Two new steroidal sapogenins from Rohdea chinensis (synonym Tupistra chinensis) rhizomes and their antifungal activity.

Two novel acylated steroidal sapogenins, 3ß-acetoxy-1α, 2α, 4ß, 5α, 7α-pentahydroxy-spirost-25(27)-en-6-one (1) and (25S)-3α-acetoxy-1α, 2ß, 4α, 5α, 7α-pentahydroxyspirostan-6-one (2), together with two known steroidal sapogenins (3 and 4), were isolated from Rohdea chinensis rhizomes. Their structures were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. In addition, the antifungal activities of the isolated compounds against Penicillium digitatum and Rhizopus stolonifera were evaluated. Compound 2 significantly inhibited R. stolonifera growth, which was comparable to the positive control (sodium benzoate and carbendazim). Compound 4 showed the highest potency to inhibit P. digitatum growth compared to other compounds.

Syntheses and antibacterial activity of Schiff bases from 16-isopropyl-5, 9-dimethyltetracyclo [10.2.2.0(1, 10).0(4, 9)] hexadec-15-ene-5, 14-dicarboxylic acid.

16-isopropyl-5, 9-dimethyltetracyclo [10.2.2.0(1, 10).0(4, 9)] hexadec-15-ene-5, 14-dicarboxylic acid (1b) was prepared from rosin through a Diels-Alder addition reaction. Then, a group of Schiff bases derived from 1b was synthesised. Their structures were characterised by IR,(1)H-NMR, MS and elemental analysis. The antibacterial activities of these newly synthesised Schiff bases were also investigated. The results show that these compounds possess antibacterial activities against Staphylococcus aureus and Escherichia coli. Among them, compounds 5a, 5b and 5c, exhibit remarkable antibacterial activity against E. coli.

2,3,6-Trichloro-5-(trichloro-meth-yl)pyridine.

The title compound, C(6)HCl(6)N, lies on a mirror plane, the asymmetric unit conataining a half-mol-ecule. Weak intra-molecular C-H⋯Cl contacts are observed.

16-Isopropyl-5,9-dimethyl-tetra-cyclo-[10.2.2.0.0]hexa-dec-15-ene-5,13,14-trimethanol ethanol monosolvate.

The title compound, C(24)H(40)O(3)·C(2)H(6)O, is a substituted tetra-cyclo-[10.2.2.0(1,10).0(4,9)]hexa-decane derivative obtained from the reduction of maleopimaric acid which was isolated from a maleic anhydride modified rosin. In the crystal, the triol mol-ecule and the ethanol solvent mol-ecule are linked by hydroxyl O-H⋯O hydrogen bonds, giving a two-dimensional network structure.

16-Isopropyl-5,9-dimethyl-tetra-cyclo-[10.2.2.0.0]hexa-dec-15-ene-5,14-dimethanol.

The title compound, C(23)H(38)O(2), a tetra-cyclo-[10.2.2.0(1,10).0(4,9)] hexa-decane structure, crystallized with four independent mol-ecules in the asymmetric unit. In the crystal, these independent mol-ecules are linked by O-H⋯O hydrogen bonds, forming a polymeric chain propagating in [100].

Methyl 12-bromo-dehydro-abietate.

THE TITLE COMPOUND [SYSTEMATIC NAME: (1R)-methyl 6-bromo-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa-hydro-phen-anthrene-1-carboxyl-ate], C(21)H(29)BrO(2), was synthesized from N-bromo-succinimide and methyl dehydro-abietate, which was prepared through an esterification reaction using dehydro-abietic acid and methanol as raw materials. The three six-membered rings adopt planar (mean deviation = 0.002 Å) half-chair and chair conformations. The two cyclo-hexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by weak inter-molecular C-H⋯O contacts along the b axis.

16-Isopropyl-5,9-dimethyl-tetra-cyclo-[10.2.2.0.0]hexa-dec-15-ene-5,13,14-tricarboxylic acid dimethyl-formamide disolvate.

The title compound, C(24)H(34)O(6)·2C(3)H(7)NO, which was isolated from fumaric-modified rosin, has four asymmetrically fused six-membered rings and three carboxylic acid substituents. It contains two fused and unbridged cyclo-hexane rings, which form a trans ring junction with a chair conformation. The asymmetric unit includes one fumaropimaric acid and two dimethyl-formamide mol-ecules. The crystal structure is stabilized through inter-molecular O-H⋯O hydrogen bonds between dimethyl-formamide and fumaropimaric acid.

4-Isopropyl-N-phenyl-cyclo-hexa-1,3-diene-1-carboxamide.

In the crystal structure of the title compound, C(16)H(19)NO, mol-ecules are linked through a pair of N-H⋯O hydrogen bonds, forming chains along the a axis.

(1R,4aS,10aR)-1,4a-Dimethyl-N-[(morpholin-4-yl)carbothio-yl]-7-(propan-2-yl)-1,2,3,4,4a,9,10,10a-octa-hydro-phenanthrene-1-carboxamide.

In the title compound, C(25)H(36)N(2)O(2)S, the cyclo-hexane and morpholine rings adopt chair conformations. The cyclo-hexene and cyclo-hexane rings form a trans ring junction with the two methyl groups in axial positions. The N-H and C=O bonds in the urea group are anti to each other. The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen bonds.

Dehydro-abietic acid.

THE TITLE COMPOUND [SYSTEMATIC NAME: (1R,4aS,10aR)-7-iso-prop-yl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa-hydro-phen-anthrene-1-carboxylic acid], C(20)H(28)O(2), has been isolated from disproportionated rosin which is obtained by isomerizing gum rosin with a Pd-C catalyst.. Two crystallographically independent mol-ecules exist in the asymmetric unit. In each mol-ecule, there are three six-membered rings, which adopt planar, half-chair and chair conformations. The two cyclo-hexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds.

15-Hydroxy-ethyl-19-isopropyl-5,9-dimethyl-14,16-dioxo-15-aza-penta-cyclo-[10.5.2.0.0.0]nona-dec-18-ene-5-carboxylic acid.

The title compound, C(26)H(37)NO(5), which was synthesized from monoethano-lamine and maleopimaric acid, consists of two fused and unbridged cyclo-hexane rings. They form a trans ring junction with a chair conformation. The two methyl groups are in axial positions. In the crystal, inter-molecular O-H⋯O hydrogen bonds link adjacent mol-ecules into a layer structure. Two C-H⋯O interactions are also present.

2-Hydr-oxy-6,6-dimethyl-bicyclo-[3.1.1]heptane-2-carboxylic acid.

The title compound, C(10)H(16)O(3), with a bicyclo-[3.1.1]heptane unit, was obtained by oxidation of ß-pinene. The asymmetric unit contains two independent mol-ecules with similar geometry: the six-membered rings in both mol-ecules adopt envelope conformations. In the crystal, the independent mol-ecules exist as O-H⋯O hydrogen-bonded dimers. The dimers are linked into helical chains along the b axis by O-H⋯O hydrogen bonds.

7-Isopropyl-1,4a-dimethyl-1,2,3,4,4a,5,6,7,8,9,10,10a-dodeca-hydro-phenan-threne-1-carboxylic acid.

The title compound, C(20)H(32)O(2), has been isolated from hydrogenated rosin. There are two independent mol-ecules in the asymmetric unit. In each mol-ecule, the cyclo-hexane ring assumes a chair conformation, while the two cyclo-hexene rings adopt half-chair and envelope conformations. Inter-molecular O-H⋯O hydrogen bonding between carboxyl groups links pairs of independent mol-ecules into dimers.

16-Isopropyl-5,9-dimethyltetra-cyclo-[10.2.2.0.0]hexa-dec-15-ene-5,14-dicarboxylic acid ethanol hemisolvate.

In the title compound, C(23)H(34)O(4)·0.5C(2)H(6)O, which was isolated from acrylic modified rosin, the endocyclic compound adopts a tetra-cyclo-[10.2.2.01,10.04,9]hexa-decane structure. In the crystal, the components are linked by O-H⋯O and C-H⋯ hydrogen bonds.

N-Benzyl-idenenordehydro-abietylamine.

THE TITLE COMPOUND [SYSTEMATIC NAME: (1R,4aS,10aR,E)-N-benzyl-idene-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa-hydro-phenanthren-1-amine], C(26)H(33)N, has been synthesized from nor-dehydro-abietylamine and benzaldehyde. The two cyclo-hexane rings form a trans ring junction with classic chair and half-chair conformations, respectively, the two methyl groups are on the same side of tricyclic hydro-phenanthrene structure. The dihedral angle between two benzene rings is 44.2 (4)°. The C=N bond is in an E configuration.

2-[(1S,3S)-3-Acetyl-2,2-dimethyl-cyclo-butyl]-N-(m-tol-yl)acetamide.

The title compound, C(17)H(23)NO(2), contains two chiral centres and was synthesized from 2-(3-acetyl-2,2-dimethyl-cyclo-butyl)acetic acid and m-toluidine. The cyclobutane ring is not flat but flexed as though folded from the dimethyl-substituted C atom to the unsubstituted C atom, with a dihedral angle of 25.9°. The crystal structure is stabilized by N-H⋯O and C-H⋯O hydrogen-bonding inter-actions.