A Photochemical Route to 3- and 4-Hydroxy Derivatives of 2-Aminocyclobutane-1-carboxylic Acid with an all-cis Geometry.

Short gram-scale syntheses of both enantiomers of 2-amino-3-hydroxycyclobutane-1-carboxylic acid and of 2-amino-4-hydroxycyclobutanecarboxylic acid with an all-cis geometry are described. The sequences feature highly endo-selective [2 + 2]-photocycloaddition reactions followed by fully regioselective ring opening/Hofmann rearrangement/nitrogen protection, in a consecutive or one-pot protocol, followed by efficient resolution using a chiral oxazolidinone.

Isolation and Synthesis of Laxaphycin B-Type Peptides: A Case Study and Clues to Their Biosynthesis.

The laxaphyci's B family constitutes a group of five related cyclic lipopeptides isolated from diverse cyanobacteria from all around the world. This group shares a typical structure of 12 amino acids from the l and d series, some of them hydroxylated at the beta position, and all containing a rare beta-amino decanoic acid. Nevertheless, they can be differentiated due to slight variations in the composition of their amino acids, but the configuration of their alpha carbon remains conserved. Here, we provide the synthesis and characterization of new laxaphycin B-type peptides. In doing so we discuss how the synthesis of laxaphycin B and analogues was developed. We also isolate minor acyclic laxaphycins B, which are considered clues to their biosynthesis.

First total synthesis and stereochemical revision of laxaphycin B and its extension to lyngbyacyclamide A.

The first total synthesis of laxaphycin B was accomplished through stepwise automated Solid Phase Peptide Synthesis (SPPS), leading to the structural revision of its stereochemistry especially with regard to the configuration of one of the two 3-hydroxyleucines of this cyclic dodecapeptide of marine origin. The analogous Lyngbyacyclamide A was obtained by an extension of this synthesis.

Soluble fms-like tyrosine kinase-1 antibody for diagnosis purposes (WO2010075475).

BACKGROUND: The application (WO2010075475) is involved in the diagnosis of angiogenesis-dependent diseases related with the soluble FMS-like tyrosine kinase-1 (sFlt-1) biomarker. OBJECTIVE: It aims to identify, characterize and produce antibodies raised against sFlt-1 for the diagnosis of preeclampsia as well as other cardiovascular diseases. METHODS: The diagnostic kit is based on a double mAb sandwich assay, comprising of a capture anti-sFlt-1 mAb, grafted onto paramagnetic particles that are able to bind sFlt-1 both in bound and free forms. An acridinium conjugated anti-sFlt-1 antibody, which binds to s-Flt1 on another epitope, serves as a chemioluminescent label. RESULTS: Using this assay, the total amount of sFlt-1 could be estimated in various biological samples. CONCLUSION: Antibodies against the free and bound forms of sFlt-1 offer new opportunities in the diagnostics of preeclampsia and other angiogenesis-dependent disorders. Furthermore, as demonstrated in this patent, the immunoassay could be automated and is fast and reliable.