Zhi-Yun Du

Methyl 4-bromo-3-hy-droxy-benzoate.

In the title compound, C8H7BrO3, the methoxycarbonyl group is twisted at a dihedral angle of 8.06u2005(4)° with respect to the benzene ring. In the crystal, molecules are connected by O—H⋯O hydrogen bonds into helical chains running along the b axis.

(3E,5E)-3,5-Bis(4-hy­droxy-3,5-di­methoxy­benzyl­idene)oxan-4-one monohydrate

In the title compound, C(23)H(24)O(8)·H(2)O, the six-membered ring of the oxan-4-one (tetra-hydro-pyran-4-one) ring displays an envelope conformation with the heterocyclic O atom at the flap position. The dihedral angles between the terminal benzene rings is 37.23u2005(10)°. Classical intermolecular O-H⋯O and weak C-H⋯O hydrogen bonds are present in the crystal structure.

γ-Lactone Derivatives and Terpenoids from Selaginella uncinata and Their Protective Effect Against Anoxia

Selaginella uncinata (Desv. ex Poir.) Spring, a common and important species of Selaginella genus, is widely distributed in southwest China. As a traditional plant medicine, it is used for the treatment of jaundice, dysentery, edema, and rheumatism [1]. In our previous papers, we reported on the anti-anoxic effects of the 60% ethanolic extract of Selaginella uncinata and the anti-anoxic biflavonoids isolated from the EtOAc-soluble fraction of the 60% EtOH extract [2, 3]. In our continuous research work on the isolation of the anti-anoxic compounds, two -lactone derivatives, viburnolide A (1) and viburnolide B (2), and four terpenoids, isololiolide (3), dehydrololiolide (4), cis, trans-abscisic acid (5), and trans, trans-abscisic acid (6), have been isolated from the EtOAc-soluble and n-butanol-soluble fractions. Although the biflavonoids, flavonoids, chromone glycosides, and phenolic compounds are common in Selaginella genus [4–9], few reports have revealed the existence of -lactone derivatives and terpenoids constituents until now, and the six compounds 1–6 were isolated from this genus for the first time. Compound 1. Brown yellow, amorphous powder. UV (MeOH, max, nm) (log ): 356 (2.38), 276 (3.48), 227 (4.28). ESI-MS m/z: 507 [M + Na]+, 483 [M – H]– and 967 [2M – H]–1. 1H NMR (400 MHz, DMSO-d6, , ppm, J/Hz): 2.90 (1H, dd, J = 17.4, 9.2, H-3A), 3.04 (1H, dd, J = 17.4, 12.2, H-3B), 3.07 (1H, m, H-5 ), 3.20 (1H, m, H-2 ), 3.22 (1H, m, H-3 ), 3.28 (1H, m, H-4 ), 3.51 (2H, m, H-6 ), 3.94 (1H, s, H-8), 3.96 (1H, dd, J = 9.1, 5.3, H-11B), 4.21 (1H, dd, J = 7.0, 5.3, H-12), 4.31 (1H, dd, J = 9.1, 7.0, H-11A), 4.70 (1H, d, J = 7.5, H-1 ), 4.80 (1H, dd, J = 12.2, 9.2, H-4), 6.76 (2H, d, J = 8.5, H-15, 17), 7.16 (2H, d, J = 8.5, H-14, 18). 13C NMR (100 MHz, DMSO-d6, , ppm): 174.2 (C-2), 170.8 (C-6), 157.7 (C-16), 122.8 (C-13), 130.0 2 (C-14, 18), 115.6 2 (C-15, 17), 107.2 (C-9), 89.1 (C-5), 96.1 (C-1 ), 88.2 (C-8), 77.1 (C-5 ), 76.7 (C-3 ), 73.4 (C-2 ), 73.2 (C-12), 69.1 (C-4 ), 75.0 (C-11), 59.9 (C-6 ), 43.0 (C-4), 32.5 (C-3). The spectral data presented are in a good agreement with published data on viburnolide A [10].

(3E,5E)-3,5-Bis(4-hy-droxy-benzyl-idene)oxan-4-one.

In the title compound, C19H16O4, there are two 4-hydroxybenzyl substituents on the oxan-4-one (tetrahydropyran-4-one) ring, which exhibits an envelope conformation. The dihedral angles between pyranone ring and the two benzene rings are 26.69u2005(9) and 36.01u2005(9)° while the benzene rings make a dihedral angle of 20.88u2005(10)°. In the crystal, molecules are linked by intermolecular O—H⋯O hydrogen bonds into a supramolecular three-dimensional twofold interpenetrating hydrogen-bonded network.

1,3-Bis[4-(meth­oxy­carbon­yl)benz­yl]benzimidazolium bromide monohydrate

In the title compound, C25H23N2O4 +·Br−·H2O, the dihedral angles between the benzimidazole ring system and the two benzene rings are 87.77u2005(11) and 63.05u2005(11)°; the dihedral angle between the two benzene rings is 66.25u2005(13)°. The crystal structure exhibits C—H⋯O and O—H⋯Br interactions; it is also stabilized by π–π stacking interactions, with a face-to-face separation of 3.456u2005Å between parallel benzimidazole ring systems.

(2E,6E)-2,6-Bis(3-bromo-4-hydroxy-5-methoxybenzylidene)cyclohexanone

In the title compound, C22H20Br2O5, the dihedral angle between the two benzene rings is 12.0u2005(3)°. The cycloxadhexaxadnone ring has an envelope conformation with the flap atom displaced by 0.675u2005(6)u2005A from the plane of the other five atoms. The crystal structure has intra- and interxadmolecular hydrogen bonds between the hydrxadoxy and methxadoxy groups.

1,4-Bis[4-(meth­oxy­carbon­yl)benz­yl]-1H-1,2,4-triazol-4-ium bromide

In the title salt, C20H20N3O4 +·Br−, the dihedral angle between the benzene rings is 8.69u2005(16)°, and those between the benzene rings and the triazole ring are 69.98u2005(18) and 72.17u2005(18)°. In the crystal, C—H⋯Br hydrogen bonds link the cations and anions into chains along the c axis.

5-Hydr­oxy-1-methyl-3,4-dihydro-2H-pyrrolium hydrogensulfate

The title compound, C5H10NO+·HSO4 −, has been synthesized by reaction of 1-methylpyrrolidin-2-one with H2SO4 in a 1:1 molar ratio. The substituted pyrrolium ring adopts an envelope conformation. The hydrogensulfate anions form infinite helical chains parallel to the a axis via strong O—H⋯O hydrogen bonds. The pyrrolium cations are pendant from the chains. These cations are the hydrogen donors in the strong O—H⋯O hydrogen bonds to the hydrogensulfates. In addition, there are weak C—H⋯O hydrogen bonds in the structure.

3-[(R)-3,3-Dichloro-2-hydroxy­prop­yl]-8-hydr­oxy-6-meth­oxy-1H-isochromen-1-one

The title compound, C13H12Cl2O5, is an isocoumarin compound which has been isolated from the ethyl acetate extract of the fermentation broth of actinomycete Streptomyces sp. (V4) from the South China Sea. There are intra- and intermolecular hydrogen bonds and halogen bonds [Cl⋯Cl = 3.434u2005(2)u2005Å; C—Cl⋯Cl = 121.6°]. The intermolecular O—H⋯O hydrogen bonds link molecules into chains along the b axis.

4-(1-Phenylethyl)benzene-1,3-diol

There are two crystallographically independent molxadecules of the title compound, C14H14O2, in the asymmetric unit. Interxadmolecular O—H⋯O hydrogen bonding between hydrxadoxy groups occurs in the crystal structure, resulting in a supraxadmolecular structure.