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Fang Wang, Christopher A DeRosa, Margaret L Daly, Daniel Song, Cassandra L Fraser
Difluoroboron β-diketonate (BF2 bdk) compounds show environment-sensitive optical properties in solution, aggregation-induced emission (AIE) and multi-stimuli responsive fluorescence switching in the solid state. Here, a series of 4-azepane-substituted β-diketone (bdk) ligands ( L-H , L-OMe , L-Br ) and their corresponding difluoroboron dyes ( D-H , D-OMe , D-Br ) were synthesized, and various responsive fluorescence properties of the compounds were studied, including solvatochromism, viscochromism, AIE, mechanochromic luminescence (ML) and halochromism...
September 1, 2017: Materials Chemistry Frontiers
Evgeny G Shakhmatov, Philip V Toukach, Sergey P Kuznetsov, Elena N Makarova
Fractions containing arabinogalactan proteins (AGPs) and pectic polysaccharides were isolated from above-ground parts of Heracleum sosnowskyi. Major units of their structure were elucidated using ion-exchange chromatography, gel chromatography, and NMR spectroscopy. The carbohydrate backbone of the polysaccharides consisted of 1,3-β-D-galactopyranosyl residues, whereas side chains of the branched region consisted of the residues of 1,6-β-galactopyranose, 1,5-α-L-arabinofuranose, 1,4-β-D-glucuronic acid, and 1,6-β-D-glucopyranose...
February 15, 2014: Carbohydrate Polymers
Nessana Dartora, Lauro M de Souza, Simone M M Paiva, Camila T Scoparo, Marcello Iacomini, Philip A J Gorin, Yanna D Rattmann, Guilherme L Sassaki
The present study evaluated the anti-inflammatory activity of a polysaccharide from maté, using a clinically relevant model of sepsis induced by cecal ligation and puncture (CLP). A polysaccharide from maté (SPI) was obtained from aqueous extraction followed by fractionation, being identified as a rhamnogalacturonan with a main chain of →4)-6-OMe-α-D-GalpA-(1→ groups, interrupted by α-L-Rhap units, substituted by a type I arabinogalactan. SPI was tested against induced-polymicrobial sepsis, at doses of 3, 7 and 10 mg/kg...
February 15, 2013: Carbohydrate Polymers
Adamara M Nascimento, Lauro M de Souza, Cristiane H Baggio, Maria Fernanda de P Werner, Daniele Maria-Ferreira, Luisa M da Silva, Guilherme L Sassaki, Philip A J Gorin, Marcello Iacomini, Thales R Cipriani
The plant Acmella oleracea (L.) R.K.Jansen (Asteraceae), locally known as jambu, is widely used in Legal Amazon in local dishes and in folk medicine. A polysaccharide (SC) was isolated from this plant, following aqueous extraction, which contained uronic acid, galactose, arabinose, rhamnose, and glucose in a 15:2:1:1:0.5 molar ratio and had a M(w) 226,000 g/mol. Methylation analysis and NMR spectroscopy indicated that SC is a rhamnogalacturonan composed of a long chain of →4)-6-OMe-α-D-GalpA-(1→, interspersed with some α-L-Rhap residues, partly substituted by side-chains of type II arabinogalactans...
January 2013: Phytochemistry
Anna Turska-Szewczuk, Ryszard Russa
The O-specific polysaccharide (OPS) obtained by mild-acid degradation of the lipopolysaccharide isolated from Mesorhizobium huakuii strain S-52 was studied by sugar and ethylation analyses along with (1)H and (13)C NMR spectroscopy. It was concluded that the OPS was composed of trisaccharide repeating units containing two residues of 6-deoxy-l-talose (6dTal) and one l-rhamnose (Rha), whose sequence in the OPS was determined by NOESY and HMBC experiments. The minor 3-O-acetylation (about 10%) of 6-deoxytalose glycosidically substituted at position-2 was judged by relative signal intensities of corresponding O-acetylated and non-acetylated 6dTal residues...
June 1, 2011: Carbohydrate Research
Won-Sik Han, Jung-Kyu Han, Hyun-Young Kim, Mi Jin Choi, Yong-Soo Kang, Chyongjin Pac, Sang Ook Kang
We prepared a series of new heteroleptic ruthenium(II) complexes, Ru(NCS)(2)LL' (3a-3e), where L is 4,4'-di(hydroxycarbonyl)-2,2'-bipyridine and L' is 4,4'-di(p-X-phenyl)-2,2'-pyridine (X = CN (a), F (b), H (c), OMe (d), and NMe(2) (e)), in an attempt to explore the structure-activity relationships in their photophysical and electrochemical behavior and in their performance in dye-sensitized solar cells (DSSCs). When substituent X is changed from electron-donating NMe(2) to electron-withdrawing CN, the absorption and emission maxima reveal systematic bathochromic shifts...
April 18, 2011: Inorganic Chemistry
Theodora Katsila, Evangelos Balafas, George Liapakis, Patrizia Limonta, Marina Montagnani Marelli, Konstantinos Gkountelias, Theodore Tselios, Nikolaos Kostomitsopoulos, John Matsoukas, Constantin Tamvakopoulos
Gonadotropin-releasing hormone (GnRH) receptor agonists have wide clinical applications including the treatment of prostate cancer and endocrine disorders. However, such agonists are characterized by poor pharmacokinetic properties, often requiring repeated administration or special formulations. Therefore, the development of novel peptide analogs with enhanced in vivo stability could potentially provide therapeutic alternatives. The pharmacological evaluation of a bioactive peptide [Des-Gly¹⁰,Tyr⁵(OMe),D-Leu⁶,Aze-NHEt⁹]GnRH, analog 1, is presented herein and compared with leuprolide...
March 2011: Journal of Pharmacology and Experimental Therapeutics
Upadhyayula S Raghavender, Kantharaju, Subrayashastry Aravinda, Narayanaswamy Shamala, Padmanabhan Balaram
Peptide nanotubes with filled and empty pores and close-packed structures are formed in closely related pentapeptides. Enantiomorphic sequences, Boc-(D)Pro-Aib-Xxx-Aib-Val-OMe (Xxx = Leu, 1; Val, 2; Ala, 3; Phe, 4) and Boc-Pro-Aib-(D)Xxx-Aib-(D)Val-OMe ((D)Xxx = (D)Leu, 5; (D)Val, 6; (D)Ala, 7; (D)Phe, 8), yield molecular structures with a very similar backbone conformation but varied packing patterns in crystals. Peptides 1, 2, 5, and 6 show tubular structures with the molecules self-assembling along the crystallographic six-fold axis (c-axis) and revealing a honeycomb arrangement laterally (ab plane)...
January 27, 2010: Journal of the American Chemical Society
Rajkishor Rai, Srinivasarao Raghothama, Rajagopalan Sridharan, Padmanabhan Balaram
Designed octapeptides Boc-Leu-Val-Val-Aib-(D)Xxx-Leu-Val-Val-OMe ((D)Xxx = (D)Ala, 3a;(D)Val, 3c and (D)Pro, 5a) and Boc-Leu-Phe-Val-Aib-(D)Ala-Leu-Phe-Val-OMe (3b) have been investigated to construct models of a stable type I' beta-turn nucleated hairpin and to generate systems for investigating helix-hairpin conformational transitions. Peptide 5a, which contains a central Aib-(D)Pro segment, is shown to adopt a stable type I' beta-turn nucleated hairpin structure, stabilized by four cross-strand hydrogen bonds...
2007: Biopolymers
No abstract text is available yet for this article.
July 1963: Revue D'hygiène et de Médecine Sociale
Akio Sugihara, Yuji Shimada, Shigeo Sugihara, Takahisa Nakai, Tomisaburo Kakuno, Toshihiro Nagao, Yomi Watanabe, Yoshio Tominaga
A unique enzyme with some properties favorable for the synthesis of D-amino acid-containing peptides has been purified from the culture broth of Saccharothrix sp. AS-2. The purification steps included ammonium sulfate fractionation, chromatographies on CM-Toyopearl 650M and ProtEx Butyl, and sucrose density-gradient isoelectric focusing. The enzyme, consisting of four subunits of 56 kDa, showed its maximum transfer activity at around pH 8.2 and 35 degrees C, and had an isoelectric point of 5.8. The enzyme yielded homooligomers from methyl esters of D-Asp(OMe), D-Met, D-Phe, D-Trp, D-Tyr, and L-Glu(OMe), but showed no hydrolytic activity toward any of the D- or L-amino acid methyl esters tested...
February 2002: Journal of Biochemistry
M Beban, P S Miller
Triplex forming oligonucleotides (TFOs) are potentially useful in targeting RNA for antisense therapeutic applications. To determine the feasibility of targeting polypurine RNA with nuclease-resistant oligonucleotides, TFOs containing 2'-deoxy or 2'-O-methyl (2'-OMe) backbones, designed to form pyrimidine motif triplexes with RNA, were synthesized. TFOs were made which can form trimolecular triplexes, or bimolecular, 'clamp' triplexes with polypurine RNA and DNA. It was found that the relative stabilities of the triplexes formed followed the order: M...
June 21, 2000: Biochimica et Biophysica Acta
N S Darbinian, Iu G Popov, A V Mochul'skiĭ, D Oming, E S Piruzian, V T Vasilevko
The modified hybrid beta-1,3-glucanase gene (glc) of Clostridium thermocellum was expressed in tobacco Nicotiana tabacum. The glc gene was cloned into two plasmids, pC27-glc and pC29-glc, in which its expression was controlled by the TR2' promoter of the 2' gene of T-DNA and the rbcS promoter of Arabidopsis, respectively. These constructions were used for transformation of agrobacteria followed by transfer into plants. In transformed plants, each plasmid caused a high level of activity of thermostable bacterial glucanase not observed in reference plants...
February 1996: Genetika
G Zala, S Giezendanner, R Flury, J Wüst, C Meyenberger, R Ammann, H P Wirth
The efficacy of high dose omeprazole/amoxicillin (OME/AMOX) for eradication of Helicobacter pylori (HP) is controversial. Reported eradication rates range from 0% to 90%. Different therapy schedules and unknown factors may be crucial; in particular, pretreatment with OME has been thought to endanger HP eradication by subsequent OME/AMOX. Preliminary findings suggested that smoking may impair eradication with OME/AMOX. The aims of this study were (1) to establish whether HP eradication rates differ depending on whether eradication with OME/AMOX was performed before or after ulcer therapy with OME, (2) to determine whether smoking impairs HP eradication by OME/AMOX and (3) to evaluate the efficacy of OME/AMOX in our population...
August 9, 1994: Schweizerische Medizinische Wochenschrift
W Stüber, R Koschinsky, M Reers, D Hoffmann, J Czech, G Dickneite
The dipeptide Mtr-Asp-D-Adf-Pip 10 represents a potent thrombin inhibitor. In comparison to NAPAP, 10 exhibited improved tolerability and a longer half-life in vivo, i.e., 20 +/- 5 min. We have coupled aminopolyethyleneglycolmonomethylether of various molecular weights to the carboxyl moiety of 10 and evaluated their biological properties. First, Mtr-Asp-OBut was coupled to the amino group of the PEG employing TOTU as an activating agent. This was followed by the removal of the OBut protecting group and coupling of D-Adf-Pip using TOTU as well...
March 1995: Peptide Research
E Ozeki, T Miyazu, S Kimura, Y Imanishi
Three cyclic hexapeptides bearing carboxyl groups, cyclo(L-Asp-L-Phe-L-Pro)2, cyclo(L-Aad-L-Phe-L-Pro)2 (Aad represents alpha-amino adipic acid residue), and cyclo(D-Asp-D-Phe-L-Pro)2 were synthesized and investigated on conformation, complexation with metal ions, and interaction with lipid membrane. These cyclic hexapeptides were found to take several different conformations, though their reference compounds, cyclo(L-Leu-L-Phe-L-Pro)2 and cyclo[D-Asp(OMe)-D-Phe-L-Pro]2, took a single C2 symmetric conformation...
August 1989: International Journal of Peptide and Protein Research
D H Coy, Z Mungan, W J Rossowski, B L Cheng, J T Lin, J E Mrozinski, R T Jensen
Of the various types of potent bombesin(Bn)/gastrin releasing peptide receptor antagonists that have been discovered, the desMet14-methyl ester peptides are devoid of residual agonist activity and are among the most potent in terms of in vitro receptor blockade and also in terms of their prolonged inhibition of bombesin-stimulated amylase and protein release in the rat. We have now examined the in vitro and in vivo properties of a new series of methyl ester analogues, [D-Phe6]Bn(6-13)OMe, [D-Phe6,D-Ala11]Bn(6-13)OMe, N alpha-propionyl-[D-Ala24]GRP(20-26)OMe, and [D-pentafluoro-Phe6,D-Ala11]Bn(6-13)OMe, which have an additional D-amino acid substituent and some highly lipophilic moieties at the N-terminus...
July 1992: Peptides
A Baumert, D Gröger, W Maier
Radioactive d-lysergyl-Val-Leu-OMe, d-lysergyl-Val-Val-OMe and d-lysergyl-Val-Val-Pro-OMe were synthetized according to the dicyclohexylcarbodiimide/1-hydroxybenzotriazole procedure. These compounds are not used by intact mycelium of Claviceps as immediate precursors for cyclolalkaloid biosynthesis.
July 15, 1977: Experientia
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