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Noncovalently Functionalized Commodity Polymers as Tailor-Made Additives for Stereoselective Crystallization
Stereoselective inhibition of the nucleation and crystal growth of one enantiomer aided by “tailor-made” polymeric additives is an efficient method to obtain enantiopure compounds. However, the conventional preparation of polymeric additives from chiral monomers are laborious and limited in structures, which impedes their rapid optimization and applicability. Herein, we report a “plug-and-play” strategy to facilitate synthesis by using commercially available achiral polymers as the platform to attach various chiral small molecules as the recognition side-chains through non-covalent interactions. A library of supramolecular polymers made up of two vinyl polymers and six small molecules were applied with seeds in the selective crystallization of seven racemates in different solvents. They showed good to excellent stereoselectivity in yielding crystals with high enantiomeric purities in conglomerates and racemic compound forming systems. This convenient, low-cost modular synthesis strategy of polymeric additives will allow for high-efficient, economical resolution of various racemates on different scales.
Wan, Xinhua,Wang, Zhaoxu,Ye, Xichong,Zhang, Jie
supporting information
p. 20243 - 20248
(2021/08/09)

Cβ-Selective Aldol Addition of d -Threonine Aldolase by Spatial Constraint of Aldehyde Binding
d-Threonine aldolase (DTA) is a useful biocatalyst that reversibly converts glycine and aldehyde to β-hydroxy-α-d-amino acid. However, low activity and poor diastereoselectivity limit its applications. Here we report DTA from Filomicrobium marinum (FmDTA) that shows much higher activity and Cβ-stereoselectivity in d-threonine production compared with those of other known DTAs. We determine the FmDTA structure at a 2.2 ? resolution and propose a DTA catalytic mechanism with a kernel of the Lys49 inner proton sink and metal ion in the aldol reaction cycle. The enzyme is rationally engineered to have high Cβ-stereoselectivity based on spatial constraint at the anti-specific aldehyde position in the mechanism, and the rational strategy is further applied to other DTAs for syn-production. The final FmDTAG179A/S312A variant exhibits a near-perfect 99.5% de value for d-threonine and maintains the de value above 93% even under kinetically unfavorable conditions. This study demonstrates how a detailed understanding of the reaction mechanism can be used for rational protein engineering.
Park, Sung-Hyun,Seo, Hogyun,Seok, Jihye,Kim, Haseong,Kwon, Kil Koang,Yeom, Soo-Jin,Lee, Seung-Goo,Kim, Kyung-Jin
p. 6892 - 6899
(2021/06/28)

Mechanism of eukaryotic serine racemase-catalyzed serine dehydration
Eukaryotic serine racemase (SR) is a pyridoxal 5′-phosphate enzyme belonging to the Fold-type II group, which catalyzes serine racemization and is responsible for the synthesis of D-Ser, a co-agonist of the N-methyl-D-aspartate receptor. In addition to racemization, SR catalyzes the dehydration of D- and L-Ser to pyruvate and ammonia. The bifuctionality of SR is thought to be important for D-Ser homeostasis. SR catalyzes the racemization of D- and L-Ser with almost the same efficiency. In contrast, the rate of L-Ser dehydration catalyzed by SR is much higher than that of D-Ser dehydration. This has caused the argument that SR does not catalyze the direct D-Ser dehydration and that D-Ser is first converted to L-Ser, then dehydrated. In this study, we investigated the substrate and solvent isotope effect of dehydration of D- and L-Ser catalyzed by SR from Dictyostelium discoideum (DdSR) and demonstrated that the enzyme catalyzes direct D-Ser dehydration. Kinetic studies of dehydration of four Thr isomers catalyzed by D. discoideum and mouse SRs suggest that SR discriminates the substrate configuration at C3 but not at C2. This is probably the reason for the difference in efficiency between L- and D-Ser dehydration catalyzed by SR.
Goto, Masaru,Hemmi, Hisashi,Ito, Tomokazu,Matsuoka, Mai,Matsushita, Kazuma,Mizobuchi, Taichi,Nasu, Ryoma,Watanabe, Soichiro,Yoshimura, Tohru
(2020/06/08)

Synthesis of the Siderophore Coelichelin and Its Utility as a Probe in the Study of Bacterial Metal Sensing and Response
A convergent total synthesis of the siderophore coelichelin is described. The synthetic route also provided access to acetyl coelichelin and other congeners of the parent siderophore. The synthetic products were evaluated for their ability to bind ferric iron and promote growth of a siderophore-deficient strain of the Gram-negative bacterium Pseudomonas aeruginosa under iron restriction conditions. The results of these studies indicate coelichelin and several derivatives serve as ferric iron delivery vehicles for P. aeruginosa.
Williams, Jade C.,Sheldon, Jessica R.,Imlay, Hunter D.,Dutter, Brendan F.,Draelos, Matthew M.,Skaar, Eric P.,Sulikowski, Gary A.
supporting information
p. 679 - 682
(2019/02/07)

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce
Pseudomonas cichorii, which causes varnish spots on lettuce and seriously damages lettuce production during the summer season in the highland areas of Japan (e.g., Nagano and Iwate prefectures) was isolated. The structure of a toxin produced by this organism was analyzed based on the detailed evaluation of its 2D NMR and FABMS spectra, and this compound has not been reported previously. We propose the name cichorinotoxin for this toxin. In conjunction with the D or L configurations of each amino acid, which were determined by Marfey’s method, we propose the structure of cichorinotoxin to be as follows: 3-hydroxydecanoyl-(Z)-dhThr1-D-Pro2-D-Ala3-D-Ala4-D-Ala5-D-Val6-D-Ala7-(Z)-dhThr8-Ala9-Val10-D-Ile11-Ser12-Ala13-Val14-Ala15-Val16-(Z)-dhThr17-D-alloThr18-Ala19-L-Dab20-Ser21-Val22, and an ester linkage is present between D-alloThr18 and Val22 (dhThr: 2-aminobut-2-enoic acid; Dab: 2,4-diaminobutanoic acid). Thus, the toxin is a lipodepsipeptide with 22 amino acids. The mono- and tetraacetate derivatives and two alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce.
Komatsu, Hidekazu,Shirakawa, Takashi,Uchiyama, Takeo,Hoshino, Tsutomu
p. 299 - 309
(2019/02/20)

Preparation and purification method of amino acid compound
The invention relates to the field of industrial organic synthesis, in particular to a preparation and purification method of an amino acid compound. The method comprises the following steps that (1)alpha-amino nitrile compounds or hydantoin compounds or mixtures thereof are heated to react to obtain alpha-amino acid salt under the condition that volatile alkali and a suitable solvent exist; (2)after the alpha-amino acid salt obtained in step (1) is distilled, the alpha-amino acid salt is recrystallized in an organic solvent to obtain the alpha-amino acid compound. According to the method, reaction conditions are mild, materials can be recycled, and introduction of metal ions and use of ammonium carbonate salt are avoided, so that post-treatment is simple and no waste salt is generated.
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Paragraph 0066; 0067

(2018/06/21)

A α - amino acid compound synthesis and purification method
The invention relates to a synthesis and purification method for an alpha-amino acid compound. The synthesis and purification method is characterized by comprising the following steps: (1) adding substituted alpha-amino nitrile or a substituted hydantoin-based compound into alkali M(OH)x or metal oxide MxO, adding water or an alcohol and water mixed solvent, and heating for reaction to obtain alpha-amino acid salt; (2) adding ammonium carbonate or ammonium bicarbonate or introducing carbon dioxide into the solution in the step (1), separating to obtain filter liquor and precipitates MxHyCO3, performing reduced pressure concentration on the filter liquor, and recrystallizing in an alcohol solvent to obtain the alpha-amino acid compound (I). The synthesis and purification method for the alpha-amino acid compound is simple, the yield and purity of the obtained alpha-amino acid compound are high; furthermore, recycling utilization and cleaning production of materials can be realized; the synthesis and purification method is especially suitable for synthesis of the alpha-amino acid compound with high water solubility.
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Paragraph 0069; 0070

(2018/05/16)

Self-Reporting Inhibitors: A Single Crystallization Process To Obtain Two Optically Pure Enantiomers
Collection of two optically pure enantiomers in a single crystallization process can significantly increase the chiral separation efficiency but this is difficult to realize. Now a self-reporting strategy is presented for visualizing the crystallization process by a dyed self-assembled inhibitor made from the copolymers with tri(ethylene glycol)-grafting polymethylsiloxane as the main chain and poly(N6-methacryloyl-l-lysine) as side chains. When applied with seeds together for the fractional crystallization of conglomerates, the inhibitors can label the formation of the secondary crystals and guide the complete separation process of two enantiomers with colorless crystals as the first product and red crystals as the second. This method leads to high optical purity of d/l-Asn?H2O (99.9 % ee for d-crystals and 99.5 % for l-crystals) in a single crystallization process. It requires a small amount of additives and shows excellent recyclability.
Ye, Xichong,Cui, Jiaxi,Li, Bowen,Li, Na,Zhang, Jie,Wan, Xinhua
p. 8120 - 8124
(2018/06/29)

Cloning and characterization of D-threonine aldolase from the green alga Chlamydomonas reinhardtii
D-Threonine aldolase (DTA) catalyzes the pyridoxal 5’-phosphate (PLP)-dependent interconversion of D-threonine and glycine plus acetaldehyde. The enzyme is a powerful tool for the stereospecific synthesis of various β-hydroxy amino acids in synthetic organic chemistry. In this study, DTA from the green alga Chlamydomonas reinhardtii was discovered and characterized, representing the first report to describe the existence of eukaryotic DTA. DTA was overexpressed in recombinant Escherichia coli BL21 (DE3) cells; the specific activity of the enzyme in the cell-free extract was 0.8 U/mg. The recombinant enzyme was purified to homogeneity by ammonium sulfate fractionation, DEAE-Sepharose, and Mono Q column chromatographies (purified enzyme 7.0 U/mg). For the cleavage reaction, the optimal temperature and pH were 70?°C and pH 8.4, respectively. The enzyme demonstrated 90% of residual activity at 50?°C for 1?h. The enzyme catalyzed the synthesis of D- and D-allo threonine from a mixture of glycine and acetaldehyde (the diastereomer excess of D-threonine was 18%). DTA was activated by several divalent metal ions, including manganese, and was inhibited by PLP enzyme inhibitors and metalloenzyme inhibitors.
Hirato, Yuki,Tokuhisa, Mayumi,Tanigawa, Minoru,Ashida, Hiroyuki,Tanaka, Hiroyuki,Nishimura, Katsushi
p. 18 - 23
(2017/02/05)

A new d-threonine aldolase as a promising biocatalyst for highly stereoselective preparation of chiral aromatic β-hydroxy-α-amino acids
d-Threonine aldolase is an enzyme belonging to the glycine-dependent aldolases, and it catalyzes the reversible aldol reaction of glycine and acetaldehyde to give d-threonine and/or d-allo-threonine. In this study, a putative d-threonine aldolase gene from Delftia sp. RIT313 was cloned and expressed in Escherichia coli BL21 (DE3). The purified enzyme (DrDTA, 47 KDa) exhibited 21.3 U mg-1 activity for the aldol addition of glycine and acetaldehyde in MES-NaOH buffer (pH 6.0) at 50 °C. Both pyridoxal 5′-phosphate and metal ions were needed for the reaction, and the existence of the metal ions enhanced the stability of the enzyme. It was found that the conversion and Cβ-stereoselectivity were dramatically influenced by the reaction temperature, co-solvent, amount of enzyme and reaction time, and it is possible to enable the reaction under kinetic control to retain suitable conversion and high stereoselectivity at the β-carbon, thus tackling the "Cβ-stereoselectivity problem". DrDTA showed high activity toward aromatic aldehydes with electron-withdrawing substituents. Under the optimized reaction conditions, phenylserines with a 2′-fluoro- or 3′-nitro-substituent were obtained with >90% conversion and >90% de. In addition, dl-threo-phenylserine and dl-threo-4-(methylsulfonyl)phenylserine were efficiently resolved with an excellent enantiomeric excess value (ee, >99%) using a whole cell biocatalyst in a two-phase system at 1.0 M and 0.3 M, respectively, the highest substrate concentration reported so far. These results suggested that DrDTA might be a promising biocatalyst for producing chiral aromatic β-hydroxy-α-amino acids.
Chen, Qijia,Chen, Xi,Cui, Yunfeng,Ren, Jie,Lu, Wei,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
p. 5964 - 5973
(2017/12/26)

SEPARATING AGENT AND MANUFACTURING METHOD THEREOF
An embodiment of the present invention is a separating agent wherein a group represented by a chemical formula of: or a group represented by a chemical formula of: is introduced on a surface thereof.
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Paragraph 0067; 0068; 0069; 0070; 0071; 0072; 0093; 0094

(2015/01/07)

(2R,1'S,2'R)- And (2S,1'S,2'R)-3-[2-mono(di,tri)fluoromethylcyclopropyl] alanines and their incorporation into hormaomycin analogues
Efficient and scalable syntheses of enantiomerically pure (2 R ,1' S ,2' R )- and (2 S ,1' S ,2' R )-3-[2-mono(di,tri)fluoromethylcyclopropyl] alanines 9a - c , as well as allo-D-threonine ( 4 ) and ( 2 S,3R)-β-methylphenylalanine (3), using the Belokon' approach with (S )- and (R )-2-[( N-benzylprolyl)amino]benzophenone [(S)- and (R)-10 ] as reusable chiral auxiliaries have been developed. Three new fluoromethyl analogues of the naturally occurring octadepsipeptide hormaomycin ( 1 ) with (fluoromethylcyclopropyl) alanine moieties have been synthesized and subjected to preliminary tests of their antibiotic activity.
De Meijere, Armin,Kozhushkov, Sergei I.,Yufit, Dmitrii S.,Grosse, Christian,Kaiser, Marcel,Raev, Vitaly A.
supporting information
p. 2844 - 2857
(2015/02/19)

Cyclic lipodepsipeptides verlamelin A and B, isolated from entomopathogenic fungus Lecanicillium sp.
Verlamelin and its new derivative (verlamelin B) were isolated from fermentation broth of entomopathogenic fungus Lecanicillium sp. HF627. As the structural elucidation of verlamelin so far was only preliminary, we studied and determined the absolute structure of these two compounds to be cyclo(5S-hydroxytetradecanoic acid-D-alloThr/Ser-D-Ala-L-Pro-L-Gln-D-Tyr-L-Val). This is the first study that precisely analyzed the structure of verlamelin.
Ishidoh, Kei-Ichi,Kinoshita, Hiroshi,Igarashi, Yasuhiro,Ihara, Fumio,Nihira, Takuya
p. 459 - 463
(2014/07/08)

Improved synthesis of d-allothreonine derivatives from l-threonine
The improved synthesis of protected d-allothreonine derivatives [Fmoc-d-alloThr(tBu)-OH (1) and Fmoc-d-alloThr-OtBu (2)] is described. The epimerization of cheap l-threonine (l-Thr) (3) with catalytic salicylaldehyde afforded a mixture of l-Thr (3) and d-alloThr (4) and separation of ammonium salt gave d-alloThr (4) in 96% de. The chemoselective deprotection of tert-butyl ether or tert-butyl ester of Fmoc-d-alloThr(tBu)-O tBu (5) easily succeeded in converting Fmoc-d-alloThr( tBu)-OH (1) or Fmoc-d-alloThr-OtBu (2), respectively.
Kikuchi, Mari,Konno, Hiroyuki
p. 7098 - 7101
(2013/07/26)

Ohmyungsamycins A and B: Cytotoxic and antimicrobial cyclic peptides produced by Streptomyces sp. from a volcanic island
Ohmyungsamycins A and B (1 and 2), which are new cyclic peptides, were isolated from a marine bacterial strain belonging to the Streptomyces genus collected from a sand beach on Jeju, a volcanic island in the Republic of Korea. Based on the interpretation of the NMR, UV, and IR spectroscopic and MS data, the planar structures of 1 and 2 were elucidated as cyclic depsipeptides bearing unusual amino acid units, including N-methyl-4-methoxytrytophan, β-hydroxyphenylalanine, and N,N-dimethylvaline. The absolute configurations of the α-carbons of the amino acid residues were determined using the advanced Marfey's method. The configurations of the additional stereogenic centers at the β-carbons of the threonine, N-methylthreonine, and β-hydroxyphenylalanine units were assigned by GITC (2,3,4,6-tetra-O-acetyl- β-d-glucopyranosyl isothiocyanate) derivatization and the modified Mosher's method. We have developed a new method utilizing PGME (phenylglycine methyl ester) derivatization coupled with chromatographic analysis to determine the absolute configuration of N,N-dimethylvaline. Our first successful establishment of the absolute configuration of N,N-dimethylvaline using PGME will provide a general and convenient analytical method for determining the absolute configurations of amino acids with fully substituted amine groups. Ohmyungsamycins A and B showed significant inhibitory activities against diverse cancer cells as well as antibacterial effects.
Um, Soohyun,Choi, Tae Joon,Kim, Heegyu,Kim, Byung Yong,Kim, Seong-Hwan,Lee, Sang Kook,Oh, Ki-Bong,Shin, Jongheon,Oh, Dong-Chan
p. 12321 - 12329
(2014/01/17)

Structure and biosynthesis of xenoamicins from entomopathogenic xenorhabdus
During the search for novel natural products from entomopathogenic Xenorhabdus doucetiae DSM17909 and X. mauleonii DSM17908 novel peptides named xenoamicins were identified in addition to the already known antibiotics xenocoumacin and xenorhabdin. Xenoamicins are acylated tridecadepsipeptides consisting of mainly hydrophobic amino acids. The main derivative xenoamicin A (1) was isolated from X. mauleonii DSM17908, and its structure elucidated by detailed 1 D and 2 D NMR experiments. Detailed MS experiments, also in combination with labeling experiments, confirmed the determined structure and allowed structure elucidation of additional derivatives. Moreover, the xenoamicin biosynthesis gene cluster was identified and analyzed in X. doucetiae DSM17909, and its participation in xenoamicin biosynthesis was confirmed by mutagenesis. Advanced Marfey's analysis of 1 showed that the absolute configuration of the amino acids is in agreement with the predicted stereochemistry deduced from the nonribosomal peptide synthetase XabABCD. Biological testing revealed activity of 1 against Plasmodium falciparum and other neglected tropical diseases but no antibacterial activity.
Zhou, Qiuqin,Grundmann, Florian,Kaiser, Marcel,Schiell, Matthias,Gaudriault, Sophie,Batzer, Andreas,Kurz, Michael,Bode, Helge B.
supporting information
p. 16772 - 16779
(2014/01/06)

Lahorenoic acids A-C, ortho-dialkyl-substituted aromatic acids from the biocontrol strain pseudomonas aurantiaca PB-St2
Three new aromatic acids, named lahorenoic acids A (1), B (2), and C (3), have been isolated along with the known compounds phenazine-1-carboxylic acid (4), 2- hydroxyphenazine-1-carboxylic acid (5), 2-hydroxyphenazine (6), 2,8-dihydroxyphenazine (7), cyclo-Pro-Tyr (8), cyclo-Pro- Val (9), cyclo-Pro-Met (10), and WLIP (11) and characterized from the biocontrol strain Pseudomonas aurantiaca PBSt2. The structures of these compounds were deduced by 1D and 2D NMR spectroscopic and mass spectral data interpretation. Compounds 2, 4, and 7 showed moderate antibacterial activity against mycobacteria and other Grampositive bacteria, while 4 was also found to exhibit cytotoxic and antifungal properties.
Mehnaz, Samina,Saleem, Rahman Shah Zaib,Yameen, Basit,Pianet, Isabelle,Schnakenburg, Gregor,Pietraszkiewicz, Halina,Valeriote, Fred,Josten, Michaele,Sahl, Hans-Georg,Franzblau, Scott G.,Harald, Gross
p. 135 - 141
(2013/06/05)

Imaging mass spectrometry and genome mining reveal highly antifungal virulence factor of mushroom soft rot pathogen
Soft rot diseases caused by a variety of bacteria account for severe losses in agriculture, devastating fruits, vegetables, and cultivated mushrooms. After bacterial infection, often owing to direct contact or transmission by insects, virulence factors and lytic enzymes cause degradation of plant and mushroom tissues, thereby turning crop into mush. In many cases, the chemical mediators of soft rot diseases have remained elusive, as in the long-known mushroom pathogen Janthinobacterium agaricidamnosum. This motile Gram-negative bacterium has been found to be the causative agent of soft rot disease of the cultured button mushroom, Agaricus bisporus. Typical symptoms of the infection are lesions turning into sticky blotches on the cap surface and a complete dissolution of the mushroom within only a few days (Figure 1A, B). We reasoned that knowledge on the causative agent of the soft rot would have a double benefit. Foremost, it could aid in understanding the pathobiology of the mushroom pathogen, which may be a starting point for protective measures. Second, there is an increasing need for novel antifungals, since the incidents of severe and even lethal fungal infections and resistance towards antifungals are on the rise. We hypothesized that mushroom soft rot bacteria could excrete antifungal agents as virulence factors, which might also be active against human pathogens. Herein we report the discovery and full characterization of a highly antifungal virulence factor from the soft rot pathogen Janthinobacterium agaricidamnosum guided by imaging mass spectrometry and genome mining.
Graupner, Katharina,Scherlach, Kirstin,Bretschneider, Tom,Lackner, Gerald,Roth, Martin,Gross, Harald,Hertweck, Christian
supporting information
p. 13173 - 13177
(2013/03/14)

Cytotoxic cyclic depsipeptides from the Australian marine sponge Neamphius huxleyi
Three new cyclic depsipeptides, neamphamides B (2), C (3), and D (4), were isolated from the Australian sponge Neamphius huxleyi. The planar structural characterization of these molecules was elucidated using 2D NMR experiments and ESI-FTICR-MSn. Their configurations were determined by Marfey's method and J-based NMR analysis. These new metabolites inhibited the growth of human cell lines (A549, HeLa, LNCaP, PC3, and NFF) with IC50 values ranging from 88 to 370 nM. However, neamphamide D causes A549 cell proliferation at subcytotoxic doses and should be treated cautiously as a cytotoxic compound.
Tran, Trong D.,Pham, Ngoc B.,Fechner, Gregory,Zencak, Dusan,Vu, Hoan T.,Hooper, John N.A.,Quinn, Ronald J.
p. 2200 - 2208
(2013/02/25)

Genomics-driven discovery of taiwachelin, a lipopeptide siderophore from Cupriavidus taiwanensis
A genome mining study led to the identification of a previously unrecognised siderophore biosynthesis gene cluster in the nitrogen-fixing bacterium Cupriavidus taiwanensis LMG19424. Based upon predicted structural residues, a convenient strategy for an NMR-assisted isolation of the associated metabolite was designed. The structure of the purified siderophore, taiwachelin, was fully characterized by spectroscopic methods and chemical derivatisation.
Kreutzer, Martin F.,Nett, Markus
p. 9338 - 9343
(2013/01/15)

Totopotensamides, polyketide-cyclic peptide hybrids from a mollusk-associated bacterium Streptomyces sp.
Two new compounds, the peptide-polyketide glycoside totopotensamide A (1) and its aglycone totopotensamide B (2), were isolated from a Streptomyces sp. cultivated from the gastropod mollusk Lienardia totopotens collected in the Philippines. The compounds contain a previously undescribed polyketide component, a novel 2,3-diaminobutyric acid-containing macrolactam, and a new amino acid, 4-chloro-5,7-dihydroxy-6-methylphenylglycine. The application of Marfey's method to phenylglycine derivatives was explored using quantum mechanical calculations and NMR.
Lin, Zhenjian,Flores, Malem,Forteza, Imelda,Henriksen, Niel M.,Concepcion, Gisela P.,Rosenberg, Gary,Haygood, Margo G.,Olivera, Baldomero M.,Light, Alan R.,Cheatham, Thomas E.,Schmidt, Eric W.
experimental part
p. 644 - 649
(2012/06/29)

An efficient route to both enantiomers of allo-threonine by simultaneous amino acid racemase-catalyzed isomerization of threonine and crystallization
We present an efficient method for the production of D- and L-allo-threonine (allo-Thr) with very high purity by enzymatic isomerization of L- or D-threonine (Thr) and simultaneous crystallization. Isomerization of Thr to allo-Thr is catalyzed by a purified amino acid racemase (AArac12996) from Pseudomonas putida NBRC12996, which can easily be obtained from a recombinant E. coli strain by secretion into the medium and subsequent anion exchange chromatography. Crystallization of D- and L-allo-Thr was performed in a repetitive batch mode over a period of up to 55 days at 30 °C. Total amounts of 30.8 g D-allo-Thr and 32.4 g L-allo-Thr were obtained with a very good diastereomeric excess of deD-allo>99.2% and de L-allo>98.4%, respectively, and in good yields (D-allo-Thr: 83%, L-allo-Thr: 79%). The enzyme's remarkable high stability under process conditions resulted in enzyme specific yields of 2.56 g D-allo-Thr per mg AArac12996 and 1.62 g L-allo-Thr per mg AArac12996. In contrast to chemical multi-step syntheses of allo-Thr, our process consists of only one enzyme-catalyzed reaction step with simultaneous product crystallization. The process is performed under low energy consumption (30 °C, atmospheric pressure) in water and avoids the use and production of any toxic or harmful compounds. Recovery of the enantiomerically pure products is performed by simple filtration which reduces downstream processing significantly compared to chromatographic methods which are usually applied. Copyright
Wuerges, Kerstin,MacKfeld, Ursula,Pohl, Martina,Luetz, Stephan,Wilhelm, Susanne,Wiechert, Wolfgang,Kubitzki, Tina
experimental part
p. 2431 - 2438
(2011/11/06)

Solid phase total synthesis of callipeltin e isolated from marine sponge Latrunculia sp.
Solid phase total synthesis of callipeltin E (1), truncated linear peptide isolated from marine sponge, Latrunculia sp. was achieved. Our strategy based on traditional Fmoc-SPPS was in common use TFA-treatment final deprotection to reach callipeltin E (1) contained acid-sensitive βMeOTyr.
Kikuchi, Mari,Nosaka, Kazuto,Akaji, Kenichi,Konno, Hiroyuki
scheme or table
p. 3872 - 3875
(2011/08/09)

Preparation of optically active allothreonine by separating from a diastereoisomeric mixture with threonine
A simple procedure is described to obtain D-and L-allothreonine (D-and L-aThr). A mixture of N-acetyl-D-allothreonine (Ac-D-aThr) and N-acetyl-L-threonine (Ac-L-Thr) was converted to a mixture of their ammonium salts and then treated with ethanol to precipitate ammonium N-acetyl-L- threoninate (Ac-L-Thr.NH3) as the less-soluble diastereoisomeric salt. After separating Ac-L-Thr.NH3 by filtration, Ac-D-aThr obtained from the filtrate was hydrolyzed in hydrochloric acid to give D-aThr of 80% de, recrystallized from water to give D-aThr of >99% de. L-aThr was obtained from a mixture of the ammonium salts of Ac-L-aThr and Ac-D-Thr in a similar manner.
Yajima, Tatsuo,Ichimura, Serina,Horii, Shirabe,Shiraiwa, Tadashi
experimental part
p. 2106 - 2109
(2011/06/25)

Grassypeptolides A-C, cytotoxic bis-thiazoline containing marine cyclodepsipeptides
Grassypeptolides A-C (1-3), a group of closely related bis-thiazoline containing cyclic depsipeptides, have been isolated from extracts of the marine cyanobacterium Lyngbya confervoides. Although structural differences between the analogues are minimal, comparison of the in vitro cytotoxicity of the series revealed a structure-activity relationship. When the ethyl substituent of 1 is changed to a methyl substituent in 2, activity is only slightly reduced (3-4-fold), whereas inversion of the Phe unit flanking the bis-thiazoline moiety results in 16-23-fold greater potency. We show that both 1 and 3 cause G1 phase cell cycle arrest at lower concentrations, followed at higher concentrations by G2/M phase arrest, and that these compounds bind Cu2+ and Zn 2+. The three-dimensional structure of 2 was determined by MS, NMR, and X-ray crystallography, and the structure of 3 was established by MS, NMR, and chemical degradation. The structure of 3 was explored by in silico molecular modeling, revealing subtle differences in overall conformation between 1 and 3. Attempts to interconvert 1 and 3 with base were unsuccessful, but enzymatic conversion may be possible and could be a novel form of activation for chemical defense.
Kwan, Jason C.,Ratnayake, Ranjala,Abboud, Khalil A.,Paul, Valerie J.,Luesch, Hendrik
experimental part
p. 8012 - 8023
(2011/03/20)

New polypeptides inducing apoptosis and uses thereof
The present invention concerns a polypeptide comprising the sequence X1WX2X3X4RX5X6X7 X8 X9, and derivatives thereof, wherein X1 is an amino acid selected in the group consisting in histidinc (H), tyrosinc (Y), aspartic acid (D), glutamine (Q), and leucine (L), preferably histidine (H) or tyrosine (Y); X2 is a polar amino acid, charged or not, and selected in the group consisting in serine (S) threonine (T), lysine (K), arginine (R), asparagine (N), aspartic acid (D), cysteine (C), glycine (G), glutamine (Q), histidine (H), and glutamic acid (E); X3 is a polar amino acid, charged or not, and selected in the group consisting in serine (S), threonine (T), asparagine (N), cysteine (C), histidine (H), leucine (L), tyrosine (Y), alanine (A), and isoleucine (1); X4 is an amino acid selected in the group consisting in threonine (T), arginine (R), asparagine (N), alanine (A), isoleucine (I), leucine (L), methionine (M), phenylalanine (F), tryptophane (W), valine (V) and tyrosine; X5 is an amino acid selected in the group consisting in leucine (L), methionine (M), isoleucine (I), tryptophane (W), tyrosine (Y), histidine (H), glutamine (Q), lysine (K), and arginine (R); X6 is an amino acid selected in the group consisting in leucine (L), and glutamic acid (E); X7 is an amino acid selected in the group consisting in cysteine (C), asparagine (N), alanine (A), tyrosine (Y), serine (S), glutamine (Q), and proline (P); X8 is a hydrophobic amino acid selected in the group consisting in alanine (A), isoleucine (I), leucine (L), methionine (M), phenylalanine (F), tryptophane (W), valine (V) and tyrosine; and X9 is a threonine or an hydrophobic amino acid selected in the group consisting in alanine (A), isoleucine (I), leucine (L), methionine (M), phenylalanine (F), tryptophane (W), valine (V) and tyrosine.
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(2009/02/10)

Compositions and Methods for Binding Lysophosphatidic Acid
Compositions and methods for making and using anti-LPA agents, for example, monoclonal antibodies, are described.
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(2009/06/27)

Modulating neuronal outgrowth via the major histocompatibility complex class I (MHC I) molecule
The invention relates to methods and compositions for treating neural damage caused by injury or disease, by enhancing neural outgrowth and/or repair responses in the nervous system. Preferably, the methods and compositions utilize agents which interfere with the ability of the major histocompatibility complex (MHC) Class I molecule (MHC I) to inhibit neurite outgrowth. Such agents include antibodies directed to MHC I, MHC I fragments and/or analogs, and agents which interfere with MHC I interaction with its neuronal receptor and the receptor's signaling pathway.
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(2009/07/10)

METHOD AND COMPOSITIONS FOR TREATING SKIN
A skin care composition comprising at least one keratinocyte CLOCK or PER1 gene activator and at least one DNA repair enzyme; a method for inhibiting damage to human keratinocytes due to environmental aggressors by applying a composition comprising at least one keratinocyte CLOCK or PER1 gene activator and at least one DNA repair enzyme; and a method for repairing DNA damage in human keratinocytes.
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(2009/09/08)

GEP, a novel chondrogenic growth factor and target in cartilage disorders
The present invention relates to the expression and regulating growth factors in chrondrocytes and developing cartilage, particularly granulin-epithelin precursor (GEP). The invention relates to the modulation and manipulation of these growth factors, GEP, and/or the molecules they interact with, for instance COMP, in cartilage disorders, including arthritis. Assays and screening methods for the determination of the expression and activity of GEP, or of GEP-COMP, are provided, including for screening for the presence or extent of cartilage or arthritic disease and for identifying modulators or compounds/agents for treatment or prevention of cartilage or arthritic diseases.
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(2009/09/25)

NOVEL ATTENUATED POLIOVIRUS
A novel and stable attenuated poliovirus, which replicates in neuroblastoma cells, is produced by engineering an indigenous replication element (cre), into the 5′ non-translated genomic region and inactivating the native cre element located in the coding region of 2C (mono-crePV). The stably attenuated poliovirus replicates in a neuroblastoma model (Neuro-2aCD155 tumors) expressing CD155, the poliovirus receptor, and is effective for oncolytic treatment and cure of solid tumors, such as neuroblastoma.
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(2009/10/06)

Cell Model for Alzheimer's Disease Pathology
The present invention encompasses compositions and methods for studying in cell culture the pathologic changes associated with Alzheimer's disease. The present invention further relates to methods for studying and detecting early events in the conversion of healthy neurons to Alzheimer's disease neurons.
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(2009/12/04)

EPSPS Mutants
The present invention relates to the production of a non-transgenic plant resistant or tolerant to a herbicide of the phosphonomethylglycine family, e.g., glyphosate. The present invention also relates to the use of a recombinagenic oligonucleobase to make a desired mutation in the chromosomal or episomal sequences of a plant in the gene encoding for 5-enol pyruvylshikimate-3-phosphate synthase (EPSPS). The mutated protein, which substantially maintains the catalytic activity of the wild-type protein, allows for increased resistance or tolerance of the plant to a herbicide of the phosphonomethylglycine family, and allows for the substantially normal growth or development of the plant, its organs, tissues or cells as compared to the wild-type plant irrespective of the presence or absence of the herbicide. Additionally the present invention relates to mutant E. coli cells that contain mutated EPSPS genes.
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(2009/12/24)

Method for the production of high-level soluble human recombinant interferon alpha in e. coli and vectors useful for such a production
Method for the production of high-level soluble human recombinant interferon alpha protein (rhuIFNα) in E. coli and vectors useful for such a production. Said method comprises the steps of: (1) Transforming an E. coli selected in the group consisting of E. coli protease deficient host strains, and E. coli reductase deficient host strains, with a recombinant expression vector comprising the sequence encoding the glutathione-S-transferase (GST), a junction sequence including a recognition site for a specific protease and a sequence able to encode an interferon alpha (IFN alpha) protein under the control of an inducible promoter, said vector encoding a GST-IFN alpha fusion protein (2) Expressing said interferon alpha protein in conditions comprising the induction of the expression with 0.1 mM-0.5 mM IPTG and a growth temperature of 25° and/or 37°C, depending on said E. coli strain and (3) Isolating the expressed IFN alpha protein.
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(2009/01/20)

Growth Hormone Secretagogue Receptor 1A Ligands
The present invention relates to new growth hormone secretagogue receptor 1A (GHS-R 1A) ligands, and pharmaceutical compositions comprising any of the new GHS-R1 A ligands. The ligands are suitable for a wide range of applications, and thus the present invention also relates to use of the GHS-R1 A ligands according to the present invention in the manufacture of a medicament for the treatment of an individual in need thereof. In another aspect, the present invention relates to a method of treatment of an individual in need thereof, comprising administering to said individual one or more of the GHS-R1A ligands disclosed herein, such as e.g. for treatment of cancer cachexia.
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(2009/01/20)

Cell-proliferation inhibiting VPg proteins, fragments or analogs thereof and their applications
Use of VPg proteins, fragments or analogs thereof having the ability to bind an eukaryotic initiation factor eIF4E, for inhibiting cell-proliferation.
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(2009/01/24)

Compositions, kits, and methods relating to the human FEZ1 gene, a novel tumor suppressor gene
The invention relates to isolated polynucleotides homologous with a portion of one strand of the human tumor suppressor gene, FEZ1, and to the tumor suppressor protein encoded thereby, Fez1. The polynucleotides are useful, for example, as probes, primers, portions of expression vectors, and the like. The invention also includes diagnostic, therapeutic, cell proliferation enhancement, and screening methods which involve these polynucleotides and protein. The invention further includes kits useful for performing the methods of the invention.
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(2008/06/13)

Cell adhesion and extracellular matrix proteins
Various embodiments of the invention provide human cell adhesion and extracellular matrix proteins (CADECM) and polynucleotides which identify and encode CADECM. Embodiments of the invention also provide expression vectors, host cells, antibodies, agonists, and antagonists. Other embodiments provide methods for diagnosing, treating, or preventing disorders associated with aberrant expression of CADECM.
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(2008/06/13)

Synthesis of γ-halogenated and long-chain β-hydroxy-α-amino acids and 2-amino-1,3-diols using threonine aldolases
The l- and d-threonine aldolase catalyzed formation of γ-halogenated and long-chain l- and d-3-alkylserine-derivatives 1-12, respectively, was shown starting from glycine and halogenated C2- or C4-C12 aldehydes. lTA from Pseudomonas putida accepted all tested aldehydes with strongly varying diastereoselectivity (de up to 93%). Only aldehydes smaller than decanal were converted by dTA from Alcaligenes xylosoxidans with good selectivities (de up to 73%). Utilizing isobutanal enantio- and diastereopure d-syn-2-amino-3-hydroxy-4-methylpentanoic acid was obtained (ee>99%, de>95%), which was converted to the corresponding 2-amino-1,3-diol.
Steinreiber, Johannes,Fesko, Kateryna,Mayer, Clemens,Reisinger, Christoph,Schürmann, Martin,Griengl, Herfried
p. 8088 - 8093
(2008/02/08)

Determination of the complete absolute configuration of petriellin A
We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey's derivatives and Marfey's derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids. CSIRO 2006.
Aurelio, Luigi,Brownlee, Robert T. C.,Dang, Jason,Hughes, Andrew B.,Polya, Gideon M.
p. 407 - 414
(2008/02/04)

Plant peptide with antimicrobial activity
The invention concerns novel peptides, in particular plant peptides, having an antimicrobial activity and a cytotoxic activity, in particular for plant cells. The invention also concerns polynucleotides coding for said peptides, vectors comprising said polynucleotides, micro-organisms and cells transformed with said vectors, transgenic organisms whereof all of part of the cells contain and/or express said vectors, uses of said peptides and said polynucleotides, in particular as plant-specific antimicrobial agents. The invention further concerns an antimicrobial and/or cytotoxic method for treating plants.
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(2008/06/13)

Interleukin-2:remodeling and glycoconjugation of interleukin-2
The invention includes methods and compositions for remodeling a peptide molecule, including the addition or deletion of one or more glycosyl groups to a peptide, and/or the addition of a modifying group to a peptide.
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(2008/06/13)

Novel protein and use thereof
A novel gene likely inhibiting the onset and progress of cancer. A protein having an amino acid sequence which is the same or substantially the same as the amino acid sequence represented by SEQ ID NO:4 or its salt; a polynucleotide encoding the same; and medicinal use, etc. thereof are provided.
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(2008/06/13)

Process for producing alpha 2,3/ alpha 2,8-sialyltransferase and sialic acid-containing complex sugar
The present invention can provide a process for producing a protein having α2,3/α2,8-sialyltransferase activity using a transformant comprising a DNA encoding a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism belonging to the genus Pasteurella and a process for producing a sialic acid-containing complex carbohydrate using a transformant capable of producing a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism.
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(2008/06/13)

CIS-ELEMENT REGULATING TRANSCRIPTION, TRANSCRIPTIONAL REGULATORY FACTOR BINDING SPECIFICALLY THERETO AND USE OF THE SAME
The present invention provides a novel fructose responsive transcription control cis-element and a transcriptional regulatory factor that interacts therewith, a non-human animal having them transferred or inactivated, a diagnostic method for genetic susceptibility to a metabolic disorder using them, and a screening method for a prophylactic or therapeutic drug for a metabolic disorder using them.
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(2008/06/13)

Small peptides having apoptotic activities and their applications
The present invention relates to nine residue peptides (M32-40) from flavivirus M ectodomain able to modulate specifically the apoptotic activity of diverse flavivirus, to pharmaceutical composition comprising the same and their use for the treatment and/or the prevention of flavivirus-linked infections and cancers.
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(2008/06/13)

Novel enoyl reductases and methods of use thereof
The present provides structurally related enzymes that act as enoyl reductases. These enoyl reductases share a common amino acid consensus sequence, and bind a flavin cofactor. One particular enoyl reductase provided, FabK, catalyzes the identical reaction as the NADH-dependent enoyl-ACP reductase, FabI. Nucleic acids encoding the enoyl reductases, the enoyl reductases, and anitbodies for the enoyl reductases are also included. Methods are also provides for identifying agents that can act to prevent and/or treat bacterial infections.
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(2008/06/13)

Enzymes derived from thermophilic organisms that function as a chromosomal replicase, preparation and use thereof
The present invention relates to an isolated DNA molecule from a thermophilic bacterium which encodes a DNA polymerase III-type enzyme subunit. Also encompassed by the present invention are host cells and expression system including the heterologous DNA molecule of the present invention, as well as isolated replication enzyme subunits encoded by such DNA molecules. Also disclosed is a method of producing a recombinant thermostable DNA polymerase III-type enzyme, or subunit thereof, from a thermophilic bacterium, which is carried out by transforming a host cell with at least one heterologous DNA molecule of the present invention under conditions suitable for expression of the DNA polymerase III-type enzyme, or subunit thereof, and then isolating the DNA polymerase III-type enzyme, or subunit thereof.
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(2008/06/13)

ENZYME FOR CLEAVAGE OF THE ANCHOR REGION OF SURFACE PROTEINS FROM GRAM POSITIVE BACTERIA
The invention relates to an enzyme which cleaves surface proteins of gram-positive bacteria, to methods of detecting the enzyme, and methods of isolating the enzyme. In particular, the enzyme is isolated from a group A Streptococcus, and cleaves at the sequence LPXTGX (SEQ ID NO:1). A method for screening putative inhibitors of the enzyme which cleaves the anchor region of surface proteins from gram positive bacteria is also disclosed.
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(2008/06/13)

Assays for screening compounds which interact with cation channel proteins, mutant prokaryotic cation channel proteins, and uses thereof
Assays for screeing potential drugs or agents that can interact and potentially bind to cation channel proteins, and potentially have uses in treating conditions related to the function of cation channel proteins is provided, along with prokaryotic cation channel proteins mutated to mimic eukaryotic cation channels, which can then be used in assays of the present invention.
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(2008/06/13)