Computational Study of some Double Headed Acyclo-C-Nucleosides

Pyrimidine acyclo-C-nucleosides by ring transformations of 2-formyl-L-arabinal.

The protected 2-formyl-L-arabinal 2 reacted with thiourea and cyanamide in the presence of sodium hydride to afford via ring transformations the 5-[1R,2S-1,2- bis(benzyloxy)-3-hydroxypropyl]-1,2-dihydropyrimidines 3 and 4, respectively. Similarly, treatment of 2 with 3-amino-2H-1,2,4-triazole yielded 6-[1R,2S-1,2- bis(benzyloxy)-3-hydroxypropyl][1,2,4]-triazolo[1,5-a]pyrimidine (5).

A double-headed polyp

A 50-year-old man was seen as an outpatient for isolated, minimal and intermittent lower gastrointestinal bleeding. He had a history of well-controlled hypertension and diabetes. During his colonoscopy, a polyp with two heads that shared a common long and large stalk was encountered in the sigmoid colon (Fig. 1A). The heads were approximately 2 cm and 3 cm in size. Because of their overall size...

A Double-Headed Monster

A Double-Headed Monster

A double-headed monster was born in the Railway Hospital, Samastipur, on 5th July, 1948. It is an interesting case because of its rarity; the photograph (plate XXII) tells its own story. Dr. Mody, in his jurisprudence, gives a picture of such monster without any detail. The woman was a sweeper by caste, second para, and fairly well built. She came to hospital in a precarious condition, having b...

The synthesis of double-headed nucleosides by the CuAAC reaction and their effect in secondary nucleic acid structures.

Four double-headed nucleosides were prepared by the CuAAC reaction. Hereby, a triazole-containing linker connects an additional thymine or adenine to the 2'-position of 2'-deoxyuridine, a thymine to the 5'-position of thymidine and a thymine to the 6'-position of an LNA-thymidine monomer. Whereas no conclusive recognition effects of the additional thymines were found when introduced in LNA or a...