Identification of Formaldehyde-Induced DNA-RNA Cross-Links in the A/J Mouse Lung Tumorigenesis Model.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent lung carcinogen present in tobacco products, and exposure to it is likely one of the factors contributing to the development of lung cancer in cigarette smokers. To exert its carcinogenic effects, NNK must be metabolically activated into highly reactive species generating a wide spectrum of DNA damage. We have identified a new class of DNA adducts, DNA-RNA cross-links found for the first time in NNK-treated mice lung DNA using our improved high-resolution accurate mass segmented full scan data-dependent neutral loss MS screening strategy.

Broadening the Scope of the Zwitterionic 1,3-Diaza-Claisen Rearrangement through a Tethering Strategy.

Expansion of the scope of the 1,3-diaza-Claisen rearrangement beyond bridged-bicyclic tertiary allylic amines has been investigated through a tethering strategy. Isothioureas tethered to tertiary allylic amines are converted to carbodiimides through a reaction with AgOTf/EtN. Intramolecular cyclization of the tertiary allylic amine to the carbodiimide equilibrates with a zwitterionic intermediate.

Hypervalent iodine catalyzed Hofmann rearrangement of carboxamides using oxone as terminal oxidant.

Hofmann rearrangement of carboxamides to carbamates using Oxone as an oxidant can be efficiently catalyzed by iodobenzene. This reaction involves hypervalent iodine species generated in situ from catalytic amount of PhI and Oxone in the presence of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) in aqueous methanol solutions. Under these conditions, Hofmann rearrangement of various carboxamides affords corresponding carbamates in high yields.

(Tosylimino)phenyl-λ3-iodane as a reagent for the synthesis of methyl carbamates via Hofmann rearrangement of aromatic and aliphatic carboxamides.

A new, mild procedure for the Hofmann rearrangement of aromatic and aliphatic carboxamides using (tosylimino)phenyl-λ(3)-iodane, PhINTs, as a reagent is reported. Because of the mild reaction conditions, this method is particularly useful for the Hofmann rearrangement of substituted benzamides, which usually afford complex reaction mixtures with other hypervalent iodine oxidants. The mild reaction conditions and high selectivity in the reaction of carboxamides with PhINTs allow the isolation of the initially formed labile isocyanates or their subsequent conversion to stable carbamates by treatment with alcohols.

Characterization and quantification of wound-induced hair follicle neogenesis using in vivo confocal scanning laser microscopy.

Background: In vivo confocal scanning laser microscopy (CSLM) is a recently developed non-invasive technique for visualizing microscopic structures with the skin. CSLM has been used to characterize proliferative and inflammatory skin diseases, neoplastic skin lesions and pigmented lesions.

Objective: Here, we assessed the ability of CSLM to evaluate the formation of neogenic hair follicles after a full-thickness wound in mice.