Concise Synthesis and Antimicrobial Evaluation of the Guanidinium Alkaloid Batzelladine D: Development of a Stereodivergent Strategy.

Herein, we describe a stereodivergent route to (±)-batzelladine D (), (+)-batzelladine D (), (-)-batzelladine D (), and a series of stereochemical analogues and explore their antimicrobial activity for the first time. The concise synthetic approach enables access to the natural products in a sequence of 8-12 steps from readily available building blocks. Highlights of the synthetic strategy include gram-scale preparation of a late stage intermediate, pinpoint stereocontrol around the tricyclic skeleton, and a modular strategy that enables analogue generation.

Mast cell degranulation and calcium influx are inhibited by an Echinacea purpurea extract and the alkylamide dodeca-2E,4E-dienoic acid isobutylamide.

Ethnopharmacological Relevance: Native Americans used plants from the genus Echinacea to treat a variety of different inflammatory conditions including swollen gums, sore throats, skin inflammation, and gastrointestinal disorders. Today, various Echinacea spp. preparations are used primarily to treat upper respiratory infections.

Structure, synthesis and biological properties of the pentacyclic guanidinium alkaloids.

The pentacyclic guanidinium alkaloids (PGAs) are a family of marine natural products that possess a polycyclic guanidine-containing core and a long alkyl chain tethered spermidine-derived tail that is rarely observed in other natural products. These natural products exhibit potent activities on a wide range of organisms and therefore have attracted the attention of many synthetic chemists; however, the structure-activity relationships and mechanisms of action of PGAs remain largely elusive. Herein we summarize the structure, synthesis, toxicity and mechanisms of action of PGAs and highlight their potential as chemical probes and/or therapeutic leads.

Synthesis and biological evaluation of a series of fatty acid amides from Echinacea.

Alkylamides are lipophilic constituents of Echinacea and possess numerous biological activities. Although significant effort has been focused on the study of crude Echinacea extracts, very little is known regarding the activities of the individual constituents that make up these herbal treatments. Herein we explore the SAR of simple alkylamides found in Echinacea extracts with respect to their ability to decrease the production of the pro-inflammatory mediator TNF-α.

Complexes of Gilman reagents with C-S and C-N double bonds: sigma or pi bonding?

Upon rapid injection, a variety of thiocarbonyl compounds react with the Gilman reagent Me(2)CuLi at -100 degrees C inside the probe of an NMR spectrometer to give high yields of complexes. Typical examples of substrates include carbon disulfide, methyl dithioacetate, methyl dithiobenzoate, thiobenzophenone, ethylene trithiocarbonate, and phenyl isothiocyanate. Evidence suggesting the formal oxidation state of copper in these complexes to be Cu(III) is presented.

5-Meth-oxy-1-(3,4,5-trimethoxy-phen-yl)-1H-indole.

The title compound, C(18)H(19)NO(4), was prepared as an indole derivative with possible anti-mitotic properties. The planes of the indole and trimethoxy-phenyl rings make a dihedral angle of 45.35 (5)° with one another.

Methyl 5,6-dimeth-oxy-1H-indole-2-carboxyl-ate.

The title compound, C(12)H(13)NO(4), was prepared as a precursor to an indole derivative with possible anti-mitotic properties. The mol-ecule is very nearly planar; the maximum deviation of any non-H atom from the mean plane of the indole ring is 0.120 (3) Å for each of two meth-oxy C atoms.