chemie a biochemie Akademie věd České republiky, ÚOCHB AV ČR, (RVO: 61388963)Internal Funding Agency of Tomas Bata University in Zlin [IGA/FT/2023/001]; MEYS CR [LM2023042]; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences [RVO: 61388963]; Ministry of Education, Youth and Sports [LUAUS23144

Modes of micromolar host-guest binding of beta-cyclodextrin complexes revealed by NMR spectroscopy in salt water

Multitopic supramolecular guests with finely tuned affinities toward widely explored cucurbit[n]urils (CBs) and cyclodextrins (CDs) have been recently designed and tested as functional components of advanced supramolecular systems. We employed various spacers between the adamantane cage and a cationic moiety as a tool for tuning the binding strength toward CB7 to prepare a set of model guests with K-CB7 and K beta-CD values of (0.6-5.0) x 10(10) M-1 and (0.6-2.6) x 10(6) M-1, respectively. These accessible adamantylphenyl-based binding motifs open a way toward supramolecular components with an outstanding affinity toward beta-cyclodextrin. H-1 NMR experiments performed in 30% CaCl2 /D2O at 273 K along with molecular dynamics simulations allowed us to identify two arrangements of the guest@beta-CD complexes. The approach, joining experimental and theoretical methods, provided a better understanding of the structure of cyclodextrin complexes and related molecular recognition, which is highly important for the rational design of drug delivery systems, molecular sensors and switches.Internal Funding Agency of the Tomas Bata University in Zlin [IGA/FT/2020/001]; Czech Science FoundationGrant Agency of the Czech Republic [18-05421S]; Ministry of Education, Youths and Sports of the Czech Republic (MEYS CR) [LQ1601]; CIISB, Instruct-CZ Center of Instruct-ERIC EU consortium - MEYS CR infrastructure project [LM2018127]; MEYS CR from the Large Infrastructures for Research, Experimental Development and Innovations [CZLM2018140]Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: CZ-LM2018140, LM2018127; Grantová Agentura České Republiky, GA ČR: 18-05421S, LQ1601; Univerzita Tomáše Bati ve Zlíně: IGA/FT/2020/001; Masarykova Univerzita, M

Cuvette washing apparatus

Nově navržené zařízení se používá pro čištění vnitřního prostoru kyvet s vnitřním průměrem v rozmezí 2-10 mm, ale lze ji uzpůsobit tak, aby bylo možné vymývat i kyvety větších průměrů. Promývačka je vhodná zejména pro NMR a EPR, ale také další podobné kyvety ze skla i jiných materiálů.Newly designed equipment used to clean the inside of cuvettes with an internal diameter of 2-10 mm. It can be adapted in order to rinse out even larger cuvettes. The washer is suitable especially for use with NMR and EPR cuvettes, but also other similar ones made from various materials | glass,metal, plas

Theoretical and experimental studies of IR and NMR spectra of gem-2,2-diamino-4,4,6,6-tetraphenoxy-1,3,5-cyclo-triaza-lambda5-phosphorine

Pomocí DFT byla studována vibrační spektra gem-2,2-diamino-4,4,6,6-tetrafenoxy-cyklo-trifosfazenu. Vybrané vibrační pásy byly přiřazeny k normálním vibračním módům na základě DFT výpočtů. K těmto výpočtům byl použit program ADF. Byla změřena 1H, 13C NMR spektra, spektra vyššího řádu: 31P, 31P{1Ham.(sel.)} and 31P{1Harom.(sel.)} a ze spekter byly odečteny hodnoty interakčních konstant 1J(C,H), 2J(C,H) a 2J(PI,PII). Byl simulován téměř kompletní spinový systém ABB'M4X4X4' odpovídající symetrii molekuly C2 a poprvé byly zjištěny hodnoty interakčních konstant 2J(PI,Ham.), 4J(PII,Ham.), 4J(PII,Harom.), 6J(PI,Harom.) a 6J(PII,H'arom.). Pro simulaci byl použit program gNMR. Data získaná z naměřených NMR spekter byla také porovnána s výsledky kvantově chemických výpočtů.The vibrational spectra of gem-2,2-diamino-4,4,6,6-tetraphenoxy-1,3,5-cyclo-triaza-lambda5-phosphorine were studied using density functional theory. Selected vibrational bands were assigned to normal modes on the basis of DFT calculation with the ADF program package. The 1H and 13C NMR spectra, the higher order 31P, 31P{1Ham.(sel.)} and 31P{1Harom.(sel.)} NMR spectra were measured and the values of 1J(C,H), 2J(C,H) and 2J(PI,PII) were found. Nearly the complete spin system (ABB'M4X4X4') for the symmetry C2 was simulated with the gNMR simulation program and the values of 2J(PI,Ham.), 4J(PII,Ham.), 4J(PII,Harom.), 6J(PI,Harom.) and 6J(PII,H'arom.) were determined for the first time. The experimental NMR data were also compared with quantum chemical calculation results

Adamantylated trisimidazolium-based tritopic guests and their binding properties towards cucurbit[7]uril and beta-cyclodextrin

Two new homotritopic guests based on tris(benz) imidazolium salts with adamantane binding sites were prepared. NMR and calorimetric titration experiments revealed that each of the three sites independently binds beta-cyclodextrin (beta-CD) or cucurbit[7]uril (CB7) units to form binary host-guest complexes with 1:3 stoichiometry. The association constants for the single binding site for beta-CD and CB7 were determined using titration calorimetry and are in the order of 10(5) and 10(9-10) dm(3) mol(-1), respectively. In addition, both guests were able to form ternary systems with beta-CD and CB7 in ratios of 1:1:2 and 1:2:1, respectively.Internal Funding Agency of the Tomas Bata University in Zlin [IGA/FT/2015/005

Conformational dimorphism of isochroman-1-ones in the solid state

Isochroman-1-one derivatives, which are relatives of coumarins, display a broad spectrum of biological activity; therefore, these derivatives attract the attention of chemists. A series of new isochroman-1-ones were prepared by the reaction of benzyl-derived Grignard reagents with acyl chlorides. All of the prepared compounds were characterized using single-crystal X-ray diffraction as well as FT-IR, NMR and MS techniques. Single crystal X-ray diffraction analysis revealed that the isochromanones can adopt two distinct conformations in the solid state. For one of the compounds, two polymorphs with unique forms crystallized separately under different temperatures. The packing of all of the examined crystals is stabilized via weak intramolecular C-H⋯π and/or C-H⋯O interactions. Although the closed conformer was predominantly found in the actual crystals, the open conformer is thermochemically more stable for all of the examined compounds according to DFT calculations

Assembling a supramolecular 3D network with tuneable mechanical properties using adamantylated cross-linking agents and β-cyclodextrin-modified hyaluronan

Hydrogels based on the supramolecular host-guest concept can be prepared if at least one constituent is a polymer chain modified with supramolecular host or guest (or both) units. Low-molecular-weight multitopic counterparts can also be used, however, guest molecules in the role of cross-linking agents are seldom reported, although such an approach offers wide-ranging possibilities for tuning the system properties via easily achievable structural modifications. In this paper, a series of adamantane-based star-like guest molecules was used for crosslinking of two types of beta-cyclodextrin-modified hyaluronan (CD-HA). The prepared 3D supramolecular networks were characterised using nuclear magnetic resonance, titration calorimetry and rheological measurements to confirm the formation of the host-guest complexes between adamantane moieties and beta-cyclodextrin units, including their typical properties such as self-healing and dynamic nature. The results indicate that the nature of the cross-linker (amides versus esters) has a greater impact on mechanical properties than the length of the guest's arms. In addition, the results show that the length of the HA polymer chain is more important than the degree of modification with supramolecular units. In conclusion, it was proven that the modular concept employing low-molecular-weight cross-linking guests is valuable for the formulation of supramolecular networks, including hydrogels.Tomas Bata University in Zlin, TBU: RP/CPS/2022/001, RP/CPS/2022/003project OP RDE Junior Grants of TBU in Zlin [CZ.02.2.69/0.0/0.0/19_073/0016941]; Internal Funding Agency of TBU [IGA/FT/2022/001]; [RP/CPS/2022/001]; [RP/CPS/2022/003

Author's personal copy Reactions of P 4 S 10 and pyPS 2 Cl with N,N 0 -diphenylurea and N,N 0 -diphenylthiourea

Abstract The reaction of P 4 S 10 (1) with N,N 0 -diphenylurea (PhNH) 2 CO (2) results in new heterocyclic compounds: the pyridinium salt of 1,3-diphenyl-2-sulfido-2-thioxo-1,3-diaza