Rapid evaluation of the initial and equilibrium parameters of CsCl and RbCl in equilibrium ultracentrifugation.

Two types of tables and graphs have been calculated. One type relates the initial density of the gradient solution to its equilibrium density at the bottom of the tube. The other type lists the function I(p) (defined by C. R. McEwen, 1967, Anal. Biochem.19, 23–29) and can be used to obtain the equilibrium density at any radius from the axis, provided the equilibrium density at one radius is known. Tables are calculated for CsCl and RbCl as gradient materials, and for Beckman Instruments rotors SW 41 and SW 65.     

Nematicidal effect of volatiles produced by Trichoderma sp.

Trichoderma is an important biocontrol agent that produces metabolites harmful to nematodes. We investigated the volatile organic compounds (VOCs) of Trichoderma sp. YMF 1.00416 and examined their abilities to kill nematodes. Chemical investigations of the VOCs from this strain led to the isolation and identification of three metabolites: a new compound, 1β-vinylcyclopentane-1α,3α-diol (1) and two known metabolites, 6-pentyl-2H-pyran-2-one (2) and 4-(2-hydroxyethyl)phenol (3). Nematicidal activity assays showed that compound 2 was nematicidal, and killed > 85% of Panagrellus redivivus, Caenorhabditis elegans, and Bursaphelenchus xylophilus in 48 h at 200 mg/L in a 2 mL vial. Our results will help identify new nematicides.     

Influence of dietary fibre on nutrient digestibility and energy utilisation in growing pigs fed diets varying in soluble and insoluble fibres from co-products

The co-products from the industry are used to reduce costs in pig diets. However, the co-products used in pig diets are limited because of a high fibre content which is not digested by endogenous enzymes and is resistant to degradation in the small and large intestines. The aim of this study was to investigate digestibility of nutrients and energy, and energy utilisation in pigs fed diets with various soluble and insoluble dietary fibre (DF) from co-products. The experiment was performed as a 4 × 4 Latin square design (four diets and four periods) using four growing pigs (66.2 ± 7.8 kg) surgically fitted with a T-cannula in the end of the small intestine. The pigs were fed four experimental diets: low-fibre control (LF), high-fibre control (HF), high-soluble fibre (HFS) and high-insoluble fibre (HFI) diets. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of ash, organic matter, CP, fat, carbohydrates, starch and non-starch polysaccharides (NSP) divided into cellulose and soluble and insoluble non-cellulosic polysaccharide residues were measured using chromic oxide as marker. The recovery of total solid materials, organic matter and total carbohydrates in ileal digesta in pigs fed the HF and HFS diets was higher than in pigs fed LF and HFI, whereas recovery of organic matter and total carbohydrates in faecal materials in the HFS diet was lowest (P < 0.05). AID of organic matter, total carbohydrates and starch was lowest for HFS diet (P < 0.05). ATTD of organic matter and CP was higher for LF diet compared with other diets (P < 0.05), whereas total NSP, cellulose and non-cellulosic polysaccharides residues were highest for HFS diet (P < 0.05). Lactic acid in ileal digesta was influenced by dietary composition (P < 0.05) whereas neither type nor level of DF affected short chain fatty acids. The digestible energy, metabolisable energy, net energy and retained energy intake were similar among diets without influence of DF inclusion (P > 0.05). The metabolisable energy:digestible energy ratio was lower when feeding the HFS diet because of a higher fermentative methane loss. Faecal nitrogen and carbon were positively correlated with DM intake and insoluble DF in the diets (P < 0.05), but nitrogen and carbon (% of intake) were similar among diets. The present findings suggest that high-DF co-products can be used as ingredients of pig diets when features of DF are considered.     

Subunit CydX of Escherichia coli cytochrome bd ubiquinol oxidase is essential for assembly and stability of the di-heme active site

Cytochrome bd ubiquinol oxidase uses the electron transport from ubiquinol to oxygen to establish a proton gradient across the membrane. The enzyme complex consists of subunits CydA and B and contains two b- and one d-type hemes as cofactors. Recently, it was proposed that a third subunit named CydX is essential for the function of the complex. Here, we show that CydX is indeed a subunit of purified Escherichia coli cytochrome bd oxidase and that the small protein is needed either for the assembly or the stability of the active site di-heme center and, thus, is essential for oxidase activity.Structured summary of protein interactionscydA physically interacts with cydB by affinity technology (View interaction)cydA physically interacts with cydB by molecular sieving (View interaction)cydB, cydA and cydX physically interact by molecular sieving (View interaction)cydB, cydA, and cydX physically interacts by affinity technology (1, 2)     

Antifungal activity of alkyl and heterocyclic aza-derivatives of gossypol as well as their complexes with NaClO4 against Fusarium oxysporum f. sp. lupini

Eight alkyl and six heterocyclic aza-derivatives of gossypol (2–15) have been synthesized using gossypol (1) extracted from Gossypium Herbaceum cottonseeds. The ability of gossypol aza-derivatives to form complexes with NaClO₄ has been investigated by electrospray ionisation (ESI) mass spectra recorded in the positive and negative ion detection modes. The gossypol aza-derivatives have been characterized by FT-IR, ¹H and ¹³C NMR spectroscopic methods and subsequently tested for their antifungal properties against Fusarium oxysporum. Four alkyl aza-derivatives (2–5), present in the enamine–enamine tautomeric form, have shown activity comparable or higher than that of gossypol against this fungus. To improve the antifungal activity the complexes of the most active compounds 2–5 with NaClO₄ were prepared. Complexes of 2 and 5 with NaClO₄ have shown antifungal activity higher than that of the uncomplexed compounds.     

The 13C-n.m.r. spectra of peracetylated cello-oligosaccharides

The reaction of 1,4-anhydro-2-deoxy-5,6-O-isopropylidene-d-arabino-hex-1-enitol (1) with m-chloroperbenzoic acid in ethanol gives 2,3-unsaturated ethyl glycosides together with saturated ethyl glycosides formed by trans-ring opening of 1,2-epoxide intermediates. Similar results are obtained on peroxidation of 1,4-anhydro-2-deoxy-3-O-(2,3:5,6-di-O-isopropylidene-α-d-mannofuranosyl)-5,6-O-isopropylidene-d-arabino-hex-1-enitol (2). Products resulting from osmylation of 1 and 2 and cleavage of the osmate esters are also described. 2-Deoxy derivatives are prepared from 1 and 2 by methoxymercuration-demercuration and also by reduction of 2-bromo-2-deoxy derivatives obtained by ethoxybromination.     

Secondary metabolites,phytochemical characterization and antioxidant activities of different extracts of Sideritis congesta P.H. Davis et Hub.-Mor.

Sideritis congesta, an endemic plant to Turkey, is extensively consumed as energizing herbal tea and used as a remedy in folk medicine. This study was designed to comparatively evaluate the phytochemical composition and antioxidant potentials of different extracts (methanol, infusion) and fractions (chloroform, ethyl acetate, and remaining water) of S. congesta. Antioxidant potentials of the samples were evaluated by DPPH radical scavenging, FRAP, CUPRAC, and total antioxidant capacity tests. Total phenolic, phenolic acid, and flavonoid contents were also evaluated spectrophotometrically. Moreover, presence of twenty-two phenolic metabolites were affirmed by using LC-MS/MS in MRM scan mode and then the quantification of verbascoside, martynoside, and leucoseptoside A was performed by using HPTLC densitometry. EtOAc fraction contained the highest phenolic content and the antioxidant activity, as well as the highest verbascoside and martynoside contents followed by R-H₂O fraction. Phytochemical studies on R-H₂O fraction, yielded seven compounds, including a phenylethanoid glycoside, verbascoside (1), two flavonoids, stachyspinoside (2), isoscutellarein 7-O-(6‴-O-acetyl)-β-allopyranosyl-(1 → 2)-β-glucopyranoside (3), a phenolic acid chlorogenic acid (4), an iridoid glycoside ajugoside (5), and a monoterpenoid glucoside mixture betulalbuside A (6) and 1-hydroxylinaloyl 6-O-β-D-glucopyranoside (7). The molecular structures of the isolated compounds were determined by NMR and MS experiments. This is the first phytochemical study on the polar constituent of S. congesta and the first report of the isolation of compounds 2, 6 and 7 from the genus Sideritis L.     

Analysis of permethylated hexopyranosyl-2-acetamido-2-deoxyhexitols by g.l.c.-m.s.

The major product obtained on acetonation of d-mannose with a 2-molar excess of isopropenyl methyl (or ethyl) ether is 4,6-O-isopropylidene-α-d-mannopyranose (3a), the product of kinetic acetonation: a larger excess of the reagent leads, to the 2,3:4,6-diisopropylidene acetal (6). The course of the reaction and side-products formed were examined in detail. The 1,2,3-triacetate of 3a was deacetonated to give α-d-mannopyranose 1,2,3-triacetate; similar reactions were performed on the β anomers. The 1-acetate of the diacetal 6 could be selectively deacetonated to give 1-O-acetyl-2,3-O-isopropylidene-α-d-mannopyranose. The reactions provide access to protected derivatives of d-mannose, and partially acylated derivatives, having modes of substitution different from those obtainable by classical acetonation procedures conducted under conditions of thermodynamic control.     

Phenolic derivatives in raspberry (Rubus L.) germplasm collection in Bulgaria

Leaves of 22 accessions of the Bulgarian raspberry (Rubus L.) germplasm collection – five Bulgarian and seven foreign cultivars, eight elite clones and two wild species, Rubus occidentalis L. and Rubus odoratus L., were analysed for phenolic constituents. The quantitative determination of caffeic (1), p-coumaric (2) and ferulic (3) acids, hyperoside (4), tiliroside (5), and isoquercitrin (6) was performed by RP-HPLC using linear gradient elution and UV detection at 254 and 310 nm. The detection limits ranged from 0.23 μg/ml (4) to 0.55 μg/ml (2). Caffeic acid was the dominant phenolic acid in the majority of the samples being present in amounts between 0.05 ± 0.01 mg/g dry weight in R. occidentalis and 1.43 ± 0.06 mg/g in the cultivars. The highest content of flavonols was found in the Bulgarian raspberry elite clones: 1.70 ± 0.002 mg/g (6), 0.60 ± 0.004 mg/g (5) and 0.97 ± 0.01 mg/g (4). Data were analyzed by hierarchical clustering (HC) and principal component analysis (PCA). The HC and PCA scoring plot showed that the samples could be classified into three clusters. Cluster C1 comprised cultivars characterized by high content of phenolic acids (1–3). Seven cultivars and the wild species R. occidentalis formed the cluster C2 presenting low content of phenolic compounds. Cluster C3 grouped the Bulgarian raspberry elite clones and R. odoratus sharing the highest content of flavonols (5 and 6). The Bulgarian elite clone E23617 displayed the highest content of the studied phenolic derivatives. The PCA loading plot showed that 1 can be used to distinguish between different raspberry varieties.     

Pattern formation in the egg of the leafhopper Euscelis plebejus Fall. (Homoptera): Developmental capacities of fragments isolated from the polar egg regions

The egg of the leafhopper Euscelis plebejus has been separated into three fragments [for nomenclature, see Sander, K. (1976). Advan. Insect Physiol.12, 125–238] by two constrictions in order to exclude the middle egg part from possible terminal influences on pattern specification. Middle fragments of freshly laid eggs (two pronuclei or one nucleus) differentiate middle segments of the embryonic pattern. The segment composition of those partial patterns varies with the position of the two constrictions. Eggs subdivided at later stages of development produce similar partial patterns in the middle fragment, but with more segments. The mode of segment expression in single and double fragmented eggs is compatible with the assumption that the metameric pattern is differentiated by a sequence of short-range inductions rather than by an extensive gradient field.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.     

Secondary metabolites from Scutellaria albida L. ssp. velenovskyi (Rech. f.) Greuter & Burdet

Fourteen compounds (Fig.1) were isolated from the aerial parts of Scutellaria albida L. ssp. velenovskyi (Rech. f.) Greuter & Burdet, including four iridoids (1–4) catalpol, macfadienoside, mussaenosidic acid, albidoside; four flavonoids (5–8) hispidulin 7-Ο-β-D-glucuronide, scutellarin, xanthomicrol, eriodictyol; four phenylethanoid glycosides (9–12) verbascoside, leucosceptoside A, martynoside, 2-(3-hydroxy-4-methoxy-phenyl)-ethyl-1-Ο-β-D-glucopyranoside; the sugar ester 6′-β-D-glucopyranosyl-E-p-coumarate (13), as well as the acetogenic glucoside (Z)-3-hexenyl-1-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (14). The structures of the isolates were established by means of NMR and HRMS spectral analyses. This is the first phytochemical study on S. velenovskyi and the first report of an acetogenic glycoside in the genus Scutellaria L. A chemical review on the isolated secondary metabolites in this study has been carried out. The chemotaxonomic value of the isolates is also discussed. Based on the literature data, the analysis revealed that the chemical profile of S. velenovskyi is close to that of the taxa belonging to the S. albida group.     

Determination of a thermally labile metabolite of a novel growth hormone secretagogue in human and dog plasma by liquid chromatography with ion spray tandem mass spectrometric detection

A sensitive and selective assay for the determination of N-{1(R)-[(1,2-dihydro-1-methylsulfonylspiro[3H-indole-3,4′-piperidin]-1′-yl)carbonyl]-2-(phenylmethoxy)-ethyl}-2-hydroxyamino-2-methylpropanamide (I), a hydroxyl amine metabolite of a novel growth hormone secretagouge (II) has been developed utilizing high-performance liquid chromatography with ion spray tandem mass spectrometric detection (HPLC–MS–MS). The analyte and an internal standard (III) were isolated from the basified biological matrix using a liquid–liquid extraction with methyl tert.-butyl ether (MTBE). The organic extract was evaporated to dryness at room temperature. The residue was reconstituted in the mobile phase and injected into the HPLC–MS–MS system. Multiple reaction monitoring using the precursor→product ion combinations of m/z 545→267 and 543 →267 was used to quantify I and III, respectively, after chromatographic separation under isocratic conditions. The assay was validated in the concentration range of 0.5 to 500 ng/0.1 ml in both human and dog plasma. The precision of the assay, expressed as relative standard deviation, was less than 10% over the entire concentration range with the exception of the low concentration of 0.5 ng/0.1 ml which was 14.0% for human plasma. The HPLC–MS–MS method provided sufficient sensitivity to completely map the pharmacokinetic time course of I following a single 5 mg dose of II to human subjects and a 0.5 mg/kg dose to beagle dogs.     

Two new glycosides from the whole plant of Anemone rivularis var. flore-minore

Phytochemical investigation on the whole plant of Anemone rivularis var. flore-minore led to the isolation of a new labdane-type diterpene glycoside (1) and a new trihydroxyfuranoid lignanoid glycoside (2), together with three known triterpene and triterpenoid glycosides (3–5). The structures of the two new compounds were elucidated as β-d-glucopyranosyl (13S)-13-hydroxy-7-oxo-labda-8,14-diene-18-oate (1) and (7S,7′R,8R,8′S)-7′-butoxy-7,9′-epoxy-4,4′,9-trihydroxy-3,3′-dimethoxylignane 9-O-β-d-glucopyranoside (2), on the basis of extensive spectral analysis and chemical evidence. Compound 1 is characterized by a glucose (Glc) esterified C-18 carboxyl group, which is a rarely encountered labdane-type diterpene glycoside in nature. The two new compounds (1 and 2) reported here are the first examples of diterpene glycoside and lignanoid glycoside found in the genus Anemone, and the known triterpene and triterpenoid glycosides (3–5) are identified for the first time from the title plant.     

The measurement of partial specific volumes and sedimentation coefficients by sucrose density centrifugation

The method of Martin and Ames (1961, J. Biol. Chem.236, 1372) gives good estimates of the s_20,w of proteins when the SW40 rotor is used with a sucrose gradient. Viscosities of sucrose in D₂O were measured, and the data were used in computer simulations to test alternate approaches to estimating $\text{v}$ and s_20,w values by comparisons with standards. The method of Meunier et al. (1972, FEBS Lett.24, 63) for $\text{v}$ was shown to be optimal. For s_20,w estimations, substantial errors were found with the methods of Bon et al. (1973, Eur. J. Blochem.35, 372) and especially Meunier et al. When standards and unknowns have the same $\text{v}$, and the gradient is made up in water or dilute buffer, the simple ratio method of Martin and Ames gives most accurate results for s_20,w. For all other cases, an alternative procedure is described.     

Chemical constituents from the roots of Fallopia convolvulus (L.) A. Löve

Twenty compounds, including three sterols (1–3), three phenols (4, 14 and 15), four anthraquinones (5, 7, 8 and 16), one chromone (6), two stilbenes (9 and 10), three amides (11–13), three flavonoids (17–19) and one organic acid (20), were obtained by modern phytochemical isolation methods. Their structures were identified by spectroscopic methods and in comparison with the published data in the references. Among them, compound 2, 3, 11 and 13 were firstly discovered from genus Fallopia, and compounds 1, 5–8, 10, 14, 15, 17, 19 and 20 were obtained from F. convolvulus for the first time. The chemotaxonomic significance of these compounds was also discussed, which revealed the relationships between F. convolvulus and some other species of Polygonaceae family.     

Flavonoids and anthraquinones from Murraya tetramera C. C. Huang (Rutaceae)

Phytochemical investigation of Murraya tetramera C. C. Huang led to the isolation of ten flavonoids (1−10) and three anthraquinones (11−13). Their structures were determined on the basis of MS, NMR, specific optical rotation, and CD spectroscopic data analysis, and by comparison of the obtained data with those reported in the literature. This is the first report for the occurrence of compounds 2, 4–7, and 11–13 in the Murraya species, and all the compounds were isolated from M. tetramera for the first time with the exception of compound 3. The chemotaxonomic significance of these compounds was also discussed.     

First record of Cotesia scotti () (Hymenoptera: Braconidae: Microgastrinae) comb. nov. parasitising Spodoptera cosmioides (Walk, 1858) and Spodoptera eridania (Stoll, 1782) (Lepidoptera: Noctuidae) in Brazil

This is the first report of Cotesia scotti (Valerio and Whitfield) comb. nov. in Brazil, attacking larvae of the black armyworm, Spodoptera cosmioides, and the southern armyworm, S. eridania. The moth larvae were found respectively, infesting a protected cropping of organic tomato in Hidrolândia, Goiás, Brazil, and a transgenic soybean crop in São José dos Pinhais, Paraná, Brazil. Biological, molecular and morphological characters were used to confirm the identity of the specimens. Parasitoid identification presented a challenge since the species has most diagnostic characters of the genus Cotesia Cameron, but few in the poorly defined genus Parapanteles Ashmead. Based on morphological and molecular evidence, we transfer Parapanteles scotti to the genus Cotesia. The new combination is discussed by comparison with morphologically similar species and available molecular data.     

Active transport in the photosynthetic bacterium Chromatium vinosum.

Whole cells of Chromatium vinosum show energy-dependent uptake of several amino and organic acids. The energy for metabolite uptake can be provided by light, via cyclic electron flow, or by ATP hydrolysis catalyzed by a N,N′-dicyclohexylcarbodiimide-sensitive ATPase. Metabolite transport is inhibited by uncouplers known to collapse transmembrane electrochemical proton gradients, suggesting that such a gradient may provide the driving force for transport in C. vinosum.     

Conformational studies on l-amino-l-deoxypentitols

The conformations of the four 1-amino-1-deoxy-D-pentitols and their hydrochlorides in deuterium oxide solution have been analyzed by 250-MHz, ¹H-n.m.r. spectroscopy. The data indicate that the D-arabino (2) and D-lyxo (3) isomers adopt extended, planar, zigzag conformations, whereas the D-xylo (4) and D-ribo (1) isomers have the carbon chain in a nonplanar, “sickle” arrangement. The conformational assignments parallel closely those previously advanced for various related series of acetylated derivatives in organic solvents, and for nonacetylated analogs in solution and in the crystalline state. The spectral changes that take place in solution upon converting the amines 1–4 into their amine-salt forms are discussed, and the conformational data are considered in relation to the reactivity of 1–4 on deamination with nitrous acid and with respect to related reactions leading to ring closure under kinetic conditions.