Ethyl 2-[(4-chloro-phen-yl)hydrazono]-3-oxobutanoate

Design and synthesis of small molecule-sulfotyrosine mimetics that inhibit HIV-1 entry

In the absence of a cure or vaccine for HIV/AIDS, small molecule inhibitors remain an attractive choice for antiviral therapeutics. Recent structural and functional studies of the HIV-1 surface envelope glycoprotein gp120 have revealed sites of vulnerability that can be targeted by small molecule and peptide inhibitors, thereby inhibiting HIV-1 infection. Here we describe a series of small molecule entry inhibitors that were designed to mimic the sulfated N-terminal peptide of the HIV-1 coreceptor CCR5. From a panel of hydrazonothiazolyl pyrazolinones, we demonstrate that compounds containing naphthyl di- and tri-sulfonic acids inhibit HIV-1 infection in single round infectivity assays with the disulfonic acids being the most potent. Molecular docking supports the observed structure activity relationship, and SPR confirmed binding to gp120. In infectivity assays treatment with a representative naphthyl disulfonate and a disulfated CCR5 N-terminus peptide results in competitive inhibition, with combination indices >2. In total this work shows that gp120 and HIV-1 infection can be inhibited by small molecules that mimic the function of, and are competitive with the natural sulfated CCR5 N-terminus.

Ethyl 2-[(2,6-dimethylphenyl)hydrazono]-3-oxobutanoate

The title compound, C₁₄H₁₈N₂O₃, crystallizes with two independent mol­ecules in the asymmetric unit, having closely comparable geometries. Both mol­ecules are essentially planar [maximum deviations from the mean plane of 0.069 (1) and 0.068 (1) Å for the two mol­ecules] and contain an intra­molecular N—H⋯O hydrogen bond which generates a ring with graph-set motif S(6). In the crystal, the mol­ecules are linked into chains along the c axis by inter­molecular C—H⋯O hydrogen bonds, and inter­molecular C—H⋯π inter­actions are also present.

Ethyl 2-[(3-chloro-phen-yl)hydrazono]-3-oxobutanoate

The mol-ecule of the title oxobutanoate derivative, C(12)H(13)ClN(2)O(3), adopts a keto-hydrazo tautomeric form and is roughly planar, the angle between the benzene ring and the mean plane through the hydrazone and aliphatic chain being 1.49 (6)°. This planarity is further aided by the formation of an intra-molecular N-H⋯O hydrogen bond which generates an S(6) ring motif. The aromatic ring and aliphatic chain have a trans configuration with respect to the N-N bond. In the crystal packing, centrosymmetric R(2) (2)(16) dimers are formed through pairs of weak C-H⋯O(3-oxo) inter-actions. These dimers are linked together through weak C-H⋯O(carboxyl-ate C=O) inter-actions into ribbons along the b-axis direction. These ribbons are stacked along the a-axis direction. The crystal also exhibits Cl⋯Cl [3.4988 (6) Å] and C⋯O [3.167 (2)-3.335 (2) Å] short contacts.