Flavonoid Chemistry Research Articles

ORIGIN OF TRIPSACUM ANDERSONII (GRAMINEAE)

Tripsacum andersonii Gray (Gramineae) is a species with 2n = 64 chromosomes. Chromosome behaviour during meiosis of microsporogenesis suggests that the species combines three homologous haploid Tripsacum genomes of x = 18 (54 chromosomes), and an alien haploid genome of x = 10 chromosomes. Cytogenetic studies indicate that T. andersonii originated as a hybrid between a species of Tripsacum (2n = 36) and a species of Zea (2n = 20). Comparative morphology and flavonoid chemistry fail to identify the Zea species involved in this intergeneric hybrid. Chromosome morphology suggests that it was either Z. mays L. subsp. mays (domesticated maize) or subspecies mexicana (Schrad.) Iltis (annual teosinte). The Tripsacum parent probably was T. latifolium Hitchc. of Central America. It resembles T. andersonii in vegetative morphology. Tripsacum maizar Hernandez et Randolph and T. laxum Nash, which resemble T. andersonii in flavonoid chemistry, are eliminated as possible parents on the basis of growth habit and the morphology of their hybrids with maize.

A New Species of Physaria (Cruciferae) from Wyoming

The proposal to give Physaria condensata Rollins protection under the Endan gered Species Act prompted extensive field work on this and other related specie: in Wyoming. Since 1977, observations by R. Dorn and me have indicated muct variation in growth forms within various species. Not only was P. condensat~ capable of forming condensed rosettes, but individuals of apparently other mon common species occasionally expressed this habit when found growing in harst habitats. These occasional occurrences of tightly condensed individuals prompte( the following study. Field observations of vegetative, flowering, and fruiting characters along wit! growth forms were measured over a three year period. A descriptive analysis o the habitat was also recorded. Laboratory analyses including flavonoid chemistry volatile chemistry, and scanning electron micrographs were done on thirty-fou populations of six different taxa. Specimens examined in this study represen personal collections deposited at RM and GH and borrowed specimens from th, following institutions: COLO, DAO, GH, ID, MONT, MONTU, NDA, NEB NY, RM, SDU, US, and UTC. The leaf flavonoids expressed no detectable distinctions between species o populations. The flavonoid compounds were studied by UV spectroscopy whicl indicated di- and triglycosides of a methylated derivative of quercetin. The vol atiles were steam distilled using a circulatory steam apparatus (Kaiser & Lan E 1951 as described in von Rudloff, 1969). Of the fifteen compounds detected, al were found in each population studied. Only quantitative differences were noted Scanning electron micrographs did show differences between certain species. Th differences are discussed below. The study confirmed that two main groups of physarias occur in Wyoming those with two funiculi per locule and those with four or more funiculi per loculc The condensed growth form species of Physaria in Wyoming are members of th four funiculi group. The earlier hypothesis that P. condensata may be one of th more common species responding to climatic conditions can now be dismissec In southwestern Wyoming, individuals ofP. acutifolia Rydb. occasionally expres the condensed growth form. These individuals can be distinguished as P. acutifoli by the linear shape of the replum and only two funiculi. Physaria didyrnocarpa (Hook.) A. Gray, which has four funiculi, occasionall has a condensed growth form. Physaria condensata has an obovate replum, entir leaves with acute tips, and an inflorescence that barely exceeds the leaves. Physari didymocarpa has a linear replum, dentate leaves with obtuse tips, and an inflc rescence that greatly exceeds the leaves.

Analysis of Flavonoids by HPLC

Abstract During the past ten years there has been a dramatic increase of interest in the field of flavonoid chemistry. This was mainly due to the application of HPLC to the study of flavonoids. These compounds, natural plant constituents with a structure based on the aromatic heterocycle, 3-phenylbenzopyrone, are ideally suited for analysis by HPLC. The basic complex structure can be varied by the number and position of hydroxyl substituents and other derivatives (sugars, methyl). These variations cause changes in the way the compounds react to solvents and columns commonly used in HPLC allowing separation and identification.

Distribution of novel cyclic bisbibenzyls in Marchantia and Riccardia species

Marchantins A, B and C, three new cyclic bisbibenzyls with two ether links have been isolated from the liverworts Marchantia polymorpha, M. paleacea var. diptera and M. tosana (Marchantiales). Riccardia multifida (Metzgeriales) also contained two new cyclic bisbibenzyls, riccardins A and B, with an ether and a biphenyl link. The presence of cyclic bisbibenzyls has not been confirmed in Dumortiera hirsuta and Preissia quadrata (Marchantiales). The present chemical data support that D. hirsuta and P. quadrata are not closely allied to Marchantia by flavonoid chemistry and some species of Marchantiales have close affinities to those of Metzgeriales.

Taxonomy of Hemizonia sect. Madiomeris (Asteraceae: Madiinae)

Taxonomic review based on morphology, flavonoid chemistry, cytol- ogy, breeding experiments, and ecogeographic considerations suggests emendation of the circumscription of Hemizonia sect. Madiomeris and recognition of 17 taxa (14 species, one with two and one with three subspecies) within the section. New names are: Hemizonia increscens, H. increscens subsp. foliosa, and H. increscens subsp. villosa. Hemizonia martirensis, heretofore unassigned to a section, is included in sect. Madiomeris. Chromosome counts for 16 of the 17 taxa demonstrate an aneuploid series of n = 9, 10, 11, 12, and 13. Hemizonia sect. Madiomeris comprises 14 species distributed in the foot- hills and valleys from central California into Baja California Norte. Mem- bers of this section are distinguished from those in the other three sec- tions of the genus by one or more of the following characteristics: annual habit, beaked ray achenes, lack of apiculations on leaves and phyllaries, and receptacular bracts usually confined to an outer connate ring. The concept of sections in Hemizonia originated with de Candolle (1836) when he described the sections Madarioides and Olocarpha. Section Madarioides contained H. congesta and H. angustifolia while sect. Olocarpha contained H. luzulaefolia and H. macradenia. De Candolle (1836) also described the genus Hartmannia (non Spach 1835) containing three species: H. corymbosa, H. fasciculata, and H. ciliata. Torrey and Gray (1843) treated the species of Hartmannia under Hemizonia. They neither recognized the sections of de Candolle, nor did they offer any sectional designations of their own. Six groups of species, however, were denoted by being set off by printer's marks. Nuttall (1848) circumscribed the sect. Madiomeris to include a new species, Hemizonia macrocephala Nutt., but did not provide any evidence as to its relationship to any other sections in the genus. Gray (1874) named four subgenera under Hemizonia, of which one was Hartmannia DC., including H. angustifolia and H. macradenia within the subgenus. He circumscribed the subgenus Euhemizonia to include only H. congesta and H. luzulaefolia. Greene (1897) transferred H. an- gustifolia and H. corymbosa to a segregate genus Zonanthemis. He also moved all species of Hemizonia subg. Hartmannia to the segregate genus Deinandra, noting that Hartmannia DC. (1836) was a later homonym of Hartmannia Spach (1835). Greene (1897) treated sect. Olocarpha DC. (Holocarpha is orthographically correct) as a distinct genus, including within it, H. macradenia. Jepson (1925) and Munz (1935) did not recog-

Biosystematics and Evolution of Cultivated Coca (Erythroxylaceae)

ABSTRAcr. Erythroxylum coca vars. coca and ipadu and E. novogranatense vars. novogranatense and truxillense are closely related taxa cultivated in South America for their cocaine-bearing leaves. Taxonomically they have been variously treated, ranging from one to three separate species. Erythroxylum novogranatense var. truxillense is morphologically somewhat intermediate between E. c. var. coca and E. n. var. novogranatense and has been suggested to be a hybrid between the two. Evidence from artificial hybridizations, leaf flavonoid chemistry, and breeding system studies was used to clarify the taxonomic and evolutionary relationships of these plants. This evidence suggests that E. n. var. truxillense is intermediate between E. coca and E. n. novogranatense but it is not a hybrid between them. These three taxa represent a linear evolutionary series, with E. c. var. coca the ancestral taxon, E. n. var. truxillense derived from it, and E. n. var. novogranatense derived from E. n. var. truxillense. Eythroxylum c. var. ipadu was independently derived from E. c. var. coca. All of the taxa are partially isolated genetically except E. c. var. coca and E. c. var. ipadu. The taxonomic treatment that best reflects their relationships is to regard E. novogranatense var. novogranatense and E. n. var. truxillense as varieties of a species distinct from E. coca. Only limited material of E. c. var. ipadu was available for study, but it might better be regarded as a cultivar of E. coca.

Flavonoid chemistry and systematics of the Dilleniaceae

A comparative study of the flavonoid chemistry of the Dilleniaceae is presented, in which special emphasis is given to the neotropical genera. Flavonoids are present, in diminishing order of frequency, as rhamnosides, galactosides, sulphates, arabinosides, glucuronides and glucosides. Besides the common aglycones there are also several O-methylated compounds. The distribution of the substances is reticulate and does not permit the recognition of taxa between the level of genus and family. An evolutionary interpretation is presented.

Allozyme Divergence in Coreopsis cyclocarpa (Compositae)

Coreopsis cyclocarpa is a diploid, suffrutescent perennial occurring in the grasslands of high plateau regions of Mexico. The species consists of two allo- patric varieties, var. pinnatisecta and the typical one. They are very similar morpho- logically and appear to differ only by a feature of the leaves. The two infraspecific taxa are highly interfertile. Electrophoresis was utilized to ascertain the amount of divergence between the varieties at 20 genetic loci coding for soluble enzymes. There is high genetic identity among populations of the same variety, with mean values of 0.98 for populations of var. cyclocarpa and 0.95 for var. pinnatisecta. When comparing mean identities for populations of the two varieties, the value is 0.75, indicating genetic divergence between the taxa. It is suggested that genetic differentiation between the two varieties is a reflection of the time they have been isolated. In an earlier study one of us (Crawford 1970) reported on the mor- phology, flavonoid chemistry, chromosome number, and artificial hy- bridizations involving Coreopsis cyclocarpa Blake and C. pinnatisecta Blake. The two taxa are perennial suffructescent plants growing in the moun- tains of Mexico with the latter found primarily in the states of Oaxaca and Guerrero and the former in Jalisco. Both taxa flower at the same time of year and occur in similar open grassy areas of high plateau regions (Crawford 1970). The present known geographic ranges of the two taxa indicate a disjunction of about 700 km, although additional collecting in Guerrero and Michoacan might narrow this hiatus. The only reliable morphological character for distinguishing them is leaf mor- phology, with C. cyclocarpa having simple linear leaves whereas those of C. pinnatisecta are pinnatisect with linear segments (Crawford 1970). Both taxa are diploid with a chromosome number of 2n = 24, and artificial crosses in the greenhouse produced fully fertile F1, F2, and backcross hybrids. Meiosis was regular and seed set was not reduced (Crawford 1970). In addition, the leaf characters used to separate the two taxa segregate in the F2 generation. On the basis of these data, the two taxa were reduced to varietal status. The purpose of the present study was to measure genetic divergence between the two varieties of Coreopsis cyclo- carpa utilizing data from the electrophoretic separation of allozymes. The advantages of enzyme electrophoresis for addressing systematic ques- tions in plants were discussed by Gottlieb (1977a, 1981 a), who also point- ed out that most electrophoretic studies comparing different taxa have been done with annuals, there being a paucity of data for perennial angiosperms. The present study of allozymes in woody, perennial, in- terfertile, morphologically similar plants will provide data for the com-

A New Variety of Coreopsis Mutica (Compositae) from Mexico

Coreopsis mutica var.simplicifolia is described from the state of Guanajuato in Mexico. The new variety is distinguishable by its simple lanceolate to linear-lanceolate leaves. In addition, var.simplicifolia is al lopatric with other C.mutica and has a distinctive leaf flavonoid chemistry. The chromosome number of the variety is 2n = 56.

Blue flower pigmentation and evolutionary advancement

Blue flowers occur in those taxa of the angiosperms which are characterized by an evolutionary trend towards the herbaceous habit. They are relatively rare in the more primitive groups of both the dicots and the monocots and are much more frequent in the more highly advanced subclasses, the Asteridae, Commelinidae and Liliidae. These facts can be rationalized by considering the changes in flavonoid chemistry known to accompany the evolution of woody to herbaceous forms with respect to the chemical composition of the blue pigment complexes.

Leaf Flavonoid Chemistry of Coreopsis (Compositae) Section Palmatae

Examination of leaf flavonoids of all taxa ofCoreopsis sectionPalmatae revealed that most members synthesize an array of common flavone (mostly luteolin and apigenin) glycosides. Each diploid species or diploid member of a species is characterized by a particular ensemble of compounds. These taxa includeC. major, C. verticillata, C. pulchra, C. palmata, andC. tripteris. The latter species differs from all other taxa in producing flavonol (kaempferol and quercetin) glycosides and what appear to be 6-oxygenated compounds. Tetraploids ofC. verticillata exhibit the same flavonoids as diploid members of the species, thus flavonoid chemistry supports the hypothesis that they originated from diploids within the species. Certain populations of hexaploid and octoploidC. major are similar chemically to diploids, suggesting they also originated as intraspeciflc polyploids. Other populations of these polyploids exhibit a flavonoid profile which differs from the profile of the diploids, and this profile is nearly identical to the octoploidCoreopsis × delphinifolia. The latter taxon has been viewed by Smith (1976) and Mueller (1974) as an interspecific hybrid betweenC. verticillata andC. major and/orC. tripteris. Species-specific compounds from the former species occur inC. × delphinifolia but no compounds unique to either of the latter two species are discernable. Flavonoid chemistry is not useful in ascertaining whether either or both species have been involved withC. verticillata in producing plants referable toC. × delphinifolia. There is morphological intergradation between octoploidC. major andC. × delphinifolia, and all plants not appearing to be “pure”C. major exhibit a flavonoid chemistry likeC. × delphinifolia. All plants of sectionPalmatae considered to be alloploids (includingC. × delphinifolia) produce the same array of leaf flavonoids, including several “novel” compounds not expressed in the putative parental taxa. Two of the “novel” flavonoids are present in the geographically restricted diploidC. pulchra. The systematic and phylogentic significance of this is not readily apparent.

Essai chimiosystématique sur la tribu des Lotées

Abstract A survey of the leaves and flowers of 62 representatives of the tribe Loteae (Leguminosae) showed the presence of several classes of flavonoids: flavonol 7-methyl ethers (rhamnocitrin, rhamnetin), 8- O -substituted flavonols (gossypetin, limocitrin, sexangularetin, corniculatusin), 3′,4′,5′-tri- O -substituted flavonols (myricetin, mearnsetin, syringetin, laricitrin), proanthocyanidins and flavone- C -glycosides. The trisubstitution of the B-ring and the 8- O -substitution of the A-ring allow the definition of a major group including the genera Dorycnium, Bonjeania, Lotus and Tetragonolobus . The presence of proanthocyanidins and 7- O -methylation determine a second group consisting of the genus Anthyllis . Finally, Securigera , on the basis of its flavonoid chemistry, appears to be rather remote from other members of the tribe.

The flavonoids of Megalodonta beckii and isolation of 2′-3-Dihydroxy-4-methoxy-4′-glucosyl chalcone

A new naturally occurring chalcone glycoside, 2′,-dihydroxy-4-methoxy-4′-O-β-d-glucosyl chalcone, and other chalcones, aurones, flavonols, and anthocyanins are reported from Megalodonta (Bidens) beckii. The plan is an amphibious aquatic with heterophyllous leaves, but the presence of certain flavonoids is correlated with vegetative versus floral tissues rather than vegetative leaf form. The implications of flavonoid chemistry with respect to the relationship of M. beckii to several sections of Bidens are discussed.

Flavonoid Chemistry of Coreopsis Grandiflora (Compositae)

The leaf flavonoid chemistryof Coreopsis grandiflora, which includes var.harveyana, var.longipes, var.saxicola and the typical var.grandiflora, is quite uniform with 6-hy-droxyquercetin 7-O-glucoside, luteolin 7-O-glucoside, marein-maritimein chal-cone-aurone pair and lanceolin-leptosin chalcone-aurone pair as consistent com-ponents. Flavonoid data lend support to the hypothesis that the hexaploid var.longipes originated from parents which would be included withinC. grandiflora, i.e., there is no evidence that other species were involved in its formation. One population of var.grandiflora and several collections of var.saxicola contain additional flavonoid components in the form of flavonol 3-O-glycosides. In nearly all instances the additional compounds are attributable to hybridization withC. lanceolata orC. pubescens because these flavonols are characteristic of these two species and morphological considerations also suggest it. Flavonoid chemistry supports the treatment of var.saxicola as a variety ofC. grandiflora rather than as a distinct species.

Flavonoid patterns in the farina of goldenback and silverback ferns

Most species of the fern genus Pityrogramma show a farinose indument caused by a deposit of exuded flavonoid aglycones. Some 220 samples, comprising 14 species, have been studied for the chemical composition of their farinas. Flavones, flavonols and C -methylated flavonoid are rarely found. The presence of certain chalcones and dihydrochalcones, however, appears to be to some extent characteristic for the genus. In some cases the farina flavonoid pattern is species-specific; in one species also variety-specific patterns and even chemotypes are observed. In general, the flavonoid chemistry in Pityrogramma parallels frond morphology to a great extent. This supports the concept that around a core of generalized species a few variant species exist which are best treated as belonging to Pityrogramma .

Karyotypic Relationships among Species of Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea (Saxifragaceae)

A base chromosome number of x = 7 characterizes many genera of the Saxifraginae. A high degree of karyotypic constancy was found among species representing six of these genera (Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea). Boykinia aconitifolia and six species of Sullivantia are characterized by the same karyotype. Four species of Heuchera, Mitella diphylla, Tiarella cordifolia, and Tolmiea menziesii (the last at the tetraploid level) possess a second karyotype that differs from the first in the position of the centromere of only one chromosome pair. These karyological observations suggest generic relationships that agree with those based on morphology, flavonoid chemistry, and crossability.

Systematic Implications of Flavonoid Pigments in the Fern Genus Hemionitis (Adiantiaceae)

The closely related fern generaHemionitis L. andGymnopteris Bernhardi are separated primarily on differences in leaf architecture and venation. Studies indicate that these characters are highly variable and unreliably diagnostic. Further, the type species of the two genera readily hybridize with each other. Spore morphology, as exhibited by SEM, does not support the traditional alignment of the species in these two genera: some species ofHemionitis andGymnopteris have the same rugose to papillate spores, while other species from both genera possess crested spores. The flavonoid chemistry of these taxa coincides with spore type, i.e., taxa from both genera which possess crested spores produce kaempferol and quercetin 3-0-glycosides, while species with tuberculate spores produce only quercetin 3,4′-0-glycosides. The spore and chemical data suggest a realignment of these taxa within a single genus, which would avoid the rather tenuous dependence on a single vegetative character for generic distinctions.

Flavonoid Chemistry of Arceuthobium (Viscaceae)

Flavonoid compounds from 36 of the 38 known taxa of the genusArceuthobium (dwarf mistletoes) were examined. The flavonoid chemistry of the genus is rather uniform, all taxa producing 3-O-glycosides of the flavonols quercetin and myricetin. No infraspecific chemical variation was encountered, and in those instances where subspecific taxa are recognized, their chemistry was uniform. At the subgeneric level, members of subgenusArceuthobium synthesize primarily glucosides, whereas galactosides are more common in subgenusVaginata. In two of the four Old World species of subgenusArceuthobium (A. juniperi- procerae andA. oxycedri) only myricetin 3-O-glucoside was detected. There are no absolute flavonoid differences between subgenera, sections, or series. On the other hand, flavonoids are useful in several instances at the species level. In several cases, chemical data lend support to the recognition of species which in the past have been considered doubtfully distinct on the basis of morphology.

ALLOZYME VARIATION IN SEVERAL CLOSELY RELATED DIPLOID SPECIES OF CHENOPODIUM OF THE WESTERN UNITED STATES

Twelve allozyme loci were examined in a complex of closely related diploid (2n = 18) members of the genus Chenopodium occurring in the western United States. These plants are generally treated taxonomically as belonging to C. atrovirens, C. desiccatum, C. hians, C. leptophyllum, and C. pratericola. Also included were populations referable to C. incognitum. The enzymes examined and the allelic designations are given as follows: leucine aminopeptidase, Lap; phosphoglucoisomerase, Pgi‐1, Pgi‐2; glutamate‐oxaloacetate transaminase, Got‐1, Got‐2, Got‐3; glutamate dehydrogenase, Gdh; phosphoglucomutase, Pgm‐1, Pgm‐2; malate dehydrogenase, Mdh‐1, Mdh‐2; and malic enzyme, Me. All populations were fixed for the same allele at Gdh, Pgi‐2, and Mdh‐1. Chenopodium hians was fixed for a unique allele at Got‐3 and contained two alleles at the Lap locus and two at Pgi‐1 which were not detected elsewhere. Chenopodium leptophyllum likewise has unique alleles at Lap and Pgi‐1. The other three taxa, C. atrovirens, C. desiccatum and C. pratericola, have alleles at Lap and Pgi‐1 which were not found in C. hians or C. leptophyllum. The former three species have the same alleles in highest frequency at all polymorphic loci except Me, where C. desiccatum is consistently separable from C. atrovirens and C. pratericola. Allozyme data are concordant with information from morphology, flavonoid chemistry and seed protein profiles in suggesting that: (1) Chenopodium hians and C. leptophyllum are best regarded as distinct species; (2) C. atrovirens and C. pratericola are very similar and perhaps should not be recognized at the specific level; (3) C. desiccatum appears most closely allied to C. pratericola; (4) plants referable to C. incognitum represent two biological entities, one the same as C. atrovirens, and the other conspecific with C. hians; (5) little genetic variation is detectable in any taxon of these weedy annuals; (6) interspecific hybridization is not a cause of taxonomic difficulties in these plants.

Correlations between flavonoid chemistry, anatomy and geography in the restionaceae

Comparisons of the flavonoid patterns in stems and inflorescences between Australasian and South African members of the Restionaceae indicate significant differences with geography. Nine of 14 Australasian species contain gossypetin or a related 8-hydroxyflavonoid and proanthocyanidins are uncommon. By contrast, the 33 South African taxa studied contain common flavonols, flavones and glycoflavones, while proanthocyanidins are present in 29. Two anatomically related South African genera, Chondropetalum and Elegia, contain, in addition, myricetin 3-galactoside, together with the 3-galactosides of the myricetin methyl ethers, larycitrin and syringetin. These results confirm the conclusions derived from anatomy that members of Hypolaena, Leptocarpus and Restio, genera represented in both Australia and South Africa, have the distinctive flavonoids characteristic of their geographic origin rather than of their systematic position. The family as a whole is different in flavonoid pattern from other monocotyledonous families with which it is sometimes associated.