R-(-)-β-O-methylsynephrine, a natural product, inhibits VEGF-induced angiogenesis in vitro and in vivo

R-(-)-β-O-methylsynephrine (OMe-Syn) is an active compound isolated from a plant of the Rutaceae family. We conducted cell proliferation assays on various cell lines and found that OMe-Syn more strongly inhibited the growth of human umbilical vein endothelial cells (HUVECs) than that of other normal and cancer cell lines tested. In angiogenesis assays, it inhibited vascular endothelial growth factor (VEGF)-induced invasion and tube formation of HUVECs with no toxicity. The anti-angiogenic activity of OMe-Syn was also validated in vivo using the chorioallantonic membrane (CAM) assay in growing chick embryos. Expression of the growth factors VEGF, hepatocyte growth factor, and basic fibroblast growth factor was suppressed by OMe-Syn in a dose-dependent manner. Taken together, our results indicate that this compound could be a novel basis for a small molecule targeting angiogenesis.     

Leucocyanidin: Synthesis and properties of (2R,3S,4R)-(+)-3,4,5,7,3′,4′-hexahydroxyflavan

An isomer of leucocyanidin, (2R,3S,4R)-(+)-3,4,5,7,3′,4′-hexahydroxyflavan has been synthesized from (+)-taxifolin, isolated in its phe     

5′-Monohydroxyphylloquinone from Anacystis and Euglena

The monohydroxy analogue of phylloquinone found in Anacystis nidulans and Euglena gracilis has been characterized as 5′-monohydroxyphylloquinone by MS analysis.     

Phylogeny of the Rhizobium–Allorhizobium–Agrobacterium clade supports the delineation of Neorhizobium gen. nov.

The genera Agrobacterium, Allorhizobium, and Rhizobium belong to the family Rhizobiaceae. However, the placement of a phytopathogenic group of bacteria, the genus Agrobacterium, among the nitrogen-fixing bacteria and the unclear position of Rhizobium galegae have caused controversy in previous taxonomic studies. To resolve uncertainties in the taxonomy and nomenclature within this family, the phylogenetic relationships of generic members of Rhizobiaceae were studied, but with particular emphasis on the taxa included in Agrobacterium and the “R. galegae complex” (R. galegae and related taxa), using multilocus sequence analysis (MLSA) of six protein-coding housekeeping genes among 114 rhizobial and agrobacterial taxa. The results showed that R. galegae, R. vignae, R. huautlense, and R. alkalisoli formed a separate clade that clearly represented a new genus, for which the name Neorhizobium is proposed. Agrobacterium was shown to represent a separate cluster of mainly pathogenic taxa of the family Rhizobiaceae. A. vitis grouped with Allorhizobium, distinct from Agrobacterium, and should be reclassified as Allorhizobium vitis, whereas Rhizobium rhizogenes was considered to be the proper name for former Agrobacterium rhizogenes. This phylogenetic study further indicated that the taxonomic status of several taxa could be resolved by the creation of more novel genera.     

1,3-β-Glucan synthase from Citrus phloem

1,3-β-Glucan synthase activity has been demonstrated in particulate fractions of bark extracts from Mexican lime. With respect to substrate, the enzyme kinetics did not conform to the Michaelis-Menten equation. The value of the Hill coefficient was 1.2 and S_0.5 is 1.1 mM. The enzyme had an optimum pH of 7.5. Maltose, sucrose, and especially cellobiose and glucose, were enzyme activators when tested at physiological concentrations. In the presence of 15 mM MgCl₂ the enzymic activity was stimulated at 10 μM UDP-glucose but decreased at 1 mM UDP-glucose, suggesting a minor 1,4-β-glucan synthase activity.     

(+)-9α-Hydroxymatrine from Sophora macrocarpa

A new quinolizidine alkaloid, (+)-9α-hydroxymatrine, was isolated from the leaves of Sophora macrocarpa. Its structure was determined by a combination of spectroscopic methods, among which nuclear Overhauser enhancement experiments played a crucial role. Some generalizations are made regarding the mass spectra of matrinoids.     

2(S),4(R)-4-(β-d-Galactopyranosyloxy)-4-isobutyl-glutamic acid: A new amino acid in Reseda odorata

2(S),4(R)-4-(β-d-Galactopyranosyloxy)-4-isobutylglutamic acid (I) has been isolated from the flowers of Reseda odorata, wherein it occurs in substantial quantity. Hydrolysis of I gives d-galactose, 2(S),4(R)-4-hydroxy-4-isobutylglutamic acid (II) and 3(R),5(S)-3-hydroxy-3-isobutyl-2-pyrrolidone-5-carboxylic acid (III) and its treatment with nitrous acid yields a galactoside of a non-nitrogenous hydroxy acid lactone (IV). The structures of I and its degradation products are supported by PMR, ¹³C-NMR and other spectroscopic methods. ¹³C-NMR spectroscopy of the model compound 2-(β-d-galactopyranosyloxy)isobutyric acid confirmed the structure of the natural product. The S- (or l-) configuration at C(2) in the amino acid moiety of I has been established by the use of the Clough—Lutz—Jirgenson rule and the R-configuration at C(4) of the same unit has been assigned tentatively. I represents the first example of a glycoside of a higher plant amino acid in which the carbohydrate residue is linked to an aliphatic hydroxy group.     

Biosynthesis of α-spinasterol from (2- 14C (4R)-4-3H1) mevalonic acid by Spinacea oleracea and Medicago sativa

Leaves of Spinacea oleracea and Medicago sativa were incubated with (2-¹⁴C, (4R)-4³H₁ mevalonic acid and the sterols isolated. Cycloartenol had a ³H: ¹⁴C atomic ratio of 6:6 whilst oxidation to cycloartenone resulted in a ratio of 5:6 showing that tritium was present in the 3α-position and that the cycloartenol was symmetrically labelled. Separation of the 4-demethyl sterols gave α-spinasterol and a mixture of stigmast-7-enol and 24-methylcholest-7-enol, which had ³H: ¹⁴C atomic ratios of 3:5. Ozonolysis of α-spinastery] acetate gave the terminal side chain fragment as 2-ethyl-3-methyl butanoic acid. The acid contained ¹⁴C but no tritium thus showing that the C-24 hydrogen of cycloartenol is lost during the alkylation reactions leading to the C-24 ethyl group of α-spinasterol.     

八肋游仆虫大核基因组中组蛋白基因 H4A和H4B的克隆及分析

组蛋白作为核小体的基本组分,是染色质的结构和功能必需的。组蛋白的变体和修饰共同参与染色质修饰及基因的表达调控。真核生物细胞中的5种组蛋白在进化中高度保守,然而纤毛虫的组蛋白H4与其他真核生物相比有较大的差异。本实验应用PCR技术从八肋游仆虫(Euplotes octocarinatus)中获得了2种组蛋白H4基因,分别为H4A和H4B,GenBank登录号为:JN715068和JN715069。序列分析表明,H4A基因开放阅读框324 bp,预测编码107个氨基酸,分子量为11.6 ku,等电点为10.99。而H4B基因编码框384 bp,编码127个氨基酸,分子量为14.4 ku,等电点为9.93。Blast结果显示,H4A序列与其他生物中H4的一致性相对较高,达81%～94%,而H4B的一致性为36%～70%。H4A和H4B的一致性仅为44.7%。实时荧光定量PCR表明,H4A的转录本高于H4B。结果提示:在进化过程中八肋游仆虫可能进化出特殊的组蛋白H4基因,不同的组蛋白H4可能发挥不同的功能。     

In vitro, ex vivo and in vivo models: A comparative analysis of Paracoccidioides spp. proteomic studies

Members of the Paracoccidioides complex are human pathogens that infect different anatomic sites in the host. The ability of Paracoccidioides spp. to infect host niches is putatively supported by a wide range of virulence factors, as well as fitness attributes that may comprise the transition from mycelia/conidia to yeast cells, response to deprivation of micronutrients in the host, expression of adhesins on the cell surface, response to oxidative and nitrosative stresses, as well as the secretion of hydrolytic enzymes in the host tissue. Our understanding of how those molecules can contribute to the infection establishment has been increasing significantly, through the utilization of several models, including in vitro, ex vivo and in vivo infection in animal models. In this review we present an update of our understanding on the strategies used by the pathogen to establish infection. Our results were obtained through a comparative proteomic analysis of Paracoccidioides spp. in models of infection.     

Progress in antischistosomal N,N′-diaryl urea SAR

N,N′-Diaryl ureas have recently emerged as a new antischistosomal chemotype. We now describe physicochemical profiling, in vitro ADME, plasma exposure, and ex vivo and in vivo activities against Schistosoma mansoni for twenty new N,N′-diaryl ureas designed primarily to increase aqueous solubility, but also to maximize structural diversity. Replacement of one of the 4-fluoro-3-trifluoromethylphenyl substructures of lead N,N′-diaryl urea 1 with azaheterocycles and benzoic acids, benzamides, or benzonitriles decreased lipophilicity, and in most cases, increased aqueous solubility. There was no clear relationship between lipophilicity and metabolic stability, although all compounds with 3-trifluoromethyl-4-pyridyl substructures were metabolically stable. N,N′-diaryl ureas containing 4-fluoro-3-trifluoromethylphenyl, 3-trifluoromethyl-4-pyridyl, 2,2-difluorobenzodioxole, or 4-benzonitrile substructures had high activity against ex vivo S. mansoni and relatively low cytotoxicity. N,N-diaryl ureas with 3-trifluoromethyl-4-pyridyl and 2,2-difluorobenzodioxole substructures had the highest exposures whereas those with 4-fluoro-3-trifluoromethylphenyl substructures had the best in vivo antischistosomal activities. There was no direct correlation between compound exposure and in vivo activity.     

Grindelane diterpenoids from Grindelia campórum and Chrysothamnus paniculatus

The structures of nine grindelic acid related diterpenes isolated as methyl esters from Grindelia camporum and Chrysothamnus paniculatus, were elucidated based on their spectral properties.     

Visual learning and memory of Drosophila melanogaster wild type CS and the mutants dunce1, amnesiac, turnip and rutabaga

Dunce¹, amnesiac, turnip and rutabaga, mutants of Drosophila melanogaster deficient in olfactory learning and/or memory, were tested for visual learning ability and memory. All these mutants are able to learn conditioned visual information, but not as well as the corresponding wildtype CS. Memory of all four mutants is reduced during the first 30 min after training, but indistinguishable from that of the wildtype two hours after conditioning.     

Echium and Pontechium specific floral cues for host–plant recognition by the oligolectic bee Hoplitis adunca

Flowering plants often have specific floral cues, which allow bees and other pollinators to differentiate between them. Many bee species exhibit specialised associations with flowers (oligolecty) and it is important for them to find and recognise their specific host plants. In this study we compared the visual and olfactory floral cues of different Echium and Pontechium (Boraginaceae) species with the closely related Anchusa officinalis (Boraginaceae). We tested whether plant-specific cues occur in Echium and Pontechium which may allow oligolectic Hoplitis adunca (Megachilidae) to recognise its host plants and to distinguish them from Anchusa non-hosts. Our investigations showed that Echium/Pontechium provides a specific scent bouquet. Furthermore, we identified compounds which were not described as floral scent before ((Z)-3-nonenal and 1,4-benzoquinone). These unique volatiles and the specific bouquet could act as a recognition cue for H. adunca. The corolla colours differed between all species, but were grouped together in the bee colour categories blue and UV-blue and can indicate potential host flowers for H. adunca.     

Hidden diversity uncovered in Hygrophorus sect. Aurei (Hygrophoraceae), including the Mediterranean H. meridionalis and the North American H. boyeri, spp. nov.

For many years, the binomial Hygrophorus hypothejus was widely applied to collections from various geographical regions in different continents, assuming a circum-boreal and circum-mediterranean distribution for this species. This hypothesis, however, had never been put to the test. To assess the diversity and species-limits within this complex of yellow-coloured waxcaps, a phylogenetic, morphological and taxonomical investigation into Hygrophorus sect. Aurei and similar species in sect. Olivaceoumbrini was carried out, including material of pan-European origin, as well as the east and west coasts of North America. Following sequencing of the ITS rDNA locus, nine lineages are confirmed in sect. Aurei, most of them highly continentalised. Of these, two are new to science, introduced here as Hygrophorus boyeri sp. nov., from Pinus banksiana and P. rigida forests in eastern North America and from P. muricata and P. contorta forests in western North America, and Hygrophorus meridionalis sp. nov., from Pinus brutia and Pinus halepensis forests in the island of Cyprus and mainland Greece. H. hypothejus is lectotypified and epitypified, and here resolved as a strictly European species, with the old forgotten taxon Hygrophorus siccipes revived as its North American vicariant. The placement of Hygrophorus fuligineus in sect. Aurei is phylogenetically confirmed and detailed comparisons between morphologically similar and phylogenetically affiliated taxa in sect. Aurei and sect. Olivaceoumbrini are provided. The chronic confusion associated with Hygrophorus fuscoalbus, a highly controversial taxon described from Germany nearly two centuries ago and variously interpreted since, is discussed, concluding that this name is too ambiguous to be applied to any currently recognized species.     

Synthesis of glycos-3-yl-α,γ-diamino acids. Synthesis of four diastereomeric spiro-3,4′-(R and S)-3-deoxy-1,2:5,6-di-O-isopropylidene-α-d-ribo-hexofuranose)-3′-(R and S)-acetamido-2′-pyrrolidinones

Treatment of (Z)-3-deoxy-1,2:5,6-di-O-isopropylidine-3-C-(methoxycarbonyl)-methylene-α-d-ribo-hexofuranose (1) with diazomethane in ether afforded the unstable Δ¹- and Δ²-pyrazolines 2 and 2a. High-pressure hydrogenation of the latter compounds over Raney nickel afforded a mixture of amines 3, 5, 7, and 9 (in 80% yield), which were separated by chromatography. Acetylation of these compounds yielded the N-acetyl derivatives 4, 6, 8, and 10. X-Ray analysis of compounds 8 and 10 showed them to be spiro-3,4′-(R)-(3-deoxy-1,2:5,6-di-O-isopropylidine-α-d-ribo-hexofuranose)-3′-(R)-[and 3′-(S)]-acetamido-2′-pyrrolidinone, respectively. The structures of compounds 4 and 6 (determined by chemical means) were the corresponding spiro-3,4′-(S)-3′-(R)-acetamido-2′-pyrrolidinone and 3′-(S)-acetamido-2′-pyrrolidinone, respectively.     

Synthesis of 1,2,4-tri-O-acetyl-5-deoxy-3-O-methyl-5-C-[(R)- and -(S)-phenylphosphinyl]-β-d-ribopyranose

5-Deoxy-1,2-O-isopropylidene-5-C-(methoxyphenylphosphinyl)-3-O-methyl-α-d-ribofuranose (4) was prepared from 1,2-O-isopropylidene-3-O-methyl-α-d-ribo-pentodialdo-1,4-furanose by an addition reaction with methyl phenylphosphinate, followed by deoxygenation of the terminal HOCHP group of the adduct by successive reaction with 1,1′-thiocarbonyldiimidazole and tributyltin hydride. Treatment of 4 with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by deacetonation with mineral acid, and acetylation with acetic anhydride—pyridine, gave mainly the two title compounds, which were isolated by column chromatography on silica gel, and characterized by 90-MHz, ¹H-n.m.r.-spectral analysis.