13992-15-9Relevant articles and documents
Superarming of glycosyl donors by combined neighboring and conformational effects
Heuckendorff, Mads,Premathilake, Hemali D.,Pornsuriyasak, Papapida,Madsen, Anders .,Pedersen, Christian M.,Bols, Mikael,Demchenko, Alexei V.
, p. 4904 - 4907 (2013)
A novel glycosyl donor that combines the concepts of both conformational and electronic superarming has been synthesized. The reactivity and selectivity of the donor have been tested in competition experiments.
Photooxidation of thiosaccharides mediated by sensitizers in aerobic and environmentally friendly conditions
Traverssi, Miqueas G.,Pe?é?ory, Alicia B.,Varela, Oscar,Colomer, Juan P.
, p. 9262 - 9273 (2021/03/16)
A series of β-d-glucopyranosyl derivates have been synthesized and evaluated in photooxidation reactions promoted by visible light and mediated by organic dyes under aerobic conditions. Among the different photocatalysts employed, tetra-O-acetyl riboflavin afforded chemoselectively the respective sulfoxides, without over-oxidation to sulfones, in good to excellent yields and short reaction times. This new methodology for the preparation of synthetically useful glycosyl sulfoxides constitutes a catalytic, efficient, economical, and environmentally friendly oxidation process not reported so far for carbohydrates.
Chemical Synthesis and Biological Evaluations of Adiponectin Collagenous Domain Glycoforms
Wu, Hongxiang,Zhang, Yiwei,Li, Yuanxin,Xu, Jianchao,Wang, Yu,Li, Xuechen
supporting information, p. 7808 - 7818 (2021/05/26)
The homogeneously glycosylated 76-amino acid adiponectin collagenous domains (ACDs) with all of the possible 15 glycoforms have been chemically and individually synthesized using stereoselective glycan synthesis and chemical peptide ligation. The following biological and pharmacological studies enabled correlating glycan pattern to function in the inhibition of cancer cell growth as well as the regulation of systemic energy metabolism. In particular, hAdn-WM6877 was tested in detail with different mouse models and it exhibited promising in vivo antitumor, insulin sensitizing, and hepatoprotective activities. Our studies demonstrated the possibility of using synthetic glycopeptides as the adiponectin downsized mimetic for the development of novel therapeutics to treat diseases associated with deficient adiponectin.
Leveraging Trifluoromethylated Benzyl Groups toward the Highly 1,2- Cis-Selective Glucosylation of Reactive Alcohols
Njeri, Dancan K.,Ragains, Justin R.,Valenzuela, Erik Alvarez
supporting information, p. 8214 - 8218 (2021/11/13)
Here, we demonstrate that substitution of the benzyl groups of glucosyl imidate donors with trifluoromethyl results in a substantial increase in 1,2-cis-selectivity when activated with TMS-I in the presence of triphenylphosphine oxide. Stereoselectivity is dependent on the number of trifluoromethyl groups (4-trifluoromethylbenzyl vs 3,5-bis-trifluoromethylbenzyl). Particularly encouraging is that we observe high 1,2-cis-selectivity with reactive alcohol acceptors.
Synthesis of Glycosyl Fluorides by Photochemical Fluorination with Sulfur(VI) Hexafluoride
Bannykh, Anton,Khomutnyk, Yaroslav,Kim, Sungjin,Nagorny, Pavel
supporting information, p. 190 - 194 (2021/01/13)
This study describes a new convenient method for the photocatalytic generation of glycosyl fluorides using sulfur(VI) hexafluoride as an inexpensive and safe fluorinating agent and 4,4′-dimethoxybenzophenone as a readily available organic photocatalyst. This mild method was employed to generate 16 different glycosyl fluorides, including the substrates with acid and base labile functionalities, in yields of 43%-97%, and it was applied in continuous flow to accomplish fluorination on an 7.7 g scale and 93% yield.
Total Synthesis of a Partial Structure from Arabinogalactan and Its Application for Allergy Prevention
Krumb, Matthias,J?ger, Maximilian,Voss, Alice,Immig, Loreen,Peters, Karin,Kowalczyk, Danuta,Bufe, Albrecht,Opatz, Till,Holst, Otto,Vogel, Christian,Peters, Marcus
supporting information, p. 928 - 933 (2020/10/29)
Arabinogalactan, a microheterogeneous polysaccharide occurring in plants, is known for its allergy-protective activity, which could potentially be used for preventive allergy treatment. New treatment options are highly desirable, especially in a preventive manner, due to the constant rise of atopic diseases worldwide. The structural origin of the allergy-protective activity of arabinogalactan is, however, still unclear and isolation of the polysaccharide is not feasible for pharmaceutical applications due to a variation of the activity of the natural product and contaminations with endotoxins. Therefore, a pentasaccharide partial structure was selected for total synthesis and subsequently coupled to a carrier protein to form a neoglycoconjugate. The allergy-protective activity of arabinogalactan could be reproduced with the partial structure in subsequent in vivo experiments. This is the first example of a successful simplification of arabinogalactan with a single partial structure while retaining its allergy-preventive potential.
Transition-metal-free synthesis of aryl 1-thioglycosides with arynes at room temperature
Liao, Li-Hua,Liu, Yao,Yan, Nan,Yu, Xiao-Bing,Zhang, Xiang-Mei,Zhong, Qian
, p. 26666 - 26671 (2021/08/17)
A mild, convenient and transition-metal-free protocol for the synthesis of aryl 1-thioglycosides is presentedviaarynes generatedin situcombined with glycosyl thiols in the presence of TBAF(tBuOH)4. The methodology provides a general and efficient way to prepare a series of functionalized thioglycosides in good to excellent yields with a perfect control of the anomeric configuration at room temperature. In addition, the reaction conditions tolerate a variety of the pentoses and hexoses, and the reaction also performs smoothly on protected monosaccharides and disaccharides.
Chemical glucosylation of pyridoxine
Bachmann, Thomas,Rychlik, Michael
, (2020/02/13)
The chemical synthesis of pyridoxine-5′-β-D-glucoside (5′-β-PNG) was investigated using various glucoside donors and promoters. Hereby, the combination of α4,3-O-isopropylidene pyridoxine, glucose vested with different leaving and protecting groups and the application of stoichiometric amounts of different promoters was examined with regards to the preparation of the twofold protected PNG. Best results were obtained with 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl fluoride and boron trifluoride etherate (2.0 eq.) as promoter at 0 °C (59%). The deprotection was accomplished stepwise with potassium/sodium hydroxide in acetonitrile/water followed by acid hydrolysis with formic acid resulting in the chemical synthesis of 5′-β-PNG.
Total Synthesis of the Echinodermatous Ganglioside LLG-3 Possessing the Biological Function of Promoting the Neurite Outgrowth
Huang, Yuahn-Sieh,Shih, Jing-Feng,Tsai, Yow-Fu,Wu, Yu-Fa
supporting information, p. 7491 - 7495 (2020/10/09)
A total synthesis of echinodermatous ganglioside LLG-3 with neuritogenic activity was accomplished by a convergent strategy. The synthesis of 2-hydroxyethyl 8-O-Me-α-sialoside 2 was started from the phenyl 7,8-di-O-Pico-thiosialoside 5, which can be chemoselectively removed the picoloyl group, and then the methyl group in 8-O-MeNeu5Ac moiety was chemoselectively prepared using TMSCHN2/FeCl3. For preparation of the terminal disialic unit, oxidative amidation was initially utilized by our group to efficiently construct the α(2,11) linkage of 8-O-Me-Neu5Acα(2,11)Neu5Gc. Herein, we also demonstrate that the synthesized ganglioside LLG-3 exhibited the neuritogenic activity toward the primary cortical neurons and that biological activity is superior to that of ganglioside DSG-A.
Total Synthesis of Tiacumicin B: Implementing Hydrogen Bond Directed Acceptor Delivery for Highly Selective β-Glycosylations
Beau, Jean-Marie,Fran?ois-Eude, Marc,Genta-Jouve, Grégory,Jeanne-Julien, Louis,Masson, Guillaume,Norsikian, Stéphanie,Roulland, Emmanuel,Servajean, Vincent,Tresse, Cedric
supporting information, p. 6612 - 6616 (2020/03/03)
A total synthesis of tiacumicin B, a natural macrolide whose remarkable antibiotic properties are used to treat severe intestinal infections, is reported. The strategy is in part based on the prior synthesis of the tiacumicin B aglycone, and on the decisive use of sulfoxides as anomeric leaving groups in hydrogen-bond-mediated aglycone delivery (HAD). This new HAD variant permitted highly β-selective rhamnosylation and noviosylation. To increase convergence, the rhamnosylated C1–C3 fragment thus obtained was anchored to the C4–C19 aglycone fragment by adapting the Suzuki–Miyaura cross-coupling used for the aglycone synthesis. Ring-size-selective macrolactonization provided a compound engaged directly in the noviolysation step with virtually total β selectivity. The final efficient removal of all the protecting groups provided synthetic tiacumicin B.
