Synthesis of novel homo-N-nucleoside analogs composed of a homo-1,4-dioxane sugar analog and substituted 1,3,5-triazine base equivalents

Synthesis, molecular docking, ctDNA interaction, DFT calculation and evaluation of antiproliferative and anti-Toxoplasma gondii activities of 2,4-diaminotriazine-thiazole derivatives

Synthesis, characterization, and investigation of antiproliferative activities against human cancer cell lines (MV4-11, MCF-7, and A549) and Toxoplasma gondii parasite of twelve novel 2,4-diaminotriazine-thiazoles are presented. The toxicity of the compounds was studied at three different cell types, normal mouse fibroblast (Balb/3T3), mouse fibroblast (L929), and human VERO cells. The structures of novel compounds were determined using ¹H and ¹³C NMR, FAB(+)-MS, and elemental analyses. Among the derivatives, 4a–k showed very high activity against MV4-11 cell line with IC₅₀ values between 1.13 and 3.21 µg/ml. Additionally, the cytotoxic activity of compounds 4a–k against normal mouse fibroblast Balb/3T3 cells is about 20–100 times lower than against cancer cell lines. According to our results, compounds 4a, 4b, 4d, and 4i have very strong activity against human breast carcinoma MCF-7, with IC₅₀ values from 3.18 to 4.28 µg/ml. Moreover, diaminotriazines 4a–l showed significant anti-Toxoplasma gondii activity, with IC₅₀ values 9–68 times lower than those observed for sulfadiazine. Molecular docking studies indicated DNA-binding site of hTopoI and hTopoII as possible anticancer targets and purine nucleoside phosphorylase as possible anti-toxoplasmosis target. Our UV–Vis spectroscopic results indicate also that diaminotriazine-thiazoles tends to interact with DNA by intercalation. Additionally, the structure and the interaction and binding energies of a model complex formed by compound 4a and two thymine molecules are investigated using quantum mechanical methods.

Nucleosides 9: Design and synthesis of new 8-nitro and 8-amino xanthine nucleosides of expected biological activity

The coupling reaction of 1,3-dimethylxanthine (theophylline), 3-benzylxanthine and 3-benzyl-1-methylxanthine with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose afforded the corresponding protected nucleosides, respectively. Nitration of each of the theophylline and 3-benzy-1-methyllxanthine protected nucleosides yielded the corresponding 8-nitronucleosides derivatives, which were reduced to give the corresponding 8-aminonucleoside derivatives. Debenzoylation of protected nucleosides formed by using methanolic sodium methoxide afforded the corresponding free N-nucleosides, respectively. The structures of products have been elucidated and reported and also some of the products were screened for their antimicrobial activity. Some of tested products showed moderate activity.

Effective Synthesis of Nucleosides Utilizing O-Acetyl-Glycosyl Chlorides as Glycosyl Donors in the Absence of Catalyst: Mechanism Revision and Application to Silyl-Hilbert-Johnson Reaction

An effective synthesis of nucleosides using glycosyl chlorides as glycosyl donors in the absence of Lewis acid has been developed. Glycosyl chlorides have been shown to be pivotal intermediates in the classical silyl-Hilbert-Johnson reaction. A possible mechanism that differs from the currently accepted mechanism advanced by Vorbrueggen has been proposed and verified by experiments. In practice, this catalyst-free method provides easy access to Capecitabine in high yield.