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Chloroform or dichloromethane extracts of 357 southern Brazilian plant species were tested for the presence of peroxides by thinlayer chromatography, using the spray reagent from Huber & Frohlke. From the species tested, 71 (20%) showed positive results and most of them (56%) are Asteraceae species. The species tested were mainly from Asteraceae, but 55 more families were screened, in a total of 77 genera surveyed.

From the fresh aerial parts of Senecio selloi (Asteraceae), two diastereomeric triterpenes with a hitherto unknown skeleton have been isolated. The structure has been elucidated mainly by advanced NMR experiments, including inverse techniques, HMQC, HMBC, ROESY.

Nine new alkaloids przewaline, przewalskine, przewalskinine, przewalstine, przewalstinine, przewalstidine, przewalstidinine, przewalidine chloride, and 8-hydroxypseudocoptisine chloride were isolated from Thalictrum przewalskii Maxim., together with the known alkaloids berberinium chloride, magnoflorine chloride, N-methylpalaudinium chloride, thalphenine chloride, and N-methylnantenium chloride. Their structures were determined by spectroscopy including EI-MS, FAB-MS, (1)H-NMR, (13)C-NMR, C,H-COSY, C,H-COLOC, HMQC and HMBC techniques.

From Eupatorium cannabinum L., a hitherto unknown α-methylene-γ-butyrolactone, 3β-peroxyeucannabinolide, was isolated. This compound and eupatoriopicrin from the same plant showed a weak sensitizing capacity in guinea pigs. 2-oxoludartin and dehydroleucodin, isolated from Kaunia rufescens (syn. Eupatorium rufescens), were strong sensitizers in the same sensitizarian procedure. Nat. Toxins 5:223–227, 1997. © 1998 Wiley-Liss, Inc.

Three new compounds, docosanoic cinnamate, 7-hydroperoxy-5,6-E-dehydro-6,7-dihydronerol and 2-(3-methylbut-3-enyl)-3-methyl-2,5-dihydrofuran were isolated from the leaves of Heterothalamus alienus and their structures determined by spectroscopical methods.

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.

A new C 50 -hydroperoxide (1) with a hitherto unknown constitution, containing cadinane hydroperoxide and hyperforin (2) as partial structures, was isolated from the stems and leaves of St. John's wort (Hypericum perforatum L., Hypericaceae). The structure was elucidated by high-resolution NMR techniques (1D and 2D NMR experiments).

Aus Achillea filipendulina LAM. (Asteraceae) wurden zwei bisher nicht bekannte diastereomere, irregulare acyclische Monoterpenperoxide 5, 6 vom Typ des Santolinatriens isoliert (4α- bzw. 4β-Peroxyachipendol). Die Konstitution von 5 wurde durch Rontgenstrukturanalyse gesichert. 5 und 6 bilden durch Reduktion die in der Lit. beschriebenen Alkohole 8, 9, deren Struktur aufgrund dieser Ergebnisse korrigiert werden mus. Zusatzlich wurden in A. filipendulina Ascaridol (1), trans-Pinocarveylhydroperoxid (2) und Isolyratylhydroperoxid A (3) und B (4) nachgewiesen. Peroxides as Constituents of Plants, XV: Irregular Monoterpene Peroxides from Achillea filipendulina LAM. From Achillea filipendulina LAM. (Asteraceae) two hitherto unknown diastereomeric, irregular acyclic monoterpene peroxides 5, 6 of santolina triene type have been isolated (4α- and 4β-peroxyachipendole). The constitution of 5 was confirmed by X-ray analysis. Reduction of 5 and 6 results in the formation of the alcohols 8 and 9, respectively. Constitutions of 8 and 9, reported in lit., have to be corrected. In addition, ascaridole (1), trans-pinocarveylhydroperoxide (2) and isolyratylhydroperoxide A (3) and B (4) have been found.

Three bisepoxylignan glycosides were isolated from Stauntonia hexaphylla . One is a new compound, (+)-1-hydroxysyringaresinol-1-β- d -glucoside named staunoside C, whilst the other two, (+)-fraxiresinol-1-β- d -glucoside and (+)-1-hydroxypinoresinol-1-β- d -glucoside, are reported in this genus for the first time. Structures were established on the basis of spectroscopic analysis and chemical evidence, and their 1 H NMR signals were assigned in detail by means of 2D-NMR techniques.

On the basis of spectroscopic and chemical methods, the structures of two new bisdesmosidic triterpenoid glycosides, named staunoside D and E, which were isolated from Stauntonia hexaphylla, were established as 3-O-(beta-D-glucopyranosyl(1-->2)-[beta-D- glucopyranosyl(1-->3)]-beta-D-glucopyranosyl)-hederagenin-28- O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] ester and 28-O-[alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl]ester, respectively. Three known triterpenoid glycosides were also isolated. A new proglycoside was isolated from the cleavage of the ester-glycosidic linkage and its structure characterized.

Aus den oberirdischen Teilen der Eberraute (Artemisia abrotanum L., Asteraceae) wurden neben (+)-Davanon (1) und Arteinculton (3) die bekannten Peroxyhalbketale 2, 5 und 7 isoliert. Als neue Peroxide vom Davanon-Typ konnten Epi-Arteinculton (4) und Spiro-Arteinculton (6) durch dc Vergleich in der Pflanze nachgewiesen werden. Bei der Singulett-Sauerstoff-Oxidation von 1 werden 2, 3, 4, 5und 7 gebildet, bei der Triplett-Sauerstoff-Oxidation 2, 3, 5, 6, 7 und Hydroxy-Davanon. Peroxides as Plant Constituents, XII: Davanone Type Peroxides from Artemisia abrotanum and Their Preparation From the aerial parts of Artemisia abrotanum L. (Asteraceae), besides (+)-Davanone (1) and Arteincultone (2), the known peroxy-semiketals 2, 5, and 7 were isolated. In addition, the previously unknown davanone type peroxides epi-arteincultone (4) and spiro-arteincultone (6) were identified in A. abrotanum by TLC. By means of singlet oxygen oxidation of 1, compounds 2, 3, 4, 5, and 7 are formed, by triplet oxygen oxydation compounds 2, 3, 5, 6, 7 as well as hydroxy-davanone.

Die α-Methylen-γ-butyrolactone 1-28 wurden auf molluskizide Wirkung gegen Biomphalaria glabrata untersucht. Die racem. Verbindung 25 ist am wirksamsten. Die Synthese erfolgte durch modifizierte Reformatzky-Reaktion aus den entspr. Carbonylverbindungen und Brommethylacrylsaureethylester. 7-10, 17 und 22-27 wurden erstmalig synthetisiert. α-Methylene-γ-butyrolactones with Molluscicidal Activity The α-methylene-γ-butyrolactones 1-28 were tested in vitro for molluscicidal activity against Biomphalaria glabrata. The racemic compound 25 shows the best activity. The synthesis was carried out by modified Reformatzky reaction of the corresponding carbonyl compounds and bromomethylacrylic acid ethyl ester. 7-10, 17 and 22-27 have been synthesized for the first time.

From the leaves of Microglossa pyrifolia Lam. (Asteraceae) four new acetylenic glucosides (1-4) have been isolated. The aglucones 2a and 4a are new polyynes. The aglucone 3a could only be isolated as a mixture of E/Z-isomers in a ratio of 4:1. The structures of 1-4 were elucidated by spectroscopic and biochemical methods. Compound 1 shows antibacterial activity.

From the leaves of BLUMEA ARFAKIANA Martelli (Asteraceae), used in traditional medicine in Papua New Guinea, besides stigmasterol and beta-eudesmol, four graniline esters ( 1-4) have been isolated. Furthermore, blumealactone C ( 5), deacetylblumealactone C ( 6), and deoxyblumealactone C ( 7) have been identified.

Der 1,2-Dioxolanring des Sesquiterpenperoxids Nardosinon (1) aus Nardostachys chinensis Batalin (Valerianaceae) wird durch Flussigphasen-Autoxidation aus dem Cyclopropan-Ring des Aristolan-Ketons Gansongon (3) gebildet, welches in der gleichen Pflanze vorkommt. 3 wurde auch aus (−)-9-Aristolen (6) synthetisiert. Als Nebenprodukte der Bildung von 1 wurden die Hydroperoxide 11 und 12 sowie Kanshon C (15) isoliert. Mit p-Benzochinon entsteht aus 3 der Ether 16. Zusatz verschiedener Phenole fuhrt zu einer Erhohung der Ausbeute an 1 bis zu 50%. Der mogliche Reaktionsablauf wird diskutiert. Peroxides as Plant Constituents, VII: Formation of the Sesquiterpeneperoxide Nardesinone from an Aristolane Precursor++) The 1,2-dioxolanering of the sesquiterpeneperoxide nardosinone (1) from Nardostachys chinensis Batalin (Valerianaceae) is formed by liquid-phaseautoxidation of the cyclopropane from the aristolane ketone, gansongone (3), which exists in the same plant. 3 was also obtained synthetically from (−)-9-aristolene (6). Beside 1 the two hydroperoxides 11 and 12 and in addition kanshone C (15) were isolated. Using p-benzoquinone, 3 was converted to the ether 16. In the presence of different phenols, the yield of 1 was increased up to 50%. The possible pathway of the reaction is discussed.

Pindrolactone, a new tetracyclic triterpenoid, has been isolated from the leaves of Abies pindrow and its structure advanced as 3α-hydroxylanosta-7,9(11),22E,24-tetraen-26,23-olide.

The structure ofjatamansic acid has been revised from 2D-NMR data, an INADEQUATE experiment and X-ray diffraction analysis. The stereochemistry was con

A sesquiterpene lactone manshurolide with an hitherto unknown carbon skeleton was isolated from Aristolochia manshuriensis. Its structure was elucidated by spectroscopic means and X-ray analysis.

1,4-Epidioxy-bisabola-2,12-diene (3) and aromatic hydroperoxides (4, 5) were prepared by photoxidation of gamma-curcumene (1). Reduction and esterification of 6 and 7 afforded compounds 9 to 10. All compounds were tested in vitro for antimalarial activity. The activity could not be increased significantly, compared with 3. The most active compounds, 3 and 9, did not show in vivo antimalarial activity in mice.

Two bisabolane-type sesquiterpenes, zingiberene-3,6-beta-endoperoxide (1) and zingiberene-3,6-alpha-endoperoxide (2) have been isolated from the aerial parts of Senecio selloi and Eupatorium rufescens. Their structures were determined by spectroscopic methods. Both compounds show schizonticidal activity against Plasmodium falciparum (EC50 = 10 microg/ml).

Two new isoflavones, together with quercitrin have been isolated from whole plants of Eschscholtzia californica . The structures of the new isoflavones were determined as 2′-methoxyformononetin and 7-methoxy-2′,4′-dihydroxyisoflavone by spectroscopic methods.

From the air dried root of Melia azedarach L. (Meliaceae) the following constituents were isolated: 24–methylene cycloartanone, cycloeucalenone, 4–stigmasten–3–one and 4–campesten–3–one, 24–methylenecycloartanol, triacontanol–(1), cycloeucalenol, β–sitosterol, β–sitosterol–β–D–glucoside, vanillic aldehyde, trans–cinnamic acid and vanillic acid. In the fruits, besides known constituents one compound could be isolated for which we propose the structure of 21,23 :24,25–diepoxi–tirucall–7–en–21–ol. The structure of a protolimonoid C30H46O5 could not be elucidated. In addition, besides triacontanol, vanillic aldehyde, trans–cinnamic acid, 3β–hydroxy–5–stigmasten–7–one and 3β–hydroxy–5–campesten–7–one, the same cyclolanostane derivatives as in the root were identified.

From the ethanol extract of the blossoms of Anthemis nobilis L. (syn. Chamaemelum nobile L.), six new hydroperoxides (1-6) were isolated, besides the known 1 beta-hydroperoxyisonobilin (7). The structures were elucidated by spectroscopic methods and in some cases ascertained by synthesis. Compounds 2 and 3 show a medium antibacterial activity.

Aus den oberirdischen Teilen von Artemisia maritima L. ssp. maritima (Asteraceae) wurde neben dem bekannten Sesquiterpenhydroperoxid Arteinculton (1) em neues cyclisches funfgliedriges Sesquiterpen-Peroxyhalbketal (2) isoliert. Die Struktur wurde durch spektroskopische Methoden aufgeklart.

From the aerial parts of KADSURA INTERIOR A. C. Sm. (Schizan-draceae) a neolignan, interiorin ( 1), with a new skeleton was isolated. Its structure was elucidated by spectroscopic methods and by single X-ray diffraction analysis.

Aus dem Ethanolextrakt der trockenen Bluten von Anthemis nobilis L. (syn. Chamaelum nobile) wurde 1β-Hydroperoxyisonobilin (1) isoliert, ein Sesquiterpen-Peroxid vom Germacran-Typ. Die Struktur wurde aus spektroskopischen Daten und der Reduktion zu Hydroxyisonobilin (2) abgeleitet. Peroxides as Plant Constituents, III: 1β-Hydroperoxyisonobiline, a new Hydroperoxide from the Flowers of Anthemis nobilis The ethanol extract of dried flowers of Anthemis nobilis afforded 1β-Hydroperoxyisonobiline (1), a sesquiterpenoid peroxide with a germacranolide moiety. The structure was determined by spectroscopic means and by reduction to Hydroxyisonobiline (2).

Aus den Wurzeln und Rhizomen von Nordostachys chinensis Batalin (Valerianaceae) werden zwei Sesquiterpene isoliert. Aufgrund des Abbaues zum Aristolan (5) und der UV-, IR-NMR- und Massenspektren wird fur die Verbindungen die Struktur des 9-Aristolen-1α-ols (1) und des 1.2.9.10-Tetradehydro-aristolans (4) abgeleitet. 9-Aristolen-1α-ol and 1,2,9,10-Tetradehydroaristolane, New Aristolanetype Sesquiterpenes From roots and rhizomes of Nardostachys chinensis Batalin (Valerianaceae) two sesquiterpenes are isolated. The structures have been established as 9-aristolen-1α-ol (1) and 1,2,9,10-tetradehydro-aristolane (4) by means of degradation to aristolane (5) and spectroscopic methods.

A new sesquiterpene ether, nardonoxide ( 1), with the nardosinane skeleton, was isolated from the underground parts of NARDOSTACHYS CHINENSIS Batalin (Valerianaceae), growing in the province Sichuan (China). The structure of 1 was elucidated by spectroscopic methods, including 2D-NMR-spectroscopy.

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).

A new instable aristolane type sesquiterpene ketone, gansongone ( 1), was isolated from the fresh underground parts of NARDOSTACHYS CHINESIS Batalin (Valerianaceae), growing in the province Sichuan (China). The structure of 1 was elucidated by spectroscopic and chemical methods. The structure of the corresponding alcohol 2, which was also found in N. CHINENSIS and formerly regarded as 9-aristolene-1alpha-ol ( 5) has to be revised to l(10)-aristolene-9beta-ol ( 2) from results of 2D-NMR-spectroscopy and oxidation to 1. Besides 1 and 2, the following compounds have been identified in the ethanol extract of the fresh plant material of N. CHINENSIS: nardosinone, nardosinondiol, deoxonarchinol A, beta-sitosterol, oleanolic acid, ethyl beta- D-glucopyranoside.

Die Strukturen des 1.8.9.10-Tetradehydro-aristolanons-(2) (3) und des 9-Hydroxy-1(10)-aristolenons-(2) (Debilon, 4) aus Nardostachys chinensis Batalin (Valerianaceae) werden durch Darstellung aus 1(10)-Aristolen (1) sichergestellt. Preparation of 1.8.9.10-Tetradehydroaristolan-2-one and 9-Hydroxy-1(10)-aristolen-2-one The structures of 1.8.9.10-tetradehydroaristolan-2-one (3) and of 9-hydroxy-1(10)-aristolen-2-one (4) from Nardostachys chinensis Batalin (Valerianaceae) are confirmed by preparation from 1(10)-aristolene (1).

Four sesquiterpene lactones have been isolated from the underground parts of Aristolochia yunnanensis growing in the Yunnan province of China. Three were identified as the known germacranolides costunolide, dehydrocostuslactone and α-cyclocostunolide. The structure of the fourth compound, the non-oxidized melampolide, was elucidated by spectroscopic methods and X-ray analysis.

The previously unknown (+)-isobicyclogermacrenal was isolated from Aristolochia manshuriensis. Its structure was elucidated by spectroscopic means and X-ray analysis.