Difference in Volatile Aroma Components of Stropharia rugosoannulata under Two Cultivated Environments Investigated by SPME-GC-MS.

In order to study the effect of both greenhouse and forest cultivating environments on Stropharia rugosoannulata, its volatile aroma compounds were measured by a headspace solid phase micro extractions-gas chromatograph-mass spectrometer (SPME-GC-MS). The optimal adsorption temperature was 75 °C and the optimal adsorption time was 40 min. A total of 36 volatile aroma compounds were identified by GC-MS, including 8 aldehydes, 2 ketones, 4 alcohols, 15 alkenes, and 4 alkanes. Hexanal, 3-Octanone, 2-Undecanone, (E)-Nerolidol, and (Z)-ß-Farnesene made great aromatic contributions. Among them, Hexanal, 3-Octanone, 2-Undecanone were the key aroma compounds for which odor activity values (OAVs) were more than 1. (E)-Nerolidol showed odor modification in the forest samples and showed a key aroma effect in greenhouse samples. (Z)-ß-Farnesene showed odor modification in greenhouse samples. 3-Octanone was the largest contributing compound for which the OAV was more than 60. The total content of volatile aroma compounds first increased and then decreased with growth time; it reached the highest level at 48 h: 2203.7 ± 115.2 µg/kg for the forest environment and 4516.6 ± 228.5 µg/kg for the greenhouse environment. The aroma was the most abundant at this time. All samples opened their umbrella at 84 h and become inedible. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were combined to analyze the aroma difference of S. rugosoannulata under two cultivation modes. PCA and HCA could effectively distinguish the aroma difference in different growth stages. Under different culturing methods, the aroma substances and their changes were different. The samples were divided into two groups for forest cultivation, while the samples were divided into three groups for greenhouse cultivation. At the end of growth, the aroma of S. rugosoannulata with the two cultivation modes was very similar. OPLS-DA clearly distinguished the differences between the two cultivation methods; 17 key aroma difference factors with variable importance projection (VIP) > 1 were obtained from SPLS-DA analysis.

Tetrabutylammonium bromide-based hydrophobic deep eutectic solvent for the extraction and separation of dihydromyricetin from vine tea and its inhibitory efficiency against xanthine oxidase.

In this study, deep eutectic solvent oscillation-assisted extraction (DES-OS) combined with macroporous resin adsorption and desorption technology was used to achieve the rapid green extraction and separation of the characteristic component dihydromyricetin (DMY) from vine tea. Multivariate data analysis showed that the DES system composed of tetrabutylammonium bromide (N444Br) and pyruvic acid (molar ratio 1 : 2) had good extraction performance for DMY. The influence parameters of DES-OS were studied, and optimized by the single-factor test and response surface methodology (RSM) with Box-Behnken design (BBD). The extraction model of DMY was established and verified. The results showed that the extraction yield of DMY could reach 40.1 mg g-1 under the optimal conditions (DES water contents of 71.18%, extraction time of 2.80 h, extraction temperature of 46.40 °C), which is in good agreement with the predicted value. In addition, Fourier transform infrared spectroscopy (FT-IR) was used to characterize the solvent before and after extraction. Scanning electron microscopy (SEM) results further confirmed that tetrabutylammonium bromide:pyruvate enhanced the destruction of the cell wall structure, resulting in the release of more DMY. Furthermore, different macroporous resins were selected for the separation of DMY for the DES-OS extract, and it was found that the DM301 resin had the ideal recovery performance under optimized dynamic condition. Finally, the product was found to have an inhibitory effect against xanthine oxidase (XO) as a mixed-type competitive inhibitor with IC50 values of (5.79 ± 0.22) × 10-5 mol L-1. The inhibitory mechanisms of DMY on XO were explored by enzyme kinetics, spectroscopy, molecular docking and molecular dynamics analysis approaches, which provided a theoretical basis for the above inhibition assays.

Inhibitory mechanism of two homoisoflavonoids from Ophiopogon japonicus on tyrosinase activity: insight from spectroscopic analysis and molecular docking.

The inhibition mechanism of two homoisoflavonoids from Ophiopogon japonicus including methylophiopogonanone A (MO-A) and methylophiopogonanone B (MO-B) on tyrosinase (Tyr) was studied by multiple spectroscopic techniques and molecular docking. The results showed that the two homoisoflavonoids both inhibited Tyr activity via a reversible mixed-inhibition, with a half inhibitory concentration (IC50) of (10.87 ± 0.25) × 10-5 and (18.76 ± 0.14) × 10-5 mol L-1, respectively. The fluorescence quenching and secondary structure change of Tyr caused by MO-A and B are mainly driven by hydrophobic interaction and hydrogen bonding. Molecular docking analysis indicated that phenylmalandioxin in MO-A and methoxy in MO-B could coordinate with a Cu ion in the active center of Tyr, and interacted with amino acid Glu322 to form hydrogen bonding, occupying the catalytic center to block the entry of the substrate and consequently inhibit Tyr activity. This study may provide new perspectives on the inhibition mechanism of MO-A and MO-B on Tyr and serve a scientific basis for screening effective Tyr inhibitors.

Interaction between iron and dihydromyricetin extracted from vine tea.

In this research, the interaction between dihydromyricetin (DMY) obtained from vine tea and iron ions (Fe (II) and Fe (III)) was investigated at pH 3.0, 5.0, and 7.0 with UV absorption and fluorescence quenching spectroscopy. The effects of DMY on the stability and solubility of iron ion were also studied. The results showed the presence of iron ions changed the UV absorption spectra of DMY at the experimental pH values. And the fluorescence spectra showed that iron ion had enhanced fluorescence effect on DMY. In addition, DMY was capable of protecting Fe (II) from being oxidized and improving the solubility of Fe (III).

Methylophiopogonanone B of Radix Ophiopogonis protects cells from H2O2­induced apoptosis through the NADPH oxidase pathway in HUVECs.

Methylophiopogonanone B (MO­B), which belongs to a group of homoisoflavonoids, present in Ophiopogon japonicus, has been identified as an active component with antioxidative and anti­tumor properties. The present study investigated whether MO­B may exert protective effects on human umbilical vein endothelial cells (HUVECs) against H2O2­induced injury in vitro, and whether the MO­B effects may be modulated by the NADPH pathway. HUVECs were treated with MO­B in the presence or absence of H2O2. Malondialdehyde (MDA), reactive oxygen species (ROS) levels, and superoxide dismutase (SOD) activity were analyzed to evaluate cell injury and the antioxidative potential of MO­B. The results revealed that MO­B inhibited the production of MDA and ROS, but enhanced SOD activity. Furthermore, MO­B could alleviate H2O2­induced apoptosis in HUVECs, which is consistent with the expression of apoptosis­associated genes and proteins in cells, including Bax/Bcl­2 and caspase­3. To explore the potential mechanism, the present study investigated the effects of MO­B on NADPH­related signaling via the analysis of neutrophil cytochrome b light chain (p22phox) expression, which is the membrane­associated subunit of NADPH oxidase. MO­B could improve the survival of endothelial cells and therefore may be a potential drug in the treatment of cardiovascular diseases.

Application of Ionic Liquid-Based Ultrasonic-Assisted Extraction of Flavonoids from Bamboo Leaves.

Ionic liquids (ILs), known as environmentally benign "green" solvents, were developed as an optimal solvent for the green extraction and separation field. In this paper, an ionic liquid-based ultrasonic-assisted extraction (IL-UAE) of flavonoids (FVs) from bamboo leaves of Phyllostachys heterocycla was developed for the first time. First, 1-butyl-3-methylimidazolium bromide ([Bmim] Br), with the best extraction efficiency, was selected from fifteen ionic liquids with diverse structure, like carbon chains or anions. Then, the influencing parameters of ionic liquid (IL) concentration, liquid-solid ratio, ultrasonic time, and ultrasonic power, were investigated by single factor tests, and further optimized using response surface methodology (RSM). In the optimization experiment, the best conditions were 1.5 mol/L [BMIM]Br aqueous solution, liquid-solid ratio 41 mL/g, ultrasonic time 90 min, and ultrasonic power 300 W. Furthermore, the microstructures of bamboo leaves and the recovery of FVs and [BMIM]Br were also studied. Therefore, this simple, green and effective IL-UAE method has potentiality for the extraction of FVs from bamboo leaves for the large-scale operations.

Repellent Effects of Different Celery Varieties in Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype Q.

Y-tube olfactometer and net cages experiments were used to investigate the repellent effects of different celery varieties in biotype Q of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on cucumber, Cucumis sativus L. (Cucurbitaceae). Y-tube olfactometer tests showed that whiteflies have strong repellent behavior to different celery varieties. Intercropping different celery varieties with cucumbers had significant repellent effects and oviposition deterrent effects in whiteflies. Results obtained demonstrated that the Western Europe celery varieties, Juventus and Ventura, and the Chinese celery variety, Jinnan, had good repellent efficacy against the whitefly. D-Limonene, ß-myrcene, and (E)-ß-ocimene might be the main active components in celery that affected the selection behavior of B. tabaci. In Western Europe celery varieties, D-limonene was the main volatile component for the repellent effects in B. tabaci; however, the two Chinese celery varieties that showed repellent effects had relatively higher volatilization quantities of ß-myrcene than of D-limonene.

Molecular cloning and characterization of an ADP-ribosylation factor 6 gene (ptARF6) from Pisolithus tinctorius.

ADP-ribosylation factor 6 (ARF6) is an evolutionarily conserved molecule that has an essential function in intracellular trafficking and organelle structure. To better understand its role during presymbiosis between plant roots and compatible filamentous fungi, the full-length cDNA sequence of ARF6 from Pisolithus tinctorius was cloned and a variety of bioinformatics analyses performed. The full-length sequence was 849 bp long and contained a 549 bp open reading frame encoding a protein of 182 amino acids. A phylogenetic analysis showed that ptARF6 was the ortholog of the ADP ribosylation factor 6/GTPase SAR1 gene from the white-rot basidiomycete Trametes versicolor. A domain architecture analysis of the ARF6 protein revealed a repeat region, which is a common feature of ARF6 in other species. Recombinant ARF6 protein was expressed with an N-terminal 6×His tag and purified using Ni(2+)-NTA affinity chromatography. The molecular mass of the recombinant protein was estimated by SDS-PAGE to be 25 kDa. The recombinant ARF6 protein bound strongly to 18:1 and 18:2 phosphatidic acids. Thus, ARF6 may participate in the signaling pathways involved in membrane phospholipid composition. The intracellular distribution of ptADP6 in HEK239T cells also indicates that ptADP6 may function not only in plasma membrane events but also in endosomal membranes events. Real-time quantitative PCR revealed that the differential expression of ptARF6 was associated with the presymbiotic stage. ptARF6 may be induced by presymbiosis during the regulation of mycorrhizal formation.

A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato.

With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective.

Analysis of the mating and reproductive traits of Plutella xylostella (Lepidoptera: Plutellidae).

The reproductive traits of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) were investigated and analyzed by different analytical methods. Simple statistical analysis showed relatively higher mating rates maintained from 21:00 to 2:00, thereafter dropping to a minimum at about 18:00. Mating rates were affected by female and male age. Mating was most likely to take place between females and males that were 1 d old. Correlation and factor analysis indicated that mating delayed females have a relatively lower and unsuccessful mating rate and relatively shorter copulation duration, with lower egg hatchability and fecundity; in addition, the mating delayed male would reduce female's fertility. Delay of mating prolonged life of both males and females. A higher and successful mating rate would cause a higher egg hatchability and fecundity. Canonical correlation analysis showed that mating age and successful copulation of female play a decisive role for her fecundity and longevity, and mating age and mating rates of male play a decisive role for his longevity.

Cloning and expression analysis of G-protein Gαq subunit and Gß1 subunit from Bemisia tabaci Gennadius (Homoptera: Aleyrodidae).

The heterotrimeric G proteins play an essential role in a wide variety of signal transduction pathways, mediating the process of chemical signals from the environment in all higher eukaryotic organisms. In this article, two G-protein subunit genes encoding Gαq and Gß1 were cloned from Bemisia tabaci Gennadius. The full-length cDNA sequence of BtGαq consisted of 2,336 bp with an ORF of 1,062 bp encoding 353 amino acids and BtGß1 had a full length of 1,942 bp with an ORF of 1,023 nucleotides encoding 340 amino acids. The amino acid sequences of BtGαq and BtGß1 from B. tabaci B biotype were identical to those from the Q biotype. Phylogenetic analysis identified G protein α and ß subunit families from insects based on their amino acid sequences. The expression patterns of BtGαq and BtGß1 at different development stages and in different body regions were analyzed by real-time quantitative PCR and Western blot. The results show that BtGαq and BtGß1 are neither developmental stage-specific nor tissue-specific. The transcript levels of BtGαq in the B biotype are similar to that in the Q biotype, the transcript levels of BtGß1 at egg, first instar and pupae in B biotype were significantly higher than that in Q biotype. The transcript levels of BtGαq and BtGß1 in the head were significantly higher than those in thorax and abdomen indicating that they are involved in nervous system and sensory functions.

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles.

Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most serious pests of Brassicaceae crops worldwide. Electrophysiological and behavioral responses of P. xylostella to green leaf volatiles (GLVs) alone or together with its female sex pheromone were investigated in laboratory and field. GLVs 1-hexanol and (Z)-3-hexen-1-ol elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relatively weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactometer experiments. (E)-2-Hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate induced attraction of males, reaching up to 50%, significantly higher than the response to the unbaited control arm. In field experiments conducted in 2008 and 2009, significantly more moths were captured in traps baited with synthetic sex pheromone with either (Z)-3-hexenyl acetate alone or a blend of (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, and (E)-2-hexenal compared with sex pheromone alone and other blend mixtures. These results demonstrated that GLVs could be used to enhance the attraction of P. xylostella males to sex pheromone-baited traps.

Effects of temperature and humidity on emergence dynamics of Plutella xylostella (Lepidoptera: Plutellidae).

The effects of temperature and humidity on the emergence patterns of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were studied at four temperatures (20, 25, 28, and 33 degrees C),three relative humidities (50, 70, and 90%) and a photoperiod of 14:10 (L:D) h. Both sexes emerged primarily in the late afternoon to early morning, and the peaks of emergence varied depending on temperature and humidity. Females emerged significantly earlier than males. Incubation at 33 degrees C and 90% RH had a significant effect on the emergence rate, but no significant interaction was found between temperature and humidity. Emergence duration was 25.3 h for both sexes at 90% RH, with emergence duration at 33 degrees C lower than the other treatments. The sex ratios of diamondback moth under different temperature and humidity treatments were approximately 1:1, and there were no significant effects of temperature and humidity or interactions between these two factors.

Hemolymph juvenile hormone titers in worker honey bees under normal and preswarming conditions.

Swarming is an important mechanism by which honey bee, Apis mellifera L., colonies reproduce, yet very little is known about the physiological changes in workers that are preparing to swarm. In this study, we determined the endocrine status of worker honey bees in preswarming colonies and in normal (nonswarming) colonies. Juvenile hormone (JH) titers in worker bees were similar in both groups before queen cells were present, but they became significantly lower in preswarming colonies compared with normal colonies when queen cells occurred in preswarming colonies. The lower JH titers in the preswarming colonies suggest that behavioral development is delayed in these colonies, consistent with previous reports that preswarming colonies have reduced foraging activities. Understanding the endocrine status of bees preparing for swarming will help us to better understand the biology of swarming.

Biochemical and physiological changes in plants as a result of different sonic exposures.

The effects of two different sonic exposures on two vegetables, namely Chinese cabbage and cucumber at two growth stages, including seedlings and mature plants were investigated. The 3 h exposures included either 20 kHz sound waves or "green music" that comprised classic music and natural sounds such as those of birds, insects, water, etc. Analysis of variance between groups (ANOVA) was used to determine the appropriate statistics parameters for the different treatments. Both exposures caused significant elevations in the level of polyamines (PAs) and increased uptake of oxygen O(2) in comparison with the controls. For Chinese cabbage the highest PAs' levels were determined for both seedlings and mature plants that were exposed to "green music". The oxygen uptake in Chinese cabbage also increased as a result of sonic exposures, and the highest oxygen uptake was also observed after "green music" treatment. For cucumber, the highest content of PAs for both seedlings and mature cucumber plants was determined as a result of 20 kHz ultrasound exposure. 20 kHz exposure of mature plants also resulted in the highest level of oxygen uptake. No statistically significant differences in the vitamin C level were determined between the different sonic treatments and sham exposed vegetables.