Interaction of indoles with glycosyl halides in the presence of silver oxide

Metabolism of crucifer phytoalexins in Sclerotinia sclerotiorum: detoxification of strongly antifungal compounds involves glucosylation

“…The 1 H NMR spectrum, obtained in CD 3 OD, indicated the presence of the intact brassilexin (1) tricyclic system plus a doublet at d H 5.75 (J = 9 Hz, 1H) and several multiplets at d H 3.49-3.96, suggesting the presence of a carbohydrate moiety. Both the molecular formula (C 15 H 16 N 2 O 5 S obtained by HRMS-ESI) and the 13 C NMR spectral data corroborated the presence of a carbohydrate residue. The identity of the carbohydrate moiety was assigned as a b-glucopyranosyl residue from 1 H-1 H homonuclear decoupling experiments (axial-axial couplings, J = 7-9 Hz, between the various protons).…”

“…1). The metabolites were found to be an unknown compound with t R = 4.5 min (12), the known phytoalexin brassicanal A (14), and 3-(amino)methylenindoline-2-thione (13), resulting from reduction of the isothiazole ring of brassilexin (11) 7 (Scheme 2). Enamine 13 was detected in culture immediately after adding brassilexin (11), while brassicanal A ( 14) was detected after 6 h of incubation and the unknown metabolite (12) was detected after 12 h. To determine the sequence of the biotransformation steps, enamine 13 was synthesized and administered to cultures of S. sclerotiorum.…”

“…In addition, both compounds showed a signal for an exchangeable hydrogen and the absence of the SCH 3 signal. The 13 . That is, the SCH 3 group of 1-methoxyspirobrassinin (24) had been transformed to a carbonyl group in 25 and to a thiocarbonyl group in 26.…”

“…In addition, compound 28 showed a proton resonance attributable to the NH and the absence of the proton resonance due to SCH 3 . The 13 To establish the sequence of biotransformation steps, compound 29 was administered to cultures of S. sclerotiorum. As expected, spirobrassinin (22) was detected in the HPLC chromatogram of the broth extract of these cultures, demonstrating it to be a metabolite of 29 resulting from enzymatic oxidation followed by decarboxylation of 27 (Scheme 8).…”

Synthesis of 4‐Cyanoindole Nucleosides, 4‐Cyanoindole‐2ʹ‐Deoxyribonucleoside‐5ʹ‐Triphosphate (4CIN‐TP), and Enzymatic Incorporation of 4CIN‐TP into DNA

“…Ribonucleoside syntheses are similarly well established, where typical methods utilize either a Lewis acid‐mediated (TiCl 4 ) chlorination of 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐ D ‐ribofuranose (Harki et al., ) or utilize intermediates 5 (Kane & Mann, ; Stewart & Williams, ) and 6 (Rosemeyer & Seela, ; Ugarkar et al., ; Wilcox & Otoski, ). We found that displacement of 1‐chloro‐2,3,5‐tri‐O‐benzoyl‐β‐ D ‐ribofuranose with the sodium salt of 4CI yielded what is likely a trapped amide acetal intermediate indicating a lack of nucleophilicity and thus did not produce the desired coupling product (see Kobayashi, Nakatsuji, Li, Tsuzuki, & Takemoto, and Sokolova, Shevchenko, & Preobrazhenskaya, for examples of such structures). We therefore chose to use the 5 / 6 sequence.…”