Search

High-performance liquid chromatography coupled to a diode-array detector (HPLC-DAD) is used to investigate 30 samples which were removed from 27 ancient Egyptian fabrics of the Fill-Trevisiol collection. Attention is focused in this paper on fabrics of the Roman and Byzantine periods, with red and deep violet–blue wool weft threads which are Z-spun. The following dyes are identified in fabrics which date to the Roman period (first–fifth c. ad): mollusc purple, madder, and indigo/woad (Indigofera species and other, Isatis tinctoria L.). The results for the Byzantine (fifth–seventh c. ad) fabrics are richer in terms of identified dyes: apart from the three aforementioned dyes, the use of kermes (Kermes vermilio Planchon) and cochineal is revealed as the two coccid dyes have been detected in six Egyptian–Byzantine fabrics. Moreover, a yellow dye (probably Reseda luteola L.) is identified in one sample. Finally, samples taken from two fabrics, which date to the Islamic period, were dyed using indigo/woad and lac (Kerria lacca, Kerr). Mixing madder and indigo/woad to imitate true purple was a common practice in ancient Egypt and this is confirmed by the HPLC results in several samples. Semi-quantitative results are obtained from the HPLC peak areas and lead to the following conclusions. Madder dyes which were rich or poor in alizarin, compared to purpurin, and could have been therefore obtained from Rubia tinctorum L. and Rubia peregrina L., respectively are detected in Byzantine fabrics. Only alizarin-rich madder dyes are identified in some samples from Roman fabrics, but in some other samples the relative alizarin-to-purpurin ratio cannot be measured with confidence. Cochineal is found in two samples. The biological source of cochineal (Porphyrophora hamelii Brandt) is possible to be chemically identified only in one sample. The HPLC results of the molluscan dye detected in a Roman fabric are compared with the relative compositions of extracts of the three Mediterranean molluscs leading to the speculation that the Roman purple sample was probably dyed using Hexaplex trunculus L. The molluscan dye was furthermore detected in a Byzantine sample where it was combined with madder. Finally, it is reported that the standard (hydrochloric) acid hydrolysis method which is commonly applied to extract dyes from archaeological samples does not have any noticeable effect on the relative composition of the molluscan dye.

Samples removed from funeral figurines, dated the third to the second century BC (Hellenistic period) and found in Macedonia, Greece, are investigated using high-performance liquid chromatography. Two results are reported that provide new insights into ancient polychromy. Firstly, high-performance liquid chromatography results, in combination with historical information, indicate that insect species of cochineal, most probably Porphyrophora hamelii Brandt, was used in Hellenistic objects. Secondly, madder detected in the archaeological samples contains high amounts of purpurin (alizarin is either not detected or detected in trace). This relative composition, which is recorded using the hydrochloric acid method for dyestuff extraction, is consistent with that prepared from wild madder (Rubia peregrina L.), which is a common plant in the Mediterranean region.

Pre-dispersal seed removal of fleshy fruits and Quercus coccifera (Fagaceae) acorns in a recently burned Mediterranean habitat. The seed fate in early successional habitats can determine plant composition and regeneration capacity after disturbance. Pre-dispersal seed removal has been poorly studied in Mediterranean habitats, especially in burned and logged habitats. We assessed it for two years in pine forests with experiments excluding vertebrates from fleshy fruits (infructescences of Smilax aspera and Rubia peregrina) and acorns (branches of Quercus coccifera). We compared one unburned and one burned area (control). Acorn removal was nil in the burned area while in the unburned habitat seed removal occurred from the beginning of the experiments. It is suggested that the greater vegetation cover in the unburned area shelter rodents from predators and increased their activity. In contrast, reduced cover in the burned area and the occurrence of gnawed acorns on the ground suggest acorn removal by rodents mainly in the post-dispersive stage. Smilax aspera seed removal was slower, and total loss of fruits due to senescence higher, in the burned area. Seed removal appears to be conditioned by interannual variations related to the activity and density of granivores and frugivores, the availability of fleshy fruits, and the maturation of fruits. In post-fire managed areas the role of granivores and frugivores in the regeneration process should be taken into account. La depredación pre-dispersiva de semillas se refiere al ‘ataque’ o la muerte que puede experimentar una semilla en la planta madre o en el suelo junto a ella, antes de ser dispersada. Se evaluó la remoción pre-dispersiva de semillas por parte de vertebrados en tres especies de plantas, dos con frutos carnosos (Smilax aspera y Rubia peregrina) y otra de frutos no carnosos (Quercus coccifera). El estudio se realizó durante dos años en bosques mediterráneos de Cataluña al noreste de la Península Ibérica. Se comparó pinar quemado y sometido a gestión forestal “vs” pinar no quemado (control), mediante la evaluación de ramas con frutos cubiertos con malla metálica (experimentos de exclusión) para impedir el acceso de depredadores y ramas sin protección. La remoción de semillas de Q. cocciferapor parte de vertebrados fue nula en el área quemada durante los dos años del muestreo mientras que en el área no quemada la remoción ocurrió desde el inicio de los experimentos. Se sugiere que la mayor cobertura vegetal en el área no quemada favorece una mayor actividad de roedores gracias a la protección que ésta proporciona ante eventuales depredadores. Por otro lado, en el área quemada, la escasa cobertura vegetal y la presencia de bellotas roídas en el suelo son indicadores de remoción de bellotas por roedores en la etapa post-dispersiva. En el caso de Smilax aspera, la remoción de semillas fue más lenta, y la pérdida total de frutos por senescencia mayor, en el área quemada que en la no quemada. La incidencia de los animales sobre especies de frutos carnosos parece estar condicionada por variaciones interanuales relacionadas con la actividad y presencia de granívoros y frugívoros, la disponibilidad de frutos carnosos y la maduración de las diásporas. En hábitats quemados posteriormente gestionados se recomienda considerar la función de la fauna granívora y frugívora en el proceso de regeneración de estos ambientes doblemente perturbados.

This study aims at testing whether whole plant and aerial metamer traits of Rubia peregrina L., a small clonal shrub, differed in magnitude of response to variations in light, nutrient or water availability, comparing plants at the same age. The second aim was to test whether it was possible to identify a limited set of traits to assess phenotypic plasticity. Almost all traits significantly differed among treatments. These differences were partly due to changes in plant size for two whole plant and one metamer traits. No difference in grand plasticity, calculated with adjusted means correcting for size effect, was found between whole plant and aerial metamer traits. Some traits responded only to one resource (e.g. mean internode length to light) or two resources (e.g. SLA to light and nutrient). Root Mass Ratio was the most responsive of traits showing similar magnitude of plasticity to each of the three resources. These results suggest that (i) no clear difference in plasticity exists between whole plant and aerial metamer traits; (ii) allocation-related traits are of more general value than aerial metamer traits to assess the plasticity of a species.

An Agrobacterium rhizogenes-mediated transformation system for Rubia peregrina L. has been established by co-cultivation of callus cultures or by direct infection of explants with A. rhizogenes LBA 9402 harbouring the binary vector pMON 9703 containing gus and npt-II genes as markers. The putative transformed roots were selected on medium containing kanamycin (25 mg l-1). Antibiotic resistant root clones were subjected to histochemical analysis for the localisation of β-glucuronidase activity. Polymerase chain reaction was used to confirm the presence of gus, npt-II and T L border sequences in the transformed root clones. Spontaneous regeneration of shoots was observed from 30 day-old transgenic roots. Total anthraquinone and alizarin contents of transgenic root cultures were measured by spectrophotometry and by high performance liquid chromatography. The accumulation of total anthraquinones in transformed roots was found to be approximately 2-fold higher than that found in one year-old field grown roots (2.12±0.12 and 1.23±0.12 mg g-1 dry weight, respectively). Alizarin was found to be the major anthraquinone in transformed root cultures and was found to be approximately 3-fold higher than in field grown roots.

The isolation, characterisation and quantification of anthraquinones, from hypogeal apparatus of Rubia peregrina L. (Wild Madder) growing wild in Sardinia (Italy) are described. The present study allowed us to perform an easy and fast HPLC analytical method for the detection of anthraquinones in all underground parts of plant. Concentrations of these compounds are variable in the different hypogeal parts before and after hydrolysis of the crude methanolic extracts. Before hydrolysis, we found that pseudopurpurin was 0.18% in rhizomes, alizarin 0.02% in rhizomes and principal stolons, and purpurin 0.56% in stolons of second order. Rubiadin is the major constituent of R. peregrina and reached a higher concentration in principal stolons of up to 4.8%. After hydrolysis, we found some drastic changes: an increase of purpurin in rhizomes (0.04%) and pseudopurpurin in all hypogeal parts (around 0.57%), and a decrease of purpurin in all parts of hypogeal apparatus. The most important change was found in rubiadin concentration, which reached its maximum in principal stolons (11.3%). No anthraquinones were found in the aerial parts of the plant.

Anthocyanin composition in the berries of Pistacia lentiscus L., Phillyrea latifolia L. and Rubia peregrina L., three wild shrubs which are widely distributed in the Mediterranean region, was determined for the first time. The pigments were extracted from the berries with 0.1% HCl methanol solution, purified on a C-18 solid-phase cartridge and characterized by means of high-performance liquid chromatography (HPLC)–diode array detection (DAD)–mass spectrometry (MS) analysis. The major anthocyanin of P. lentiscus berries has been identified as cyanidin 3- O -glucoside. Delphinidin 3- O -glucoside and cyanidin 3- O -arabinoside have also been found in minor quantities. The major anthocyanin in the extracts of P. latifolia and R. peregrina berries was cyanidin 3- O -rutinoside. Low quantities of cyanidin 3- O -glucoside have also been found. The attractive color and the great abundance of these plants in the Mediterranean area make them a new and very good source of natural pigments and antioxidant agents.

The n -hexane–dichloromethane (1:1) extract of the roots of Onosma argentatum and the methanol extract (partitioned between water and chloroform, ethyl acetate and n -butanol, respectively), of the underground parts (roots and rhizomes) of Rubia peregrina were tested in vitro for their antioxidant and antimicrobial activities. The highest antioxidant activity (98%) was observed at 0.1% concentration for the roots of O. argentatum. It was 96% at 0.25% concentration on the ethyl acetate fraction of R. peregrina . O. argentatum extract was effective on Staphyloccoccus aureus , Bacillus subtilis and Escherichia coli. The ethyl acetate and chloroform fractions of R. peregrina were effective on S. aureus and E. coli , respectively. These two species did not have any antifungal activity.

The examination of the original polychromy of a fourth century B.C. classical Greek marble basin revealed a number of unusual pigments. In addition to natural cinnabar, and Egyptian blue, analysis has shown the presence of wild madder (Rubia peregrina) as the colorant in a purple pigment. This is one of the very few instances in which the use of madder as a colorant in classical painting has been established analytically. The white pigment was found to be neutral lead carbonate (cerussite). The use of this carbonate in painting is extremely rare. The yellow pigment was identified as misy (jarosite). The use of jarosites, iron sulphates, as pigments in painting has not been reported previously.

Rubia peregrina L. is a weed able to survive under extreme hydric and thermal stress conditions. Morphological and physiological studies were conducted in an attempt to understand the survival strategies used by this plant. Its main morphological characteristic is the presence of underground stems, partially red and partially yellow, which form a closely branching underground network. They can be considered to be stolons because of a lack of a thickened endodermis, a typical structure found in rhizomes. The yellow and red dyes are glycosil-alizarines. Ultrastructural and pigment studies showed that the yellow segments have starch-filled plastids and carotenoids, while the red segments have no starch reserves. The yellow structures have a higher water content and a correspondingly higher PEP-case (phosphoenolpyruvate carboxylase) activity than the other organs. The survival of the plant after hydric and thermal stress is due to several factors: low transpiration with good photosynthesis in the aerial part and the capacity to conserve water and to have large starch reserves in the subterranean portion. The reserves provide energy and substrates and probably also function as gravity receptors (statoliths). The PEP-case activity helps maintain turgor by means of the malate-cation relationship, and the alizarinic pigments perform an antiparasitic role. Under favorable conditions new buds emerge from the underground stems which then cover the infested area with branches and leaves.