Oxidative Dearomatization of Pyridines.

Dearomatization of pyridines is a well-established synthetic approach to access piperidines. Although remarkably powerful, existing dearomatization processes have been limited to the hydrogenation or addition of carbon-based nucleophiles to activated pyridiniums. Here, we show that arenophile-mediated dearomatizations can be applied to pyridines to directly introduce heteroatom functionalities without prior substrate activation.

Role of omega-3 endocannabinoids in the modulation of T-cell activity in a multiple sclerosis experimental autoimmune encephalomyelitis (EAE) model.

Epidemiological studies show that omega-3 fatty acid consumption is associated with improved conditions in neurodegenerative diseases such as multiple sclerosis (MS). However, the mechanism of this association is not well understood. Emerging evidence suggests that parent molecules such as docosahexaenoic acid are converted into downstream metabolites that are capable of directly modulating immune responses.

Amaryllidaceae Alkaloids Decrease the Proliferation, Invasion, and Secretion of Clinically Relevant Cytokines by Cultured Human Colon Cancer Cells.

Alkaloids isolated from members of the plant family are promising anticancer agents. The purpose of the current study was to determine if the isocarbostyrils narciclasine, pancratistatin, lycorane, lycorine, crinane, and haemanthamine inhibit phenomena related to cancer progression in vitro. To achieve this, we examined the proliferation, adhesion, and invasion of cultured human colon cancer cells via MTT assay and Matrigel-coated Boyden chambers.

Dearomative Ring Expansion of Polycyclic Arenes.

Benzocycloheptenes constitute a common structural motif embedded in many natural products and biologically active compounds. Herein, we report their concise preparation from non-activated polycyclic arenes using a two-step sequence involving dearomative [4+2]-cycloaddition with arenophile in combination with palladium-catalyzed cyclopropanation, followed by cycloreversion-initiated ring expansion. The described strategy provides a working alternative to the Buchner reaction, which is limited to monocyclic arenes.

Nutritional and physico-chemical implications of avocado meal as a novel dietary fiber source in an extruded canine diet.

This study assessed the effects of a diet containing avocado meal (AMD), an underutilized by-product avocado oil processing, on apparent total tract digestibility (ATTD) and fecal fermentative end-products when compared with beet pulp (BPD) and cellulose (CD) diets targeting 15% total dietary fiber (TDF). The concentration of persin, a natural fungicidal toxin present in avocado, was also determined on several parts of the fruit and avocado meal. Nine intact female beagles (4.

Development of a Scalable and Sublimation-Free Route to MTAD.

The cyclic azodicarbonyl 4-methyl-1,2,4-triazoline-3,5-dione (MTAD) is a versatile and powerful reagent used mainly in cycloaddition chemistry. Though known for more than 50 years, its unsafe preparation, as well as purification by sublimation, hampered its widespread applicability on a larger scale. Herein we report a scalable and safe route to MTAD, which avoids the generation of methyl isocyanate.

Enantioselective Synthesis of Isocarbostyril Alkaloids and Analogs Using Catalytic Dearomative Functionalization of Benzene.

Enantioselective total syntheses of the anticancer isocarbostyril alkaloids (+)-7-deoxypancratistatin, (+)-pancratistatin, (+)-lycoricidine, and (+)-narciclasine are described. Our strategy for accessing this unique class of natural products is based on the development of a Ni-catalyzed dearomative trans-1,2-carboamination of benzene. The effectiveness of this dearomatization approach is notable, as only two additional olefin functionalizations are needed to construct the fully decorated aminocyclitol cores of these alkaloids.

Synthesis of (+)-Pancratistatins via Catalytic Desymmetrization of Benzene.

A concise synthesis of (+)-pancratistatin and (+)-7-deoxypancratistatin from benzene using an enantioselective, dearomative carboamination strategy has been achieved. This approach, in combination with the judicious choice of subsequent olefin-type difunctionalization reactions, permits rapid and controlled access to a hexasubstituted core. Finally, minimal use of intermediary steps as well as direct, late stage C-7 hydroxylation provides both natural products in six and seven operations.