In the title compound, C26H24N2O2, the benzimidazole ring system is almost planar [maximum displacement = 0.025 (1) Å] and makes dihedral angles of 80.48 (5) and 41.57 (5)° with the benzene rings, which are inclined to one another by 65.33 (6)°. In the crystal, mol­ecules are linked via C—H⋯π and weak π–π inter­actions [centroid–centroid distance = 3.8070 (7) Å and inter­planar distance = 3.6160 (5) Å].

The title compound, C17H16N2O3, has an E conformation about the azobenzene (–N=N–) linkage. The benzene rings are twisted slightly with respect to each other [6.79 (9)°], while the dihedral angle between the plane through the carb­oxy group and the attached benzene ring is 3.2 (2)°. In the crystal, mol­ecules are oriented with the carb­oxy groups head-to-head, forming O—H⋯O hydrogen-bonded inversion dimers. These dimers are connected by C—H⋯O hydrogen-bonds into layers lying parallel to the (013) plane.

The title compound congestiflorone, C28H32O4, which was isolated from the stem bark of Mesua congestiflora, consists of a benzophenone skeleton with two attached pyran rings to which a cyclo­hexane ring and a C6 side chain are bonded. The benzene ring is significantly distorted from planarity (r.m.s. deviation = 0.0007 Å) due to the constraints imposed by junctions with the two pyran rings. The cyclo­hexane ring is in a chair conformation, one pyran ring is in a boat conformation, while the other is a distorted chair. The phenyl and benzene rings make a dihedral angle of 55.85 (9)°. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, mol­ecules are linked via C—H⋯O inter­actions.

The title dammarane triterpenoid, C30H50O4, assigned the name chrysura, was isolated from an ethyl acetate extract of Walsura chrysogyne leaves (Meliaceae). It has 20S*,24S* relative stereochemistry and an oxepanone ring with two methyl groups at position 4. The two cyclo­hexane rings adopt chair conformations. The cyclo­pentane and tetra­hydro­furan rings have envelope conformations; their mean planes make a dihedral angle of 13.1 (3)°, indicating that the rings are only slightly tilted with respect to each other. There is an intra­molecular C—H⋯O hydrogen bond in the mol­ecule, which forms S(6) and S(7) ring motifs. In the crystal, mol­ecules are linked via O—H⋯O and C—H⋯O hydrogen bonds, forming chains propagating along [001] which stack along the b-axis direction.

In the title compound, C19H29NO, the C—C and C—N bond distances of the benzonitrile group are 1.445 (2) and 1.157 (2) Å, respectively. The aliphatic fragment adopts a bent zigzag arangement which differs from the planar zigzag arrangement normally observed in n-alkanes or long-chain alkyl­benzenes. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds occur. A C—H⋯N inter­action also occurs. In the crystal, mol­ecules are packed with the nitrile and aliphatic groups oriented in a head-to-tail fashion involving, forming a ripple-like motif along the a axis.

The title compound [systematic name: 5,10-di­hy­droxy-2,2-di­methyl-12-(2-methyl­but-3-en-2-yl)­pyrano[3,2-b]xanthen-6(2H)-one], C23H22O5, isolated from the stem bark of Calophyllum soulattri, consists of four six-membered rings and a 2-methyl­but-3-en-2-yl side chain. The tricyclic xanthone ring system is almost planar [maximum deviation = 0.093 (2) Å], whereas the pyran­oid ring is in a distorted boat conformation. The 2-methyl­but-3-en-2-yl side chain is in a synperiplanar conformation. There are two intra­molecular O—H⋯O hydrogen bonds. In the crystal, mol­ecules are linked by C—H⋯O inter­actions, forming a zigzag chain propagating in [010].

In the title compound, C13H19NO2, the dihedral angle between the benzene ring and the plane throught the non-H atoms of the amide group is 29.3 (1)°. The benzene ring and the alkane carbon skeleton plane are twisted slightly with respect to each other [5.40 (5)°]. In the crystal, mol­ecules are oriented with the amide groups head-to-head, forming N—H⋯O hydrogen-bonded dimers. The dimers are connected by further N—H⋯O hydrogen bonds into a ladder-like motif along the b axis.

The title compound (trivial name α-mangostin), C24H26O6, isolated from Cratoxylum glaucum, is characterized by a xanthone skeleton of three fused six-membered rings and two 3-methyl­but-2-enyl side chains. The three rings in the structure are nearly coplanar, with an r.m.s. deviation for the tricyclic ring system of 0.0014 Å. The two 3-methyl­but-2-enyl side chains are in (+)-synclinal and (-)-anti­clinal conformations. Intra­molecular O—H⋯O and C—H⋯O inter­actions occur. The crystal structure is stabilized by inter­molecular O—H⋯O, C—H⋯O and C—H⋯π inter­actions.

The title compound, Artonol B, C24H20O7, isolated from the stem bark of Artocarpus kemando, consists of four six-membered rings and one five-membered ring. The tricyclic xanthone ring system is almost planar [maximum deviation 0.115 (5) Å], whereas the pyran­oid ring is in a distorted boat conformation·The furan ring is almost coplanar with the fused aromatic ring, making a dihedral angle of 3.76 (9)°. The phenol ring serves as a intra­molecular hydrogen-bond donor to the adjacent carbonyl group and also acts as an inter­molecular hydrogen-bond acceptor for the methyl groups of adjacent mol­ecules, forming a three-dimensional network in the crystal.

The triazole ring in the title compound, C14H12N4O2·H2O, makes dihedral angles of 36.9 (1) and 37.3 (1)° with the two benzene rings. Each hy­droxy group is a hydrogen-bond donor to a two-coordinate N atom of an adjacent mol­ecule; these O—H⋯N hydrogen bonds generate a layer parallel to the ab plane. Adjacent layers are linked by N—-H⋯O and Owater—H⋯O hydrogen bonds into a three-dimensional network.