Contribution of microwave accelerated distillation in the extraction of the essential oil of Zygophyllum album L.

Introduction – The aerial parts of Zygophyllum album L. are used in folk medicine as an antidiabetic agent and as a drug active against several pathologies. In this work we present the chemical composition of Algerian essential oils obtained by microwave accelerated distillation (MAD) extraction, a solventless method assisted by microwave. Objective – Under the same analytical conditions and using GC‐FID and GC‐MS, the chemical composition of the essential oil of Zygophyllum album L. extracted by MAD was compared with that achieved using hydrodistillation (HD). Methodology – The extracted compounds were hydrosoluble, and they were removed from the aqueous solution by a liquid extraction with an organic solvent. Results – Employing MAD (100°C, 30 min), the essential oil contained mainly oxygenated monoterpenes with major constituents: carvone and α‐terpineol. However, most of the compounds present in the hydrodistilled volatile fraction were not terpene species, with β‐damascenone as a major constituent. Conclusion – The MAD method appears to be more efficient than HD: after 30 min extraction time, the obtained yields (i.e. 0.002%) were comparable to those provided by HD after 3 h extraction. MAD seems to be more convenient since the volatile fraction is richer in oxygenated monoterpenes, species that are recognised for their olfactory value and their contribution to the fragrance of the essential oil. Copyright © 2010 John Wiley & Sons, Ltd.     

大连地区岛屿与大陆藜（Chenopodium album L.）种群遗传多样性的ISSR分析

采用ISSR分子标记对分布于大连市周边的4个藜的天然种群100个个体进行了遗传多样性及遗传结构的研究。13个引物共检测了157个位点,多态位点比率为67.52%,Shannon信息指数在物种水平上为0.332 9。根据G_ST值,藜遗传变异有40.03%发生在种群间。遗传距离分析表明,DT种群与MLN种群遗传一致度最高,遗传距离与地理距离之间没有相关性。     

Toxocara canis: Potential activity of natural products against second-stage larvae in vitro and in vivo

The anthelmintic activity of extracts from Chenopodiumambrosioides, Pycnanthusangolensis and Nutridesintox® was in vitro and in vivo investigated, against Toxocaracanis larvae. The in vitro assays results showed that the aqueous extract of Nutridesintox® was the most effective, followed by C. ambrosioides extracts, hexane, dichloromethane and the infusion. P. angolensis extracts showed a lower anthelmintic activity compared to the other natural products. For the in vivo assays, Nutridesintox®, the hexane extract and the infusion of C. ambrosioides were administered orally to T. canis-infected mice, in single doses, during three consecutive days. The efficacy was evaluated on the 17th day post-infection, not only by counting T. canis larvae in the tissues but also by ELISA detection of IgM and IgG antibodies and histological analysis of liver and lungs. The different treatments did not reduce the larvae burden and had no influence on the antibodies dynamic. Interestingly, a reduction on the inflammatory infiltrates was observed in the liver and lung sections of the group treated with the hexane extract of C. ambrosioides. In conclusion, the hexane extract of C. ambrosioides is of further research interest, as it showed an anthelmintic activity in vitro and a reduction on the inflammatory reaction produced by the infection of T. canis larvae in vivo.     

寄主植物对橄榄星室木虱自然种群的影响

通过野外调查和室内测试,结果表明:橄榄星室木虱Pseudophacopteron canarium在橄榄Canarium album和乌榄C.nigrum上均能完成生长发育,且其种群数量都有不同程度的增长,其中橄榄的2个品系间的星室木虱种群趋势指数(I)差异不大,分别为24.4165和20.0738,而乌榄的明显比橄榄的低,仅为9.7575,即乌榄的木虱数量增速较慢。在供试的寄主植物品种中,乌榄叶片中单宁含量是橄榄的3倍以上,而蛋白质含量相对较低。     

Benzyladenine-induced inhibition of flowering in Chenopodium rubrum in vitro is not related to the levels of isoprenoid cytokinins

The effect of 6-benzylaminopurine (BAP) on floweringand on endogenous levels of isoprenoid cytokinins wasinvestigated in explanted terminal shoots of Chenopodium rubrum cultivated in vitro. Themother plants were grown under continuous light andexplants were cut off when the 6th leaf primordiumoriginated at the shoot apex. The explants wereexposed to one dark period of 13 hours inductive forflowering or to continuous light on medium with orwithout BAP (0.05;0.2;0.4 mg.l^-1). Undernon-inductive conditions no flowering was observedeither in the control or after BAP treatment. Afterreceiving one inductive dark period, the controlexplants flowered. However, BAP application either atthe beginning of the inductive dark period and/orduring the following light cultivation inhibitedflowering and stimulated initiation and growth of leafprimordia. In the case of the most efficient BAPconcentration (0.05 mg.l^-1) flowering wasinhibited by 80% and the number of leaf primordia wasincreased by 3. Explantation caused a significantincrease in the total amount of endogenous cytokininsin the explants within first 13 h, provided they werekept in light. When explants were kept in darkness,only a slight increase in cytokinin levels wasobserved. BAP treatment had no influence on the levelsof endogenous cytokinins either in light or indarkness. We may thus conclude, that BAP applicationinhibited flowering of photoperiodically inducedterminal shoot explants and stimulated leaf primordiaformation with no significant effect on changes inlevels of endogenous isoprenoid cytokinins. This maysuggest the direct ability of BAP to regulate morphogenesis.     

Plant sex and phenological stage affect interactions with rhizosphere nematode communities

Background: In dioecious plants, females and males associate differently with mycorrhizal fungi, but interactions with other rhizosphere organisms are less well studied.

Aims: We investigated the effect of plant sex on rhizosphere nematode communities associated with Corema album, a dioecious shrub occurring in coastal habitats.

Methods: Rhizosphere samples were collected from males and females in three populations (150 plants), during fruiting and flowering. Nematode communities were characterised and compared between plant sexes through statistical analyses of the abundance of trophic groups, plant parasitic nematode (PPN) genera and ecological indices.

Results: Free-living nematodes showed no statistically significant differences owing to plant sex. Conversely, PPN community composition was significantly different between plant sexes during fruiting but not flowering, suggesting that physiological requirements over the annual phenological cycle of the plant influence ecological interactions with the rhizosphere.

Of the 13 PPN genera identified, the ectoparasitic Criconema and Hemicriconemellawere more abundant in the rhizosphere of males during fruiting, whereas the endoparasitic Meloidogyne associated more frequently with females, suggesting that plant host suitability is related to PPN feeding strategy.

Conclusions: It appears that interactions of individuals of different sexes of C. album with the rhizosphere nematode community vary with phenological stage, especially for PPN.     

The 23-kDa light-stress-regulated heat-shock protein of Chenopodium rubrum L. is located in the mitochondria

The 23-kDa nuclear-encoded heat-shock protein (HSP) of Chenopodium rubrum L. is regulated by light at the posttranslational level. Higher light intensities are more effective in inducing the accumulation of the mature protein under heat-shock conditions. Based on this and other properties the protein was considered to belong to the group of small chloroplastic HSPs. However, we have now obtained the following evidence that this 23-kDa HSP is localized in the mitochondria: (i) Immunogold-labelled protein was almost exclusively restricted to the mitochondria in electron microscope thin sections. (ii) Using purified, isolated mitochondria from potato tubers the in-vitro-synthesized translation product of 31 kDa was readily transported into mitochondria where it was processed to the 23-kDa product. (iii) The protein could be detected by Western blotting in a preparation of washed mitochondria of Chenopodium, while under the same conditions no signal could be obtained in a preparation of isolated chloroplasts. (iv) Finally, sequence comparison with the published sequences of mitochondrial proteins by Lenne et␣al. (1995, Biochem J 311:805–813) and LaFayette et␣al. (1996, Plant Mol Biol 30:159–169) showed clearly that the 23-kDa protein is considerably more similar to these two proteins than to the group of plastid small HSPs. From these data we infer that mitochondria are involved in the response of the plants to high light stress under heat-shock conditions. Received: 11 July 1996 / Accepted: 24 August 1996