What is Vilon?
Vilon is CAS 76469-93-9, formula C11H21N3O5, molecular weight 275.30, two residues. At that mass it sits at the boundary between peptide and small molecule, with a single amide bond joining a basic lysine to an acidic glutamate. The result is a compact zwitterion with high aqueous solubility and no hydrophobic character, which governs both handling and chromatography.
The family comes from Vladimir Khavinson and colleagues at the St Petersburg Institute of Bioregulation and Gerontology, whose work moved from cytomedines, peptide fractions of animal organs such as Thymalin, to cytogens, the shortest synthetic sequences that reproduced activity in their assays. Vilon is the endpoint of that reduction. The proposed mechanism is that such peptides enter the nucleus and interact with promoter-region DNA or with histones, and the group published chromatin decondensation observations in lymphocyte preparations as support.
Those findings have not been widely replicated outside the originating network, and no structural study has confirmed sequence-specific binding of a dipeptide to DNA. The general objection is worth stating plainly, that a two-residue molecule presents very little surface for specific recognition. What is established is the identity and chemistry of the compound.
Reconstitution & handling
The powder dissolves instantly in bacteriostatic or sterile water added slowly down the vial wall, since a 275 dalton zwitterionic dipeptide is essentially freely soluble. Concentration is the labeled milligram content divided by the diluent volume added, and the low molecular weight means a given mass corresponds to a comparatively high molar concentration. A brief swirl is sufficient, and the solution should be clear and colorless.
Storage & stability
Sealed vials are kept at -20 degrees Celsius, protected from light and moisture, since the cake is hygroscopic. Reconstituted material is refrigerated at 2 to 8 degrees Celsius, aliquoted for single use, and kept clear of repeated freeze-thaw cycles. With one amide bond, no aromatic residue and no sulfur, Vilon is among the most chemically robust items here, and hydrolysis of that bond is the only meaningful degradation route in solution.
How it's tested
Purity is determined by reverse-phase HPLC at 214 and 220 nanometres, and retention requires an ion-pairing agent or a polar-embedded stationary phase, since a 275 dalton zwitterion has little affinity for a standard C18 surface. Identity is confirmed by mass spectrometry against the theoretical average mass of 275.30. Net peptide content is measured so the labeled figure reflects peptide rather than counter-ion.