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PubMedDate not supplied

Phellinus caribaeo-quercicolus sp. nov., parasitic on Quercus cubana: taxonomy and preliminary phylogenetic relationships.

Phellinus caribaeo-quercicolus sp. nov. is described from several collections made in western Cuba, so far exclusively on Quercus cubana. The species is characterized by a perennial, resupinate basidiomes, cushion-shaped to nodulose and multi-layered when old, apically hooked to hamate hymenial setae, and ellipsoid to broadly ellipsoid, thin- to thick-walled, hyaline to faintly yellowish basidiospores, 4.5-5.5 x 3.5-4.5 microm. The species is compared to other Phellinus species with hooked setae, especially Phellinus undulatus, also recorded in Cuba. The preliminary phylogenetic relationships of Ph. caribaeo-quercicolus within the poroid Hymenochaetales complex of genera is presented and discussed here.

Basidiomycota↗
PubMed1998

[Chemical constituents of Quercus mongolica Fisch].

OBJECTIVE: To study the chemical constituents of the leaves of Quercus mongolica. METHOD: Using techniques of silical gel column chromatography and HNMR, 13CNMR. RESULT: Four compounds were isolated and identified as friedelin, glutinol, lupeo and beta-sitosterol respectively. CONCLUSION: All the compounds were isolated from this plant for the first time.

Drugs, Chinese Herbal↗
PubMed1998

[Studies on the chemical constituents of Quercus mongolica].

Seven compounds were isolated from Quercus mongolica Fisch., six (1-VI) of them were identified as fridelin (I), beta-amyrin (II), 1-octadecanol (III), beta-sitosterol (IV), daucosterol (V) and gallic acid (VI) by means of chemical, physical and spectrosopic evidiences.

Fatty Alcohols↗
PubMed2003

[Analysis on leaf forms in Quercus mongolica community].

Leaf-size classes of 337 vascular plants in Quercus mongolica community in northeast, China were analyzed according to Raunkiaer system. The dominant type was microphyll which percentage is 45.4%, followed by compound leaf (23.1%), mesophyll (22.6%), nanophyll (6.8%), macrophyll (0.9%), aphyllous (0.9%), leptophyll (0.3%). The leaves edges of 337 plants were investigated and the percentage of entire leaves plants is 22.3%. Leaf-size classes spectra of trees, shrubs and herbs were figured out. The mesophyll ratio in trees was higher than that in shrubs and herbs. The mesophyll ratio in shrubs was the lowest. Different sites had different leaf-size classes spectra. Microphyll also was the dominant type in every site. No significant relationships were found between leaf-size classes spectra and latitude and altitude.

Altitude↗
PubMed2003

[Population dynamics of Quercus variabilis on northern slope of Qinling mountains].

Studies on the population dynamics, age structure, spatial distribution pattern, life table, and survival curve of Quercus variabilis showed that the Q. variabilis population on the northern slope of Qinling mountains was increasing. The number of young-aged individuals was larger, and that of middle-aged and old individuals was smaller. The life tables for different age classes showed that the mortality at age classes I and II was the highest, and the mortality rate was decreased with increasing age. However, at age classes VII and VIII, the mortality rose again for their decrepitude. The expected life span of age classes III, IV and V was higher, and decreased gradually with increasing age. The survival curves were the type of Deevey III, and the distribution pattern of population was aggregative as a whole. As the age increased, the intensity of aggregation decreased, and tended to a random distribution at higher elevations. A wise management should accelerate the recovery of Q. variabilis population and the enhancement of its productivity. The altitude 800-1,100 m was the favorable habitat for Q. variabilis population. As for the Q. variabilis at lower altitude, its protection should be reinforced, and the disturbance from human beings should be reduced. Forest thinning and other fostering management at middle altitude should be given in time. The target trees at higher altitude should be fostered.

Altitude↗
PubMedDate not supplied

Cryopreservation of embryogenic cultures from mature Quercus suber trees using vitrification.

Recent progress in somatic embryogenesis from selected mature trees of Quercus suber, has led to a demand for maintenance of a large number of selected embryogenic lines. To facilitate the management of this material a protocol for the long-term storage of this germplasm should be defined. This study reports on the use of a simple vitrification procedure for the successful cryopreservation of three cork oak embryogenic lines. High embryo recovery levels (88-93 percent) were obtained by first preculturing 2-4 mg clumps of two or three globular embryos on semisolid medium containing 0.3 M sucrose for three days, followed by incubation in PVS2 vitrification solution at 0 degree C for 60 min before direct immersion in liquid nitrogen. The mean number of embryos produced per explant was significantly greater for cryostored embryos than for untreated stock cultures, but the productivity of the latter was recovered in subsequent subcultures of the material produced by cryostored embryos. The germination and plant regeneration rates achieved by cultures derived from cryostored embryos, around 60 percent, were similar to those of non-cryopreserved stock cultures.

Cryopreservation↗
PubMed2005

Quercus suber cork extract displays a tensor and smoothing effect on human skin: an in vivo study.

Recently, it has become indispensable for anti-aging active ingredients to provide a visible and immediate smoothing antiwrinkle effect. In Quercus suber, suberin is the most important structural component of cork cell walls. Studies have shown that suberin is made up mostly of hydroxycarboxylic acids and that it is endowed with many special mechanical and chemical properties that evoke a possible smoothing effect on the surface of the skin. Therefore, we were interested in investigating the effect of this cork extract on the skin's surface in a double-blind clinical study. The study was conducted in 15 healthy volunteers, aged 22 to 52 years. The volunteers applied a gel formula with 3% of cork extract, or placebo gel, on each forearm. Skin surface roughness was evaluated visually by pictures and by silicone replicas 1 and 2 h after application, followed by statistical analysis using the matched-pairs McNemar statistical test. McNemar analysis of the pictures revealed that application of cork extract on the skin resulted in a highly significant reduction of roughness 1 h after application. This effect was observed in 73.3% of volunteers. Two hours after cork extract application, a highly significant improvement of skin roughness was found in 78.6% of volunteers. Moreover, silicone replica treatment confirmed significant improvement in average of roughness at 2 h. These results demonstrate that cork extract provides a remarkable and highly significant tensor and smoothing effect on the skin, which could be of great use in anti-aging skin care products.

Administration, Cutaneous↗
PubMedDate not supplied

Cryopreservation of Quercus robur L. embryogenic calli.

Embryogenic calli of pedunculate oak (Quercus robur L.) were cryopreserved using direct immersion in liquid nitrogen. The pretreatment consisted of culture on a solid medium with increasing sucrose concentrations (0.25 M for 1 day, 0.5 M for 1 day, 0.75 M for 2 days, and 1.0 M for 3 days), followed by air desiccation of embryogenic calli to 17.3 percent (fresh weight basis). This method of cryoprotection was compared to a liquid cryoprotection treatment using high concentrations of sucrose solutions, followed by glycerol solutions. Regrowth of frozen tissue pretreated on a solid medium was significantly higher than those pretreated in the liquid solutions.

Cell Line↗
PubMed2006

[Effects of ramets adjustment on Quercus liaotungensis growth and seed generation].

This paper studied the effects of different ramets adjustment measures on the growth and seed generation of Quercus liaotungensis shrub in the upper reach of Minjiang River. The results showed that artificially adjusting ramets number largely affected the growth of plant height and sexual reproduction of Q. liaotungensis. The adjustment had little effect on the basal diameter of remained ramets, but obviously affected their height if 2 or 3 ramets per shrub were remained. The number, total length, and total biomass of new branches of adjusted shrub had more increase than those of unadjusted one, especially for the shrub of remaining 2 ramets. In adjusted shrub, the number and total biomass of leaves increased obviously, and the leaf area decreased gradually with increasing number of remained ramets. The shrub with three remained ramets generated most seed, while natural shrub had the biggest weight of single seed.

Biodiversity↗
PubMed1999

Effects of aqueous extracts from Quercus ilex L. root bark, Punica granatum L. fruit peel and Artemisia herba-alba Asso leaves on ethanol-induced gastric damage in rats.

The gastroprotective effect of tannic acid and the aqueous extract of Quercus ilex L. root bark, Punica granatum L. fruit peel and Artemisia herba-alba Asso leaves was investigated in the rat against ethanol-induced damage. Tannic acid, Q. ilex and P. granatum extracts gave 100% precipitation of ovine haemoglobin in vitro, whereas A. herba-alba extract was devoid of any protein-binding property. Oral administration of these plant extracts or tannic acid induced a significant decrease in gastric lesions (47.7%-76%). The observed protection was more pronounced when the test solution was given at the same time with ethanol, except for Q. ilex extract. The acid content of the stomach was significantly increased by P. granatum (368%) and A. herba-alba (251%) extracts prepared in ethanol. It is suggested that monomeric and polymeric polyphenols can strengthen the gastric mucosal barrier.

Algeria↗
PubMed1999

Inhibition of oncogene product enzyme activity as an approach to cancer chemoprevention. Tyrosine-specific protein kinase inhibition by purpurogallin from Quercus sp. nutgall.

Inhibitors of oncogene product enzyme activity were sought as a prescreen for potential cancer chemopreventive agents. Purpurogallin, a polyphenol from Quercus sp. nutgall, was found to inhibit the tyrosine-specific protein kinase of the human erb-b oncogene product (epidermal growth factor receptor) for both autophosphorylation (IC50 = 27.5 microM) and phosphorylation of an exogenous substrate (IC50 = 45.3 microM). An examination of enzyme kinetics indicated that purpurogallin is a competitive inhibitor of both ATP (Ki = 54.9 microM for autophosphorylation, Ki = 33.9 microM for phosphorylation of exogenous substrate) and the tyrosine-containing acceptor substrate poly(glutamate, alanine, tyrosine) 6:3:1 (Ki = 83.7 microM).

Benzocycloheptenes↗
PubMed1976

Pharmacology of Quercus infectoria.

The galls of Quercus infectoria (Fagaceae), a commonly available plant in Iran, were studied pharmacologically. Two fractions were employed, a dried acetone-treated methanol extract dissolved in water (Fraction A) and a subfraction prepared by chloroform-methanol extraction (Fraction B). Fraction A was active as an analgesic in rats and significantly reduced blood sugar levels in rabbits. Fraction B had CNS depressant activity. Data obtained with a treadmill indicated a decreased activity ratio by Fraction B, suggesting a possible interference in motor coordination. It potentiated the barbiturate sleeping time significantly without changing the onset time or the loss of the righting reflex. In addition, Fraction B exhibited a moderate antitremorine activity by causing a delay in the onset and a decrease in the severity of tremorine-induced tremors. The local anesthetic action of Fraction B was evident due to the complete blockade of the isolated frog sciatic nerve conduction.

Analgesics↗
PubMed1999

State and phase transition behaviors of quercus rubra seed axes and cotyledonary tissues: relevance to the desiccation sensitivity and cryopreservation of recalcitrant seeds

Freezing and melting transitions of cellular water in embryonic axes and cotyledonary tissues of recalcitrant Quercus rubra (red oak) seeds were compared under slow and rapid cooling conditions. The relevance of desiccation sensitivity (critical water content) and state/phase transition behaviors to cryopreservation was examined. Under a slow to intermediate cooling condition (</=10 degrees C min(-1)), unfrozen water content in the tissues decreased to less than the critical water content, resulting in a dehydration damage. Under a rapid cooling condition (>100 degrees C min(-1)) using liquid nitrogen (LN(2)), freeze-induced dehydration damage could be avoided if the initial water content was >0.50 g g(-1) dry wt. However, at water content >0.50 g g(-1) dry wt, the vitrified cellular matrix was highly unstable upon warming at 10 degrees C min(-1). These results offered a theoretical explanation on the difficulty for successful cryopreservation of recalcitrant red oak embryonic axes. A complete state/phase transition diagram for red oak axes was constructed, and a vitrification-based cryopreservation protocol that employed predehydration and rapid cooling was examined. State/phase transition behaviors of cellular water are important parameters for cryopreservation; however, vitrification alone was not sufficient for seed tissues to survive the cryopreservation condition. Copyright 1999 Academic Press.

Journal Article↗
PubMedDate not supplied

Response of two populations of holm oak (Quercus rotundifolia Lam.) to sulfur dioxide.

Experiments were carried out with seedlings of Quercus rotundifolia Lam., an evergreen schlerophyllous tree typical of the Spanish Mediterranean climate environments. Fruits were collected in two distant (800 km) populations located in the center (southern Spain) and northern border (northern Spain) of the area of distribution of the species. One-month-old potted plants were grown for 130 days in an enriched atmosphere of SO2 (0.23 ppm, 14 h/day) in controlled (growth chamber) conditions. Both northern and southern plants underwent a significant decrease in growth rate as a consequence of the treatment. Even so, plants appear to be quite resistant to SO2 compared with either more temperate or more productive species. The southern population was more sensitive to the treatment, as reflected by the bigger decrease in both growth and photosynthetic rates. Differences in resistance appear to be related to the biogeographic origin of the populations studied, which underlines the importance of biogeographic aspects in studies of resistance to air pollutants.

Adaptation, Physiological↗
PubMed1996

Trace metal biomonitoring in the soil and the leaves of Quercus ilex in the urban area of Naples.

The concentrations of Pb, Cu, Fe, and Mn were analyzed in surface deposit and tissue of Quercus ilex leaves from several sites of the urban area of Naples, exposed to different degrees of air pollution. These included some major roads with heavy traffic loads, squares, and three urban parks. The soil from the trunk base area of Q. ilex trees in the same sites was also analyzed for total and available metal contents. Pb, Cu, and Fe contents in the surface deposit and leaf tissue were significantly higher (p < 0.01) in leaves from roadside sites than in leaves from parks; significant correlations were found between deposit- and tissue-contents of Pb, Cu, and Fe. Mn content in leaves from roadside sites and in leaves from parks were similar and Mn content in the leaf deposit was irrelevant. Significant differences (p < 0.001) in both total and available Pb and Cu soil content were found between sampling sites. Also for available Fe and Mn soil content differences among sites were relevant, although the highest values were measured in soil from urban parks. A positive correlation between leaf and soil metal content was found only for Pb, thus suggesting that trace metal contents of leaves directly depend on atmospheric depositions. Seasonal variations of Pb, Cu, and Fe were pronounced at a polluted site, whereas no relevant seasonal variation was observed at a control site; moreover, metal accumulation was high at the polluted site. Mn content and seasonal dynamics were comparable at control and polluted sites.

Air Pollutants↗
PubMed2000

Spatial determination of elements in green leaves of oak trees (Quercus robur) by laser ablation-ICP-MS.

Laser ablation inductively coupled plasma mass spectrometry (laser ablation-ICP-MS) has been applied to the spatially resolved determination of the elements Mg, Ca, Cu, Ni, Ba, Al, Pb, Sr and Mn in green leaves of oak trees. Instrument operating parameters such as the laser wavelength and the pulse energy have been optimized to provide the sensitivity and reproducibility required for the analysis. The method provides spatial resolution down to 300 microm with the use of the 355 nm wavelength (3rd harmonic of the 1,064 nm Nd:YAG laser wavelength) and the pulse energy of 50 mJ. Plant standards and cellulose, doped with multi element solution standards, dried and pressed to pellets were used as calibration samples. To compensate for signal fluctuations caused by the variation of the ablated sample mass 13C was used as a "natural" internal standard. The accuracy of the calibration was verified with selected samples analyzed by ICP-MS (high pressure digestion, 170 degrees C, 10(7) Pa, HNO3, 2 h) and by laser ablation-ICP-MS. Recovery rates between 93% (Cu) and 108% (Mn) were obtained. Leaves taken from oak trees (Quercus robur) were analyzed.

Calibration↗
PubMed1971

Recherches sur les enzymes catalysant la biosynthese des acides phénoliques chez Quercus pedunculata (EHRH.): I - Formation des premiers termes des series cinnamique et benzöique.

Occurence of PAL, cinnamate-hydroxylase and p-coumarate-hydroxylase, is found in cell-free extracts from Quercus pedunculata roots; moreover, an enzyme system which catalyzes benzoïc acid formation from cinnamic acid is caracterized for the first time. Role of these enzymes and their interactions within the same organ are discussed.

Journal Article↗
PubMed1988

Ozone-induced nitrate formation in needles and leaves of Picea abies, Fagus sylvatica and Quercus robur.

Much attention has been paid to ozone as a major cause of novel forest decline in Europe. In combination with acidic mist, O(3) has been observed to increase ion leaching. Besides cations lake Mg(2+), Ca(2+), K(+), NH(4)(+), considerable amounts of nitrate were found to be leached by acidic mist from needles of Norway spruce. Controlled fumigation experiments, with 100, 300, and 600 microg O(3)m(-3) over 22 days continuously, have led to a nitrate accumulation of 94.1 +/- 14.8, 119.4 +/- 28.7 and 198.9 +/- 14.9 microg NO(3)(-1) g(-1) FW, respectively, in leaves of Quercus robur. Similar values were found in leaves of Fagus sylvatica and current and previous year needles of Picea abies. Nitrate levels of controls receiving charcoal filtered air were well below 40 microg NO(3)(-) g (-1) FW. Statistically significant elevated nitrate levels were observed after only 48 h of continuous fumigation with 600 microg O(3)m(-3), in all tree species tested, and after 144 h in the 100 microg O(3)m(-3) treatment. In another experiment, trees of Picea abies were kept in two charcoal (C) and two Purafil plus charcoal (P/C) ventilated chambers, and fumigated with O and 500 microg O(3)m(-3) in cabinets of each filter-type in order to eliminate NO(x) from chamber air. After 29 days of continuous ozone fumigation, NO(3)(-) accumulation in needles amounted to 102.0 +/- 37.7 and 137.4 +/- 40.5 microg g(-1) FW in P/C and C-filtered chambers, respectively. Nitrate contents of controls were below 30 microg NO(3)(-)g(-1) FW at the end of the experiment. No significant differences in NO(3)(-) accumulation between filter treatments were observed. Since NO(x) was reduced by more than 95% in the Purafil/charcoal versus the charcoal treatment, NO(3)(-) accumulation in needles can be attributed predominantly to the influence of ozone and not to direct NO(2) uptake of needles by the possible oxidation of NO to NO(2) in the presence of ozone.

Journal Article↗