Eberhard Breitmaier

Triterpenes and triterpenoidal glycosides from the fruits of Ilex paraguariensis (Maté)

A new triterpenoid glycoside, 3b-O-a-L-arabinopyranosyl rotundic acid, named here mateside (4), and the known triterpenes ursolic acid (1), acetylursolic acid (2), 23-hydroxyursolic acid (3), the saponins ziyu-glycoside I (5) and ilexoside II (6), were isolated from fruits of Ilex paraguariensis. Their structures were established on the basis of 1D and 2D NMR spectroscopic methods. The threshold bitterness values for mateside and ilexoside II were also determined and compared with saponins obtained from leaves of I. paraguariensis and other Ilex species. The high bitterness of Ilexoside II, one of the main saponins found the fruits, but not in the leaves of I. paraguariensis, suggests that the utilization of the fruits in the Mate production can produce a strong taste variation and unknown physiological effects.

Dibenzyl trisulphide and trans-n-methyl-4-methoxyproline from Petiveria alliacea.

Abstract A highly polar compound isolated from the stem of Petiveria alliacea was shown to be trans-N-methyl-4- methoxyproline on the basis of its microanalysis and spectral data. Dibenzyl trisulphide, previously unknown as a natural product, was isolated from the roots. Other compounds not yet reported as constituents of this plant are β- sitosterol, pinitol, allantoin, lignoceryl alcohol, lignoceric acid, lignoceryl lignocerate and α-friedelinol.

Tropane alkaloids from Schizanthus litoralis

Abstract Six new tropane alkaloids have been isolated from the leaves of the endemic Chilian plant Schizanthus litoralis (Solanaceae). The new structures include a new tropanol dimer of itaconic acid together with 6β-senecioyloxytropan-3α-methylmesaconate, 6β-cinnamoyloxytropan-3α-methylmesaconate, 6β-senecioyloxytropan-3α-ol and cis-trans N-(4-hydroxyphenethyl) ferulamides. Other known alkaloids were also isolated. Their structures were elucidated by spectroscopic methods.

Pyrrolizidine alkaloids of Heliotropium spathulatum

Abstract Isolation and structural determination of the pyrrolizidine alkaloids of Heliotropium spathulatum are reported. The alkaloids lycopsamine, amabiline, curassavinine, coromandalinine, heliovicine, coromandaline, curassavine and the two new pyrrolizidine alkaloids, heliospathine and heliospathuline were determined by spectroscopic methods. Traces of another new alkaloid were detected.

Alkaloids from Hypecoum leptocarpum

Two new alkaloids, named isohyperectine and leptocarpine, were isolated from the whole plants of Hypecoum leptocarpum, along with the eight known alkaloids, dihydrosanguinarine, 8-acetonyldihydrosanguinarine, 8-methoxydihydrosanguinarine, oxohydrastinine, allocryptopine, protopine, hyperectine and corydamine. All structures were determined by spectroscopic methods.

Cucurbitacins from Wilbrandia ebracteata

Abstract Three new cucurbitacins were isolated from the roots of Wilbrandia ebracteata and their structures established as 16α, 23α-epoxy-2β,3β,20β-trihydroxy-10α,23β-cucurbit-5,24-dien-11-one, 16α,23α-epoxy-2β,3β,20β-trihydroxy- 10α,23α-cucurbit-5,24-dien-11-one and 2β,3β,16α,20,25-pentahydroxy-10α-cucurbit-5,23-dien-11-one, mainly by spectroscopy.

Oxidized aristolane sesquiterpenes from Aristolochia debilis

Abstract The underground parts of Aristolochia debilis have afforded three new aristolane type sesquiterpenes: 1(1O)-aristolenal-(15), 1α-hydroperoxy-1(10)aristolenone-(2); and 9α-hydroxy-9-aristolenone-(8).

Cyclobakuchiols A and B from Psoralea Glandulosa

Bioactivity guided fractionation of the dichloromethane extract from Psoralea glandulosa yielded the isolation of a diasteromeric mixture of cyclobakuchiols A and B as possible anti-inflammatory active compounds.

Fluorine-19 nuclear magnetic resonance spectroscopy of sterol and bile acid trifluoroacetates

Abstract A new analytical method for hydroxysteroids by 19F-NMR-spectroscopy of the trifluoroacetyl derivatives is described.

A 4-methyl-7-hydroxyphthalide glycoside and other constituents from Quillaja saponaria Molina

A so far unknown 4-methyl-7-hydroxyphthalideglycoside has been isolated from the methanol extract of the bark of Quillaja saponaria molina. Its structure has been established from NMR experiments as 7-O(-)[beta-glucopyranosyl-(1-->6)-beta-arabinopyranosyl]-7-hydrox y-4-methy l -1[3H]-isobenzofuranone. Two known compounds, 3,4,5-trimethoxyphenyl-beta-D-glucopyranoside and lyoniresinol-3 alpha-O-beta-D-glycopyranoside were also identified.