6β-Hydroxyipolamiide,an iridoid glucoside from Stachytarpheta mutabilis

A new iridoid glucoside has been isolated from Stachytarpheta mutabilis and assigned the structure and configuration of 6β-hydroxyipolamiide on the basis of ¹H NMR and ¹³C NMR evidence. The conversion of this compound into penta- acetyllamiol proved the above assignment.     

Characterization of an acid-labile, thermostable β-glycosidase from Thermoplasma acidophilum

A recombinant putative β-galactosidase from Thermoplasma acidophilum was purified as a single 57 kDa band of 82 U mg⁻¹. The molecular mass of the native enzyme was 114 kDa as a dimer. Maximum activity was observed at pH 6.0 and 90°C. The enzyme was unstable below pH 6.0: at pH 6 its half-life at 75°C was 28 days but at pH 4.5 was only 13 h. Catalytic efficiencies decreased as p-nitrophenyl(pNP)-β-d-fucopyranoside (1067) > pNP-β-d-glucopyranoside (381) > pNP-β-d-galactopyranoside (18) > pNP-β-d-mannopyranoside (11 s⁻¹ mM⁻¹), indicating that the enzyme was a β-glycosidase.     

Purification and characterisation of β-N-acetylhexosaminidase from the butter clam, saxidomus purpuratus

A β-N-acetylhexosaminidase [EC 3.2.1.30] has been purified ～98-fold from an extract of the digestive organs of Saxidomus purpuratus by using ammonium sulfate fractionation, and chromatography on Toyopearl HW-50, CM-cellulose, and Sepharose 4B. The purified enzyme, the molecular weight of which was estimated to be ～66,000 by gel filtration, was composed of two sub-units of molecular weight 30,000 as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The purified enzyme had a pH optimum of 3.8 and an optimum temperature of 55°, and its activity was enhanced ～2-fold in the presence of 0.1m sodium chloride. The Michaelis constants toward p-nitrophenyl 2-acetamido-2-deoxy-β-d-glucoside and -galactoside were 1.2 × 10^?4 and 1.3 × 10^?4m, respectively.     

Phytoene,phytofluene and ζ-carotene isomers from a Scenedesmus obliquus mutant

A number of mutant strains of the green alga, Scenedesmus obliquus, when grown in the dark, accumulated ζ-carotene as their major carotenoid together with appreciable concentrations of phytoene and phytofluene. The phytoene was almost entirely the 15-cis isomer, and phytofluene was also present mainly as the 15-cis form, whereas the ζ-carotene could be separated into three isomers, predominantly all-trans ζ-carotene accompanied by the 15-cis and an unidentified cis isomer. All the ζ-carotene isomers, when illuminated in the presence of iodine, gave the same equilibrium mixture of stereo-isomers, including a product with unusual spectroscopic and chromatographic properties, which may be a cyclic compound. The pathway of carotenoid biosynthesis in S. obliquus is discussed. On illumination, most of the ζ-carotenic strains were killed, but PGI strain survived, due to the production of cyclic carotenoids with chromophores long enough to protect chlorophyll from photosensitized oxidation.     

Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae Isolated from Vegetables Imported from the Dominican Republic,India, Thailand,and Vietnam

To examine to what extent fresh vegetables imported into Switzerland represent carriers of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae, 169 samples of different types of fresh vegetables imported into Switzerland from the Dominican Republic, India, Thailand, and Vietnam were analyzed. Overall, 25.4% of the vegetable samples yielded one or more ESBL-producing Enterobacteriaceae, 78.3% of which were multidrug resistant. Sixty isolates were obtained: Escherichia coli, 26; Klebsiella pneumoniae, 26; Enterobacter cloacae, 6; Enterobacter aerogenes, 1; and Cronobacter sakazakii, 1. We found 29 isolates producing CTX-M-15, 8 producing CTX-M-14, 7 producing CTX-M-55, 3 producing CTX-M-65, 1 each producing CTX-M-1, CTX-M-3, CTX-M-27, and CTX-M-63, 5 producing SHV-2, 3 producing SHV-12, and 1 producing SHV-2a. Four of the E. coli isolates belonged to epidemiologically important clones: CTX-M-15-producing B2:ST131 (1 isolate), D:ST405 (1 isolate), and D:ST38 (2 isolates). One of the D:ST38 isolates belonged to the extraintestinal enteroaggregative E. coli (EAEC) D:ST38 lineage. Two of the K. pneumoniae isolates belonged to the epidemic clones sequence type 15 (ST15) and ST147. The occurrence of antibiotic-resistant pathogenic and commensal Enterobacteriaceae in imported agricultural foodstuffs constitutes a source of ESBL genes and a concern for food safety.     

2′-p-Hydroxybenzoyl mussaenosidic acid,a new iridoid glucoside from Vitex negundo.

Ethanolic extract of the leaves of Vitex negundo yielded a new iridoid named 2′-p-hydroxybenzoyl mussaenosidic acid. The structure was established on the basis of chemical and spectral data.     

Cloning, sequencing, expression, and antigenic characterization of rMSP4 from Anaplasma marginale isolated from Paraná State, Brazil

Anaplasmosis is a bovine intraerythrocytic disease caused by the bacterium Anaplasma marginale; it causes significant economic losses in tropical and subtropical regions, worldwide. The msp4 gene of an A. marginale strain isolated in Paran , Brazil, was amplified by PCR and sequenced; its cloning into the pET102/D-TOPO vector produced an msp4-6xHis-V5-HP thioredoxin fusion gene construct. This recombinant clone was over-expressed in Escherichia coli BL21(DE-3); the expressed fusion protein was found almost entirely in the insoluble form (inclusion bodies) in the cell lysate. The inclusion bodies were solubilized with urea and the recombinant protein was purified by Ni-NTA column and dialyzed. This method produced a relatively high yield of rMSP4, which was used to immunize rabbits. The deduced amino acid sequence encoded by MSP4 showed 99% homology to A. marginale isolates from Florida, USA, and from Minas Gerais, Brazil. Both rMSP4 and native MSP4 were recognized by post-immunization rabbit serum, showing that rMSP4 has conserved epitopes. As antigenicity was preserved, rMSP4 might be useful for the development of vaccine against anaplasmosis.     

Characterization of a novel α4/4-conotoxin,Qcl.2, from vermivorous Conus quercinus

As part of continuing studies of the identification of gene organization and cloning of novel α-conotoxins, the first α4/4-conotoxin identified in a vermivorous Conus species, designated Qcl.2, was originally obtained by cDNA and genomic DNA cloning from Conus quercinus collected in the South China Sea. The predicted mature toxin of Qc1.2 contains 14 amino acid residues with two disulfide bonds （Ⅰ-Ⅲ, Ⅱ-Ⅳ connectivity） in a native globular configuration. The mature peptide of Qcl.2 is supposed to contain an N-terminal post-translationally processed pyroglutamate residue and a free carboxyl C-terminus. This peptide was chemically synthesized and refolded for further characterization of its functional properties. The synthetic Qcl.2 has two interconvertible conformations in aqueous solution, which may be due to the cis-trans isomerization of the two successive Pro residues in its first Cys loop. Using the Xenopus oocyte heterologous expression system, Qcl.2 was shown to selectively inhibit both rat neuronal α3β2 and α3β4 subtypes of nicotinic acetylcholine receptors with low potency. A block of -63% and 37% of the ACh-evoked currents was observed, respectively, and the toxin dissociated rapidly from the receptors. Compared with other characterized α-conotoxin members, the unusual structural features in Qcl.2 that confer to its receptor recognition profile are addressed.     

7-Oxo-, 7α-hydroxy- and 7β-hydroxysterols from Euphorbia fischeriana

7-Oxo, 7α-hydroxy- and 7β-hydroxysterols (campesterol, stigmasterol and sitosterol derivatives) were isolated from the roots of Euphorbia fischeriana, a drug used for its antitumour properties in traditional Chinese medicine. Some of these steroids show antitumour activity and might be related to the presumed activity of the drug.     

New fossils of Australopithecus anamensis from Kanapoi,West Turkana,Kenya (2003–2008)

Renewed fieldwork from 2003 through 2008 at the Australopithecus anamensis type-site of Kanapoi, Kenya, yielded nine new fossils attributable to this species. These fossils all date to between 4.195 and 4.108 million years ago. Most were recovered from the lower fluvial sequence at the site, with one from the lacustrine sequence deltaic sands that overlie the lower fluvial deposits but are still below the Kanapoi Tuff. The new specimens include a partial edentulous mandible, partial maxillary dentition, two partial mandibular dentitions, and five isolated teeth. The new Kanapoi hominin fossils increase the sample known from the earliest Australopithecus, and provide new insights into morphology within this taxon. They support the distinctiveness of the early A. anamensis fossils relative to earlier hominins and to the later Australopithecus afarensis. The new fossils do not appreciably extend the range of observed variation in A. anamensis from Kanapoi, with the exception of some slightly larger molars, and a canine tooth root that is the largest in the hominin fossil record. All of the Kanapoi hominins share a distinctive morphology of the canine–premolar complex, typical early hominin low canine crowns but with mesiodistally longer honing teeth than seen in A. afarensis, and large, probably dimorphic, canine tooth roots. The new Kanapoi specimens support the observation that canine crown height, morphology, root size and dimorphism were not altered from a primitive ape-like condition as part of a single event in human evolution, and that there may have been an adaptive difference in canine function between A. anamensis and A. afarensis.     

Hypoxyvermelhotins A–C,new pigments from Hypoxylon lechatii sp. nov

A new species of Hypoxylon was discovered, based on material collected in French Guiana and recognised on the basis of new combination of morpholological characters in comparison with type and authentic material of macroscopically similar taxa. These findings were corroborated by the rather isolated positions of its ITS-nrDNA and beta-tubulin DNA sequences in molecular phylogenies. However, the most salient feature of this fungus only became evident by a comparison of its stromatal HPLC profile, revealing several secondary metabolites that were hitherto not observed in stromata of any other member of the Xylariaceae. Part of the stromata were subsequently extracted to isolate these apparently specific components, using preparative chromatography. Five metabolites were obtained in pure state, and their chemical structures were elucidated by means of high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. They turned out to be tetramic acid derivatives of the so-called vermelhotin type. Aside from vermelhotin, previously isolated from cultures of endophytic fungi, we identified three novel congeners, for which the trivial names hypoxyvermelhotins A–C were proposed. Like vermelhotin, they constitute orange-red pigments and a preliminary biological characterisation revealed them to have rather strong cytotoxic and moderate to weak antimicrobial effects. These results further illustrate the high diversity of unique secondary metabolites in stromata of the hypoxyloid Xylariaceae, a family in which biological diversity seems to parallel the chemical diversity of their bioactive principles to a great extent.     

Three metaltolerance Halobacillus sp. isolated from salt lakes in Shaanxi, China

Three Gram positive, spore forming, halophilic bacterial strains were isolated from a salt lake in shanxi China and subjected to a polyphasic taxonomic study. Strains A375, A381 and A389 grew in the presence of 0~24% (w/v) NaCl in complex medium. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains A375, A381 and A389 were located in the genus Halobacillus. Levels of 16S rRNA gene sequence similarity between the isolated strains and the type trains of Halobacillus species were in range 91.6%~98.9%. On the basis of phenotypic and chemotaxonomic properties and phylogenetic analysis, strains A375, A381 and A389 should be placed in the Halobacillus species. Metaltolerance test verify that all strains can tolerate different levels of metal salts.     

Renalia hueberi, a new plant from the lower Devonian of Gaspé

A new genus and species, Renalia hueberi, is described from the Battery Point Formation, Gaspé Sandstone, Quebec. It consists of 1 mm wide axes, at least 11 cm long, bearing dichotomous lateral branches terminated by round to reniform sporangia. The sporangia dehisce along the distal margin and the line of dehiscence is bordered by thick-walled, rectangular cells. Spores are trilete, curvaturate and smooth to granulose. Renalia hueberi is superficially similar to the genus Cooksonia, but it differs from the presently known cooksonias in having both pseudomonopodial branching and dehiscent sporangia. It is interpreted however as being evolved from Cooksonia-like plants, and exhibits a sporangial position most comparable to that of the rhyniophytes and a mode of dehiscence characteristic of zosterophylls.     

Bistachybotrysins A–C,three phenylspirodrimane dimers with cytotoxicity from Stachybotrys chartarum

Bistachybotrysins A–C (1–3), three phenylspirodrimane dimers representing an unusual [6,6,7,6]-tetracyclic skeleton with a central 2,10-dioxabicyclo[4.3.1]decan-7-ol core fused with two phenyl units, were isolated from a fungal strain, Stachybotrys chartarum CGMCC 3.5365. The structures of 1–3 were elucidated through extensive spectroscopic data analysis, including Mo₂(AcO)₄-induced and calculated electronic circular dichroism (ECD). 1 and 2 exhibited potent cytotoxicity against four human tumor cell lines with IC₅₀ values in the range of 2.8–7.5?μM. Furthermore, a possible biogenesis for 1–3 is proposed.     

Purification and partial characterization of a new,sporulation specific,exo-β-glucanase from Saccharomyces cerevisiae

A new exo-β-glucanase, sporulation-specific, was purified from sporulating $\text{S. cerevisiae}$ ($\text{AP}\text{1}\text{,}\text{a}\text{α}$). Characterization of this new activity shows that the enzyme is a glycoprotein with substrate specificities, kinetic parameters and aminoacid composition clearly different from those of its vegetative counterpart.     

Plant regeneration from suspension cells induced from hypocotyls derived from interspecific cross Alstroemeria pelegrina × A. magenta and transformation with Agrobacterium tumefaciens

Embryogenic cell suspension cultures were established using the ovule culture of an interspecific cross, Alstroemeria pelegrina var. rosea × A. magenta. Ovules harvested 14 days after pollination were cultured on Murashige and Skoog (MS) medium without plant growth regulators (PGRs); calli were produced on the hypocotyl surface in germinating zygotic embryos. Suspension cells were induced from the calli by using liquid MS media containing 2,4-dichlorophenoxyacetic acid or 4-amino-3,5,6-trichloropyridine-2-carboxylic acid (picloram). Adventitious embryos developed from the suspension cells on half-strength MS medium supplemented with 0.5 mg l⁻¹ of both α-naphthaleneacetic acid and N⁶-benzylaminopurine; they grew into plantlets on the same medium. The plantlets formed rhizomes following transfer to half-strength MS medium without PGRs, and acclimatized plants were easily established. Subsequently, Agrobacterium-mediated transformation system was applied. The suspension cells were co-cultivated with A. tumefaciens strain EHA101/pIG121Hm or LBA4404/pTOK233, both of which contain neomycin phosphotransferase II, hygromycin phosphotransferase and intron-containing ?-glucuronidase (intron-GUS) genes. Seven days after co-cultivation, the cells were subjected to GUS assay; staining was most pronounced in the cells subcultured in a picloram-containing liquid medium and co-cultivated with EHA101/pIG121Hm. The co-cultivated cells were transferred to the MS medium containing picloram and 20 mg l⁻¹ hygromycin; 1 month later, several hygromycin-resistant callus lines showing GUS activity were obtained. Transgenic plants were obtained through our plant regeneration system, and foreign gene insertion into the regenerated plants was confirmed by polymerase chain reaction.     

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.