A novel druggable interprotomer pocket in the capsid of rhino- and enteroviruses.

Rhino- and enteroviruses are important human pathogens, against which no antivirals are available. The best-studied inhibitors are "capsid binders" that fit in a hydrophobic pocket of the viral capsid. Employing a new class of entero-/rhinovirus inhibitors and by means of cryo-electron microscopy (EM), followed by resistance selection and reverse genetics, we discovered a hitherto unknown druggable pocket that is formed by viral proteins VP1 and VP3 and that is conserved across entero-/rhinovirus species. We propose that these inhibitors stabilize a key region of the virion, thereby preventing the conformational expansion needed for viral RNA release. A medicinal chemistry effort resulted in the identification of analogues targeting this pocket with broad-spectrum activity against Coxsackieviruses B (CVBs) and compounds with activity against enteroviruses (EV) of groups C and D, and even rhinoviruses (RV). Our findings provide novel insights in the biology of the entry of entero-/rhinoviruses and open new avenues for the design of broad-spectrum antivirals against these pathogens.

Crystal structures of N-(4-chloro-phen-yl)-2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]acetamide and N-(3-chloro-phen-yl)-2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]acetamide.

The title compounds, C12H12ClN5OS, (I), and C12H12ClN5OS, (II), are 2-[(di-amino-pyrimidin-2-yl)sulfan-yl]acetamides. Compound (II), crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In each of the mol-ecules, in both (I) and (II), an intra-molecular N-H⋯N hydrogen bond forms an S(7) ring motif. The pyrimidine ring is inclined to the benzene ring by 42.25 (14)° in (I), and by 59.70 (16) and 62.18 (15)° in mol-ecules A and B, respectively, of compound (II). In the crystal of (I), mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming inversion dimers with an R22(8) ring motif. The dimers are linked via bifurcated N-H⋯O and C-H⋯O hydrogen bonds, forming corrugated layers parallel to the ac plane. In the crystal of (II), the A mol-ecules are linked through N-H⋯O and N-H⋯Cl hydrogen bonds, forming layers parallel to (100). The B mol-ecules are also linked by N-H⋯O and N-H⋯Cl hydrogen bonds, also forming layers parallel to (100). The parallel layers of A and B mol-ecules are linked via N-H⋯N hydrogen bonds, forming a three-dimensional structure.

Crystal structures of 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]-N-(naphthalen-1-yl)acetamide and 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]-N-(4-fluoro-phen-yl)acetamide.

The title compounds, C16H15N5OS, (I), and C12H12FN5OS, (II), are [(di-amino-pyrimidine)-sulfan-yl]acetamide derivatives. In (I), the pyrimidine ring is inclined to the naphthalene ring system by 55.5 (1)°, while in (II), the pyrimidine ring is inclined to the benzene ring by 58.93 (8)°. In (II), there is an intra-molecular N-H⋯N hydrogen bond and a short C-H⋯O contact. In the crystals of (I) and (II), mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming inversion dimers with R22(8) ring motifs. In the crystal of (I), the dimers are linked by bifurcated N-H⋯(O,O) and C-H⋯O hydrogen bonds, forming layers parallel to (100). In the crystal of (II), the dimers are linked by N-H⋯O hydrogen bonds, also forming layers parallel to (100). The layers are linked by C-H⋯F hydrogen bonds, forming a three-dimensional architecture.

2-[(4,6-Di-amino-pyrimidin-2-yl)sulfan-yl]-N-(2-methyl-phen-yl)acetamide.

In the title compound, C13H15NOS, the plane of the pyrimidine ring makes a dihedral angle of 54.73 (9)° with that of the o-tolyl ring. The mol-ecule adopts an extended conformation, which is evident from the C-C(=O)-N-Car (ar = aromatic) torsion angle of 178.42 (15)°. In the crystal, mol-ecules are linked via pairs of N-H⋯N hydrogen bonds, forming inversion dimers with an R (2) 2(8) ring motif. The dimers are linked by N-H⋯O and C-H⋯O hydrogen bonds, with the O atom accepting three such interactions, forming sheets parallel to (100).