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Anna Schweifer

Bio: Anna Schweifer is an academic researcher from University of Vienna. The author has contributed to research in topics: Streptomyces fradiae & Diastereomer. The author has an hindex of 8, co-authored 13 publications receiving 130 citations.

Papers
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Journal ArticleDOI
TL;DR: The synthesis of the dicyclohexyl analogues of DPEA and related compounds were tested as inhibitors of [(3)H]MK-801 binding to rat brain membranes and exhibited stereospecific sensitivity to the modulator spermine.

34 citations

Journal ArticleDOI
TL;DR: In this paper, the levorotary phosphaproline has the R configuration, contrary to earlier reports, and was transformed into crystalline ureas derived from (R)- and (S)-1-phenylethyl isocyanate.

24 citations

Journal ArticleDOI
TL;DR: The first step of the mineralisation of fosfomycin by R. huakuii PMY1 is hydrolytic ring opening with the formation of (1R,2R)-1,2-dihydroxypropylphosphonic acid, which grew well on (R)- and (S)-lactic acid and hydroxyacetone, but less well on propionic acid and not on acetone.
Abstract: The first step of the mineralisation of fosfomycin by R. huakuii PMY1 is hydrolytic ring opening with the formation of (1R,2R)-1,2-dihydroxypropylphosphonic acid. This phosphonic acid and its three stereoisomers were synthesised by chemical means and tested as their ammonium salts for mineralisation as evidenced by release of Pi. Only the (1R,2R)-isomer was degraded. A number of salts of phosphonic acids such as (±)-1,2-epoxybutyl-, (±)-1,2-dihydroxyethyl-, 2-oxopropyl-, (S)-2-hydroxypropyl-, (±)-1-hydroxypropyl- and (±)-1-hydroxy-2-oxopropylphosphonic acid were synthesised chemically, but none supported growth. In vitro C–P bond cleavage activity was however detected with the last phosphonic acid. A mechanism involving phosphite had to be discarded as it could not be used as a phosphorus source. R. huakuii PMY1 grew well on (R)- and (S)-lactic acid and hydroxyacetone, but less well on propionic acid and not on acetone or (R)- and (±)-1,2-propanediol. The Pi released from (1R,2R)-1,2-dihydroxypropylphosphonic acid labelled with one oxygen-18 in the PO3H2group did not stay long enough in the cells to allow complete exchange of 18O for 16O by enzymic turnover.

14 citations

Journal ArticleDOI
TL;DR: The methyl groups of [ methyl-( S)]- and [methyl-( R)]-[ methyl-D,T]-l-methionine fed to Streptomyces fradiae were incorporated into fosfomycin, which was chemically degraded to chiral AcONa.
Abstract: The methyl groups of [methyl-(S)]- and [methyl-(R)]-[methyl-D,T]-l-methionine fed to Streptomyces fradiae were incorporated into fosfomycin, which was chemically degraded to chiral AcONa. The enzymatic test gave the (S)-configuration for the chiral AcONa derived from methionine with the (S)-[D,T]methyl group (F = 31.7) and (R) for the one derived from methionine with the (R)-[D,T]methyl group (F = 83.0). The radical SAM methyltransferase transfers the methyl group of MeCbl to HEP-CMP with inversion of configuration.

14 citations

Journal ArticleDOI
TL;DR: In this article, the carbamate derived from 2,2,6,6-tetramethylpiperidine was metalated with s -BuLi/TMEDA at −78°C with a high primary kinetic isotope effect to give an α-oxymethyllithium, which was silylated with chlorodimethylphenylsilane.

12 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

01 Dec 2007

1,121 citations

Journal ArticleDOI
TL;DR: The first complete portrait of this underground market is presented along with the relevant legal, technological, and scientific developments which have driven its evolution.
Abstract: PCP or phencyclidine was discovered in 1956 and soon became a popular street drug. Dissociatives including PCP, ketamine, and dextromethorphan have been used non-medically for their mind-altering effects for over 60 years. Many of these compounds have also been used clinically and in legitimate research. At least 14 derivatives of PCP were sold for non-medical and illict use from the late 1960s until the 1990s. With the advent of the Internet, the drug market underwent a dramatic evolution. While initially gray-market chemical vendors offering dextromethorphan and ketamine thrived, most recently the market has shifted to legal high and online-based research chemical vendors. Starting with the first dissociative research chemical, 4-MeO-PCP in 2008, the dissociative research chemical market has rapidly evolved and currently comprises at least 12 dissociatives, almost half of which were unknown in the scientific literature prior to their introduction. Several of these, including methoxetamine, have reached widespread use internationally. A historical account of non-medical use of over 30 dissociative compounds was compiled from a diverse collection of sources. The first complete portrait of this underground market is presented along with the relevant legal, technological, and scientific developments which have driven its evolution.

201 citations

Journal ArticleDOI
TL;DR: Advances in the understanding of the biochemistry and genetics of microbial phosphonate metabolism are reviewed, and the role of these compounds and of the organisms engaged in their turnover within the P cycle are discussed.
Abstract: Organophosphonates are ancient molecules that contain the chemically stable C-P bond, which is considered a relic of the reducing atmosphere on primitive earth. Synthetic phosphonates now have a wide range of applications in the agricultural, chemical and pharmaceutical industries. However, the existence of C-P compounds as contemporary biogenic molecules was not discovered until 1959, with the identification of 2-aminoethylphosphonic acid in rumen protozoa. Here, we review advances in our understanding of the biochemistry and genetics of microbial phosphonate metabolism, and discuss the role of these compounds and of the organisms engaged in their turnover within the P cycle.

170 citations

Journal ArticleDOI
TL;DR: The data presented indicate the likely importance of phosphonate-P in global biogeochemical P cycling, and by extension its role in marine productivity and in carbon and nitrogen dynamics in the oceans.
Abstract: Phosphonates are compounds that contain the chemically stable carbon-phosphorus (C-P) bond. They are widely distributed amongst more primitive life forms including many marine invertebrates and constitute a significant component of the dissolved organic phosphorus reservoir in the oceans. Virtually all biogenic C-P compounds are synthesized by a pathway in which the key step is the intramolecular rearrangement of phosphoenolpyruvate to phosphonopyruvate. However C-P bond cleavage by degradative microorganisms is catalyzed by a number of enzymes - C-P lyases, C-P hydrolases, and others of as-yet-uncharacterized mechanism. Expression of some of the pathways of phosphonate catabolism is controlled by ambient levels of inorganic P (Pi) but for others it is Pi-independent. In this report we review the enzymology of C-P bond metabolism in bacteria, and also present the results of an in silico investigation of the distribution of the genes that encode the pathways responsible, in both bacterial genomes and in marine metagenomic libraries, and their likely modes of regulation. Interrogation of currently available whole-genome bacterial sequences indicates that some 10% contain genes encoding putative pathways of phosphonate biosynthesis while ∼40% encode one or more pathways of phosphonate catabolism. Analysis of metagenomic data from the global ocean survey suggests that some 10 and 30%, respectively, of bacterial genomes across the sites sampled encode these pathways. Catabolic routes involving phosphonoacetate hydrolase, C-P lyase(s), and an uncharacterized 2-aminoethylphosphonate degradative sequence were predominant, and it is likely that both substrate-inducible and Pi-repressible mechanisms are involved in their regulation. The data we present indicate the likely importance of phosphonate-P in global biogeochemical P cycling, and by extension its role in marine productivity and in carbon and nitrogen dynamics in the oceans.

165 citations