62446-93-9Relevant articles and documents
Wittig reaction of unprotected D-aldopentoses with stabilized ylides: Metal-ion effects
Horton,Koh
, p. 231 - 247 (1993)
Each of the four D-aldopentoses (1-4) reacts in the unprotected form withg Ph3PCHCO2Me (5) in THF to given stereoselectively the corresponding trans-α,β-unsaturated C7 Wittig adducts, isolated as the corresponding 4,5,6,7-tetraacetates (7-10) or 4,5:6,7-di-O-isopropylidene derivatives (11-14). Concurrently formed are also bicyclic, 1,4-lactone derivatives, isolated as their 5,7-diacetates (15-18) or 5,7-O-isopropylidene derivatives (19), arising through intramolecular Michael addition from the initial acyclic adducts. Formation of the cyclized products is suppressed by incorporation of Cu(OAc)2 in the reaction mixture, permitting preparative isolation of the hept-3-enonate derivatives 7-10, useful as dienophiles in Diels-Alder carbocyclizations with chirality transfer. Optimized yields were 25% (D-ribo), 50% (D-arabino), 49% (D-xylo), and 61% (D-lyxo). Under Cu(OAc)2-catalyzed conditions, the formation of small proportion of 3,7-anhydroheptonic acid esters (21 and 23) was observed in the D-arabino and D-xylo series, but not with the other two pentoses. Each of the four D-aldopentoses (1-4) reacts in the unprotected form with Ph3PCHCO2Me (5) in THF to give stereoselectively the corresponding trans-α,β-unsaturated C7 Wittig adducts, isolated as the corresponding 4,5,6,7-tetraacetates (7-10) or 4,5:6,7-di-O-isopropylidene derivatives (11-14). Concurrently formed are also bicyclic, 1,4-lactone derivatives, isolated as their 5.7-diacetates (15-18) or 5,7-O-isopropylidene derivatives (19), arising through intramolecular Michael addition from the initial acyclic adducts. Formation of the cyclized products is suppressed by incorporation of Cu(OAc)2 in the reaction mixture, permitting preparative isolation of the hept-3-enonate derivatives 7-10, useful as dienophiles in Diels-Alder carbocyclizations with chirality transfer. Optimized yields were 25% (D-ribo), 50% (D-arabino), 49% (D-xylo), and 61% (D-lyxo). Under Cu(OAc)2-catalyzed conditions, the formation of small proportions of 3,7-anhydroheptonic acid esters (21 and 23) was observed in the D-arabino and D-xylo series, but not with the other two pentoses.
Glycosylation of Nα-lauryl-O-(β-d-xylopyranosyl)-l- serinamide as a saccharide primer in cells
Wang, Yinan,Kumazawa, Tomoaki,Shiba, Keisuke,Sato, Toshinori,Osumi, Kenji,Mizuno, Mamoru
, p. 33 - 40,8 (2012)
Nα-Lauryl-O-(β-d-xylopyranosyl)-l-serinamide (Xyl-Ser-C12) was synthesized as a saccharide primer to obtain oligosaccharides of glycosaminoglycan using the glycan biosynthetic potential of mouse osteosarcoma FBJ-S1 cells and Chinese hamster ovary (CHO) cells. The glycosylated products secreted into the culture medium were collected and analyzed by liquid chromatography-mass spectrometry and glycosidase digestion. The structure of the Xyl-Ser-C12 derivatives was investigated. Several glycosaminoglycan-type oligosaccharides, such as GalNAc-(GlcA-GlcNAc) n-GlcA-Gal-Gal-Xyl-Ser-C12, were detected, and identified as intermediates of the biosynthesis of heparan sulfate glycosaminoglycans. Xyl-Ser-C12 exhibited greater acceptor activity for the glycosylation of glycosaminoglycan-type oligosaccharides than p-nitrophenyl-β-d- xylopyranoside.
Synthesis and biological evaluation of 3β-O-neoglycosides of caudatin and its analogues as potential anticancer agents
Li, Xiao-San,Chen, Tang-Ji,Xu, Zhi-Peng,Long, Juan,He, Miao-Ying,Zhan, He-Hui,Zhuang, Hai-Cai,Wang, Qi-Lin,Liu, Li,Yang, Xue-Mei,Tang, Jin-Shan
, (2021/12/30)
In order to study the structure–activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3β-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3β-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3β-O-(2,3,4-tri-O-acetyl-β-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 μM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.
Isolation and characterization of triterpenoid saponins from leaves of Aralia nudicaulis L
Lavoie, Serge,Pierra, Julie,Legault, Jean,Raminoson, Diamondra,Lion, Quentin,Mshvildadze, Vakhtang,Pichette, André
, p. 184 - 189 (2021/04/23)
Three new oleanolic glycosides (1–3), along with seven known saponins from various plants (4–10) were isolated for the first time from the leaves of Aralia nudicaulis. Their structures were elucidated on the basis of spectroscopic evidence, including 1D and 2D NMR, and HRESIMS. Nudicauloside A and B (1–2) have shown moderate anti-inflammatory activity, as demonstrated by inhibition of LPS-induced NO production in raw 264.7 murine macrophages (IC50 = 74–101 μM).
Sugar-Based Polymers from d-Xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release
Rizzo, Antonio,Peterson, Gregory I.,Bhaumik, Atanu,Kang, Cheol,Choi, Tae-Lim
supporting information, p. 849 - 855 (2020/12/03)
Enyne monomers derived from D-xylose underwent living cascade polymerizations to prepare new polymers with a ring-opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well-controlled and had living character, which enabled the preparation of high molecular weight polymers with narrow molecular weight dispersity values and a block copolymer. By tuning the type of acid-sensitive linkage (hemi-aminal ether, acetal, or ether functional groups), we could change the degradation profile of the polymer and the identity of the resulting degradation products. For instance, the large difference in degradation rates between hemi-aminal ether and ether-based polymers enabled the sequential degradation of a block copolymer. Furthermore, we exploited the generation of furan-based degradation products, from an acetal-based polymer, to achieve the release of covalently bound reporter molecules upon degradation.
