Rapid analysis of free fatty acid composition in Brassica rapa L. and Brassica napus L. extracts by surface-assisted laser desorption/ionization time-of-flight mass spectrometry

A rapid and simple technique was developed to identify free fatty acids in mixtures by the surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) using powdered carbon aerogels as a “matrix”. A 3% solution of a neutral surfactant Triton X-100 was used as a fixing agent of carbon particles as well as a suppressor of background peaks. The extraction of free fatty acids from Brassica napus (rape) and Brassica rapa (turnip) seeds was performed by using both methanol-chloroform mixture and supercritical fluid extraction techniques. The quantitative analysis of the seed composition was carried out to demonstrate the effectiveness of the developed method. The detection limits were determined using a mixture of ten standard fatty acids and were found to be 3 ng of each acid per spot.     

Effects of Phytohormones and Jasmonic Acid on Glucosinolate Content in Hairy Root Cultures of Sinapis alba and Brassica rapa

Although some study have established hairy root cultures from brassicaceous plants with glucosinolates (GS) as characteristic secondary metabolite, studies are missing which compare hairy roots with the corresponding mother plants. Therefore, two different plant species—Sinapis alba and Brassica rapa subsp. rapa pygmeae teltoviensis—were transformed with the Agrobacterium rhizogenes strain A4. Aliphatic and indolyl GS were present in B. rapa, exhibiting larger quantities in leaves than in roots. Aromatic p-hydroxybenzyl GS were found particularly in the leaves of S. alba. However, the proportion of indolyl GS increased suddenly in transformed hairy roots of S. alba and B. rapa. Cultivation with the phytohormone kinetin (0.5 mg?L^?1) enhanced GS accumulation in B. rapa hairy roots, however not in S. alba, but 2,4-D (0.4 mg?L^?1) induced de-differentiation of roots in both species and reduced GS levels. GS levels especially of 1-methoxyindol-3ylmethyl GS increased in hairy roots in response to JA, but root growth was inhibited. While 2 weeks of cultivation in 100 to 200 μM JA were determined at optimum for maximum GS yield in S. alba hairy root cultures, 4 weeks of cultivation in 50 to 100 μM JA was the optimum for B. rapa.     

Simultaneous identification of glucosinolates and phenolic compounds in a representative collection of vegetable Brassica rapa

Brassica raparapa group is widely distributed and consumed in northwestern Spain. The consumption of Brassica vegetables has been related to human health due to their phytochemicals, such as glucosinolates and phenolic compounds that induce a variety of physiological functions including antioxidant activity, enzymes regulation and apoptosis control and the cell cycle. For first time in Brassica crops, intact glucosinolates and phenolic compounds were simultaneously identified and characterized. Twelve intact glucosinolates, belonging to the three chemical classes, and more than 30 phenolic compounds were found in B. rapa leaves and young shoots (turnip greens and turnip tops) by LC–UV photodiode array detection (PAD)–electrospray ionization (ESI). The main naturally occurring phenolic compounds identified were flavonoids and derivatives of hydroxycinnamic acids. The majority of the flavonoids were kaempferol, quercetin and isorhamnetin glycosylated and acylated with different hydroxycinnamic acids. Quantification of the main compounds by HPLC-PAD showed significant differences for most of compounds between plant organs. Total glucosinolate content value was 26.84 μmol g⁻¹ dw for turnip greens and 29.11 μmol g⁻¹ dw for turnip tops; gluconapin being the predominant glucosinolate (23.2 μmol g⁻¹ dw). Phenolic compounds were higher in turnip greens 51.71 μmol g⁻¹ dw than in turnip tops 38.99 μmol g⁻¹ dw, in which flavonols were always the major compounds.     

Quercetin and Rutin as Modifiers of Aphid Probing Behavior

Rutin and its aglycone quercetin occur in the fruits, leaves, seeds, and grains of many plant species and are involved in plant herbivore interactions. We studied the effect of the exogenous application of rutin and quercetin on the probing behavior (= stylet penetration activities in plant tissues) of Acyrthosiphon pisum on Pisum sativum, Myzus persicae on Brassica rapa ssp. pekinensis, and Rhopalosiphum padi on Avena sativa using the electrical penetration graph technique (EPG = electropenetrography). The reaction of aphids to quercetin and rutin and the potency of the effect depended on aphid species, the flavonol, and flavonol concentration. Quercetin promoted probing activities of A. pisum within non-phloem and phloem tissues, which was demonstrated in the longer duration of probes and a trend toward longer duration of sap ingestion, respectively. M. persicae reached phloem in a shorter time on quercetin-treated B. rapa than on the control. Rutin caused a delay in reaching sieve elements by A. pisum and deterred probing activities of M. persicae within non-phloem tissues. Probing of R. padi was not affected by quercetin or rutin. The potency of behavioral effects increased as the applied concentrations of flavonols increased. The prospects of using quercetin and rutin in plant protection are discussed.     

Evolution of Brassica rapa var. rapa L. volatile composition by HS-SPME and GC/IT-MS

Brassica rapa var. rapa L. (turnip) is highly appreciated and consumed by human. In this work, the volatile profile of B. rapa var. rapa was studied during the maturation process. The volatiles of seeds, sprouts with 6 and 9 days, and adult plant were determined using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography/ion trap-mass spectrometry (GC/IT-MS).Several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, nitrogen and sulphur compounds were characterized, totalizing 64 compounds. Isothiocyanates are the main volatiles in all matrices, being 3-butenyl isothiocyanate the major compound. Qualitative and quantitative differences were found among the analysed materials. Nitrogen and sulphur compounds decreased during the maturation process, while terpenes, aldehydes, norisoprenoids and ester compounds were present in higher amounts during germination, especially in sprouts with 9 days of development.     

Influence of Europium speciation on its accumulation in Brassica napus and over-expressing BnTR1 lines

This study aimed at influence of europium speciation on its accumulation in Brassica napus (CK) and over-expressing BnTR1 lines (OE), and the kinetics of Eu uptake were investigated. These results indicated that the uptake in the roots of OE was higher than that of CK at high concentrations of europium and even the enrichment in the roots of OE was as high as 20,000 mg/kg at 328.9 μΜ Eu, this suggested that OE might have better resistance to uranium than CK. The time kinetics in plants showed that there had the similar trend between CK and OE. The formation of Eu³⁺at pH 5 in deionized water was beneficial to plants enrichment Eu and carbonate could reduce the adsorption of Eu in two group and phosphate almost completely impress the adsorption of Eu in two group, but citric acid could enhance europium root-to-shoot translocation in two group. These results would help understanding the mechanism of Eu uptake in Brassica napus (CK) and over-expressing BnTR1 lines (OE), therefore properly developing efficient europium/americium phytoremediation.     

Computational analysis of atpB gene promoter from different Pakistani apple varieties

Apple is the fourth most important fruit crop grown in temperate areas of the world belongs to the family Rosaceae. In the present study, the promoter (∼1000 bp) region of atpB gene was used to evaluate the genetic diversity and phylogeny of six local apple varieties. atpB gene is one of the large chloroplastic region which encodes β-subunit of ATP synthase and previously it had been used largely in phylogenetic studies. During the present study, atpB promoter was amplified, sequenced and analyzed using various bioinformatics tools including Place Signal Scan, MEGA6 and BLASTn. During the phylogenetic analysis, obtained phylogram divided the studied varieties into two clusters revealing the monophyletic origin of studied apple varieties. Pairwise distance revealed moderate genetic diversity that ranges from 0.047–0.170 with an average of 0.101. While identifying different cis-acting elements present in the atpB promoter region, results exhibited the occurrence of 56 common and 20 unique cis-regulatory elements among studied varieties. The identified cis-acting regulatory elements were mapped as well. It was observed that Kala Kulu has the highest unique features with reference to the availability of cis-acting elements. Moreover, the possible functions of all regulatory elements present on the promoter sequence of atpB gene were predicted based on already reported information regarding their in vivo role.     

Chemical characterization,antioxidant properties and enzyme inhibition of Rutabaga root’s pulp and peel (Brassica napus L.)

Rutabaga (Brassica napus L.) belonging to Brassicaceae family, is a rich source of polyphenols and glucosinolates. Its consumption in human diet is highly appreciated for its nutritional contribution and health benefits. Brassica napus L. is recognized as the world's most widely grown temperate oilseed crop containing erucic acid for industrial applications, plants germination, animal feed and fuel. In this work we prepared two different extracts of Rutabaga root’s pulp and peel, e.g. ultrasound assisted extract (UAE) and homogenizer assisted extract (HAE). The four extracts have been analyzed by HPLC-MS to assess the phytochemical characterization and tested by antioxidant and enzyme inhibitor assays. Rutabaga pulp and peel extracts possess tyrosinase and glucosidase inhibitory activities together with a moderate antioxidant ability. Our results show a high level of glucosinolates, in particular neoglucobrassicin in the peel extract, which let us suppose a potential application as crop in industry and as supplement in human diet.     

含吡啶环的1,3,4-噁二唑衍生物的合成及生物活性研究

依据生物电子等排原理,在分子中同时引入吡啶环和1,3,4-噁二唑杂环合成了5-(3-吡啶基或4-吡啶基)-1,3,4-噁二唑2-硫乙酸胺类化合物,用¹HNMR,IR,质谱和元素分析对其结构进行了表征.离体试验表明,化合物B1-5小麦赤霉病菌和苹果轮纹病菌的抑制率分别为30%和42%,化合物B1-6对苹果轮纹病菌的抑制率为38%.除草活性实验结果表明,化合物B1-6对油菜和稗草具有较高的抑制作用.     

Determination of nitrite with a nano-gold modified glassy carbon electrode by cyclic voltammetry

Abstract

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was employed to determine the concentration of rare earth elements (REEs) in plants and soils. Sample preparation and analytical conditions were investigated to set up a simple routine procedure for measuring rare earth elements. For prompt sample decomposition, a microwave digestion technique was successfully used with an acid mixture of HCl+HNO₃+HF. Detection limits, reproducibility, accuracy and possible interference were also studied. ICP-MS provided extremely low detection limits for REEs (0.6–6ng/l). Precision was typically better than 6% RSD (relative standard deviation) for soil and 10% for plant. The potential of the method was evaluated by analysis of standard reference materials of soils and plants. A good agreement between the experimental results and certified values was observed. The spectroscopic interference of Ba with Eu and light REEs(LREEs, La-Eu) with heavy REEs(HREEs, Gd-Lu) were eliminated by the algebra correction.

The results suggested that REEs in soil samples existed mainly as light REEs, and the same concentration distribution patterns of Oddo-Hakins law were observed, showing negative gradient from La to Lu concentrations. The REE contents in plants were very low, less than 20μg/g and varied with plant species. Apart from rape leaf(Brassica juncea), the REE distribution patterns in other plant leaves were consistent with soils, indicating that these plants generally absorbed REEs from soil without selectivity. Rape leaf showed selective absorption for LREEs, especially for La. The REE concentration distribution in parts of hot pepper(Capsicum annuum) was characteriaed by root>leaf>stem>fruit. The REEs absorbed by hot pepper concentrated mainly in roots and leaves, very little migrated into fruit. Transfer factors(TFs) of REEs in plants were very low. Although the contents of LREEs were relatively more than those of HREEs, no distinct difference of TFs between LREEs and HREEs was observed, meaning that LREEs and HREEs have the same abilities of transportation. However, for rape leaf, the TFs of LREEs were one or two orders of magnitude higher than those of HREEs.     

3-取代苯氧甲基-6-氯哒嗪的合成及其除草活性

通过3-氯-6-溴甲基哒嗪与各种取代的苯酚在K₂CO₃/DMF体系中反应, 合成了一系列3-取代苯氧甲基-6-氯哒嗪化合物. 它们的结构均经¹H NMR, IR和元素分析确证. 在浓度为100 μg•mL^－1时, 初步的生物活性测试结果表明, 所合成的化合物对油菜和稗草均有一定的抑制作用. 并讨论了其结构与除草活性的关系.     

Flavonoid Glycosides in Brassica Species Respond to UV-B Depending on Exposure Time and Adaptation Time

Recently, there have been efforts to use ultraviolet-B radiation (UV-B) as a biotechnological tool in greenhouses. Leafy Brassica species are mainly considered for their ability to synthesize glucosinolates and are valued as baby salads. They also have a remarkable concentration of chemically diverse flavonoid glycosides. In this study, the effect of short-term UV-B radiation at the end of the production cycle was investigated without affecting plant growth. The aim was to verify which exposure and adaptation time was suitable and needs to be further investigated to use UV as a biotechnological tool in greenhouse production of Brassica species. It is possible to modify the flavonoid glycoside profile of leafy Brassica species by increasing compounds that appear to have potentially high antioxidant activity. Exemplarily, the present experiment shows that kaempferol glycosides may be preferred over quercetin glycosides in response to UV-B in Brassica rapa ssp. chinensis, for example, whereas other species appear to prefer quercetin glycosides over kaempferol glycosides, such as Brassica oleracea var. sabellica or Brassica carinata. However, the response to short-term UV-B treatment is species-specific and conclusions on exposure and adaptation time cannot be unified but must be drawn separately for each species.     

Electrorheological properties of poly(linear trans-quinacridone)-based suspensions

Ladder-like polymer poly(linear trans-quinacridine) (polyquin (2,3-b) acridine-7,14(5,12) dione, PTQA) was synthesized and identified. Anhydrous electrorheological fluid (ER fluid, ERF) with PTQA as dispersed particle and bromodiphenylmethane (BDPM) as dispersing medium were prepared; the electrorheological properties were studied. The temperature effect of PTQA suspensions was also discussed. The results showed that PTQA suspensions in BDPM performed excellent ER activity; at room temperature, the yield stress of the suspension with 30 wt.% of particles was up to 6.0 kPa (3.0 kV/mm). The shear stress increased with the rise in temperature, and the temperature effect was enhanced at higher temperature range. The differences of electrorheological properties between PTQA-based ERF and polyquin(2,3-b) acridine-12,14(5,7) dione-based ERF were attributed to the molecular structural regularity of the polymer.     

Synthetic reactions catalyzed by immobilized lipase from oilseed rape (Brassica napus L.)

Lipase from rape (Brassica napus L., immobilized onto celite, catalyzes esterification and transesterification reactions in hexane. The activity of the lipase is stimulated up to 35 fold by the addition of water (1.3% w/v). The activity of the lipase in hydrolysis is about 8 times higher than in the esterification reactions in hexane. Interesteri-fication reactions between mono- and diacylglycerols and transesterification reactions of mono- and diacylglycerols with alcohols were also catalyzed at relatively high rates but transesterification/esterification of these acylglycerols with fatty acids was comparatively slow. In transesterification reactions, triacylglycerols reacted rather slowly.     

The use of fast protein liquid chromatography with ICP-OES and ES-MS-MS detection for the determination of various forms of aluminium in the roots of Chinese cabbage

The distribution of aluminium (Al) species was investigated in the roots of Al-tolerant Chinese cabbage (Brassica rapa L. ssp. pekinensis) by employing fast protein liquid chromatography (FPLC) with inductively coupled plasma optical emission spectrometry (ICP-OES) and electrospray tandem mass spectrometry (ES-MS-MS) detection. The cabbage was exposed to a nutrient solution that contained 10 μg cm⁻³ of Al³⁺. The results demonstrated that after 24 h of exposure, Al was quantitatively taken up by the cabbage and was distributed in different parts of the plant. 36 ± 6% of total Al was located in the roots, while the remaining 64 ± 10% was transferred to the leaves. It was found that in the roots Al was partially present in the root sap (15.5%), while the majority (84.5%) was accumulated in its apoplasmic compartments. It was further demonstrated that the proportion of Al that entered the symplasm formed a complex with organic acid. Speciation analysis by FPLC with ICP-OES detection and ES-MS-MS identification of the binding ligand indicated that Al-citrate complex was the prevailing species in the root sap.The results of the present study showed that both immobilization of Al in the apoplasmic compartments of the roots and transformation of Al³⁺ to Al-citrate are most likely responsible for the tolerance of Chinese cabbage (B. rapa L. ssp. pekinensis) to the toxic effects of Al³⁺.     

Microsensor in vivo monitoring of oxidative burst in oilseed rape (Brassica napus L.) leaves infected by Sclerotinia sclerotiorum

Oxidative burst is the rapid and transient production of large amounts of reactive oxygen species, including superoxide anion, hydrogen peroxide (H₂O₂), and hydroxyl radical. A rapid and simple technique was employed for in vivo detection of oxidative burst in oilseed rape (Brassica napus L.) leaves, using a modified electrode. Platinum (Pt) micro-particles were dispersed on a Pt electrode, coated with a poly (o-phenylenediamine) film. This exhibited high sensitivity, selectivity and stability in H₂O₂ detection. Amperometry was used to obtain satisfactory linear relationships between reductive current intensities and H₂O₂ concentrations at −0.1 V potential in different electrolytes. This electrode was used in vivo to detect oxidative burst in oilseed rape following fungal infection. Oxidative bursts induced by infection of the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary exhibited notably different mechanisms between a susceptible and a resistant glucose oxidase-transgenic genotype.     

New Efficient Synthesis of 5,6-Disubstituted-3-phenyl-1,2,3-triazolo[4,5-d]pyrimidin-7-ones via a Tandem Aza-Wittig Reaction

Twelve novel 5,6-disubstituted-3-phenyl-1,2,3-triazolo[4,5-d]pyrimidine-7-ones 5a–5l were designed and successfully synthesized via tandem aza-Wittig and annulation reactions of the corresponding iminophosphorances 2, aromatic isocyanate, and substituted thiophenols in satisfactory yields. The results from the preliminary bioassay indicated that some of these compounds possess inhibitory activities against the root and stalk of Brassica napus(rape) as well as Echinochloa crusgalli (barnyard grass) at the dosages of 100 mg/L and 10 mg/L, respectively.     

Comparative Analysis and Modeling of Superoxide Dismutases (SODs) in Brachypodium distachyon L.

Superoxide dismutase (SOD, EC 1.15.1.1) is an enzyme catalyzing the dismutation of superoxide radical to hydrogen peroxide and dioxygen. To date, four types of SODs — Cu/ZnSOD, MnSOD, FeSOD, and NiSOD — have been identified. In this study, SOD proteins of Brachypodium distachyon (L.) Beauv. were screened by utilization of bioinformatics approaches. According to our results, Mn/FeSODs and Cu/ZnSODs of B. distachyon were found to be in basic and acidic character, respectively. Domain analyzes of SOD proteins revealed that iron/manganese SOD and copper/zinc SOD were within studied SOD proteins. Based on the seconder structure analyzes, Mn/FeSODs and Cu/ZnSODs of B. distachyon were found as having similar sheets, turns and coils. Although helical structures were noticed in the types of Mn/FeSODs, no the type of Cu/ZnSODs were identified having helical structures. The predicted binding sites of Fe/MnSODs and Cu/ZnSODs were confirmed for having His-His-Asp-His and His-His-His-Asp-Ser residues with different positions, respectively. The 3D structure analyzes of SODs revealed that some structural divergences were observed in patterns of SODs domains. Based on phylogenetic analysis, Mn/FeSODs were found to have similarities whereas Cu/ZnSODs were clustered independently in phylogenetic tree.