Coumarins in artemisia caruifolia

Isolation of daphnethin 7-methyl ether, daphnetin dimethyl ether, daphnetin methylene ether, daphnetin 7-methyl-8(3,3-dimethylallyl) ether and 3,4-dimethoxy-2-hydroxycinnamic acid from Artemisia caruifolia is reported.     

An insecticidal diacetylene from artemisia monosperma

The essential oil of Artemisia monosperma obtained by steam distillation of the aerial parts of the plant was shown to have insecticidal activity against house fly, cotton leaf worm and the rice weevil. The chemical structure of the active ingredient from the steam distillate was shown to be 3-methyl, 3-phenyl-1,4-pentadiyne.     

Phenolic constituents of Artemesia tridentata spp. Vaseyana

Ten coumarins and four flavonoids have been isolated from a single collection of Artemesia tridentata ssp. vaseyana (Rydb.) Beetle. The coumarins are 7-methylesculin, esculin, umbelliferone, skimmin, cichoriin, isoscopoletin, scopoletin, scoparon, esculetin and a new natural product, artelin (5,6,7,8-tetramethoxy coumarin). The flavonoids are luteolin, luteolin-7-glucoside, axillarin and eupafolin.     

Flavonoid variation in Xanthisma texanum: Infrapopulation and interpopulation variation

Fourteen flavonoids were isolated from Xanthisma texanum. Chemosystematic interpretations are made concerning the origin and distribution of the infraspecific taxa of the species.     

Biosynthesis of cyanidin in cell cultures of Haplopappus gracilis

-Dihydroquercetin proved to be a good precursor for light-stimulated cyanidin biosynthesis in cell suspension cultures of Haplopappus gracilis. Wit     

Dihydroflavonols from Cedrus deodara

The identification of taxifolin and structure elucidation of cedeodarin (6-methyltaxifolin), dihydromyricetin, cedrin (6-methyldihydromyricetin) and cedrinoside from cedar wood are described.     

The chemical composition of the litter and soil in a community of Artemisia tridentata ssp. vaseyana

The leaves, litter, and soil from within a community of Artemisia tridentata ssp. vaseyana were analyzed for secondary metabolic products. Methacrolein, five monterpenes, three sesquiterpene lactones, six coumarins, and one flavonoid were identified in the leaves; the contents of the litter were nearly identical. Soils collected directly beneath the shrubs contained the three sesquiterpene lactones, two coumarins and an unknown flavonoid. The litter and water extracts of the litter inhibited the germination of sagebrush seeds. Soils charged with monoterpenes from sagebrush leaves also inhibited seed germination. In addition, the monoterpene contents from eight sagebrush taxa collected from Western Montana are reported.     

Induction of anthocyanin formation and of enzymes related to its biosynthesis by UV light in cell cultures of Haplopappus gracilis

Only UV light below 345 nm stimulates anthocyanin formation in dark grown cell suspension cultures of Haplopappus gracilis. A linear relationship between UV dose and flavonoid accumulation, as found previously with parsley cell cultures, was not observed with the H. gracilis cells. Only continuous irradiation with high doses of UV was effective. Drastic increases in the activities of the enzymes phenylalanine ammonia-lyase, chalcone isomerase and flavanone synthase were observed under continuous UV light. The increase in enzyme activities paralleled anthocyanin formation.     

Flavanones and dihydroflavonols as biosynthetic intermediates in Matthiola incana

In anthocyanin-producing flowers of Matthiola incana, the presence of naringenin, naringenin 7-glucoside, dihydrokaempferol and dihydrokaempferol 7-glucoside could be demonstrated. The four isolated compounds initiated anthocyanin synthesis after administration to acyanic flowers of genetically defined lines of Matthiola incana and Antirrhinum majus. Therefore, these compounds cannot be regarded as end-products but rather as intermediates in anthocyanin biosynthesis. Furthermore, naringenin 7-glucoside and dihydrokaempferol 7-glucoside most probably act as a pool for their aglycones, which serve as the actual substrates.     

Ent-labdane derivatives from gutierrezia grandis

Two new diterpenes, 3α-angeloyloxy-18-hydroxy-13-furyl-ent-labda-8(17)-ene and 3α-hydroxy-18-angeloyloxy- 13-furyl-ent-labda-8(17)-ene and an only recently reported third diterpene, 3α, 18-dihydroxy-13-furyl-ent-labda-8(17)-ene, were isolated from the leaves of Gutierrezia grandis. Their structures were determined by mass spectral, IR, ¹H NMR and ¹³C NMR data was well as chemical evidence.     

Polyacetylenes of Dahlia

Two Dahlia sherffii strains and three Dahlia pinnata strains and Dahlia rudis Sorensen have been investigated for polyacetylenes. A great number of acetylenic compounds, characterized earlier from other Dahlia species was determined. The two Dahlia sherffii strains and the three Dahlia pinnata strains contain 1-phenylhept-5-ene-1,3-diyne and 1-phenyl-hepta-1,3,5-triyne and derivatives which have previously been found in one Dahlia coccinea strain and in a horticultural form. A comparison between this group of dahlias with others previously investigated, show characteristic differences in the chemical pattern. Dahlia rudis is thus closer to the D. imperialis and the D. tenuicaulis and three of the Dahlia coccinea strains. Dahlia merckii exhibits a quite unique pattern of polyacetylenes.     

Ent-norlabdane triols from Austroeupatorium inulaefolium

Two new ent-norlabdane triols were isolated from the above-ground parts of Austroeupatorium inulaefolium.     

Clerodanes from solidago virgaurea

The isolation and structure determination of four known and eight new cis-clerodane lactones from the aerial parts of Solidago virgaurea are described.     

Coumarins from Pterocaulon balansae and P. lanatum

Analysis of the petrol-diethyl ether extracts of Pterocaulon balansae and P. lanatum aerial parts afforded, besides puberulin, scopoletin-[2′     

Ecogeographic distribution of secondary constituents in Parthenium (compositae)

Over 20 taxa of the genus Partenium (Compositae) representing four sections or five ecological groupings from throughout the Americas, were examined for sesquiterpene lactones, flavonoids and alkaloids. The tropical thorn-forest, arborescent members (sect. Parthenichaeta) were found to contain three different sesquiterpene lactone types and derivatives of the flavonols; quercetin, kaempferol and quercetagetin. The desert shrubs were remarkable for their high production of methylated quercetagetin flavonols and alkaloids, but lacked any appreciable amounts of sesquiterpene lactones. The temperate, submontane perennials (sect. Bolophytum), contained lactones and flavonols in extremely low concentrations. The herbaceous annuals (sect. Argyrochaeta) contained pseudoguaianolides only and together with quercetin, and kaempferol $\text{O-}\text{glycosides}$. The herbaceous perennials contained twice as many lactones and flavonoids as the annuals. It is suggested that the ecogeographical distribution of secondary products in Parthenium is probably a result of adaptive responses to various physical and biotic factors (herbivore pressure) in the environment.     

Aromatic compounds from Artemisia campestris subsp. Glutinosa

From the weakly acid fraction of the hexane extract from Artemisia campestris subsp. glutinosa, five new aromatics have been isolated. They hav     

Polyacetylenes from Chrysanthemum leucanthemum

Fifteen acetylenic compounds have been isolated and characterized from the flower heads of Chrysanthemum leucanthemum L. Five of these acetylenes have not previously been published as naturally occurring compounds. These are: 1,7(c)-hexadecadien-10,12,14-triyne; 1,8(c)-heptadecadien-11,13,15-triyne; 4(c)-tridecen-7,9,11-triyn-l-ol; 1,8(t)-hexadecadien-10,12,14-triyn-(6·7)-oxirane; and [3(t),5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methyl-2-butenoate. The first three compounds are interesting since they are important intermediates in previously postulated biogenetic pathways. Ten acetylenes have been identified from the roots of the same plant, all of these having different structures from those of the flower heads. One of the acetylenes, [3(t), 5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methylbutyrate, from the roots has never been reported as a naturally occurring compound.     

Flavanone synthase from cell suspension cultures of Haplopappus gracilis and comparison with the synthase from parsley

Flavanone synthase was isolated and purified ca 62-fold from cell suspension cultures of Haplopappus gracilis. The enzyme preparation catalysed the formation of naringenin from 4-coumaryl-CoA and malonyl-CoA with a pH optimum of ca 8. The same enzyme was also capable of synthesizing eriodictyol from caffeyl-CoA and malonyl-CoA; in this case the pH optimum lay between 6.5 and 7. The homogeneous flavanone synthase from cell suspension cultures of parsley showed the same dependence of the pH optimum on the nature of the cinnamyl-CoA. It can be concluded that both naringenin and eriodictyol are natural products of the synthase reaction.     

Heliangolides from Leucanthemopsis pulverulenta

The structure of hispanolide (4,5-cis-3-oxogermacranolide) and three other related germacranolides, isolated from Leucanthemopsis pulverulenta, have been established by a series of chemical transformations and spectral data.