木荷叶蜂幼虫的正交模糊分析和空间分布格局

首创采用"模糊坐标系",运用正交设计方法调查木荷防火林带叶蜂幼虫的危害状况,并对调查结果进行模糊分析,而且用多种方法测定了该幼虫的空间分布格局.研究表明:引进模糊坐标系,与传统的直角坐标、曲线坐标或曲面坐标相比,具有使调查结果与实际更吻合和使用更灵活方便的特点;正交调查结果的模糊分析比极差分析、方差分析获得更丰富信息;木荷防火林带中叶蜂幼虫空间分布格局符合负二项分布,分布的基本成份是稀疏的个体群.研究结论与调查林带的全面实际观察是一致的.     

Chemical fingerprint analysis and quantitative determination of steroidal compounds from Dioscorea villosa,Dioscorea species and dietary supplements using UHPLC‐ELSD

Ultra high‐performance liquid chromatography (UHPLC) with evaporative light scattering detection was used for the quantification of steroidal saponins and diosgenin from the rhizomes or tubers of various Dioscorea species and dietary supplements that were purported to contain Dioscorea. The analysis was performed on an Acquity UPLC? system with an UPLC? BEH Shield RP₁₈ column using a gradient elution with water and acetonitrile. Owing to their low UV absorption, the steroidal saponins were observed by evaporative light scattering detection. The 12 compounds could be separated within 15 min using the developed UHPLC method with detection limits of 5–12 µg/mL with 2 μL injection volume. The analytical method was validated for linearity, repeatability, accuracy, limits of detection and limits of quantification. The relative standard deviations for intra‐ and inter‐day experiments were <3.1%, and the recovery efficiency was 97–101%. The total content of standard compounds was found to be in the ranges 0.01–14.5% and 0.9–28.6 mg daily intake for dry plant materials and solid commercial preparations, respectively. UHPLC–mass spectrometry with a quadrupole mass analyzer and ESI source was used only for confirmation of the identity of the various saponins. The developed method is simple, rapid and especially suitable for quality control analysis of commercial products. Copyright © 2013 John Wiley & Sons, Ltd.     

Rapid hydrogen peroxide release in cell suspensions ofCapsicum spp. elicited by fungal preparations

The release of H₂O₂ by plant cell suspensions elicited with crude hyphal wall preparations has been studied in a complex of plant genotypes (two cvs ofCapsicum annuum and one of C.frutescens) and fungus species(Phytophthora capsici, Ph. parasitica andVerticillium dahliae), representing several combinations of compatibility and both host and nonhost resistance. Production of H₂O₂ was revealed as peroxidasedependent and catalase-inhibited fluorescence quenching of an extracellular probe (Pyranine). All the plant genotypes responded to at least one elicitor, but the cell sensitivity showed a great age-dependent variability. Riboflavine and Mn²⁺ added in the incubation medium acted to some extent as primers for activated cell response, as well as a high Na⁺ concentration. Cell rest condition, however, was not removed. Some quantitative features of responsive plant/elicitor combinations (dose-response relation and lasting time) have been recorded. The complex PO/H₂O₂ of elicited cells could perform detectable lignin-like polymerization of an exogenous natural substrate (coniferyl alcohol). The time-course of pyranine oxidation and lignin-like polymer formation could be recorded by adopting a fluorimetric procedure that allowed sequential observations on the same cell sample. In one instance, the cell reaction seemed associated with thein planta host/parasite incompatibility.     

Simultaneous determination of naphthoquinone derivatives in Boraginaceous herbs by high-performance liquid chromatography

A high-performance liquid chromatographic method using diode-array detection (HPLC-DAD) has been developed for the simultaneous quantification of eight naphthoquinone derivatives namely shikonin, acetylshikonin, deoxyshikonin, β-acetoxyisovalerylshikonin, isobutylshikonin, β,β-dimethylacrylshikonin, 2-methyl-n-butyrylshikonin and isovalerylshikonin in nine species of the Boraginaceae family. These species, coming from different areas of China, are all used as interchangeable sourcing plants for the Chinese Materia Medica known as “Zicao”, and are Arnebia euchroma (Royle) Johnston., A. guttata Bunge, Lithospermum erythrorhizon Sieb. et Zucc., Onosma paniculatum Bur. et Franch., O. exsertum Hemsl., O. confertum W.W. Smith, O. hookerii Clarke var. longiflorum Duthie, O. hookerii Clarke and O. waltonii Duthic. Quantification of the eight naphthoquinones in all the Zicao samples are reported and compared with each other. Furthermore, two positional isomers, 2-methyl-n-butyrylshikonin and isovalerylshikonin, were successfully separated and quantified for the first time in the present study. The results showed that, besides the three officially used species (namely, A. euchroma, A. guttata and L. erythrorhizon) that were listed in Chinese pharmacopoeia as interchangeable sourcing plants for Zicao, other six species of Onosma used by native peoples in Tibet and Yunnan Province also contain various types and considerable amounts of naphthoquinones and that O. waltonii contains the most. Therefore, these species of Onosma could be developed as new sources of naphthoquinones. The entire analytical procedure is reproducible and suitable for the quantification of naphthoquinones in all related Boraginaceous plants for quality assessment purposes.     

Application Potential of Bacterial Volatile Organic Compounds in the Control of Root-Knot Nematodes

Plant-parasitic nematodes (PPNs) constitute the most damaging group of plant pathogens. Plant infections by root-knot nematodes (RKNs) alone could cause approximately 5% of global crop loss. Conventionally, chemical-based methods are used to control PPNs at the expense of the environment and human health. Accordingly, the development of eco-friendly and safer methods has been urged to supplement or replace chemical-based methods for the control of RKNs. Using microorganisms or their metabolites as biological control agents (BCAs) is a promising approach to controlling RKNs. Among the metabolites, volatile organic compounds (VOCs) have gained increasing attention because of their potential in the control of not only RKNs but also other plant pathogens, such as insects, fungi, and bacteria. This review discusses the biology of RKNs as well as the status of various control strategies. The discovery of VOCs emitted by bacteria from various environmental sources and their application potential as BCAs in controlling RKNs are specifically addressed.     

Isolation,characterization, and plasmid pUPI126-mediated indole-3-acetic acid production in Acinetobacter strains from rhizosphere of wheat

Thirty-seven strains of Acinetobacter isolated and characterized from rhizosphere of wheat were screened for indole-3-acetic acid (IAA) production. Only eight Acinetobacter strains showed IAA production. The genus Acinetobacter was confirmed by chromosomal DNA transformation assay. Biotyping of eight strains was carried out and they were found to be genospecies of A. junii, A. baumannii, A. genospecies 3, and A. haemolyticus. Five of eight strains produced IAA at the early stationary phase: A. haemolyticus (A19), A. baumannii (A18, A16, A13), and Acinetobacter genospecies 3 (A15). A. junii A6 showed maximum IAA production at log phase and A. genospecies 3 and A. baumannii (A28, A30) at late stationary phase. IAA was extracted by ethyl acetate and purified by preparative thin-layer chromatography. Purified IAA was confirmed by ¹H-nuclear magnetic resonance and infrared spectrum analysis. Pot experiments showed a significant increase in plant growth inoculated with eight Acinetobacter genospecies as compared to control plants. IAA production was found to be encoded by plasmid pUPI126. All eight strains of Acinetobacter contain a plasmid pUPI126 with a molecular weight of 40 kb. Plasmid pUPI126 was transformed into Escherichia coli HB101 at a frequency of 5 × 10⁻⁵, and E. coli HB101 (pUPI126) transformants also showed IAA activity. PUPI126 also encoded resistance to selenium, tellurium, and lead. This is the first report of plasmid-encoded IAA production in the genus Acinetobacter.     

Production of cellulolytic enzymes by coculturing ofAspergillus ellipticus andAspergillus fumigatus grown on bagasse under solid state fermentation

Production of cellulolytic enzymes on bagasse under solid state fermentation by coculture ofAspergillus ellipticus andAspergillus fumigatus was studied. Cocultivation ofA. ellipticus andA. fumigatus showed improved hydrolytic and Β-glucosidase activities as compared to the occasions when they were used separately. Various pretreatment methods were used to make cellulose accessible to enzymatic attack. Best results were obtained through pretreatment with 2% (w/v) calcium hydroxide. Maximum enzyme production was obtained after 8 d of fermentation process.     

Synthesis,Biological Evaluation,and Structure–Activity Relationships of 4-Aminopiperidines as Novel Antifungal Agents Targeting Ergosterol Biosynthesis

The aliphatic heterocycles piperidine and morpholine are core structures of well-known antifungals such as fenpropidin and fenpropimorph, commonly used as agrofungicides, and the related morpholine amorolfine is approved for the treatment of dermal mycoses in humans. Inspired by these lead structures, we describe here the synthesis and biological evaluation of 4-aminopiperidines as a novel chemotype of antifungals with remarkable antifungal activity. A library of more than 30 4-aminopiperidines was synthesized, starting from N-substituted 4-piperidone derivatives by reductive amination with appropriate amines using sodium triacetoxyborohydride. Antifungal activity was determined on the model strain Yarrowia lipolytica, and some compounds showed interesting growth-inhibiting activity. These compounds were tested on 20 clinically relevant fungal isolates (Aspergillus spp., Candida spp., Mucormycetes) by standardized microbroth dilution assays. Two of the six compounds, 1-benzyl-N-dodecylpiperidin-4-amine and N-dodecyl-1-phenethylpiperidin-4-amine, were identified as promising candidates for further development based on their in vitro antifungal activity against Candida spp. and Aspergillus spp. Antifungal activity was determined for 18 Aspergillus spp. and 19 Candida spp., and their impact on ergosterol and cholesterol biosynthesis was determined. Toxicity was determined on HL-60, HUVEC, and MCF10A cells, and in the alternative in vivo model Galleria mellonella. Analysis of sterol patterns after incubation gave valuable insights into the putative molecular mechanism of action, indicating inhibition of the enzymes sterol C14-reductase and sterol C8-isomerase in fungal ergosterol biosynthesis.     

Bioactivity and Mycochemical Profile of Extracts from Mycelial Cultures of Ganoderma spp.

Fungal mycelium cultures are an alternative to natural sources in order to obtain valuable research materials. They also enable constant control and adaptation of the process, thereby leading to increased biomass growth and accumulation of bioactive metabolites. The present study aims to assess the biosynthetic potential of mycelial cultures of six Ganoderma species: G. adspersum, G. applanatum, G. carnosum, G. lucidum, G. pfeifferi, and G. resinaceum. The presence of phenolic acids, amino acids, indole compounds, sterols, and kojic acid in biomass extracts was determined by HPLC. The antioxidant and cytotoxic activities of the extracts and their effects on the inhibition of selected enzymes (tyrosinase and acetylcholinesterase) were also evaluated. The total content of phenolic acids in the extracts ranged from 5.8 (G. carnosum) to 114.07 mg/100 g dry weight (d.w.) (G. pfeifferi). The total content of indole compounds in the extracts ranged from 3.03 (G. carnosum) to 11.56 mg/100 g d.w. (G. lucidum) and that of ergosterol ranged from 28.15 (G. applanatum) to 74.78 mg/100 g d.w. (G. adspersum). Kojic acid was found in the extracts of G. applanatum and G. lucidum. The tested extracts showed significant antioxidant activity. The results suggest that the analyzed mycelial cultures are promising candidates for the development of new dietary supplements or pharmaceutical preparations.     

Antimicrobial Triterpenoids and Ingol Diterpenes from Propolis of Semi-Arid Region of Morocco

The chemical composition and antimicrobial activity of propolis from a semi-arid region of Morocco were investigated. Fifteen compounds, including triterpenoids (1, 2, 7–12), macrocyclic diterpenes of ingol type (3–6) and aromatic derivatives (13–15), were isolated by various chromatographic methods. Their structures were elucidated by a combination of spectroscopic and chiroptical methods. Compounds 1 and 3 are new natural compounds, and 2, 4–6, and 9–11 are newly isolated from propolis. Moreover, the full nuclear magnetic resonance (NMR) assignments of three of the known compounds (2, 4 and 5) were reported for the first time. Most of the compounds tested, especially the diterpenes 3, 4, and 6, exhibited very good activity against different strains of bacteria and fungi. Compound 3 showed the strongest activity with minimum inhibitory concentrations (MICs) in the range of 4–64 µg/mL. The combination of isolated triterpenoids and ingol diterpenes was found to be characteristic for Euphorbia spp., and Euphorbia officinarum subsp. echinus could be suggested as a probable and new plant source of propolis.