Discussion on ¹³C nuclear magnetic resonance spectra of nucleoside derivatives. Reflection of structural alterations on ¹³C chemical shifts

Abstract

not available

Nucleosides XII.1 Synthesis of 5‐Modified Isoguanosines and Reinvestigation of 5′‐Deoxy‐N3,5′‐cycloisoguanosine

“…K. Anzai previously reported the preparation of 11 from the N 3 ,5¢-cyclonucleoside derivative of adenosine. 28,29 The 13 C NMR data that we obtained is identical to Anzai's result, 29 which confirmed our strucutural assignments. Chlorination at the 5¢-position of isoguanosine (3) was accomplished by the procedure reported by F. Seela et al 26 The reaction of isoguanosine (3) with thionyl chloride afforded 5¢-chloro-5¢-deoxyguanosine (9).…”

Antiestrogenic Constituents of the Thai Medicinal Plants Capparis flavicans and Vitex glabrata

“…Thus, these two fractions were subjected to silica gel column chromatography and HPLC to give 29 pure compounds, including a new compound ( 1 ). Twenty-eight known compounds were identified as (7 R ,8 R )- threo -guaiacylglycerol 8- O -4′-sinapyl ether 7- O -β- d -glucopyranoside ( 2 ), (±)-syringaresinol ( 3 ), (±)-3′,3′′-bisdemethylpinoresinol ( 4 ), isoamericanol A ( 5 ), princepin ( 6 ), (−)-dehydrodiconiferyl alcohol 4- O -β- d -glucopyranoside ( 7 ), (±)-8,8′-dimethoxy-1- O -(β- d -glucopyranosyl) secoisolariciresinol ( 8 ), spionoside B ( 9 ), tachioside ( 10 ), koaburaside ( 11 ), 4-hydroxy-2,6-dimethoxyphenol 1- O -β- d -glucopyranoside, leonuriside ( 12 ), adenosine ( 13 ), tamarixetin 3- O -β- d -galactoside, americanol A, isoprincepin, (−)-5,5′-dimethoxy-4- O -(β- d -glucopyranosyl) lariciresinol, alangilignoside B, alangilignoside C, alangilignoside D, (−)-lariciresinol 4- O -β- d -glucopyranoside, 3α- O -β- d -glucopyranosyl lyoniresinol, icariside B 1 , roseoside, isotachioside, vanilloloside, 4-hydroxy-3-methoxyphenyl 1- O -β- d -xylopyranosyl-(1→6)-β- d -glucopyranoside, alangionoside C, and 4-(hydroxymethyl)-2,6-dimethoxyphenyl 1- O -β- d -glucopyranoside, respectively, by comparison of their spectroscopic data (especially NMR) and optical rotation with the reported values in the literature.…”

“…Fraction 7 [1.4 g: eluted with chloroform−MeOH−water (7:13:8)] was subjected to semipreparative HPLC [column: Tosoh, TSKgel ODS-100 V, 2 × 25 cm; solvent: acetonitrile−water (5:95); detector: 205 nm] to give 1 (2 mg; t R 34 min) and 4-hydroxy-3-methoxyphenyl 1- O -β- d -xylopyranosyl-(1→6)-β- d -glucopyranoside (2 mg; t R 32 min). All known compounds were identified by comparison with published data. – …”

Oligonucleotide Analogues with Integrated Bases and Backbones. Part 26

“…c ) Same numbering as for 14 -16. Assignments based on a HSQC spectrum and on comparison with data in[40].…”