[13 C+D] Double Labeling with Calcium Carbide: Incorporation of Two Labels in One Step.

D-labeling is a valuable tool in advanced synthetic chemistry and pharmacy. However, D-incorporation significantly complicates the identification of products. In fact, D labels are invisible in 1 H-NMR spectra and cause undesirable splitting in 13 C-NMR spectra which decreases the detectable limits. At the same time, 2 H-NMR spectra are not effective for precise identification due to low sensitivity and the absence of correlations with 1 H atoms. Here, 13 C-label was considered as an accompanying label for D-label in [13 C+D] unit for identification of D-containing sites and to track D-labels. [13 C+D]-doubly labeled vinyl derivatives and triazoles were synthesized using 13 C-labeled calcium carbide as a source of 13 C-label and deuterium oxide as a source of D-label. The reaction occurred in one-step manner accompanied with in situ doubly labeled acetylene formation. Non-labeled, mono-labeled and doubly labeled substrates were isolated in 25-80% yields.

Synthesis and Biological Activity of Unsymmetrical Monoterpenylhetaryl Disulfides.

New unsymmetrical monoterpenylhetaryl disulfides based on heterocyclic disulfides and monoterpene thiols were synthesized for the first time in 48-88% yields. Hydrolysis of disulfides with fragments of methyl esters of 2-mercaptonicotinic acid was carried out in 73-95% yields. The obtained compounds were evaluated for antioxidant, antibacterial, antifungal activity, cytotoxicity and mutagenicity.

Caryophyllane Thiols, Vinyl Thioethers, Di- and Bis-Sulfides: Antioxidant and Membrane Protective Activities.

Caryophyllane thioterpenoids were synthesized in 23 - 81% yields. The antioxidant properties of the obtained compounds in various model systems were found. It was revealed that 4,5-epoxycaryophyll-9-ylmethanethiol has the greatest antioxidant activity. The isomerism of sesquiterpenic fragments was shown to have a significant effect on the biological activity of the compounds.