Redetermination and absolute configuration of pruniflorone M monohydrate

The title xanthone known as pruniflorone M (systematic name: (2R)-5,10-dihy­droxy-2-hy­droxy­methyl-1,1-dimethyl-1H-furo[2,3-c]xanthen-6-one), crystallized in a monohydrate form, C18H16O6·H2O. It was isolated from the green fruits of Cratoxylum formosum ssp. pruniflorum. The structure of the title compound has been reported previously [Boonnak et al. (2010 ▶). Aust. J. Chem. 63, 1550–1556], but we report here the absolute configuration determined using Cu Kα radiation. There are two crystallograpically independent mol­ecules in the asymmetric unit, which differ slightly in the bond angles. The hy­droxy­methyl substituents at position 2 of the furan rings of both pruniflorone M mol­ecules adopt R configurations. In both mol­ecules, the three rings of the xanthone skeleton are approximately coplanar, with an r.m.s. deviation of 0.0124 (2) Å for one mol­ecule and 0.0289 (2) Å for the other, and the furan ring adopts an envelope conformation. In the crystal, mol­ecules of pruniflorone M and water are linked into a two-dimensional network by O—H⋯O hydrogen bonds and weak C—H⋯O inter­actions. The crystal structure is further consolidated by π–π inter­actions with centroid–centroid distances in the range 3.5987 (13)–3.7498 (14) Å. Short C⋯C [3.378 (3) Å] and O⋯O [2.918 (3) Å] contacts are also observed

ent-(15S)-Pimar-8(14)-ene-15,16-diol

The title compound {systematic name: (S)-1-[(2S,4aR,8aR)-2,4b,8,8-tetra­methyl-2,3,4,4a,4b,5,6,7,8,8a,9,10-dodeca­hydro­phenanthren-2-yl]ethane-1,2-diol}, C20H34O2, is an ent-pimarane diterpenoid which was isolated from the stem bark of Ceriops tagal. In the asymmetric unit, there are two crystallographically independent mol­ecules, which are conformationally almost identical. In each mol­ecule, the two cyclo­hexane rings of the fused three-ring system adopt chair conformations, while the cyclo­hexene ring is in an envelope conformation, with the methylene C atom next to the side chain as the flap atom. In the crystal, mol­ecules are stacked in columns along the b axis through O—H⋯O hydrogen bonds

Brasilixanthone1

The title xanthone [systematic name: 5,13-dihy­droxy-3,3,10,10-tetra­methyl-3H-dipyrano[3,2-a:2′,3′-i]xanthen-14(10H)-one], C23H20O6, was isolated from the roots of Cratoxylum formosum ssp. pruniflorum. There are two mol­ecules (A and B) in the asymmetric unit, which show chemical but not crystallographic inversion symmetry. The xanthone skeleton in both mol­ecules is approximately planar, with an r.m.s. deviation of 0.0326 (9) Å for mol­ecule A and 0.0355 (9) Å for mol­ecule B from the plane through the 14 non-H atoms. The pyran rings in both mol­ecules adopt sofa conformations. Intra­molecular O—H⋯O hydrogen bonds generate S(5) and S(6) ring motifs. Viewed onto the bc plane, the crystal structure resembles a herringbone pattern. Stacks of mol­ecules are stabilized by π–π inter­actions with centroid–centroid distances of 3.600 (5) Å. The crystal structure is further stabilized by weak C—H⋯O and C—H⋯π inter­actions

2-(2,4,5-Trimethoxyphenyl)-2,3-dihydroquinolin-4(1H)-one

In the title aza-flavanone, C18H19NO4, an intramolecular cyclization product of chalcone, the central heterocyclic ring is in an envelope conformation and the dihedral angle between the benzene rings is 51.03 (10)°. The methoxy groups at the ortho and para positions are slightly twisted from the benzene ring to which they are bound [C—O—C—C = 21.9 (3) and −171.93 (18)°, respectively], whereas the methoxy group at the meta position is almost coplanar [C—O—C—C = 3.5 (3)°]. In the crystal, molecules are linked by N—H...O hydrogen bonds and weak C—H...O interactions into chains along the [001] direction. Weak C—H...π interactions also occur

Crystal structure of (E)-2-hydroxy-4′-methoxyazastilbene

The title azastilbene derivative, C14H13NO2 {systematic name: (E)-2-[(4-methoxybenzylidene)amino]phenol}, is a product of the condensation reaction between 4-methoxybenzaldehyde and 2-aminophenol. The molecule adopts an E conformation with respect to the azomethine C=N bond and is almost planar, the dihedral angle between the two substituted benzene rings being 3.29 (4)°. The methoxy group is coplanar with the benzene ring to which it is attached, the Cmethyl—O—C—C torsion angle being −1.14 (12)°. There is an intramolecular O—H...N hydrogen bond generating an S(5) ring motif. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming zigzag chains along [10-1]. The chains are linked via C—H...π interactions, forming a three-dimensional structure

Antimycobacterial flavonoids from Derris indica

Flavonoids (1–4), together with ten known compounds (5–14) were isolated from the stems and roots of the mangrove plant Derris indica. Their chemical structures were elucidated by analysis of their spectroscopic data. All compounds except compounds 2 and 6 exhibited antimycobacterial activity with minimum inhibitory concentrations (MIC) between 6.25 and 200 μg/mL

CCDC 247551: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures