DNA oligonucleotide conjugated pyrrolepolyamide and pyrrole-imidazole polyamide-2′-deoxyguanosine hybrids were efficiently synthesized by a post-synthetic modification method through condensation of the 2-fluoro-2′-deoxyinosine moiety of oligonucleotide 9 and FmocNH-PyXPyPy (X = Py or Im) derivatives.
To develop an efficient method for the synthesis of a highly diastereoselective (2′R)-2′-deoxy[2′-2H]guanoslne (1), studies of organic chemical conversion from 2′-bromo-2′-deoxy-N2-isobutyryl-3′,5′-O-TIPDS-guanosine (2) to 1 and a biological transdeoxyribofuranosylation of (2′R>98 % de)-2′-deoxy[2′-2H]uridine (4) were carried out. As the results, a highly diastereoselective synthesis of 1 was achieved by a biological transdeoxyribo-furanosylation between 2,6-diaminopurine and 4 by the use of Enterobacter aerogenes AJ-11125, followed by treatment with adenosine deaminase. The results will be described in detail.
DNA oligomers conjugated pyrrolepolyamide (minor groove binder)-deoxyguanosine hybrid were synthesized as novel gene expression control compounds. From Tm values and CD spectral analysis, it was found that oligomers conjugated hybrid possess high recognition ability and very high binding ability for the DNA that includes pyrrolepolyamide match site
Abstract Efficient syntheses of 2′-bromo-2′-deoxy-3′,5′-O-TPDS-uridine (5a) and 1-(2-bromo-3,5-O-TPDS-β-D-ribofuranosyl)thymine (5b) from uridine and 1-(β-D-ribofuranosyl)thymine are described, respectively. The key step is a treatment of 3′,5′-O-TPDS-O2,2′-anhydro-1-(β-D-ardbinofuranosyl)uracil (4a) and -thymine (4b) with LiBr in the presence of BF3-OEt2 in 1,4-dioxane at 60°C to give 5a and 5b in 98%, and 96% yield, respectively. 1. Partial Protection of Carbohydrate Derivatives. Part 30. For Part 29, see Kawashima, E; Aoyama, Y.; Sekine, T.; Miyahara, M.; Radowan, M. F.; Nakamura, E.; Kainosho, M.: Kyogoku, Y.; Ishido, Y.I. Org. Chem. submitted. #This paper is dedicated to Dr. Yoshihisa Mizuno, an Emeritus Professor of Hokkaido University, on the occasion of his 75th birthday. Notes 1. Partial Protection of Carbohydrate Derivatives. Part 30. For Part 29, see Kawashima, E; Aoyama, Y.; Sekine, T.; Miyahara, M.; Radowan, M. F.; Nakamura, E.; Kainosho, M.: Kyogoku, Y.; Ishido, Y.I. Org. Chem. submitted. #This paper is dedicated to Dr. Yoshihisa Mizuno, an Emeritus Professor of Hokkaido University, on the occasion of his 75th birthday.
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Xestenone is a marine norditerpenoid found in the northeastern Pacific sponge Xestospongia vanilla. The relative configuration of C-3 and C-7 in xestenone was determined by NOESY spectral analysis. However the relative configuration of C-12 and the absolute configuration of this compound were not determined. The authors have now achieved the total synthesis of xestenone using their developed one-pot synthesis of cyclopentane derivatives employing allyl phenyl sulfone and an epoxy iodide as a key step. The relative and absolute configurations of xestenone were thus successfully determined by this synthesis.
Abstract The four (2′S)-[2′-2H]-2′-deoxynucleosides (>90 atom % 2H), were synthesized from the corresponding ribonucleosides involving six steps of reactions, i.e., oxidation of their 2′-hydroxyl group, stereoselective reductive deuteration of the resulting 2′-ketonucleoside intermediates with NaB2H4 in EtOH-H2O or EtOH, triflation, bromination with LiBr, highly stereoselective Bu3SnH-Et3B reduction of the resulting bromide, and, finally, unmasking.
Attic retraction was also observed in 4. 5% of cases without inflammation, but its severity was mild. The incidence of attic retraction in cases of adhesive otitis media was 42. 7% in mild adhesive otitis media (adhesive grade I) and 60. 8% in severe adhesive otitis media (adhesive grade II), both incidences were significantly higher than the incidence of 23.8% in cases of otitis media with effusion. Thus, the incidence of attic retraction increased as the grade of adhesion became severer. In cases of otitis media with effusion, the incidence was significantly higher in the adult group (32.3%) than in the child group (17.4%). In many of the ears with otitis media with effusion, adhesive grade I and chronic otitis media, the severity of attic retraction was mild. There were more cases of milder retraction in the child group than in the adult group. Attic retraction underwent change with time in 2. 8% of cases, and cholesteatoma occurred in 1. 8% of cases. No improvement in attic retraction was achieved by insertion of a ventilation tube. Bilateral attic retraction was observed in 56. 9% of the child group and 30. 2% of the adult group, and the difference was statistically significant. Ear X-ray findings by SchUller's method revealed many ears with poorly developed mastoid cells and poor pneumatization. Good pneumatization was seen in many cases of mild attic retraction. On CT, 18.3% of the cases of attic retraction had no shadow in the middle ear cavity. In all other cases, a shadow was observed in some part of the middle ear cavity. In the operative cases, the presence or absence of attic block coincided with the presence or absence of shadow in the middle ear cavity as shown by CT.
An approach to a synthesis of stereoselective 5′-monodeuterated nucleoside combined with 13C label is described. A preparation of (5R)-D-[5-2H1;5-13C]ribose derivative of l,2:5,6-di-O-isopropyliden-α-D-allofranose was successfully achieved by a 13C Wittig reaction using Ph3Pl3CH3I - BuLi to 5-oxoribose derivative and subsequent transformation into D-[5-l3C]ribose derivative with an AD reaction, selective acylation, oxidation with NaIO4, and a stereoselective deuteride transfer reaction from Alpine-Borane-d to 5-oxo-D-[5-l3C]ribose derivative as the main reaction. (5′R)-[5′-2H1;5′-l3C]nucleosides were synthesized in the established manner from this 5-l3C/2H1-double-labeled ribose.
