Bioactive principles in the bark of Pilidiostigma tropicum

The crude dichloromethane bark extract of Pilidiostigma tropicum (Myrtaceae) from north Queensland, Australia, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of rhodomyrtoxin B and ursolic acid-3-p-coumarate as the biologically active materials. The structures of these compounds were elucidated on the basis of spectral analysis. The intercalation interaction of rhodomyrtoxin B with DNA was investigated using molecular mechanics and ab initio molecular-orbital techniques. A favorable pi-pi interaction between rhodomyrtoxin B and the cytosine-guanine base pair is predicted, but the orientation of the interaction cannot be predicted based on frontier molecular orbitals.     

Genotypic Heterogeneity of Streptococcus oralis and Distinct Aciduric Subpopulations in Human Dental Plaque

The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (χ² = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.     

Mycoflora succession on strawberry roots developing root rot symptoms

Strawberry daughter plants of the Cyclone and Surecrop cultivars began rooting in two plantings in October. Main root tips became necrotic in the fall and winter, and the necrosis spread to the crowns, until all roots were severely rotted by June. Aspergillus and Penicillium were the dominant genera isolated from apparently healthy main root tips during October through February and apparently healthy main root segments 5 to 6 cm from the tip through April. During this time, Pythium, Fusarium, and Rhizoctonia were isolated in low frequencies from the same samples. Pythium was isolated most often from lesions and was isolated in high frequency from Surecrop lesions, December through April. Fusarium and Rhizoctonia were isolated in low to moderate frequencies from October through February, but increased to higher levels from April through October of the following year. During the year, low levels of Fusarium, Rhizoctonia, and Pythium were isolated from steles of diseased mother plants. This tissue yielded moderate levels of Chaetosphaeronema, Coniothyrium, Cephalosporium, and Penicillium.     

Lignans and aporphine alkaloids in bark of Liriodendron tulipifera

Lirionol, a novel tetracyclic lignan, has been isolated from the bark of Liriodendron tulipifera and its structure determined by spectroscopic analysis. In addition, syringic acid methyl ester, (+)-pinoresinol, (+)-syringaresinol, N-(2-hydroxy-2-phenylethyl)benzamide and O-methyl-N-norlirinine have also been isolated. The structures of lirinine and related compounds isolated from the leaves of this tree-species by Yunusov et al. are also discussed.     

Inhibition of biofilm formation,quorum sensing activity and molecular docking study of isolated 3, 5, 7-Trihydroxyflavone from Alstonia scholaris leaf against P.aeruginosa

The current study is to evaluate the inhibition of biofilm formation and quorum sensing activity of isolated 3, 5, 7-Trihydroxyflavone (TF) from A.scholaris leaf extract against Pseudomonas aeruginosa. The effects of isolated TF on quorum sensing-regulated virulence factors production such as swimming motility, pyocyanin production, proteolytic, EPS, metabolic assay and inhibition of biofilm formation against P.aeruginosa was evaluated by standard protocols. In addition, the interaction between the isolated TF and active sites of QS- gene (LasI/rhlI, LasR/rhlR, and AHLase) in P.aeruginosa was evaluated by molecular docking studies using AutoDock Tools version 1.5.6. Based on the structural elucidation of the isolated compound was identified as 3, 5, 7-Trihydroxyflavone. Consequently, the isolated TF shows a significant reduction of biofilm formation through the inhibition of QS-dependent phenotypes such as pyocyanin production, proteolytic, swimming motility, EPS activities against P.aeruginosa in a dose-dependent manner. Molecular docking analysis of isolated TF can interfere the signaling [N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12-HSL) and N-butanoyl-L-homoserine lactone (C4-HSL)] molecules in P.aeruginosa by QS genes (LasI, LasR, rhlI, and AHLase) regulation. The isolated TF compound from A.scholaris reveals a greater potential to inhibit biofilm and QS dependent virulence factor production in P.aeruginosa. Docking interaction studies of TF-LasR complex express higher binding affinity than the other QS gene in P.aeruginosa.     

Two simple tetrahydroisoquinoline alkaloid N-oxides from cacti

Tehuanine N-oxide was isolated from Pachycereus pringlei, and deglucopterocereine N-oxide was isolated from Pterocereus gaumeri. These     

Further guaianolides and 5-alkylcoumarins from gutenbergia and bothriocline species

From Gutenbergia marginata ten new guaianolides were isolated. Two guaianolides isolated previously from Erlangea inyangana are identical with two further lactones and their structures have been revised. From Bothriocline ripensis ethulia coumarin and two further 5-alkylcoumarin derivatives, one being a chromone, were isolated, while B. longipes and B. eupatorioides gave nine 5-alkylcoumarins and two related compounds. The structures were elucidated by highfield NMR techniques and a few chemical transformations.     

Bacteriologic studies of liver abscesses of Awassi sheep in Jordan

A total of 337 liver abscesses of Awassi sheep that were found in different slaughterhouses in Jordan were examined for their causal agents. Fifteen different bacterial species were isolated from 297 liver abscesses. No bacteria were isolated from the remaining 40 liver abscesses. Fusobacterium necrophorum biovar B were isolated from 195 (58%) abscesses. Arcanobacterium pyogenes, F. necrophorum biovar A, Escherichia coli and Clostridium perfringens were isolated from 41 (12%), 34 (10%), 30 (9%) and 17 (5%), respectively, liver abscesses. Our study suggested that F. necrophorum biovar B is the most prevalent bacterium incriminated for liver abscesses in Awassi sheep.     

Symbiotic Association Between Symbiodinium and the Gastropod Strombus gigas: Larval Acquisition of Symbionts

The importance of the dinoflagellate Symbiodinium sp. was studied in the early life stages of the gastropod Strombus gigas. This dinoflagellate was not found in the eggs or the gelatinous mass surrounding the eggs of the mollusk; therefore, Symbiodinium is not inherited directly. To determine whether the planktonic veligers can acquire these algae from the environment, they were exposed to freshly isolated Symbiodinium from adult S. gigas (homologous). The optimal stage for Symbiodinium inoculation was found at 48 h post-hatching. Survival and growth rates of veligers and juveniles were higher when inoculated with freshly isolated Symbiodinium in conjunction with daily feeding of Isochrysis spp. Veligers inoculated with Symbiodinium freshly isolated from three host species elicited distinct responses: (1) veligers did not take up Symbiodinium isolated from the hydrozoan Millepora alcicornis suggesting that there is discrimination on contact prior to ingestion, (2) veligers did take up Symbiodinium isolated from the anemone Bartholomea annulata, but the algae did not persist in the host tissue suggesting that selection against this type took place after ingestion or that the algae did not divide in the host, and (3) veligers did take up Symbiodinium isolated from Pterogorgia anceps where it persisted and was associated with metamorphosis of the larvae. In contrast, the Symbiodinium freshly isolated from S. gigas were not associated with metamorphosis and required an inducer such as the red alga Laurencia poitei. These data present a significant advancement for the establishment of a new approach in the aquaculture of this important but declining Caribbean species.     

Cis-4-hydroxypipecolic acid and 2,4-cis-4,5-trans-4,5-dihydroxypipecolic acid from Calliandra

cis-4-Hydroxypipecolic acid and 2,4-cis-4,5-trans-4,5-dihydroxypipecolic acid were isolated from leaves of Calliandra pittieri. A system for resolving the eight imino acids isolated from Calliandra is described.     

Isolation of gliovictin from the marine deuteromycete Asteromyces cruciatus

(−)Gliovictin, a diketopiperazine isolated from terrestrial fungi of the genera Helminthosporium and Penicillium, has been isolated from culture broths of the marine deuteromycete Astermyces cruciatus.     

Chemical constituents from leaves of Cinnamomum subavenium

A new eudesmane sesquiterpene glycoside, 1α,6β-dihydroxy-5,10-bis-epi-eudesm-15-carboxaldehyde-6-O-β-d-Glucopyranoside (1), together with eleven known compounds (2–12) were isolated from the leaves of Cinnamomum subavenium Miq. Their structures were elucidated by a combination of spectroscopic data analysis and comparison with literature data. All compounds were isolated from C. subavenium for the first time. The chemotaxonomic significance of the isolated compounds was summarized.     

Neue sesquiterpene,triterpene, flavanone und andere aromatische verbindungen aus Flourensia heterolepis

The investigation of a further Flourensia species afforded in addition to already known compounds 12 new sesquiterpene acids isolated as their methyl esters, a new eudesmane diol, four lupane derivatives and two flavanones, two cinnamic acid derivatives, also isolated as methyl esters and a ketone. The structures are elucidated mainly by spectroscopic methods and by some chemical transformations. Several of the compounds isolated are more or less similar to those isolated from other Flourensia species; the considerable amounts of eudesmanes, however, are unusual. The overall picture of the genus is still relatively uniform. Close relationships to Helianthella are obvious, while to Helianthus, placed in the same subtribe, no clear relations are visible.     

The genotypic diversity of Pseudomonas brassicacearum populations isolated from roots of Arabidopsis thaliana: influence of plant genotype

Pseudomonas brassicacearum is a newly described bacterial species isolated from the rhizosphere of Arabidopsis thaliana. The P. brassicacearum populations were isolated from the rhizosphere of two ecotypes of A. thaliana (Wassilewskija (WS) and Columbia (COL)), a mutant of Columbia impaired in starch metabolism (pgm mutant), and a genetically distant plant (wheat), grown in a French eutric cambisol (Méréville). The strains were isolated on semi-selective media. Their diversity was assessed using repetitive extragenic palindromic (REP)-PCR profiling and their affiliation to the P. brassicacearum species using ARDRA and siderotyping. A total of 379 strains isolated in two experiments were clustered into 68 REP-genotypes. Statistical analysis showed that the genetic structure of the P. brassicacearum populations was homogeneous for strains isolated from different plants of the same genotype within the same experiment, but significantly differed across the four tested plant genotypes. Comparison of the REP-genotype distributions showed that some bacterial genotypes were poorly represented, whereas others were strongly stimulated by plant roots.     

2,4-cis-4,5-cis-4,5-Dihyroxypipecolic acid—a naturally occurring imino acid from Calliandra pittieri

2,4-cis-4,5-cis-4,5-Dihydroxypipecolic acid has been isolated from the leaves of Calliandra pittieri. This is the third dihydroxypipecolic acid isomer isolated from Calliandra and the first report of this compound from a natural source.     

In Vitro Biosynthesis of Vicia faba Polyphenoloxidase

Poly A⁺ mRNA was isolated from Vicia faba leaves and translated in vitro using a rabbit reticulocyte translation system. From analysis of the total translation products, the major proteins synthesized in vitro were 32 kilodaltons and 20 kilodaltons. When antibodies to Vicia faba polyphenoloxidase were added, a specific immunoprecipitable protein was observed. This protein's molecular weight was shown to be similar to that of the isolated enzyme (45 kilodaltons). The isolated enzyme successfully competed with the in vitro synthesized product for antipolyphenoloxidase. In addition, the in vitro synthesized product was not immunoprecipitated with antitomato peroxidase and comigrated with isolated and/or iodinated enzyme in sodium dodecylsulfate-polyacrylamide gel electrophoresis. Using in vitro translation and specific immunoprecipitation, a primary translation product corresponding to Vicia faba polyphenoloxidase was identified as a 45 kilodaltons protein.     

Synthesis of Glycols by Microbial Transformation of Some Monocyclic Terpenes

The transformation of three monocyclic terpenes by three soil microorganisms have been studied. The organisms were isolated on, and grew rapidly in, mineral salts medium containing the appropriate terpene substrates as sole carbon sources. These organisms belong to the class Fungi Imperfecti, and two of them have been tentatively identified as Cladosporium species. A Cladosporium species designated T₁ was isolated from terpene-soaked soil, using 1-menthene as the sole source of carbon. The major catabolic product isolated from the growth medium of this organism was found to be a cyclic 1,2-diol identified as trans-p-methane-1,2-diol. A similar but biochemically distinct Cladosporium sp. designated T₇ was isolated on D-limonene. After growth, the medium of this organism contained 1.5 g/liter of the analogous product, trans-limonene-1,2-diol. Minor quantities of the corresponding cis-1,2-diol were also isolated. The third organism, designated as laboratory culture T₈, was isolated on 3-menthene and yielded a diol identified as trans-p-menthane-3,4-diol. From these results it is concluded that the formation of diols is a common intermediate in the fungal metabolism of monocyclic terpenes.     

Reprint of: Saprolegnia strains isolated from river insects and amphipods are broad spectrum pathogens

Saprolegnia species are destructive pathogens to many aquatic organisms and are found in most parts of the world. Reports based on phylogenetic analysis suggest that Saprolegnia strains isolated from aquatic animals such as crustaceans and frogs are close to Saprolegnia strains isolated from infected fish or fish eggs and vice versa. However, it has often been assumed that host specificity occurs for each individual isolate or strain. Here we demonstrate that Saprolegnia spp. can have multiple hosts and are thus capable of infecting different aquatic organisms. Saprolegnia delica, Saprolegnia hypogyna, and 2 strains of Saprolegnia diclina were isolated from aquatic insects and amphipods while S. delica, Saprolegnia ferax, Pythium pachycaule, and a Pythium sp. were isolated from the water of a medium to fast flowing river. The ITS region of the rRNA gene was sequenced for all isolates. In challenge experiments, all four isolates from insects were found to be highly pathogenic to eggs of Atlantic salmon (Salmo salar) and embryos of the African clawed frog (Xenopus laevis). We found that Saprolegnia spp. isolated from salmon eggs were also able to successfully establish infection in nymphs of stonefly (Perla bipunctata) and embryos of X. laevis). These results suggest that Saprolegnia spp. are capable of infecting multiple hosts, which may give them an advantage during seasonal variation in their natural environments.     

Recessive Mutations in the α3 (VI) Collagen Gene COL6A3 Cause Early-Onset Isolated Dystonia

Isolated dystonia is a disorder characterized by involuntary twisting postures arising from sustained muscle contractions. Although autosomal-dominant mutations in TOR1A, THAP1, and GNAL have been found in some cases, the molecular mechanisms underlying isolated dystonia are largely unknown. In addition, although emphasis has been placed on dominant isolated dystonia, the disorder is also transmitted as a recessive trait, for which no mutations have been defined. Using whole-exome sequencing in a recessive isolated dystonia-affected kindred, we identified disease-segregating compound heterozygous mutations in COL6A3, a collagen VI gene associated previously with muscular dystrophy. Genetic screening of a further 367 isolated dystonia subjects revealed two additional recessive pedigrees harboring compound heterozygous mutations in COL6A3. Strikingly, all affected individuals had at least one pathogenic allele in exon 41, including an exon-skipping mutation that induced an in-frame deletion. We tested the hypothesis that disruption of this exon is pathognomonic for isolated dystonia by inducing a series of in-frame deletions in zebrafish embryos. Consistent with our human genetics data, suppression of the exon 41 ortholog caused deficits in axonal outgrowth, whereas suppression of other exons phenocopied collagen deposition mutants. All recessive mutation carriers demonstrated early-onset segmental isolated dystonia without muscular disease. Finally, we show that Col6a3 is expressed in neurons, with relevant mRNA levels detectable throughout the adult mouse brain. Taken together, our data indicate that loss-of-function mutations affecting a specific region of COL6A3 cause recessive isolated dystonia with underlying neurodevelopmental deficits and highlight the brain extracellular matrix as a contributor to dystonia pathogenesis.     

Structure revision of the coumarin,ceylantin

Ceylantin, isolated from Atalantia ceylanica, has been found to be identical with racemosin, isolated from A. racemosa, and the revised 5,8-dimethoxy-6,7-pyranocoumarin structure confirmed by nuclear Overhauser experiments.