ABSTRACT
Two new grayanane diterpenoid glucosides, rhodomosides A (1), B (2) and two new phenolic glycosides 3, 4 together with a known glucosyringic acid (5) were isolated from the roots of Rhododendron molle G. Don (Ericaceae). Their structures were elucidated on the basis of spectral analysis. Compounds 3, 4 and 5 were found to inhibit the proliferation of murine B lymphocytes in vitro, while compound 3 also showed stimulatory activity on the proliferation of murine T lymphocytes in vitro.
Subject(s)
B-Lymphocytes/drug effects , Diterpenes/pharmacology , Glycosides/pharmacology , Immunosuppressive Agents/pharmacology , Phytotherapy , Plant Extracts/pharmacology , Rhododendron , T-Lymphocytes/drug effects , Animals , Cyclosporine/pharmacology , Mice , Plant Roots , Spleen/cytologyABSTRACT
An approach toward the synthesis of the antifungal and cytotoxic pseudolaric acids based on the tandem metal carbene cyclization-cycloaddition reaction is described. Using this strategy, the advanced intermediate 3a bearing three of the four stereocenters of the target molecules has been synthesized. The substrate-controlled diastereoselectivity of the tandem carbene cyclization-cycloaddition was preferential for the undesired diastereomer, but reagent control through the use of Hashimoto's chiral rhodium catalyst Rh(2)(S-BPTV)(4) reversed the selectivity in favor of 3a. Ring opening of the oxabicyclic nucleus to give a hydroxycycloheptene has been demonstrated in a model study.
Subject(s)
Antifungal Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Combinatorial Chemistry Techniques , Diterpenes/chemical synthesis , Methane/analogs & derivatives , Methane/chemistry , Models, Molecular , Antifungal Agents/pharmacology , Antineoplastic Agents/pharmacology , Catalysis , Cyclization , Diterpenes/pharmacology , Hydrocarbons , Indicators and Reagents , StereoisomerismABSTRACT
Nitrotyrasacutuminine, an unusual nitrated morphine-type alkaloid was isolated from the roots of Menispermum dauricum. Its structure was determined by various 2D spectra and chemical methods.
