Month: February 2023

Chemical Synthesis of the Highly Sterically Hindered Core Undecasaccharide of Helicobacter pylori Lipopolysaccharide for Antigenicity Evaluation with Human Serum was written by Zou, Xiaopeng;Hu, Jing;Zhao, Ming;Qin, Chunjun;Zhu, Yuntao;Tian, Guangzong;Cai, Juntao;Seeberger, Peter H.;Yin, Jian. And the article was included in Journal of the American Chemical Society in 2022.Safety of 1-Bromopyrrolidine-2,5-dione This article mentions the following:

Here, we report a total synthesis of the core undecasaccharide of H. pylori lipopolysaccharide and its subunit antigens. The match and mismatch between the glycosyl donor and acceptor caused by the inert hydroxyl groups were addressed by a judicious choice of orthogonal protection strategies and glycosylation conditions. A combination of acyl remote participation and solvent effects has been applied for selective formation of the five 1,2-cis-glucosidic bonds. The high steric hindrance induced by the high carbon sugars and trinacriform architecture required that the core undecasaccharide was synthesized through a finely tuned linear assembly rather than convergent strategies. An antigenicity evaluation using glycan microarrays showed that an α-(1â†?)-glucan trisaccharide is recognized by IgG antibodies in sera of H. pylori-infected patients. The phosphate group of the inner core trisaccharide key epitope is very important for IgG recognition. These findings are an important step toward designing carbohydrate-based vaccines against H. pylori. In the experiment, the researchers used many compounds, for example, 1-Bromopyrrolidine-2,5-dione (cas: 128-08-5Safety of 1-Bromopyrrolidine-2,5-dione).

1-Bromopyrrolidine-2,5-dione (cas: 128-08-5) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. Many of the alkyl bromine derivatives are excellent alkylating agents since bromides are good leaving groups. Tribromides, like tetrabutylammonium tribromide, are used as a solid source of bromine. N-bromosuccimide (NBS) is used for the selective bromination of allylic bonds.Safety of 1-Bromopyrrolidine-2,5-dione

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Homo- and hetero-dimers of inactive organophosphorus group binding at dual sites of AChE was written by Zhao, Qian-Fei;Xie, Ru-Liang;Zhang, Tao;Fang, Jing;Mei, Xiang-Dong;Ning, Jun;Tang, Yun. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2011.Quality Control of N-(5-Bromopentyl)phthalimide This article mentions the following:

Homo- and hetero-dimers of inactive organophosphorus group(s) dramatically enhanced the acetylcholinesterase (AChE; EC 3.1.1.7) inhibiting potency, with the highest potency observed at a tether length of 6 methylene groups (I) for the homodimers, and 7 methylene groups (II) for the heterodimers. The docking model of Drosophila melanogaster AChE suggested that I and II bound at the catalytic and peripheral sites of AChE, in which two organophosphorous groups of I individually oriented towards TRP83 of catalytic sites and TRP321 of peripheral sites, and phthalicimide group of II was appropriately arranged for a π-π interaction with the Ph ring of TYR330, furthermore, the organophosphorus group introduced hydrophobic interaction with TRP83. The compounds prepared in this work demonstrated high insecticidal activity to Lipaphis erysimi and Tetranychus cinnabarinus at the concentration 300 mg/L. In the experiment, the researchers used many compounds, for example, N-(5-Bromopentyl)phthalimide (cas: 954-81-4Quality Control of N-(5-Bromopentyl)phthalimide).

N-(5-Bromopentyl)phthalimide (cas: 954-81-4) belongs to organobromine compounds. Most organobromine compounds, like most organohalide compounds, are relatively nonpolar. One prominent application of synthetic organobromine compounds is the use of polybrominated diphenyl ethers as fire-retardants, and in fact fire-retardant manufacture is currently the major industrial use of the element bromine.Quality Control of N-(5-Bromopentyl)phthalimide

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Structure-activity relationships of novel heteroaryl-acrylonitriles as cytotoxic and antibacterial agents was written by Saczewski, Franciszek;Stencel, Agnieszka;Bienczak, Andrzej M.;Langowska, Karolina A.;Michaelis, Martin;Werel, Wladyslaw;Halasa, Rafal;Reszka, Przemyslaw;Bednarski, Patrick J.. And the article was included in European Journal of Medicinal Chemistry in 2008.Related Products of 18791-79-2 This article mentions the following:

Eighteen new 2,6-disubstituted acrylonitriles, e. g. I, and two new (benzimidazol-1-yl)-acetamide derivatives were prepared and screened for antibacterial and cytotoxic activities on 12 human cancer cell lines. Based on the lead structure 2-(benzimidazol-2-yl)-3-(5-nitrothiophen-2-yl) acrylonitrile it was found that placement of Me groups at the 5,6 positions of the benzimidazole ring lead to a 3-fold increase in overall cytotoxic activity. Replacing the nitrothiophene for pyridine reduced cytotoxic activity as did replacing the nitro group for a methoxy group. Cytotoxic activity was only slightly reduced when the benzimidazole ring was replaced by a imidazo[4,5-b]pyridine or a benzthiazole ring but replacement by benzoxazole led to a substantial decrease in activity. Moving the acrylonitrile group from position 2 to position 1 of the benzimidazole ring also resulted in moderately active compounds Benzimidazol-1-ylacetamides showed only modest activity. The structure-activity relationships found in the cytotoxicity studies are mirrored in the results of the antibacterial experiments In the experiment, the researchers used many compounds, for example, 5-Bromothiophene-3-carbaldehyde (cas: 18791-79-2Related Products of 18791-79-2).

5-Bromothiophene-3-carbaldehyde (cas: 18791-79-2) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.Related Products of 18791-79-2

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

A new preparation of triphenylphosphinemethylenes by the reaction of carbenes with triphenylphosphine was written by Seyferth, Dietmar;Grim, Samuel O.;Read, Terence O.. And the article was included in Journal of the American Chemical Society in 1960.SDS of cas: 615-55-4 This article mentions the following:

Addition of HBr to the yellow solution of triphenylphosphinechloromethylene (I), prepared by adding 0.1 mole butyllithium in ether to 0.11 mole triphenylphosphine (II) and 0.13 mole methylene chloride in ether at -30°, precipitated a mixture of [Ph₃PH]Br (IIa), and [Ph₃PCH₂Cl]Br (III); dissolution of this in H₂O, caused a quant. decomposition of IIa to HBr and II. II was filtered off and aqueous Na tetraphenylborate added to the filtrate to precipitate [Ph₃PCH₂Cl][Ph₄], m. 189-92°, and 65% I. When III was purified by recrystallization from iso-PrOH-Et₂O in aqueous solution at comparable pH, the I was precipitated quant. and when phenyllithium was used as the base in the chlorocarbene generation, 40% was obtained. I was found to undergo the Wittig reaction and was used to synthesize 1-chloro-2-phenyl-1-propane from AcPh; chloromethylenecyclohexane from cyclohexanone; 1-chloro-2,4-dimethyl-1-pentene from Me iso-Bu ketone; 1-chloro-2-ethyl-1-butene from di-Et ketone, and 1,1-dibromo-2-phenyl-1-propene from AcPh. In the experiment, the researchers used many compounds, for example, 3,4-Dibromoaniline (cas: 615-55-4SDS of cas: 615-55-4).

3,4-Dibromoaniline (cas: 615-55-4) belongs to organobromine compounds. Most organobromine compounds, like most organohalide compounds, are relatively nonpolar. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.SDS of cas: 615-55-4

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Design, synthesis, and characterization of symmetrical bent-core liquid crystalline dimers with diacetylene spacer was written by Zhang, Lan-Ying;Zhang, Qi-Kai;Zhang, Yu-Dong. And the article was included in Liquid Crystals in 2013.Recommanded Product: 3-Bromophenyl acetate This article mentions the following:

Two new sym. bent-core liquid crystalline dimers (B-DA4 and B-DA12) bearing diacetylenes spacer and different terminal alkyl chains were successfully synthesized by a Sonogashira coupling reaction. The mol. structures of these dimers were confirmed by ¹H-NMR (NMR), Fourier transform-IR spectroscopy (FT-IR), Raman spectroscopy, mass spectrometry, elemental anal. Their thermal stability and liquid crystalline properties were characterized by thermogravimetric anal. (TGA), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and small-angle X-ray scattering (SAXS). Results showed that the diacetylene group may undergo thermal polymerized at about 260° far from thermal decomposition The dimers exhibited monotropic phase behavior and typical layered-structure phase with long-range order on a length scale of about 6.3 nm was observed The results mentioned above offer a promising opportunity to design diacetylene nanowires by thermal, UV irradiation or scanning tunneling microscope (STM) tip-induced polymerization The title compound thus formed included a bent-core dimer (I) and related substances. In the experiment, the researchers used many compounds, for example, 3-Bromophenyl acetate (cas: 35065-86-2Recommanded Product: 3-Bromophenyl acetate).

3-Bromophenyl acetate (cas: 35065-86-2) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. alpha-Bromoesters are employed in the Reformatsky reaction for the synthesis of beta-hydroxyesters. One prominent application of synthetic organobromine compounds is the use of polybrominated diphenyl ethers as fire-retardants, and in fact fire-retardant manufacture is currently the major industrial use of the element bromine.Recommanded Product: 3-Bromophenyl acetate

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary