The rare flavone isoetin as a yellow flower pigment in Heywoodiella oligocephala and in other Cichorieae

Isoetin (5,7,2′,4′,5′-pentahydroxyflavone) has been identified as a yellow flower pigment in Heywoodiella oligocephala, Hieracium pilosella and Hispidella hispanica. It also occurs in leaves of these plants and of 15 other taxa of the Cichorieae. It is restricted to three of the eight subtribes, occurring most characteristically in the Leontodontinae (in 5 of 7 genera surveyed). Isoetin is frequently accompanied by apigenin, luteolin, and scutellarein derivatives in these plants.     

Variations in the essential oils of Tanacetum vulgare

The essential oil content of Hungarian samples of Tanacetum vulgare varies from 0.02 to 0.66% and exhibits a heterogeneous distribution indicating genetic variation. The rotatory power of the essential oil is also widely divergent and plants containing laevo-rotatory essential oils mainly occur in large numbers in the region east of the Tisza. The essential oil composition of wild plants remained constant during their cultivation. 26 different chemoforms have been found so far in Hungary. Individuals and populations containing artemisia ketone and umbellulone as their main components are the most frequent.     

Variations in flavonoid patterns within the genus Chondropetalum (restionaceae)

HPLC and chemical analyses of the flavonoids in culms of 11 Chondropetalum species divide the genus into two groups: seven, with glycosides of myricetin larycitin and syringetin; and four, with glycosides of kaempferol, quercetin, gossypetin, gossypetin 7-methyl ether and herbacetin 4′-methyl ether. This chemical dichotomy is correlated with anatomical differences and confirms the view that the genus requires taxonomic revision. HPLC measurements on those species with myricetin derivatives show that taxa with a qualitatively similar pattern of glycosides can be readily separated on quantitative grounds. Syringetin 3-arabinoside and a glycoside of herbacetin 4′-methyl ether are reported for the first time from the genus.     

Flavonoid constituents of Eupatorium odoratum

Isosakuranetin and a new chalcone, odoratin, have been isolated from the leaves of Eupatorium odoratum. The structure of odoratin has been shown to be 2′-hydroxy-4,4′,5′,6′-tetramethoxy chalcone.     

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.     

Comparative alkane chemistry of Parthenium argentatum (guayule) and some F1 hybrids

The leaf alkanes of Parthenium argentatum (guayule), P. tomentosum var. stramonium, P. fruticosum var. trilobatum, and the first filial (F₁) generations obtained from crosses with guayule were investigated by GC and mass spectrometry and shown to be useful in chemotaxonomic studies. The identified n-alkanes ranged from C₁₉ to C₄₀ with either n-C₂₉ or n-C₃₁ as the main component. The alkane chemistry of guayule with n-C₃₁ being the main component predominated in most of the F₁ hybrids. The presence of iso-branched alkanes (C₂₇, C₂₉, C₃₁) in P. tomentosum and its hybrids could be detected by GC/MS. These preliminary investigations indicate that epicuticular wax alkanes can be useful in inheritance studies of guayule and its hybrids.     

Flavonoids of Helianthus series Angustifolii

Leaf and ray flower flavonoids were investigated for the seven species of Helianthus series Angustifolii. Flavone aglycones occur in small glandular trichomes located on leaf undersurfaces of H. angustifolius, H. floridanus and H. simulans. Other species lacked both glandular trichomes and flavone aglycones. Flavonol glycosides occur in low concentrations in leaves of all species but were not characterized. Anthochlors (chalkones) occur in leaves of H. heterophyllus and H. longifolius. Ray flower flavonoids include anthochlor and flavonol glycosides and occur in the basal region of the ligule producing a band of UV A around the head. Anthochlors are the predominant ray flower flavonoids in H. angustifolius, H. heterophyllus and H. longifolius, whereas they are absent and quercetin 7-glucoside is present in H. carnosus and H. floridanus. Cladistic analysis of flavonoid and morphological characters indicates that evolution in the series has been a radiation from ancestral types rather than a linear sequence of progressively more derived species.     

Uniformity and distinctness of phyllocladus as evidenced by flavonoid accumulation

The conifer genus Phyllocladus is shown by comparative flavonoid chemistry to be remarkably homogeneous and quite distinct from other studied genera in the Podocarpaceae. It is characterized by the accumulation (in the foliage) of a predominance of flavone O-glycosides, and in particular, luteolin 7- and 3′-O-glycosides. Lower levels of flavonol O-glycosides are also evident. Two flavone glycosides are reported for the first time, luteolin 3′-O-α-L-rhamnopyranoside and luteolin 7-O-α-L-rhamnoside.     

Sesquiterpenoid aldehyde quinones and derivatives in pigment glands of Gossypium

The resistance of Gossypium species to insects is enhanced by compounds in their lysigenous pigment glands. In cultivated cottons, glands in achlorophyllous plant parts contained predominately the terpenoid aldehyde gossypol in G. hirsutum, and gossypol and its methyl and dimethyl ethers in G. barbadense. Glands in young green tissues, however, contained hemigossypolone as the predominant terpenoid aldehyde in G. hirsutum, and a new quinone, hemigossypolone-7-methyl ether, in G. barbadense. As glands aged in green tissues, the sesquiterpenoid quinones were replaced by several C₂₅-terpenoids formed by the Diels-Alder reaction of the quinones with myrcene or trans-β-ocimene. Two C₂₅-terpenoids isolated from G. barbadense, but not G. hirsutum, were the methyl ethers of heliocides H₁ and H₄ and were designated heliocides B₁ and B₄, respectively. A dark red pigment, gossyrubilone, from glands of young leaves of both species is the isopentylimine of hemigossypolone. Similar red imines, formed from sesquiterpenoid quinones and amino acids, resembled the red coloration of the envelope cells surrounding the gland sac. The terpenoid quinones of Gossypium had physical characteristics different from quinones in Bombax which apparently were incorrectly identified as being the same. A survey of the terpenoid quinones and their heliocide derivates in wild Gossypium species and related genera in the Gossypieae showed considerable diversity which may be used for establishing biochemical and phylogenetic relationships.     

Epicuticular wax constituents of North American and European Euphorbia esula biotypes

The epicuticular leaf wax of four North American and one Austrian Euphorbia esula biotypes was examined as a potential source of chemotaxonomic information relative to intraspecies classification. Analysis (GC and GC/MS) shows general similarity of wax constituent character among all biotypes but differences in specific component yields between the North American and Austrian biotypes. Distinctive variation in occurrence of five triterpenes (α- and β-amyrin, δ-amyrenone, 24-methylenecycloartenol and lupeyl acetate) was observed between the North American and Austrian biotypes.     

Tetrahydrofuran-type terpenoids from Tanacetum vulgare

Investigation of a rare genotype of Tanacetum vulgare afforded a series of tetrahydrofuran-type terpenoids, whose pattern was different in flowers and leaves. The major constituent of the flowers was the trans Δ^3,4-hydroperoxide of davanone, whereas the leaves gave mostly a peroxyhemiketalic compound resulting from the intramolecular cyclization of the cis Δ^3,4-hydroperoxide of davanone. Structures were elucidated by spectral data and chemical reactions, including correlation with natural (+)-davanone. The peroxyhemiketalic compound upon acylation of its hydroxyl group gave an instantaneous complex reaction, resulting in the formation of a β-acyloxyenone and loss of one molecule of acetone. Among the minor constituents of the leaves, a C-10 carboxylic acid biogenetically related with davanone was isolated.     

Foliar flavonoid aglycones of Phoebanthus

The diploid Phoebanthus tenuifolius and the tetraploid P. grandiflorus yielded identical complements of foliar flavonoid aglycones, including the compounds nepetin, jaceosidin, and hymenoxin. Flavonoid data do not resolve the origin of the tetraploid species. The similarity between the flavonoids of Phoebanthus and those earlier reported for Helianthus would support a merger of the two genera.     

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.     

The stereochemistry of hydroxylation of the carotenoid lutein in Calendula officinalis

Excised, opening inflorescences of Calendula officinalis incorporated (3RS, 5R)- and (3RS, 5S)-[2-¹⁴C,5-³H₁]mevalonates into the carotenoid fraction. The ¹⁴C:³H ratios of lutein isolated from these tissues showed the hydrogen atom at C-3 of the β-ring is derived from the 5-pro-S position of mevalonate, while that at C-3 of the ε-ring is derived from the 5-pro-R position of mevalonate. Oxidation of lutein to monoketolutein showed that both hydrogen atoms at the C-15,15′ central double bond are derived from the 5-pro-R position of mevalonate.     

Tanacetols A and B,non-volatile sesquiterpene alcohols,from Tanacetum vulgare

Chemical investigation of a rare chemotype of Tanacetum vulgare attorded a series of non-volatile sesquiterpene alcohols which have been called tanacetols. The structures of tanacetols A and B, the two most abundant, have been established on the basis of spectroscopic data, chemical reactions and X-ray diffraction analysis of tanacetol A and tanacetol B acetate.     

Bakkenolide-A. Its distribution in Petasites species and cytotoxic properties

A rapid GLC method is described for the determination of bakkenolide-A in small amounts of plant material. The distribution of bakkenolide-A among the different lipid classes of Petasites albus is discussed and also the distribution among different parts of the plant during a growing season. Smaller amounts of bakkenolide-A are found in P. hybridus buds and only trace amounts in P. fragrans.Cytotoxicity tests showed bakkenolide-A has marked cytotoxic activity and potential anti-tumour properties.     

Xanthones and C-glucosylflavones from Gentiana corymbifera

A new xanthone and twelve known compounds were isolated from the aerial parts of Gentiana corymbifera. The new xanthone was shown to be 3-methylcorymbiferin (1,8-dihydroxy-3,4,5-trimethoxy-9H-xanthen-9-one) by spectral and chemical procedures. The chemotaxonomic implications are discussed.     

Dihydroflavonols of artemisia dracunculus

The two dihydroflavonols, 3,5,4′-trihydroxy-7-methoxyflavanone and 3,5,4′-trihydroxy-7,3′-dimethoxyflavanone, and naringenin were isolated from aerial parts of Artemisia dracunculus. The mass spectrum of 3,5,4′-trideuteroxy-7-methoxyflavanone is described as an example of the usefulness of deuteration in the analysis of certain flavonoids.     

Identification of ergoline alkaloids in the genus Argyreia and related genera and their chemotaxonomic implications in the convolvulaceae

The results of the identification of 21 ergoline alkaloids of 14 species of Argyreia; viz.: A. barnesii, A. capitata, A. cuneata, A. luzoninsis, A. mollis, A. maingayi, A. nervosa, A. obtusifolia, A. philippinensis, A. reticulata. A. ridleyi, A. rubicunda, A. splendens and A. sp. and 2 closely related genera; Stictocardia tiliafolia and Rivea corymbosa, by using 2-D TLC procedures are given. A brief discussion of the implications of the ergoline alkaloids and the chemotaxonomy of the Convolvulaceae is also presented.     

Flavonoid-muster,systematik und evolution bei Valerianella

Leaf extracts from 40 Valerianella species were hydrolyzed and subjected to 2-D chromatography. Luteolin and its methyl ethers, diosmetin and chrysoeriol, are evidently typical for the genus. The distribution of these derivatives and of 6-hydroxyluteolin parallel recent cytological and morphological findings and support a new systematic arrangement. Asiatic species form flavonols, while the North American and Mediterranean-Oriental groups appear progressively more advanced by the appearance of flavones and some 6-hydroxylation.