Flavonoids of the Tiarella trifoliata complex

The flavonoids of the Tiarella trifoliata L. complex consists of kaempferol, quercetin and myricetin-3-O-mono-, di- and triglycosides, kaempferol and quercetin-7-O-monoglycosides, kaempferol-3,7-O-monoglycosides and luteolin. Infrapopulationa and interpopulational variations were seen in the distribution of several of these types of compounds. The flavonoid data do not support recognition of separate species for the three taxa.     

Flavonoids of some species of Chrysosplenium

The flavonoid chemistry of eight species of Chrysosplenium has been established. The species studied were C. americanum, C. echinus, C. flagelliferum, C. glechomaefolium, C. iowense, C. rosendahlii, C. wrightii and C. valdivicum. The major compounds present were O-methylated flavones having an extra hydroxyl group at positions 6 and/or 2′ except for C. valdivicum which has isorhamnetin as its major flavonoid and only a trace of a compound bearing an extra hydroxyl group. Distribution of the O-methylated compounds in the genus correlates well with Franchet's sectional view of the genus wherein he recognized alternate-leaved vs opposite-leaved groups. The flavonoids of C. valdivicum represent a link between the more advanced members of the genus and other genera of the Saxifragaceae.     

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.     

Flavonoids and affinities of the cephalotaceae

The Western Australian endemic, insectivorious, monotypic family Cephalotaceae has been allied to Nepenthaceae, Sarraceniaceae, Saxifragaceae, and Crassulaceae. Recent workers consider it to be closest to the last two families. An examination of the flavonoids of Cephalotus follicularis revealed that quercetin $\text{3-O-}\text{glucoside and}\text{3-O-}\text{rhamnoside}$ are the major compounds with smaller amounts of myricetin $\text{3-O-}\text{glucoside}$ and luteolin $\text{7-O-}\text{glucoside}$ also present in the monoglycoside fraction. Eriodictyol $\text{7-O-}\text{glucoside}$ is possibly also present. The diglycoside fraction comprises kaempferol, quercetin and myricetin $\text{3-O-}\text{rutinosides}$. The predominantly flavonol-based profile resembles the flavonoid profile of the Saxifragaceae more closely than it does that of the Crassulaceae and supports morphological features that suggest it is most closely allied to that family.     

Flavonoids of Penthorum sedoides

In an attempt to elucidate the familial affinities of Penthorum, the flavonoids and other phenolic compounds of P. sedoides were examined. The species is characterized by a relatively simple array of kaempferol and quercetin 3-O-mono-, di- and triglycosides. Flavonoid variation was detected between populations. Also present was a group of phenolic compounds that gave positive color reactions for the existence of gallic acid-like components. Although structures were not determined for these compounds, the presence of gallic acid-like moieties in two of the compounds was confirmed by ¹H NMR. The array of these compounds and flavonoids detected in P. sedoides does not readily support inclusion of Penthorum in the Saxifragaceae.     

Further studies of flavonoids in Saxifraga

The flavonoid composition of Saxifraga cernua, S. micranthidifolia, S. tolmiei, and S. tricuspidata has been determined. The major proportion of the profiles comprise a complex mixture of flavonol 3-O-glycosides, including mono-, di-, and triglycosides. Kaempferol, quercetin, isorhamnetin, and myricetin were observed although not all taxa had all aglycones. The monoglycoside fraction of S. tolmiei was unusual in that it consisted only of quercetin 3′-O-glucoside and myricetin 7-O-glucoside; both compounds are unusual for the family. Saxifraga tricuspidata exhibited an unusually complex array of monoglycosides which was comprised of glucosides, galactosides, xylosides, several isomeric arabinosides, and acylated derivatives of some of the arabinosides. The diversity of biosynthetic capacity observed for Saxifraga (present and earlier data) reflect the complexity described for the Saxifrageae.     

Flavonoids from Zea mays pollen

The flavonol glycosides of quercetin, isorhamnetin and kaempferol were isolated from Zea mays pollen. The most prominent flavonols were diglycosides of quercetin and isorhamnetin. Flavonol 3-O-glucosides of quercetin, isorhamnetin and kaempferol, and triglucosides of quercetin and isorhamnetin, were minor components. The flavonoid pattern of maize pollen is characterized by the accumulation of quercetin and isorhamnetin diglycosides and by the absence of flavones, which are common in other maize tissues.     

Flavonoid variation in some North Americna Saxifraga species

Eight species of Saxifraga representing sections Micranthes, Hirculus, Dactyloides and Xanthizoon were studied for their flavonoids (S. california, S. integrifolia, S. michauxii, S. ferruginea, S. eschscholtzii, S. hirculus, S. caespitosa and S. aizoides). The major compounds present in most species were kaempferol and quercetin monogluocosides and galactosides. Glucosides of kaempferol and quercetin predominate in the first four species listed, while galactosides of quercetin and myricetin are dominant in the lastthree. 3-O-Methyl- and 3,3′-di-O-methylquercetin were identified from S. californica and S. integrifolia. Saxifraga caespitosa synthesizes a complex mixture of O-methylated flavonols as well as a novel O-methylated dihydrokaempferol.Species pairs S. michauxii/S. ferruginea and S. californica/S.integrifolia exhibit close flavonoid similarity which may reflect their morphological similarities.     

Tylerianthus crossmanensis gen. et sp. nov. (aff. Hydrangeaceae) from the Upper Cretaceous of New Jersey

A fossil flower with affinities to the modern families of the saxifragalean complex is described. Fossils were collected at Old Crossman Pit, Raritan Formation, New Jersey, USA. These sediments are dated on the basis of palynology as Turonian (Upper Cretaceous, ~90 million years before present). Fossils are charcoalified and preserved with exceptional three- dimensional detail. The characters observed in these flowers, when compared with those of extant flowers of several families of the saxifragalean complex, suggest a close relationship with extant members of the Saxifragaceae and Hydrangeaceae. Hypotheses on the origin of petals and staminodes and a possible mechanism of pollination are discussed. This new taxon provides additional characters in the floral morphology of the fossil saxifragoids and extends their geographical distribution in the Cretaceous to North America.     

Flavonoids of Chrysosplenium tetrandrum

Chrysosplenium tetrandrum, from northern British Columbia, accumulates a variety of flavonoid glycosides. Several kaempferol and quercetin mono- and diglycosides were identified. The major flavonoid fraction consisted of O-methylated compounds having an hydroxyl or methoxyl substituent at position-6. Aglycones identified were 5,4′-dihydroxy-3,6,7-trimethoxyflavone, 5,6,7,3′,4′-pentahydroxy-3-methoxyflavone, 5,6,3′,4′-tetrahydroxy-3,7-dimethoxyflavone, 5,6,4′-trihydroxy-3,7,3′-trimethoxyflavone, 5,3′,4′-trihydroxy-3,6,7-trimethoxyflavone, and 5,4′-dihydroxy-3,6,7,3′-tetramethoxyflavone. All occurred as glucosides. The occurrence of 6-substitution and the preponderance of O-methylated flavonoids supports removal of Chrysosplenium from Engler's Saxifraginae.     

Flavonoids of Sullivantia: Taxonomic implications at the generic level within the saxifraginae

Sullivantia species were found to produce quercetin 3-O-glycosides, several of which contain glucuronic acid, as well as pedalitin (6-hydroxy-7-O-methyl luteolin), pedalitin 6-O-glycosides, and small amounts of luteolin. Sullivantia has a unique combination of compounds that distinguishes it from other genera in the Saxifraginae for which flavonoid data are available. The nature of the flavonoid compounds is in accordance with a general trend within the Saxifragaceae of reduction and replacement of flavonols by flavones.     

Flavonoids and the systematics of Luffa

Flavonoids were characterized from leaves and flowers of six species of Luffa. Each species had a distinct flavonoid pattern. Based on leaf flavonoids, Luffa is separable into two groups of species: L. graveolens and L. operculata contain only flavonols. L. acutangula, L. aergyptiaca, L. echinata and L. forskalii contain only flavones. Flavonoid data indicate that the New World disjunct species. L. operculata, is most closely related to L. graveolens.     

Flavonoids in leaves and inflorescences of australian cyperaceae

A survey of 170 Australian species of Cyperaceae belonging to 35 genera has confirmed that this family has a highly characteristic flavonoid pattern in leaf and inflorescence. Aurone pigments, the most distinctive family constituents, were found in the leaves of 25% of the sample and in the inflorescences of 40%. Sulphuretin was found for the first time in the family, in Carex appressa. Flavones, such as tricin and luteolin, are very common; in addition, a variety of methyl ethers were detected. Luteolin 5-methyl ether was found in further genera, while luteolin 7-methyl ether, diosmetin and acacetin were detected for the first time in the Cyperaceae. Flavonols and their methyl ethers occurred in over one-third of the species, particularly in the leaves, being especially well represented in the genera Fuirena, Gahnia, Lepidosperma and Mesomelaena. Myricetin was found only twice, in two Baumea species. The 3-desoxyanthocyanidin carexidin was found in the inflorescences of eight species, i.e. in 5% of the sample. Taxonomically, the results are mainly of interest at the generic and specific level, where the patterns sometimes show useful correlations with morphology. At the tribal level, the Sclerieae are the most distinctive, with higher than average frequency of flavone C-glycosides, flavonols, proanthocyanidins and aurones, and lower than average frequency of flavones.     

Flavonoids and the chemotaxonomy of three Sophora species

Sophora microphylla, S. prostrata and S. tetraptera are distinguishable from one another by their leaf flavonoids. S. microphylla is distinguished by the present of rhamnosylvitexin and rhamnosylisovitexin and S. tetraptera by the presence of apigenin-7-O-rhamnosylglucoside-4′-O-glucoside and the 7-O-glucosides of apigenin, 7,4′-dihydroxyflavone, luteolin and 7,3′,4′-trihydroxyflavone. Sophora prostrata lacks all these flavonoids, but has several pigments which are common to all three species.     

Flavonoid glycosides of Lotus corniculatus (leguminosae)

Two-dimensional TLC of stems and leaves of Lotus corniculatus revealed the presence of ca 25 flavonoid glycosides. Among these, 14 were identified; 10 are new for this species. This pattern is qualitatively the same among different populations of this plant but the relative amounts of mono- and diglycosides varies considerably from one population to another.     

Flavonoid patterns in Leptodactylon and Linanthus

Twenty-seven flavonoids were found among three species of Leptodactylon and sixteen species of Linanthus, of which only three were identical between the two genera. This argues strongly for the maintenance of two genera; however, the underlying similarities in coumarins, flavonol glycosides, chrysoeriol and glycoflavones suggest that the two genera are closely related. The flavonoid data also suggest that Leptodactylon and Linanthus of the tribe Gilieae may actually be closer to Phlox and Microsteris of the tribe Polemonieae, than to other Gilieae.     

Flavonoids of three local Senecio species

Two isorhamnetin glycosides and two sulphated derivatives are reported for the first time in the genus Senecio.     

Flavonoids of Abies amabilis needles

Seventeen flavonol glycosides were identified from needles of Abies amabilis and these were based on 6 aglycone types: syringetin, isorhamnetin, kaempferol, quercetin, laricytrin and myricetin. Glycosides were 3-O-rutinosides, 3-O-glucosides, 3-O-galactosides or 3-O-rhamnosides. Also identified as needle constituents were rhamnosylvitexin and dihydroquercetin.