The occurrence of aurentiacin and flavokawin B on Pityrogramma triangularis var. pallida and Didymocarpus species

The two chalcones, aurentiacin and flavokawin B, were isolated from the frond exudate of Pityrogramma triangularis var. pallida. In addition, flavokawin B was obtained from the leaf exudate of Didymocarpus corchorifolia.     

Competition between introduced and native spiders (Araneae: Linyphiidae)

The European sheet-web spider Linyphia triangularis (Araneae: Linyphiidae) has become established in Maine, where it often reaches very high densities. Two lines of evidence from previous work suggest that L. triangularis affects populations of the native linyphiid spider Frontinella communis. First, F. communis individuals are relatively scarce in both forest and coastal habitat where L. triangularis is common, but more common where L. triangularis is at low density. Second, in field experiments, F. communis species are less likely to settle in experimental plots when L. triangularis is present, and F. communis disappears from study plots when L. triangularis is introduced. Here we test two mechanisms that may underlie these patterns. First, we tested whether L. triangularis invades and usurps the webs of F. communis. When spiders were released onto webs of heterospecifics, L. triangularis was more likely to take over or share webs of F. communis than the reverse. We also observed natural takeovers of F. communis webs. Second, we explored the hypothesis that L. triangularis reduces prey availability for native species. We sampled flying prey in areas with L. triangularis and those where it had been removed, and found no effect of spider presence on measured prey density. We also found no effect of prey supplementation on web tenacity in F. communis, suggesting that F. communis movements are not highly dependent on prey availability. We conclude that web takeover is likely more important than prey reduction in driving negative effects of L. triangularis on F. communis.     

Flavonoid and ceroptin pigments from frond exudates of Pityrogramma triangularis

Two chemically distinct golden-yellow flavonoid exudates occur on the underside of fronds of Pityrogramma triangularis: ceroptin and a newly described flavonol, 6-methyl-8-methoxy-3,5,7-trihydroxyflavone were detected in one of the exudates and two methylated kaempferol derivatives, 4′-methoxy-3,5,7-trihydroxyflavone and 3,5-dihydroxy-7,4′-dimethoxyflavone were isolated from the other.     

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.     

Leaf flavonoid and other phenolic glycosides as indicators of parentage in six ornamental Fuchsia species and their hybrids

In a leaf flavonoid analysis of six Fuchsia species and seven Fuchsia hybrids, flavonols were found to be abundant in all taxa except F. procumbens. Flavone glycosides were found in only three species: luteolin 7-glucoside in F. splendens; and luteolin and apigenin 7-glucuronides and 7-glucuronidesulphates, tricin 7-glucuronidesulphate and diosmetin 7-glucuronide from one or both of the New Zealand species F. procumbens and F. excorticata. Luteolin 7- glucuronidesulphate is reported for the first time. Other less common phenolics identified include the flavanone, eriodictyol 7-glucoside from F. excorticata, a galloylglucose from F. triphylla, and a galloylglucosesulphate present in all taxa. Eight of the flavonoid glycosides proved useful as marker substances for particular Fuchsia species: quercetin 3- rhamnoside, 3-glucuronide and 3-rutinoside for F.fulgens; quercetin and kaempferol 3-galactosides for F. boliviana var. luxurians; diosmetin 7-glucuronide for F. excorticata and apigenin 7-glucuronide and 7-glucuronidesulphate for F. procumbens. The chemical results on the hybrids support the view that the cultivar ‘Mary’ is a hybrid of F. boliviana var. luxurians and F. triphylla and that both F.fulgens and F. triphylla are involved as parents of the cultivars ‘Koralle’ and ‘Traudchen Bondstedt’.     

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.     

Leaf flavonoid glycosides as chemosystematic characters in Ocimum

Thirty-one accessions of nine species belonging to three subgenera of Ocimum (basil, family Lamiaceae) were surveyed for flavonoid glycosides. Substantial infraspecific differences in flavonoid profiles of the leaves were found only in O. americanum, where var. pilosum accumulated the flavone C-glycoside, vicenin-2, which only occurred in trace amounts in var. americanum and was not detected in cv. Sacred. The major flavonoids in var. americanum and cv. Sacred, and also in all other species investigated for subgenus Ocimum, were flavonol 3-O-glucosides and 3-O-rutinosides. Many species in subgenus Ocimum also produced the more unusual compound, quercetin 3-O-(6″-O-malonyl)glucoside, and small amounts of flavone O-glycosides. The level of flavonol glycosides produced was reduced significantly in glasshouse-grown plants, but levels of flavone glycosides were unaffected. A single species investigated from subgenus Nautochilus, O. lamiifolium, had a different flavonoid glycoside profile, although the major compound was also a flavonol O-glycoside. This was identified as quercetin 3-O-xylosyl(1‴→2″)galactoside, using NMR spectroscopy. The species investigated from subgenus Gymnocimum, O. tenuiflorum (=O. sanctum), was characterised by the accumulation of flavone O-glycosides. These were isolated, and identified as the 7-O-glucuronides of luteolin and apigenin. Luteolin 5-O-glucoside was found in all nine species of Ocimum studied, and is considered to be a key character for the genus.     

Isolation and functional characterization of a novel gene coding for flavonoid 3′-hydroxylase from globe artichoke

Globe artichoke (Cynara cardunculus L. var. scolymus) is rich in flavonoids which contribute to its health-promoting properties. With the aim of understanding the genetic control of flavonoid accumulation in artichoke, we isolated an artichoke full-length cDNA sequence encoding flavonoid 3′-hydroxylase (F3′H), a major enzyme of the flavonoid hydroxylation pattern. In silico studies confirmed that the deduced amino acid sequence of CcF3′H is highly similar to F3′Hs isolated from other Asteraceae. The Northern blot analysis demonstrated that CcF3′H was highly expressed in leaves and in specific parts of the heads. Its expression differed slightly among artichoke cultivars. The overexpression of CcF3′H in tobacco plants led to the accumulation of flavonoids and to an increase of flower colour intensity, thus identifying CcF3′H as promising candidate for genetic engineering. CcF3′H represents the first structural gene of the flavonoid biosynthesis isolated from C. cardunculus, and its characterization sheds light on the accumulation of flavonoids.     

Competitive interactions between a native spider (<Emphasis Type="Italic">Frontinella communis</Emphasis>, Araneae: Linyphiidae) and an invasive spider (<Emphasis Type="Italic">Linyphia triangularis</Emphasis>, Araneae: Linyphiidae)

There are numerous reports of spiders that have become established outside of their native ranges, but few studies examine their impact on native spiders. We examined the effect of the European hammock spider Linyphia triangularis (Araneae, Linyphiidae) on the native bowl-and-doily spider Frontinella communis (Araneae, Linyphiidae) in Acadia National Park, Maine, USA. First, we added L. triangularis to established plots of F. communis. Significantly more F. communis abandoned their webs when L. triangularis were added compared to control plots. Second, we tested whether F. communis were deterred from building webs in areas where L. triangularis was established. Significantly fewer F. communis built webs on plots with L. triangularis than on control plots. In both experiments, L. triangularis sometimes took over webs of F. communis or incorporated F. communis webs into their own webs, but F. communis never took over or incorporated L. triangularis webs. Competition between L. triangularis and F. communis for both webs and web sites may contribute to the decline of F. communis.     

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.     

Miospores in middle-upper Frasnian to Famennian sediments partly dated by conodonts (Boulonnais,France)

The middle-upper part of the Formation de Beaulieu exposed in the new railroad trench at Caffiers-Ferques and the Formation de Ferques exposed in the Tartinskal quarries contain well-preserved miospore assemblages. They are here restudied in comparison with new conodont data ranging from the middle asymmeyricus to the Ancyrognathus triangularis Zone. The conodonts allow precise correlations with the type Frasnian area as well as with the Russian Platform and Timan-Pechora provinces. The miospore assemblages of the Formation d'Hydrequent are also considered and their age discussed in term of the Frasnian/Famennian boundary.In the systematic part, two new combinations are proposed: Ancyrospora lysii (Taugourdeau-Lantz, 1960) nov. comb., and Pustulatisporites rugulatus (Taugourdeau-Lantz, 1967) nov. comb.     

Interesting taxa ofStaurastrum Meyen (Desmidiaceae) from Karnataka State (India)

Algae were collected from a paddy field at Belgaum during August 1985. Two new taxa ofStaurastrum Meyen (viz.S. quebecense Irénée-Marie fa.minor Bongale fa.nov. andS. sebaldii Renisch var.triangularis Bongale var. nov.) and two other taxa showing major variations (viz.S. gracile Ralfs. var.elongatulum West et West fa. andS. leutkemuelleri Donat et Ruttner ms. fa.) are reported.     

Flavonoid aglycones from Xanthocephalum gymnospermoides var. gymnospermoides

Six known flavonoid aglycones and the newly described 5,7,4′-trihydroxy-3,3′,5′-trimethoxyflavone were isolated from Xanthocephalum gymnospermnoides var. gymnospermnoides.     

Systematics of Juniperus from eastern Asia based on Random Amplified Polymorphic DNAs (RAPDs)

DNA was examined by RAPD banding for Junipers chinensis, J.c. var. sargentii, J.c. var. tsukusiensis, J. communis, J.c. var. nipponica, J.c. var. saxatilis, J. conferta, J. formosana, J. procumbens, J. rigida, J. taxifolia and J.t. var. lutchuensis. The DNA data readily separated junipers of section Sabina from section Juniperus. J.c. var. tsukusiensis from Taiwan was found to be sufficiently different from J.c. var. tsukusiensis (Yakushima) to warrant the recognition of a new variety: J. chinensis var. taiwanensis R.P. Adams and C-F. Hsieh nov. var. Juniperus formosana from mainland China was found to be different from J. formosana from Taiwan and a new variety is recognized: J. formosana var. mairei (Lemee and Lev.) R.P. Adams and C-F. Hsieh comb. nov. Juniperus communis var. nipponica was found to be very distinct from J. communis and this supports its recognition as a variety. The recognition of J. conferta as a variety of J. rigida [J. rigida var. conferta (Parl.) Patschke] is supported by the data. The data also supports the recognition of J. lutchuensis Koidz. [=J. taxifolia var. lutchuensis (Koldz.) Satake] and J. morrisonicola Hayata [=J. squamata var. morrisonicola (Hayata) H.L. Li and H. Keng] at the specific levels.     

On the occurrence of acylated flavonoid aglycones

The known acylated flavonoid aglycones are reviewed. Their substitution patterns and their distribution in plants are discussed briefly. A new pair of flavonol esters is reported in Notholaena candida var. candida, the acetate and butyrate of isognaphalin.     

Flavonoid aglycones in the resin of Hazardia squarrosa var. Grindelioides

Thirty three flavonoid aglycones have been identified from the external stem and leaf resin of Hazardia squarrosa var. grindelioides by TLC co-chromatography with authentic samples. The occurrence of compounds with oxygenation at C-6 and C-5′, which are also found in the genus Haplopappus, supports the previously believed close relationship between these two genera.     

Effects of irradiance and salinity on the growth of carpospore-derived tetrasporophytes of Gracilaria edulis and Gracilaria tenuistipitata var liui (Rhodophyta)

Gracilaria edulis and Gracilaria tenuistipitata var liui are agarophytes with high commercial value which are currently cultivated in countries like India and Thailand. They have great potential for mariculture in Malaysia. Experiments were carried out to study carpospore germination and determine the effects of irradiance and salinity on the growth of these two species. Both species showed the Dumontia type of carpospore development. Both species showed increased daily growth rate (% day^?1) with increasing irradiance and tolerance for a wide range of salinity with a preference for low salinity. G. edulis grew best at 100 μmol photons m^?2 s^?1 and 15 psu while G. tenuistipitata var liui grew best at 60–130 μmol photons m^?2 s^?1 and 15 psu. The highest growth rate obtained for G. edulis and G. tenuistipitata var liui was 13.57 and 19.7 % day^?1 respectively. tenuistipitata var liui. ANOVA showed that both irradiance and salinity have significant effect on the growth of both species (P?<?0.05). The results showed that G. tenuistipitata var liui is a good candidate for mass cultivation in Malaysian brackish waters. Besides, this study also showed the feasibility of using spore culture to provide stocks for sustainable farming of Gracilaria.     

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.