Isorhamnetin 3,7-disulphate from Flaveria bidentis

3-Glucosides and 3,5-diglucosides of pelargonidin, cyanidin, peonidin, delphinidin, petunidin and malvidin have been identified as flower pigments in Fuchsia species. These pigments in varying admixture appear to be solely responsible for different flower colours in this genus. Their production and inheritance seems to be under a complex system of genetic control.     

Flavonoids of the flowers of tamarix nilotica

The ethyl ester of kaempferol 3-O-β-D-glucuronide, the methyl and ethyl esters of quercetin 3-O-β-D-glucuronide have been isolated from an aqueous acetone extract of the flowers of Tamarix nilotica. In addition kaempferol 3-O-sulphate-7,4′-dimethyl ether and the free aglycones were isolated. The structures were established by routine methods, by FAB-MS and by ¹³C NMR spectral measurements.     

Pattern,phenology and sex ratio of Egyptian Thymelaea hirsuta populations

The distributional pattern, phenology and sex structure of the desert shrub Thymelaea hirsuta (L.) Endl. were evaluated in six major habitat types in the Mediterranean desert of Egypt.The distributional pattern changes from contagious in the less arid-to random in the more arid habitats.Soil salinity, low content of soil moisture, and extremes of temperature are of importance for the phenological activity.The plant is mainly dioecious. Males are more abundant in two of the habitats and are characterized by larger sizes compared with the females in all but one habitat.     

Sexual polymorphism and spatial segregation of Thymelaea hirsuta in Liguria (north-west Italy)

Abstract

Flowering phenology, sexual polymorphism and spatial segregation were studied over two consecutive years in a population of Thymelaea hirsuta (L.) Endl. (Thymelaeaceae) growing on coastal cliffs in north-western Italy. The study population was geographically segregated and, together with Croatian sites, it constituted the northernmost margin of the species' distribution range. Very frequent observations highlighted a sexual tendency towards dioecy already shown by T. hirsuta in other parts of the Mediterranean coast. The flowering period lasted 10?–?11 months, more or less. A high proportion of female flowers and a low number of hermaphrodite flowers were recorded, in contrast with the abundance borne by the species elsewhere; gender segregation into two different subgroups was noted, one consisting mainly of male and protogynous plants, the second consisting basically of female and protandrous specimens.     

Flavonol glycosides from Asplenium bulbiferum

From aerial parts of the fern Asplenium bulbiferum, besides kaempferol 3,7-diglucoside and kaempferol 3-O-rhamnoside- 7-O-glucoside, the new glycoside kaempferol 3-O-β-glucoside-7-O-β-galactoside has been characterized.     

Sexual polymorphism,growth, and reproductive effort in Egyptian Thymelaea hirsuta (Thymelaeaceae)

Gender phenotypes of Thymelaea hirsuta (L.) Endl. were surveyed in six major habitats in the western Mediterranean region of Egypt. Five gender phenotypes were observed at all sites: subandroecious (male), subgynoecious (female), protogynous, protandrous, and gender-labile individuals. Patterns of vegetative growth, reproductive effort, and sex-size relationships were also determined. Females and males were comparable in overall abundance (35.5% and 30.2%, respectively). However, the frequency of sex forms varied significantly among habitats. Plant size (canopy volume) was used as a measure of environmental quality for the species: the coastal dunes were by far the most favorable habitat, followed by the nonsaline depressions, inland plateau, and inland siliceous deposits. The smallest plants were associated with the inland ridges and saline depressions. Protandrous individuals, and female shrubs at the more favorable habitats (e.g., the coastal dunes and nonsaline depressions), had greater canopy volume than males. In contrast, males were larger than females at the less favorable habitats (e.g., the inland plateau and saline depressions). Advantageous growth conditions at the coastal dunes are demonstrated by the greater rate of increase in crown diameter and crown volume noted there, for each size class and sex form. The greatest rates of increase were present in smaller-sized individuals. Size differences between the sex forms were considered in terms of trade-offs between individual growth rate (GR) and reproductive effort (RE); evidence of a trade-off was mixed. Indeed, in a comparison of GR and RE at two extremes of habitat (coastal dune vs. inland plateau), females had greater GR and greater RE at the relatively benign coastal dunes, while at the more harsh, inland plateau site males showed greater GR and RE than females. Peak reproductive effort varied significantly with gender phenotype and habitat type.     

Heterocarpy in Thymelaea velutina (Poiret ex Camb.) Endl.: a case of phenotypic adaptation to Mediterranean selective pressures

Heterocarpy is described for Thymelaea velutina (Thymelaeaceae), an evergreen dioecious shrub endemic to the Balearic Islands (Spain). It consists of dry and fleshy fruits (the latter, less numerous, have not been reported previously). The phenomenon could possibly have originated by different ripening processes in the pericarp, the main factor responsible for the difference between the types of fruit. We believe it shows an incomplete transition from fleshy to dry fruits, since the latter would have a high adaptative value in a xeric environment- The close relationship between the genera Daphne and Thymelaea is verified and a theory is put forward to explain differentiation under selective environmental pressures.     

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 from Flindersia australis

Dihydrokaempferol, dihydrokaempferol 3-O-rhamnoside (engeletin) and kaempferol were isolated from the stem bark of Flindersia australis. This is the first report of the occurrence of these flavonoids in Flindersia.     

Origin and diversification of Thymelaea (Thymelaeaceae): inferences from a phylogenetic study based on ITS (rDNA) sequences

Thymelaea is a Mediterranean genus belonging to a primarily tropical and subtropical family. This genus is here presented as a particular case on which the hypothesis of an in situ evolution of the Mediterranean flora from a Tertiary subtropical stock can be phylogenetically tested. To better understand the evolutionary history of Thymelaea, molecular phylogenies based on ITS (rDNA) sequences are estimated. Phylogenetic analyses strongly support the monophyly of Thymelaea and the sister position of Daphne. Unexpected relationships between sequences of T. granatensis, T. pubescens and T. sanamunda are found and explained as a case of cryptic nuclear introgression. Phylogenetic analyses also reveal the polyphyletic character of Diarthron, sensu Tan, suggesting that Dendrostellera and Stelleropsis should be reinstated as independent genera. Based on the resulting phylogenetic hypothesis and using statistical tests it is suggested that Thymelaea experienced an initial rapid diversification. Time estimates for the origin and radiation of Thymelaea based on independent sources of evidence—paleontological, paleoclimatic and paleogeographic data, on one hand, and ITS substitution rates reported for other angiosperm groups, on the other—give strikingly similar results. The early radiation of Thymelaea is inferred to have occurred in the Upper Miocene, after this lineage diverged from that of Daphne in the Lower or Middle Miocene. Both evolutionary events are related to the overall climatic deterioration (declining temperature and increasing dryness) registered throughout the Miocene in Eurasia. The rapid and extensive diversification of Thymelaea is placed in the Iberian Peninsula or here and in the neighbouring North African territory.     

Species-specific kaempferol derivatives in ferns of the appalachian Asplenium complex

A series of kaempferol derivatives have been identified in fronds of three parental species of the Appalachian Asplenium complex. Asplenium platyneuron is characterised by the presence of the 7-glucoside of kaempferol 3,4′-dimethyl ether and also contains kaempferol 3,7-diglucoside, free and with an aliphatic acyl attachment. By contrast, A. rhizophyllum contains a remarkable caffeoyl complex of kaempferol glycosides, which appears to be chromatographically homogenous. However, on deacylation, the complex yields caffeic acid and the 7-glucoside, 3,7-diglucoside, 3-sophoroside-7-glucoside and 7,4′-diglucoside of kaempferol. Asplenium montanum, in addition to having previously characterised glycosylxanthones, has two further kaempferol derivatives. It has been confirmed that these various species specific flavonoids are inherited in an additive fashion in three interspecific hybrids.     

Reproductive ecology of Thymelaea velutina (Thymelaeaceae)- Factors contributing to the maintenance of heterocarpy

Thymelaea velutina (Thymelaeaceae) is a dioecious shrub that presents a unique type of heterocarpy which consists of the simultaneous production of dry and fleshy fruits. It is endemic to the Balearic Islands (Western Mediterranean) and is found both in dunes and mountain areas. The goal of this study was to identify which factors influence the production of both fruit types, examining the variation of their effects at a spatio-temporal scale (comparing two localities in different years). Specifically, we investigated (1) whether pollen limitation influences the type of fruit produced, and (2) the possible differences in seed size, mass, dispersal capacity, seed predation, germination patterns and seedling survival between fruit types. We also examined if the production of fleshy fruits was modified with the application of gibberellins to reproductive branches. Although fleshy fruits were consistently more abundant than dry ones at both populations, their proportion was significantly higher at the site with greater precipitation. The addition of either pollen or gibberellins did not affect the proportion of each fruit type. Seeds in fleshy fruits are consistently larger, heavier and more likely to be dispersed than seeds in dry fruits, but germinability, germination rate and seedling survival was similar among fruit types. Heterocarpy in this species is currently maintained as there is no apparent factor that exerts any strong selective pressure on either fruit type. The two fruit types might even have different `functions', one serving especially for dispersal and population expansion and the other for producing a seed bank that ensures an eventual germination.     

3个三角梅品种中类黄酮的毛细管电泳分析比较研究

甜菜色素和属于类黄酮的花青素在自然界排斥分布,然而我们在甜菜色素代谢类型植物三角梅中发现积累多种类黄酮。为了进一步证实这一现象,本研究对3种白花三角梅（Bougainvillea sp.,Bougainvillea glabra‘Alba’,and Bougainvillea‘White Stripe’）中的5种类黄酮（槲皮素、山奈酚、异鼠李素、杨梅素和芹菜素）采用毛细管电泳分析方法进行了调查。结果表明,只有3种类黄酮：槲皮素、山奈酚、异鼠李素被检测出。3个材料中,被探测出来的总黄酮含量最高的是Bougainvillea glabra‘Alba’,1 749 μg·g^-1,Bougainvillea‘White Stripe’ 1 241 μg·g^-1以及B.sp1 312 μg·g^-1。被探测出来的3种黄酮中,槲皮素含量最高852～1 114 μg·g^-1,异鼠李素161～628 μg·g^-1,而山奈酚之被检测出微量。本研究对于定性定量可食用的三角梅中的类黄酮组成是十分有意义的。甜菜色素和类黄酮在三角梅中的积累关系以及可能的功能本研究也做了讨论。     

Flavonoids of Heterogaura (Onagraceae)

Heterogaura is a monotypic genus of the tribe Onagreae of the Onagraceae. It is endemic to south western Oregon and California. Four flavonol glycosides, kaempferol 3-O-rhamnoside, quercetin 3-O-glucoside, quercetin 3-O-rhamnoglucoside and myricetin 3-O-glucoside, were found to occur in methanolic leaf extracts of each of the populations sampled. The presence of only flavonols is consistent with flavonoid analyses from other genera of the Onagreae, including Clarkia, the closest relative of Heterogaura.     

柽柳科（Tamaricaceae）植物的研究历史

柽柳科（Tamaricaceae)是一个古老的科,起源于第三纪,包括亚洲中部的内的“古地中海”沿岸地区,该科植物主要为旱生植物,其中大多数种是防风、固沙造林和水土保持的优良树种,对改造沙漠和改善气候条件具有重要的生态意义。同时,该科植物在荒漠地区还具有广泛的经济用途。