113567-34-3Relevant articles and documents
Sterically Hindered 2,4,6-Tri- tert-butylpyridinium Salts as Single Hydrogen Bond Donors for Highly Stereoselective Glycosylation Reactions of Glycals
Ghosh, Titli,Mukherji, Ananya,Kancharla, Pavan K.
, p. 3490 - 3495 (2019)
We demonstrate here that the strained and bulky protonated 2,4,6-tri-tert-butylpyridine salts serve as efficient catalysts for highly stereoselective glycosylations of various glycals. Moreover, the mechanism of action involves an interesting single hydrogen bond mediated protonation of glycals and not via the generally conceived Br?nsted acid pathway. The counteranions also play a role in the outcome of the reaction.
Boronic acid-catalyzed final-stage site-selective acylation for the total syntheses of O-3′-acyl bisabolol β-D-fucopyranoside natural products and their analogues
Nakamura, Yuki,Ochiai, Takayuki,Makino, Kazuishi,Shimada, Naoyuki
, p. 281 - 285 (2021/03/08)
The first concise total syntheses of O-3′-senecioyl α-bisabolol β-D-fucopyranoside (4a) and O-3′isovaleroyl α-bisabolol β-D-fucopyranoside (4b) were achieved through final-stage site-selective acylation via the activation of cis-vicinal diols by imidazole
Suppression of cytokine production by newly isolated flavonoids from pepper
Allam, Ahmed E.
, (2021/04/19)
New flavonoid glycoside, kaempferol 3-O-α-[(6-P-coumaroyl galactopyranosyl-O-β-(→4)-O-α-rhamnopyranosyl-(1→4)]-O-α-rhamnopyranoside 1, in addition to five known flavonoid glycosides (2–6) kaempferol 3-O-[α-rhamnopyranosyl-(1→4)-O-α-rhamnopyranosyl-(1→6)-O]-β-galactopyranoside (kaempferol 3-O-β-isorhamninoside) 2, quercetin 3-O-[(2,3,4-triacetyl-α-rhamnopyranosyl)-(1 → 6)-β-galactopyranoside 3, quercetin 3-O-[(2,4-diacetyl-α-rhamnopyranosyl)-(1 → 6)]-3,4-diacetyl-β-galactopyranoside 4, quercetin 3-O-[(2,4-diacetyl-α-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-galactopyranoside 5, quercetin 3-O-[(2,3,4-triacetyl-α-rhamnopyranosyl)-(1 → 6)-3-acetyl-β-galactopyranoside 6 were isolated from bell pepper (Capsicum annum L.) fruits and tested for both anti-inflammatory activity through cytokine production (TNF-α and IL-1β) and antioxidant activity through scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Compounds 1–3 significantly suppressed production of TNF-α / IL-1β in cultured THP-1 cells previously co-stimulated by LPS in a dose-dependent manner (10.2/49.1, 28.1/55.7, and 35.2/57.5 μM respectively) whereas compounds 4–6 have relatively weaker inhibitory activity. (45.3/73.5, 48.2/65.6, and 42.2/67.4 μM respectively). All compounds 1–6 showed no cytotoxic activity against the growth of THP-1where the percentage of cell viability was (127.4, 108.5, 105.4, 103.9, 103.4, and 104.2 μM respectively). All isolated compounds exhibited higher radical scavenging activity than ascorbic acid in (DPPH) assay. These results indicated that bell pepper fruits could be an effective candidate for ameliorating inflammatory-associated complications.
Visible Light Enables Aerobic Iodine Catalyzed Glycosylation
Krumb, Matthias,Lucas, Tobias,Opatz, Till
supporting information, p. 4517 - 4521 (2019/08/06)
A versatile protocol for light induced catalytic activation of thioglycosides using iodine as an inexpensive and readily available photocatalyst was developed. Oxygen serves as a green and cost-efficient terminal oxidant and irradiation is performed with a common household LED-bulb. The scope of this glycosylation protocol was investigated in the synthesis of O-glycosides with yields up to 95 %.
BIARYL AMIDES WITH MODIFIED SUGAR GROUPS FOR TREATMENT OF DISEASES ASSOCIATED WITH HEAT SHOCK PROTEIN PATHWAY
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Page/Page column 146; 180; 186-187, (2019/12/04)
Provided are biaryl amides and coumarin-based compounds with modified sugar groups for treatment of diseases associated with heat shock protein pathway. The compounds having the following formulas, wherein variables are as defined herein. Formulae (I), (II), (III), (IV), and (V), Pharmaceutical compositions of the compounds are also provided. These biaryl amides and coumarin-based derivatives with modified sugar groups are useful for treatment and prevention of diseases and disorders, including neurological disorders, such as neurodegenerative diseases and nerve damaging disorders, for example, diabetic peripheral neuropathy.
Stereoselective Epimerizations of Glycosyl Thiols
Doyle, Lisa M.,O'Sullivan, Shane,Di Salvo, Claudia,McKinney, Michelle,McArdle, Patrick,Murphy, Paul V.
supporting information, p. 5802 - 5805 (2017/11/10)
Glycosyl thiols are widely used in stereoselective S-glycoside synthesis. Their epimerization from 1,2-trans to 1,2-cis thiols (e.g., equatorial to axial epimerization in thioglucopyranose) was attained using TiCl4, while SnCl4 promoted their axial-to-equatorial epimerization. The method included application for stereoselective β-d-manno- and β-l-rhamnopyranosyl thiol formation. Complex formation explains the equatorial preference when using SnCl4, whereas TiCl4 can shift the equilibrium toward the 1,2-cis thiol via 1,3-oxathiolane formation.
Practical synthesis of latent disarmed S-2-(2-propylthio)benzyl glycosides for interrupted Pummerer reaction mediated glycosylation
Xu, Yang,Zhang, Qian,Xiao, Ying,Wu, Pinru,Chen, Wei,Song, Zejin,Xiao, Xiong,Meng, Lingkui,Zeng, Jing,Wan, Qian
supporting information, p. 2381 - 2384 (2017/05/29)
Practical synthetic methods to latent disarmed S-2-(2-propylthio)benzyl (SPTB) glycosides for interrupted Pummerer reaction mediated glycosylation have been discovered. Among them, both coupling reaction of PTB-Cl with glycosyl thiols and BF3·OEt2 promoted reaction of peracylated glycosides with PTB-SH produced peracylated SPTB glycosides in large scales and with high efficiency.
Two new P-coumaroyl flavonoid glycosides having Cytokine increasing activity from Centaurium spicatum L
Allam, Ahmed E.,Nafady, Alaa M.,Hassanein, Ahmed M.M.,Mostafa, Mahmoud A.H.,El-Shanawany, Mohamed A.,Takano, Fumide,Ohta, Tomihisa
, p. 144 - 151 (2016/07/20)
Two new P-coumaroyl flavonol glycosides, Kaempferol 3-O-[β-D-glucopyranosyl- (1?→?4)-α-L-rhamnopyranosyl-(1?→?4)-α-L-rhamnopyranosyl-(1?→?6)-(4 trans- P-coumaroyl)]-β-D- galactopyranoside (1) and Quercetin 3-O-[β-D-glucopyranosyl-(1?→?4)-α-L-rhamnopyranos
Synthesis and evaluation of four hederagenin glycosides as α-glucosidase inhibitor
Liu, Qing-Chao,Guo, Tian-Tian,Guo, Shou-Dong,Li, Wen-Hong,Li, Dong
, p. 142 - 149 (2013/03/14)
The four hederagenin glycosides 1-4 were efficiently synthesized through one-pot sequential glycosylations with glycose 1-(trichloroacetimidate)s as donors, resulting in a significantly simplified synthetic procedure without isolation of glycosylation intermediates. The activity of the synthetic hederagenin glycosides 1-4 against α-glucosidase type IV was evaluated; hederagenin glycoside 4 containing an α-L-rhamnopyranosyl unit showed the best activity with an IC50 value of 47.9 μM. Copyright
Two new acetylated flavonoid glycosides from Centaurium spicatum L
Allam, Ahmed E.,El-Shanawany, Mohamed A.,Backheet, Enaam Y.,Nafady, Alaa M.,Takano, Fumihide,Ohta, Tomihisa
experimental part, p. 388 - 393 (2012/08/29)
Two new acetylated flavonol glycosides, quercetin 3-O-[(2,4-diacetyl- α-L-rhamnopyranosyl)-(1→6)]- 2,4-diacetyl-β-D-galactopyranoside (1) and quercetin 3-O-[(2,4-diacetyl-α-L-rhamnopyranosyl)-(1→6)]-3,4- diacetyl-β-D-galactopyranoside (2), in addition to