This study demonstrates the effectiveness of a peptide shuttle in delivering diclofenac into and through human epidermis. Diclofenac was conjugated to a novel phenylalanyl-N-methyl-naphthalenylalanine-derived diketopiperazine (DKP) shuttle and to TAT (a classical cell penetrating peptide), and topically applied to human epidermis in vitro. DKP and TAT effectively permeated into and through huma...

Herein, we report an unprecedented, short and diastereo-selective synthesis of newly reported aza-diketopiperazine (aza-DKP) scaffolds starting from amino acids. The strategy is based on a Rh(I)-catalyzed hydroformylative cyclohydrocarbonylation of allyl-substituted aza-DKP, followed by a diastereoselective functionalization of the platform. This methodology allows the synthesis of novel bicycl...

The dispersionless Kadomtsev-Petviashvili (dKP) equation (ut + uux)x = uyy is one of the simplest nonlinear wave equations describing twodimensional shocks. To solve the dKP equation we use a coordinate transformation inspired by the method of characteristics for the one-dimensional Hopf equation ut + uux = 0. We show numerically that the solutions to the transformed equation develops singulari...

The synthesis of eight bifunctional diketopiperazine (DKP) scaffolds is described; these were formally derived from 2,3-diaminopropionic acid and aspartic acid (DKP-1-DKP-7) or glutamic acid (DKP-8) and feature an amine and a carboxylic acid functional group. The scaffolds differ in the configuration at the two stereocenters and the substitution at the diketopiperazinic nitrogen atoms. The bifu...

For the first time we show that the quasiclassical limit of the symmetry constraint of the KP hierarchy leads to the generalized Zakharov reduction of the dispersionless KP (dKP) hierarchy which has been proved to be result of symmetry constraint of the dKP hierarchy recently. By either regarding the constrained dKP hierarchy as its stationary case or taking the dispersionless limit of the KP h...

Here we study the behaviour of spin 0 sector of DKP field in spaces with torsion. First we show that in a Riemann-Cartan manifold DKP field presents an interaction with torsion when minimal coupling is performed, contrary to the behaviour of KG field, a result that breaks the usual equivalence between DKP and KG fields. Next we analyse the case of Teleparallel Equivalent of General Relativity (...

Two problems relative to the electromagnetic coupling of Duffin-Kemmer-Petiau (DKP) theory are discussed: the presence of an anomalous term in the Hamiltonian form of the theory and the apparent difference between the Interaction terms in DKP and Klein-Gordon (KG) Lagrangians. For this, we first discuss the behavior of DKP field and its physical components under gauge transformations. From this...

A ∂̄-formalism for studying dispersionless integrable hierarchies is applied to the dKP hierarchy. Connections with the theory of quasiconformal mappings on the plane are described and some clases of explicit solutions of the dKP hierarchy are presented.

Modified cyclic dipeptides represent a diverse family of microbial secondary metabolites. They display a broad variety of biological and pharmacological activities and have long been recognized as privileged structures with the ability to bind to a wide range of receptors. This is due to their conformationally constrained 2, 5-diketopiperazine (DKP) scaffold and the diverse set of DKP tailoring...

Histidyl-proline diketopiperazine (His-Pro DKP) cells in the pancreas of human fetuses aged between 12 and 19 wk were localized by the indirect antibody-enzyme method on semithin sections. To study their fine structure, two techniques were used: a superimposition technique consisting of comparison of the same cells in semithin and electron microscopic preparations, and an immunocytochemical tec...