Desoxyhemigossypol 6-methyl ether

The title sesquiterpene [systematic name: 6-methoxy-10-methyl-7-(propan-2-yl)-2-oxatricyclo[6.3.1.0^4,12]dodeca-1(11),4,6,8(12),9-pentaen-5-ol], C₁₆H₁₈O₃, was isolated from pathogen-infected stele tissue of Gossypium barbadense. There are two mol­ecules in the asymmetric unit and the dihedral angle between their naphtho­furan systems is 86.48 (2)°. In the crystal, O—H...O hydrogen bonds between the hy­droxy groups and etheric O atoms link the mol­ecules into centrosymmetric tetra­mers. These tetra­mers are assembled into (010) layers via stacking inter­actions between the naphtho­furan systems [inter­planar distance 3.473 (3) Å] and short C—H...O contacts.

2-[(1H-Benzimidazol-2-yl)imino­meth­yl]-4,6-dibromo­phenol ethanol hemisolvate

The title compound, C₁₄H₉Br₂N₃O·0.5C₂H₅OH, crystallizes with two 2-[(1H-benzimidazol-2-yl)imino­meth­yl]-4,6-dibromo­phenol mol­ecules and one ethanol solvent mol­ecule in the asymmetric unit. The benzene and benzimidazole rings subtend dihedral angles of 4.5 (3) and 5.2 (2)° in the two mol­ecules. In the crystal, one mol­ecule presents π–π stacking with the equivalent mol­ecule related by inversion, at a distance of 3.30 Å (separation between mol­ecular mean planes). A three-dimensional network is formed through N—H...N, N—H...O and O—H...N hydrogen bonds.

2-{[2-(Pyridin-4-yl)-1H-benzimidazol-1-yl]meth­yl}phenol

In the title compound, C₁₉H₁₅N₃O, the benzimidazole ring system makes dihedral angles of 44.36 (7) and 75.67 (7)° with the pyridine and benzene rings, respectively. In the crystal, phenolic O—H...N hydrogen bonds to benzimidazole N-atom acceptors give rise to a chain extending along [011].

N′-Hy­droxy­pyridine-2-carboximidamide–succinic acid (2/1)

The asymmetric unit of the title co-crystal, C₆H₇N₃O·0.5C₄H₆O₄, comprises one N′-hy­droxy­pyridine-2-carboximidamide mol­ecule and half a succinic acid mol­ecule (the whole molecule is generated by inversion symmetry). In the crystal, mol­ecules are assembled into columns along [110], via strong N—H...O, O—H...O and O—H...N hydrogen bonds.