Enantioselective Synthesis of the Hydroxy‐Analogues of <scp>D</scp>‐and <scp>L</scp>‐Methionine

Kleemann, Axel; Lehmann, Bernd; Martens, Jürgen

doi:10.1002/anie.197907971

Cited by 3 publications

(1 citation statement)

References 4 publications

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“…Unlabeled d-and l-MTHB were synthesized from d-and l-Met by reaction with HNO 2 (Kleemann et al, 1979). Met (5 mmol) was dissolved in 4.25 mL of 0.9 m H 2 SO 4 and cooled to 0°C; 1 mL of ice-cold 6.2 m NaNO 2 was added dropwise, and the reaction mixture was then incubated for 2 h at 22°C.…”

Section: Synthesis Of Mthb and Dmshb Enantiomersmentioning

confidence: 99%

Identification and Stereospecificity of the First Three Enzymes of 3-Dimethylsulfoniopropionate Biosynthesis in a Chlorophyte Alga1

et al. 1998

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Many marine algae produce 3-dimethylsulfoniopropionate (DMSP), a potent osmoprotective compound whose degradation product dimethylsulfide plays a central role in the biogeochemical S cycle. Algae are known to synthesize DMSP via the four-step pathway, L-Met 3 4-methylthio-2-oxobutyrate 3 4-methylthio-2-hydroxybutyrate 3 4-dimethylsulfonio-2-hydroxy-butyrate (DM-SHB) 3 DMSP. Substrate-specific enzymes catalyzing the first three steps in this pathway were detected and partially characterized in cell-free extracts of the chlorophyte alga Enteromorpha intestinalis. The first is a 2-oxoglutarate-dependent aminotransferase, the second an NADPH-linked reductase, and the third an S-adenosylmethioninedependent methyltransferase. Sensitive radiometric assays were developed for these enzymes, and used to show that their activities are high enough to account for the estimated in vivo flux from Met to DMSP. The activities of these enzymes in other DMSP-rich chlorophyte algae were at least as high as those in E. intestinalis, but were >20-fold lower in algae without DMSP. The reductase and methyltransferase were specific for the D-enantiomer of 4-methylthio-2-hydroxybutyrate in vitro, and both the methyltransferase step and the step(s) converting DMSHB to DMSP were shown to prefer D-enantiomers in vivo. The intermediate DMSHB was shown to act as an osmoprotectant, which indicates that the first three steps of the DMSP synthesis pathway may be sufficient to confer osmotolerance.

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Section: Synthesis Of Mthb and Dmshb Enantiomersmentioning

confidence: 99%

Identification and Stereospecificity of the First Three Enzymes of 3-Dimethylsulfoniopropionate Biosynthesis in a Chlorophyte Alga1

et al. 1998

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Composite models of modular intermeshing corotating and tangential counter‐rotating twin screw extruders

White

Szydlowski

1987

Adv Polym Technol

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Synthesis and Chemotactic Activity of the fMLP Analog HCO‐Hmb‐Leu‐Phe‐OMe

Zecchini¹,

Paradisi²,

Torrini³

et al. 1993

Archiv der Pharmazie

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The new fMLP analog HCO-Hmb-Leu-Phe-OMe (1), containing (S)-2-hydroxy-4-(methylthio)butyric acid (Hmb) in place of L-methionine at the N-terminal position, has been synthesized and fully characterized. The peptide 1 has been designed in order to improve the understanding of the role exerted by the formamido group in the binding interaction with the formylpeptide chemotactic receptors. Chemotaxis, superoxide anion production, and lysozyme release have been measured for both 1 and its deformylated analog Hmb-Leu-Phe-OMe 2. Results indicate that a strong hydrogen bond of the OH....O = C type may complement a weak H-bonding interaction involving the formylic proton as H-bond donor.

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Enantioselective Synthesis of the Hydroxy‐Analogues of D‐and L‐Methionine

Cited by 3 publications

References 4 publications

Identification and Stereospecificity of the First Three Enzymes of 3-Dimethylsulfoniopropionate Biosynthesis in a Chlorophyte Alga1

Identification and Stereospecificity of the First Three Enzymes of 3-Dimethylsulfoniopropionate Biosynthesis in a Chlorophyte Alga1

Composite models of modular intermeshing corotating and tangential counter‐rotating twin screw extruders

Synthesis and Chemotactic Activity of the fMLP Analog HCO‐Hmb‐Leu‐Phe‐OMe

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