Raymond W. Doskotch

New sesquiterpene lactones from Liriodendron tulipifera

Abstract Four new sesquiterpene lactones were obtained from L. tulipifera ; two germacranolides, lipiferolide ( 4 ) and epitulipinolide diepoxide ( 5 ) from the leaves, an elemanolide, epitulipdienolide ( 7 ), and an eudesmanolide, γ-liriodenolide ( 6 ) from the root bark. Structural determination was by physical and chemical methods and by direct correlation to the known epitulipinolide ( 3 ). Lipiferolide and epitulipinolide diepoxide possess cytotoxic activity against KB cells.

Alkaloids of Thalictrum. X. Two new alkaloids from T. minus var. adiantifolium: noroxyhydrastinine and thalifoline.

Abstract Two new isoquinolone alkaloids, noroxyhydrastinine (I) and thalifoline (II) have been obtained from T. minus L. var. adiantifolium Hort. Characterization by physical methods and chemical synthesis have shown the former to be 6,7-methylenedioxy-1-oxo-1,2,3,4-tetrahydroisoquinoline and the latter to be 2-methyl-6-methoxy-7-hydroxy-1-oxo-1,2,3,4-tetrahydroisoquinoline.

Potent antiprotozoal activity of a novel semi-synthetic berberine derivative

Treatment of diseases such as African sleeping sickness and leishmaniasis often depends on relatively expensive or toxic drugs, and resistance to current chemotherapeutics is an issue in treating these diseases and malaria. In this study, a new semi-synthetic berberine analogue, 5,6-didehydro-8,8-diethyl-13-oxodihydroberberine chloride (1), showed nanomolar level potency against in vitro models of leishmaniasis, malaria, and trypanosomiasis as well as activity in an in vivo visceral leishmaniasis model. Since the synthetic starting material, berberine hemisulfate, is inexpensive, 8,8-dialkyl-substituted analogues of berberine may lead to a new class of affordable antiprotozoal compounds.

Structure of the water-soluble feeding stimulant for Scolytus multistriatus: a revision.

Abstract The feeding stimulant for the smaller European elm bark beetle has been revised to (+)-catechin 7-β- d -xylopyranoside (III) from the structure (I) bearing the sugar at the 5-position.

Nerolidol: An antifeeding sesquiterpene alcohol for gypsy moth larvae fromMelaleuca leucadendron

A systematic procedure is reported for the isolation of a feeding deterrent, (E,S)-nerolidol (I), fromMelaleuca leucadendron leaves for the gypsy moth larvae. Testing of the related alcohols, farnesol (II) and geraniol (III) showed them to be deterrent, but the simpler isoprene-related compounds, 2-methyl-3-buten-2-ol andt-amyl alcohol were inactive.

Elm-bark-derived feeding stimulants for the smaller European Elm bark beetle.

The principal feeding stimulants for the beetle Scolytus multistriatus Marsham from the twig bark of Ulmus americana L. have been identified as (+)-catechin-5-β-D-xylopyranoside and lupeyl cerotate.

Codonocarpus alkaloids—III : The structure of codonocarpine☆

Abstract The structures of two Lunaria-type alkaloids, codonocarpine and N-methylcodonocarpine, from Codonocarptis australis were established by a series of chemical transformations and spectral studies.

Acuminatin, a new bis-phenylpropide from Magnolia acuminata L.

Abstract Three uncommon lignans calopiptin ( 1 ), galgravin ( 2 ) and veraguensin ( 3 ) were isolated from M. acuminata root-bark, along with a novel bis -phenylpropide, acuminatin ( 4 ) which was characterized by physical and chemical methods.

A revision of the structures of the lunaria alkaloids LBX and LBZ.

Für die Lunaria-Alkaloide LBX und LBZ werden die revidierten Structurformeln IV und V vorgeschlagen.

Northalrugosidine is a Bisbenzyltetrahydroisoquinoline Alkaloid from Thalictrum alpinum with in Vivo Antileishmanial Activity

Screening of a plant-derived natural product library led to the observation of in vitro antileishmanial activity by three bisbenzyltetrahydroisoquinoline alkaloids (1-3) that were purified previously from Thalictrum alpinum. A spectroscopic study of the active compounds was conducted to confirm their identities. Of the compounds tested, northalrugosidine (1) showed the most potent in vitro activity against Leishmania donovani promastigotes (0.28 μM) and the highest selectivity (29.3-fold) versus its general cytotoxicity against HT-29 human colon adenocarcinoma cells. Northalrugosidine was tested in vivo using a murine model of visceral leishmaniasis, resulting in the observation of a dose-dependent reduction of the parasitic burden in the liver and spleen without overt toxicity effects at 2.8, 5.6, and 11.1 mg/kg per animal when administered intravenously. This represents the first report of a bisbenzyltetrahydroisoquinoline alkaloid with in vivo efficacy against visceral leishmaniasis.