Chemosystematic studies in the chrysobalanaceae. I. Flavonoids in Parinari

A survey of flavonoids in 31 Asian, African and Neotropical species of Parinari showed a predominance of flavonol glycosides based on myricetin, quercertin, and kaemp-ferol. The African taxa split into two groups based on the presence or absence of myricetin glycosides. The Neotropical taxa, a complex of closely related species, are chemically very similar to each other and lack myre?etin, as does one group of African species. The Asian taxa are similar to the Neotropical ones in their flavonoid patterns and lack of myricetin glycosides. The presence of myricetin considered a primitive flavonoid character, suggest that te African species pro-ducing this flavonol represent a primitive nucleus eastward and westward ex-pansion to two myricetin-lacking phytogeographic lines. This hypothesis is in agreement with current proposals for geographic evolution in the Chrysobalanaceae.     

Flavonoid chemistry ofPolygonum sect.Tovara (Polygonaceae): A systematic survey

Polygonum sect.Tovara includes three controversial species;P. virginianum, P. filiforme, andP. neofiliforme. The flavonoid chemistry of these was examined to provide additional information on their delimitation and levels of differentiation. Eight flavonoid compounds were isolated and identified, all of which were 3-O-glycosides of the flavonols kaempferol, quercetin, and myricetin, and their acylated derivatives. Although they exhibit relatively simple flavonoid profiles, the three taxa are readily distinguished by their flavonoid constituents. In addition, they show fundamental differences in flavonol types and glycosylation patterns. These results, in conjunction with evidence from the morphology, strongly suggest thatP. virginianum, P. filiforme, andP. neofiliforme are closely allied but distinct species.     

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.     

Flavonoid glycosides and the chemosystematics of Eucalyptus camaldulensisis

Leaf flavonoid glycosides of Eucalyptus camaldulensis were identified as kaempferol 3-glucoside and 3-glucuronide; quercetin 3-glucoside, 3-glucuronide, 3-rhamnoside, 3-rutinoside and 7-glucoside, apigenin 7-glucuronide and luteolin 7-glucoside and 7-glucuronide. Two chemical races were observed based on the flavonoid glycosides. These races correspond to the northern and southern populations of species growing in Australia. The Middle Eastern species examined were found to belong to the southern Australian chemical race. The major glycosides of E. occidentalis proved to be quercetin and myricetin 3-glucuronide.     

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.     

Foliar flavonoids of eastern North AmericanVitis (Vitaceae) north of Mexico

Twenty-one flavonoid glycosides were isolated from the leaves of 22 North AmericanVitis L. taxa, representing two subgenera and five series. Three chemical groups were evident: one producing flavonols, flavones, and C-glycosylflavones, a second producing flavonols and flavones, and a third producing only flavonols. These three chemical groups did not correspond to any of the subgeneric groupings based on morphology. However, flavonoid distributions within series in each subgenus correlate well with morphological data. Parallel flavonoid evolution within each series is thought to account for this lack of subgeneric and interserial flavonoid distinction. The flavonoid data indicate that seriesCordifoliae of subgenusVitis, particularlyV. vulpina L., is the most closely related group to subgenusMuscadinia (Planch.)Rehder, and represents an evolutionary link between the two subgenera.     

Chemosystematic studies in the saxifragaceae sensu lato. 8. The flavonoids of elmera racemosa (Watson) Rydberg

The flavonoid glycosides of both varieties of Elmera racemosa were isolated and identified. The compounds were the monoglucosides of kaempferol, quercetin and myricetin, the rutinosides of the same aglycones, and the rhamnosylrutinosides of kaempferol and quercetin. All glycosides were linked at position-3 of the flavonols. The two varieties (var. racemosa and var. puberulenta C. L. Hitchcock) were identical. A comparison of the flavonoid chemistry of Elmera, Heuchera, and Tellima supports the existence of Elmera as a genus. A survey of several collections of Tellima grandiflora, Heuchera micrantha, and H. cylindrica showed only minor quantitative differences in the two-dimensional thin layer chromatograms from collection to collection. The possible origin of Tellima and Elmera from ancestral stock having Heuchera-like flavonoid chemistry is discussed.     

A morphological and chemical study of Populus acuminata Rydberg

Evidence from morphology, flavonoid chemistry, and field observations suggests thatPopulus acuminata is of hybrid origin. The putative parents areP. angustifolia, the narrow leaf cottonwood, and deltoid leaved plants that are assigned toP. sargentii (P. deltoides var.occidentalis), P. fremontii, orP. wislizenii (P. fremontii var.wislizenii). Populus angustifolia exhibits a series of flavonol glycosides (kaempferol, quercetin, and myricetin) in its leaves. By contrast, the major leaf flavonoids of the broad leaved plants are flavone glycosides (apigenin and luteolin).Populus acuminata is intermediate between the suspected parents in morphological features. Additionally, the leaves of mostP. acuminata plants contain the exact summation of the flavonoid compounds characteristic of the putative parents. A diploid chromosome number of 2n = 38 was obtained for six plants, which confirms the one previous report for the species. Meiosis was regular in all cases. Correlated data indicate that the majority of plants ofP. acuminata represent F₁ hybrids and that complex hybridization is not common. Evidence from morphological and chemical studies is presented to show that in certain instances backcrossing to both parents has occurred. Results gathered in this study show thatP. ×andrewsii is undoubtedly “typical”P. acuminata, but the type specimen is from a sucker shoot, and thus has been interpreted as a backcross toP. sargentii. Populus acuminata var.rehderi is not considered worthy of taxonomic recognition.     

The leaf flavonoids of the Zingiberales

A survey of flavonoids in the leaves of 81 species of the Zingiberales showed that, while most of the major classes of flavonoid are represented in the order, only two families, the Zingiberaceae and Marantaceae are rich in these constituents. In the Musaceae (in 9 species), Strelitziaceae (in 8 species) and Cannaceae (1 of 2 species) flavonol glycosides were detected in small amount and in the Lowiaceae no flavonoids were fully identified. In the Zingiberaceae kaempferol (in 22%), quercetin (72%) and proanthocyanidins (71%) are distributed throughout the family. The two subfamilies of the Zingiberaceae may be distinguished by the presence of myricetin (in 26%), isorhamnetin (10%) and syringetin (3%) in the Zingiberoideae and of flavone $\text{C-}\text{glycosides}$ (in 86% of taxa) in the Costoideae. A number of genera have distinctive flavonol profiles: e.g. Hedychium species have myricetin and quercetin. Roscoea species isorhamnetin and quercetin and Alpinia species kaempferol and quercetin glycosides. A new glycoside, syringetin 3-rhamnoside was identified in Hedychium stenopetalum. In the Zingiberoideae flavonols were found in glycosidic combination with glucuronic acid, rhamnose and glucose but glucuronides were not detected in the Costoideae or elsewhere in the Zingiberales. The Marantaceae is chemically the most diverse group and may be distinguished from other members of the Zingiberales by the occurrence of both flavone $\text{O-}$ and $\text{C-}\text{glycosides}$ and the absence of kaempferol and isorhamnetin glycosides. The distribution of flavonoid constituents within the Marantaceae does not closely follow the existing tribai or generic limits. Flavonols (in 50% of species). flavones (20%) and flavone $\text{C-}\text{glycosides}$ (40%) are found with similar frequency in the two tribes and in the genera Calathea and Maranta both flavone and flavonol glycosides occur. Apigenin- and luteolin-7-sulphates and luteolin-7,3′-disulphate were identified in Maranta bicolor and M. leuconeura var. kerchoveana and several flavone $\text{C-}\text{glycosides}$ sulphates in Stromanthe sanguinea. Anthocyanins were identified in those species with pigmented leaves or stems and a common pattern based on cyanidin-and delphinidin-3-rutinosides was observed throughout the group. Finally the possible relationship of the Zingiberales to the Commelinales, Liliales, Bromeliales and Fluviales is discussed.     

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.     

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.     

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.     

Flavonoids of Astilbe and Rodgersia compared to Aruncus

The flavonoid profiles of Astilbe (four taxa studied) and Rodgersia (two taxa studied) are based on simple flavonol glycosides. Astilbe has 3-O-mono-, 3-O-di-, and 3-O-triglycosides of kaempferol, quercetin, and myricetin, while Rodgersia has only mono- and diglycosides of kaempferol and quercetin. Astilbe×arendsii was also shown to accumulate dihydrochalcone glycosides. The flavonoid profile of Rodgersia is the simplest recorded so far in the herbaceous Saxifragaceae. The flavonoids of two species of Aruncus were shown to be based upon kaempferol and quercetin 3-O-mono- and 3-O-diglycosides. One of the species also exhibited an eriodictyol glycoside. The triglycoside differences were not considered important, but the differences in myricetin occurrences were taken as evidence against derivation of Saxifragaceae from an Aruncus-like ancestor. Should such an event be proposed, however, serious consideration would have to be given to the current pattern of myricetin occurrence in the two families.     

THE FLAVONOIDS OF ONAGRACEAE: TRIBE EPILOBIEAE

Data for the flavonoids of each of the species of Boisduvalia and each of the 14 species of Epilobium that constitute the 5 sections except for sect. Epilobium are presented. An analysis of nearly 100 populations showed that 7 flavonol 3-O-glycosides based on kaempferol, quercetin, or myricetin aglycones are present among the several species. All 7 compounds are present in each of the 2 genera but certain patterns of variation, especially in the loss of arabinosides, are noted among the several sections of the two genera. An intersectional comparison of the variation correlates flavonoid patterns more with the relative evolutionary advancement of specialization of the taxa than with their phyletic relationships. Further, a trend of decreased glycosylation with advancement within the tribe is documented. Both points are contrary to what is generally assumed for flavonoids in evolutionary studies.     

The affinities of Chenopodium flabellifolium (Chenopodiaceae): Evidence from seed coat surface and flavonoid chemistry

Evidence from scanning electron microscopy of seed coat surfaces and leaf flavonoid chemistry has provided new insights into the relationships of the problematical Chenopodium flabellifolium from San Martín Island, Baja California. The seed surface of C. flabellifolium is basically smooth and thus is essentially the same as members of the subsection Lejosperma of section Chenopodium. This feature distinguishes the species from the taxon that has commonly been considered its nearest relative, namely C. neomexicanum of subsection Cellulata, which has an alveolate seed surface. Leaf flavonoid chemistry also serves to separate C. flabellifolium and C. neomexicanum. Chenopodium flabellifolium has also been viewed as conspecific with C. inamoenum (= C. hians or C. leptophyllum) of subsection Lejosperma. While the seed surface indicates that C. flabellifolium is best treated as a member of this subsection, other morphological as well as chemical data suggest that its closets affinities within the subsection lie with C. fremontii. The leaves of the two species are essentially of the same shape and collectively differ strikingly from those of C. hians and C. leptophyllum. Leaf flavonoid chemistry indicates that C. flabellifolium is closer to C. fremontii than to other taxa of subsection Lejosperma occurring in the western United States because both contain kaempferol 3-O-glycosides, which have not been detected elsewhere. The two species differ consistently in that the former has the pericarp attached to the seed whereas it is separable from the seed in the latter.     

Systematic studies on mexican coreopsis (compositae). Coreopsis mutica: Flavonoid chemistry,chromosome numbers,morphology, and hybridization

Coreopsis mutica is a highly variable species occurring in the highlands from Central Mexico southeastward barely into El Salvador and Honduras. It is not continuous over this range, however, but is found in three geographic population centers: one in Guatemala and Chiapas, a second in Oaxaca, and the third in Central Mexico. Populations in Guatemala and Chiapas are uniform in chromosome number (2n = 56), leaf flavonoid chemistry, and morphology. Var.microcephala is proposed to accommodate these assemblages. Plants comprising populations centered around Cd. Oaxaca have a chromosome number of 2n = ca. 112. This large complex consists of two distinct varieties and their putative hybrids. Those plants to the northwest of Cd. Oaxaca (var.subvillosa) are constant in leaf flavonoid chemistry (producing only flavones) and possess a combination of distinctive morphological traits. To the southeast of Cd. Oaxaca plants invariably contain flavonols and anthochlors in their leaves in addition to flavones. Moreover, these plants (the newly proposed var.carnosijolia) are readily separable from var.subvillosa by a number of morphological features. Evidence is presented that the two taxa hybridize in the vicinity of Cd. Oaxaca. On the southeastern edge of the var.subvittosavar. carnosifolia complex a population was encountered which has a chromosome number of 2n = 56 and a very distinctive morphology and flavonoid chemistry. These plants have been accorded taxonomic status as var.multiligulata. Two morphologically similar, yet distinguishable, varieties occur in Central Mexico. It has been determined that the two differ also in chromosome number and leaf flavonoid chemistry. One taxon (var.leptomera) has a chromosome complement of 2n = 56 and produces only flavones in its leaves, whereas var.mutica has a chromosome number of 2n = ca. 112 and produces flavones, flavonols, and anthochlors.     

Terpenoids and flavonoids of Bridelia ferruginea

The terpenoid and flavonoid constituents of the hitherto unexamined medicinal plant Bridelia ferruginea are reported. Quercetin, quercetin 3-glucoside, rutin, myricetin 3-glucoside and myricetin 3-rhamnoside were identified.     

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.     

FLAVONOID EVOLUTION IN DENDROSERIS (COMPOSITAE,LACTUCEAE) FROM THE JUAN FERNANDEZ ISLANDS,CHILE

Leaf flavonoid chemistry was examined from the three subgenera and 11 species of the endemic genus Dendroseris (Compositae, Lactuceae) of the Juan Fernandez Islands, Chile. Eight of the species are restricted to the older island (Masatierra, ca. 4 million years old), which is also closer to the mainland. Three species, one from each subgenus, are restricted to Masafuera, which is younger geologically (1–2 million years old) and 145 km further west of Masatierra. A total of 16 compounds was identified, with the 7-0-glucosides of the flavones apigenin and luteolin accounting for 12 of the constituents. Two glucosides of the flavonol quercetin were detected. Despite considerable interpopulation variation within species, six of the taxa have distinctive flavonoid profiles. Although there are few absolute differences among the subgenera, they can be distinguished chemically. Subgenus Rea contains the greatest number of compounds, and a previous cladistic analysis based on morphological features suggested this subgenus as most primitive. Subgenus Phoenicoseris is considered highly derived morphologically, and it has a reduced flavonoid chemistry. Very little reduction in flavonoid diversity was seen in the morphologically specialized subg. Dendroseris as compared to subg. Rea. A trend in reduction of numbers of compounds was seen for two of the three species on the younger island of Masafuera when compared to their presumed ancestors on Masatierra. Flavonoids of selected species of Hieracium and Hypochaeris, presumptive mainland progenitors of Dendroseris, reveal a close chemical affinity with the former genus.     

FLAVONOIDS AND TAXONOMY OF THE LIMNANTHACEAE

To help clarify relationships within the Limnanthaceae, all 19 taxa were compared on the basis of flavonoids occurring in all tissues, and 14 of these taxa were additionally compared on the basis of flavonoids occurring only in the petals. Of the 46 flavonol glycosides encountered, 35 were identified as derivatives of six flavonol aglycone types: syringetin, isorhamnetin, kaempferol, laricytrin (myricetin 3'-methyl ether), quercetin and myricetin, all glycosylated with combinations of glucose and rhamnose. Varimax Factor Analysis with rotation of the flavonoid data indicated that the family probably contains 3 phyletic lines, an observation inconsistent with the conventional 2-generic interpretation of the family. Mason's sectional treatment of Limnanthes is supported by petal flavonoid results, but not by whole-plant flavonoid results, indicating that petal flavonoids more clearly reflect natural relationships in Limnanthes. Evolution of whole-plant flavonoids of Limnanthes appears to be partly linked to changes in breeding system.