Chloroplast DNA from lettuce and Barnadesia (Asteraceae): structure,gene localization,and characterization of a large inversion

Summary We have cloned into plasmids 17 of 18 lettuce chloroplast DNA SacI fragments covering 96% of the genome. The cloned fragments were used to construct cleavage maps for 10 restriction enzymes for the chloroplast genomes of lettuce (Lactuca sativa) and Barnadesia caryophylla, two distantly related species in the sunflower family (Asteraceae). Both genomes are approximately 151 kb in size and contain a 25 kb inverted repeat. We also mapped the position and orientation of 37 chloroplast DNA genes. The mapping studies reveal that chloroplast DNAs of lettuce and Barnadesia differ by a 22 kb inversion in the large single copy region. Barnadesia has retained the primitive land plant genome arrangement, while the inversion has occurred in a lettuce lineage. The endpoints of the derived lettuce inversion were located by comparison to the well-characterized spinach and tobacco genomes. Both endpoints are located in intergenic spacers within tRNA gene clusters; one cluster being located downstream from the atpA gene and the other upstream from the psbD gene. The endpoint near the atpA gene is very close to one endpoint of a 20 kb inversion in wheat (Howe et al. 1983; Quigley and Weil 1985). Comparison of the restriction site maps gives an estimated sequence divergence of 3.7% for the lettuce and Barnadesia genomes. This value is relatively low compared to previous estimates for other angiosperm groups, suggesting a high degree of sequence conservation in the Asteraceae.     

Acute and Subacute Toxicity of Aspilia Africana Leaves

This study was designed to evaluate the toxicity of the aqueous extract of Aspilia africana leaves. Oral doses of 500 mg/kg and 1000 mg/kg were administered for 28 days to rats after every 2 days for sub-acute toxicity. For acute toxicity, 5 doses of 2, 4, 8, 12 and 16g/Kg body weight were investigated in mice. The control groups consisted of mice or rats administered with distilled water. The signs of toxicity fluctuated lightly from one mammal to another throughout the experiment. The liver, kidneys and heart weight of rats revealed no significant differences between the test groups and the control. The results indicated that the medium lethal dose (LD₅₀) was found to be greater in females than males with an average of 6.6g/Kg body weight for both sexes. Regardless of the significant differences observed at certain points in some biochemical parameters (ALT, AST, ALP, Creatinine and Glutathione); none showed any linear dose responsiveness. On the other hand, most of the parameters investigated were found to be gender dependent. These results suggested that A Africana can be classified among substances with low toxicity.     

台湾翅果菊有性生殖与胚胎发育形态研究

利用切片技术对台湾翅果菊Pterocypsela formosana胚胎发育过程进行了显微观察.研究结果表明,花药4室,药壁发育为双子叶型,由表皮、药室内壁、中层和绒毡层4层细胞组成,腺质绒毡层;小孢子母细胞减数分裂为同时型,四分体主要为四面体型,成熟花粉为2-细胞型.子房下位,2心皮,1室,单胚珠,基生胎座;单珠被,倒弯生胚珠,具发达的珠被绒毡层;大孢子孢原细胞直接发育为大孢子母细胞,属薄珠心类型;大孢子细胞减数分裂形成直线形4分体,仅合点端1个发育为功能大孢子,功能大孢子经3次连续的有丝分裂形成7细胞8核的成熟雌配子体,雌配子体发育方式为蓼型.2个极核在受精前融合为次生核,合点端反足细胞短命,形成后不久即退化消失.珠孔受精,属有丝分裂前类型;初生胚乳核早于合子分裂,胚乳发育为核型,具胚乳吸器;胚胎发育为紫菀型菊苣变型,早期发达的胚柄对胚的发育具重要意义.     

管花蒲公英化学成分研究

目的:研究菊科管花蒲公英属Neo-Taraxacum植物管花蒲公英Neo-Taraxacum siphonathum的化学成分.方法:采用硅胶柱色谱,ODS-C_(18)反相色谱和Sephadex LH-20凝胶柱色谱以及重结晶的方法对管花蒲公英的抗氧化活性部位进行分离纯化,通过理化常数测定以及波谱分析鉴定化合物的结构.结果:从活性部位中分离并鉴定10个化合物,分别为咖啡酸(1),绿原酸(2),槲皮素(3),木犀草素(4),槲皮素-3-O-β-D-吡喃葡萄糖苷(5),槲皮素-3-O-α-D-呋喃阿拉伯糖苷(6),槲皮素-3-O-α-D-吡喃阿拉伯糖苷(7),木犀草素-7-O-β-D.吡喃葡萄糖苷(8),β-谷甾醇(9),胡萝卜苷(10).结论:该10个化合物均为首次从管花蒲公英中分离得到.     

Baccharis trimera: effect on hematological and biochemical parameters and hepatorenal evaluation in pregnant rats

AIM OF THE STUDY: This investigation evaluated the effect of a hydroethanolic extract of Baccharis trimera on pregnant Wistar rats, once the plant is well-known consumed in pregnancy and little is known on its potentially toxic effects on pregnant women. MATERIAL AND METHODS: Thirty-five female rats were distributed into three groups. Those in treatments 1 and 2 were given 8.4 mg/kg of the extract orally from gestational day (GD) 1 to 19 and from GD 6 to 15, respectively, whereas those in the control group received distilled water orally from GD 1 to 19. Body weights were recorded on GD 1, 6, 15, and 20. On GD 20 animals were anesthetized, blood samples were collected and maternal livers, kidneys, and spleens were weighed and processed for histological studies. RESULTS: No clinical signs of maternal toxicity and no changes in hematological parameters were observed. Urea levels and kidney weights differed significantly between animals receiving treatment 1 and controls. Histopathological alterations were found in kidneys and livers in both treatment groups. CONCLUSIONS: The hydroethanolic extract of Baccharis trimera administered to pregnant rats at 8.4 mg/kg was toxic to maternal kidney and liver cells, although such alterations are reversible once administration is discontinued.     

South African Helichrysum species: a review of the traditional uses, biological activity and phytochemistry

Aims of the study

In South Africa, the genus Helichrysum is widely used in traditional medicine. The uses are well documented although renaming of species and the resulting confusing taxonomic nomenclature may cause uncertainty as to which specific species was referred to in some reports. The aim of this paper is to present a collated and coherent overview of the documented traditional uses of Helichrysum species and to update the botanical identity of previously studied species.

Materials and methods

Databases (Scifinder, ISI Web of Knowledge) and several books were used to collect in information on South African Helichrysum species.

Results

The traditional uses, chemistry and biological activity of Helichrysum species have been summarized. It was attempted to give clarity as to exactly which species is refer to in the ethnobotanical literature.

Conclusions

Although a large number of ethnopharmacological uses have been documented and the chemistry of the genus has been studied extensively, only a few South African species have been investigated for their biological activity.     

Commercial Carlinae radix herbal drug: Botanical identity,chemical composition and antimicrobial properties

Context: Carlinae radix is an herbal drug, commonly used by the locals in southeastern Serbia for the treatment of respiratory and urogenital diseases and, externally, for various skin conditions. There still seems to be no detailed studies correlating the chemical composition of this drug and its ethnopharmacological uses.

Objective: Chemical composition, antimicrobial activity and mode of action of C. radix essential oil, isolated from commercial samples (confirmation of whose true biological identity was also the aim of this work) were analyzed. Antimicrobial potential of decoctions (extracts prepared by boiling plant material in a given solvent), used in ethnomedicine preferentially to the pure essential oil, was also investigated.

Materials and methods: The essential oil obtained by hydrodistillation was screened for antimicrobial activity by disc diffusion and broth microdilution methods. Effects of the oil on the growth of Staphylococcus aureus cells were investigated using turbidimetric measurements and visualized using scanning electron microscopy. Analyses of the chemical composition of the oils were done using gas chromatography and gas chromatography/mass spectrometry.

Results and discussion: Both the essential oil and the decocts exhibited a very high antimicrobial activity against all tested strains, with S. aureus as the most sensitive one [e.g., for the oil sample the values for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were 0.02, 0.04 µL/mL, respectively]. Growth curves of S. aureus demonstrated a significant decrease in turbidity (for the MIC concentration this amounted to ca. 70%) showing a concentration-dependent lysis of the cells, confirmed by scanning electron microscopy. Chemical composition, anatomical and morphological features of the sample pointed to Carlina acanthifolia L. (Asteraceae) instead of Carlina acaulis L. (Asteraceae).

Conclusion: The results showed significant antimicrobial effect of the essential oil and the decoctions and support the use of this plant in ethnomedicine for the treatment of various human infections, especially those caused by S. aureus. Adulteration of the drug would not cause significant differences in its biological activity, since chemical composition of the sample showed high similarity with those containing C. acaulis roots.     

Antibiotic Properties of Ethanol Extract of Chromolaena odorata (Asteriaceae)

Ethanol extract of Chromolaena odorata was assayed for in vitro antibiotic activity using agar diffusion and plate dilution methods. The extract produced measurable zones of inhibition (6.5–16 mm) against reference microbial strains and hospital isolates including Bacillus thuringiensis (var israeli), Bacillus stearothermophilus (NCTC 10339), Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 11699), Pseudomonas sp., Streptococcus faecalis and Klebsiella sp. Ampicillin, gentamycin and tetracycline, which were used as antibiotic controls gave inhibition zones measuring between 3.0 and 24 mm while the zones obtained in assays with phenol measured 0.5–1.0 mm. The minimum inhibitory concentration of the extract was 0.13–8.0 mg/ml. The antibiotic activity was lost or significantly reduced with increasing pH in the alkaline spectrum. Zones of inhibition were also diminished by heating the extract (40–80°C) although its antimicrobial activity was not totally lost when heated to 120°C. The antibiotic substance produced a cidal effect on the bacteria. It also resulted in the lysis and variable gram reactions in some of the cells observed, suggesting that the site of action might be the cell wall of the susceptible bacteria.     

Sesquiterpenoids and other constituents from the flower buds of Tussilago farfara

One new norsesquiterpenoid, namely tussfarfarin A (1), and four new artifacts resulting from extraction procedure, namely tussfarfarin B (2), 6-(1-ethoxyethyl)-2,2-dimethylchroman-4-ol (3), 5-ethoxymethyl-1H-pyrrole-2-carbaldehyde (4), and 3β-hydroxy-7α-ethoxy-24β-ethylcholest-5-ene (5), along with 18 known compounds, were isolated from the flower buds of Tussilago farfara. Their structures were elucidated by extensive spectroscopic analysis.     

Is it possible to rapidly and noninvasively identify different plants from Asteraceae using electronic nose with multiple mathematical algorithms?

Many plants originating from the Asteraceae family are applied as herbal medicines and also beverage ingredients in Asian areas, particularly in China. However, they may be confused due to their similar odor, especially when ground into powder, losing their typical macroscopic characteristics. In this paper, 11 different multiple mathematical algorithms, which are commonly used in data processing, were utilized and compared to analyze the electronic nose (E-nose) response signals of different plants from Asteraceae family. Results demonstrate that three-dimensional plot scatter figure of principal component analysis with less extracted components could offer the identification results more visually; simultaneously, all nine kinds of artificial neural network could give classification accuracies at 100%. This paper presents a rapid, accurate, and effective method to distinguish Asteraceae plants based on their response signals in E-nose. It also gives insights to further studies, such as to find unique sensors that are more sensitive and exclusive to volatile components in Chinese herbal medicines and to improve the identification ability of E-nose. Screening sensors made by other novel materials would be also an interesting way to improve identification capability of E-nose.