Bioactive constituents from transformed root cultures of Nepeta teydea.

A phytochemical study of an extract from transformed root cultures of Nepeta teydea, induced by Agrobacterium rhizogenes, led to the isolation of the following new compounds: the sesquiterpene (-)-cinalbicol, the diterpene teydeadione (6,11,14-trihydroxy-12-methoxy-abieta-5,8,11,13,15-penten-7-one), a degraded C23-triterpene (teydealdehyde) and three fatty acid esters of lanosta-7,24-dien-3ß-ol. The propyl ester of rosmarinic acid was also isolated for the first time from a natural source. In addition, two dehydroabietane diterpenes, eight triterpenes and eighteen known phenolic compounds were obtained. The antifeedant, cytotoxic and phytotoxic activities of the isolated compounds have also been investigated.

Biotransformation of an africanane sesquiterpene by the fungus Mucor plumbeus.

Biotransformation of 8ß-hydroxy-african-4(5)-en-3-one angelate by the fungus Mucor plumbeus afforded as main products 6α,8ß-dihydroxy-african-4(5)-en-3-one 8ß-angelate and 1α,8ß-dihydroxy-african-4(5)-en-3-one 8ß-angelate, which had been obtained, together with the substrate, from transformed root cultures of Bethencourtia hermosae. This fact shows that the enzyme system involved in these hydroxylations in both organisms, the fungus and the plant, acts with the same regio- and stereospecificity. In addition another twelve derivatives were isolated in the incubation of the substrate, which were identified as the (2'R,3'R)- and (2'S,3'S)-epoxy derivatives of the substrate and of the 6α- and 1α-hydroxy alcohols, the 8ß-(2'R,3'R)- and 8ß-(2'S,3'S)-epoxyangelate of 8ß,15-dihydroxy-african-4(5)-en-3-one, the hydrolysis product of the substrate, and three isomers of 8ß-hydroxy-african-4(5)-en-3-one 2ξ,3ξ-dihydroxy-2-methylbutanoate. The insect antifeedant effects of the pure compounds were tested against chewing and sucking insect species along with their selective cytotoxicity against insect (Sf9) and mammalian (CHO) cell lines.

Additional Insights into the Obtusallene Family: Components of Laurencia marilzae.

The obtusallenes are a significant subset of C15-halogenated acetogenins that incorporate 12-membered cyclic ethers. We have recently reported the isolation from Laurencia marilzae of 12-epoxyobtusallene IV (1) and its related α,ß-unsaturated carboxylate ester (2), both of special biogenetic relevance. Here we describe the final step of our study, the isolation of three new analogues (3-5), among these, the first bromopropargylic derivative (3) of this class of macrocyclic C15-acetogenins. The structures were elucidated by analysis of NMR and X-ray data. 12-Epoxyobtusallene IV (1), its new isomer 4, and known obtusallene IV (6) were evaluated for their apoptosis-inducing activities in a human hepatocarcinoma cell line.

Expedient synthesis of C3-symmetric hexasubstituted benzenes via Nicholas reaction/[2 + 2 + 2] cycloaddition. new platforms for molecular recognition.

An expedient methodology to synthesize macrocyclic compounds in one step based on the Nicholas reaction is disclosed. The key step features two intermolecular reactions followed by an intramolecular reaction from the starting dicobalt hexacarbonyl-propargylic complex. The macrocycles obtained were modified through [2 + 2 + 2] cycloaddition, generating two new C3-symmetric hexasubstituted benzene structures suitable for molecular recognition purposes.

2-Amino-N'-phenyl-benzohydrazide.

In the title compound, C(13)H(13)N(3)O, the NNCO unit forms dihedral angles of 35.8 (1) and 84.0 (1)° with the benzene and phenyl rings, respectively. The dihedral angles between the aromatic rings is 61.2 (1)°. An intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, mol-ecules are linked by weak N-H⋯O hydrogen bonds into C(4) chains parallel to the c axis. Neighbouring chains are linked by weak N-H⋯N hydrogen bonds, forming R(4) (4)(20) rings, and resulting in the formation of a two-dimensional network lying parallel to (010). The packing also features π-π stacking inter-actions between phenyl rings [centroid-centroid distance = 3.803 (2) Å].

Disorder in the anionic part of catena-poly[[(pyrazine-2-carboxyl-ato)copper(II)]-µ-pyrazine-2-carboxyl-ato].

The title compound, [Cu(C(5)H(3)N(2)O(2))(0.88)(C(6)H(4)NO(2))(1.12)](n), is characterized by disorder of the anion, resulting from a statistical occupation in a 0.44 (3):0.56 (3) ratio of pyrazine-2-carboxylate and pyridine-2-carboxylate. The compound was isolated during attempts to synthesize a mixed-ligand coordination polymer by solvothermal reaction between copper(II) nitrate and equimolar mixtures of pyrazine-2-carboxylic acid and pyridine-2-carb-oxy-lic acid in a mixture of water and EtOH. The difference in the two components of the compound is due to substitutional disorder of a CH group for one of the N atoms of the pyrazine ring which share the same site in the structure. In the crystal structure, the Cu(II) atom lies on an inversion centre and is six-coordinated in a distorted N(2)O(4) geometry. The carboxyl-ate group carbonyl O atoms are weakly coordinated to an equivalent Cu(II) atom that is translated one unit cell in the a-axis direction, thus forming a polymeric chain through carboxyl-ate bridges.

4',5-Dihy-droxy-7-meth-oxy-flavanone dihydrate.

The title compound, C(16)H(14)O(5)·2H(2)O [systematic name: 5-hy-droxy-2-(4-hy-droxy-phen-yl)-7-meth-oxy-chroman-4-one dihydrate], is a natural phytoalexin flavone isolated from the native chilean species Heliotropium taltalense and crystallizes with an organic mol-ecule and two water mol-ecules in the asymmetric unit. The 5-hy-droxy group forms a strong intra-molecular hydrogen bond with the carbonyl group, resulting in a six-membered ring. In the crystal, the components are linked by O-H⋯O hydrogen bonds, forming a three-dimensional network. The 4-hy-droxy-phenyl benzene ring is bonded equatorially to the pyrone ring, which adopts a slightly distorted sofa conformation. The title compound is the hydrated form of a previously reported structure [Shoja (1990 ▶). Acta Cryst. C46, 1969-1971]. There are only slight variations in the mol-ecular geometry between the two compounds.

4-[3-(Isonicotino-yloxy)propoxycarbon-yl]pyridinium diiodidoargentate(I).

The structure of the title compound, (C(15)H(15)N(2)O(4))[AgI(2)], consists of an organic 4-[3-(isonicotino-yloxy)propoxycarbon-yl]pyridinium cation which has a gauche-gauche (O/C/C/C-O/C/C/C or GG') conformation and lies on a twofold rotation axis, which passes through the central C atom of the aliphatic chain, and an inorganic [AgI(2)](-) anion. In the complex anion, the Ag(+) cation is bound to two I(-) anions in a linear geometry. The anion was modelled assuming disorder around a crystallographic inversion centre near the location of the Ag(+) cation. The crystal packing is stabilized by a strong inter-molecular N-H⋯N hydrogen bond, which links the cations into zigzag chains with graph-set notation C(16) running along the face diagonal of the ac plane. The N-bound H atom is disordered over two equally occupied symmetry-equivalent sites, so that the mol-ecule has a pyridinium ring at one end and a pyridine ring at the other.

Propane-1,3-diaminium bis-(pyridine-4-carboxyl-ate) monohydrate.

The asymmetric unit of the title compound, C(3)H(12)N(2) (2+)·2C(6)H(4)NO(2) (-)·H(2)O, consists of half of a doubly protonated propane-1,3-diammonium dication, a pyridine-4-carboxyl-ate anion and half of a solvent water mol-ecule; the dication and the solvent water are located on a twofold rotation axis which passes through the central C atom of the dication and the water O atom. The carboxyl-ate group of the anion appears to be delocalized on the basis of the C-O bond lengths. In the crystal, the components are linked by inter-molecular N-H⋯O, N-H⋯N and O-H⋯O hydrogen bonds.

Diaqua-bis-(5-methyl-pyrazine-2-carboxyl-ato-κN,O)cadmium.

In the title compound, [Cd(C(6)H(5)N(2)O(2))(2)(H(2)O)(2)], the Cd(II) ion is coordinated in a severely distorted octa-hedral geometry. The N atoms are cis to each other, while the water O atoms and ligand O atoms are mutually trans. The crystal structure is stabilized by a network of O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distances = 3.730 (3) and 3.652 (3) Å] between the 5-methyl-pyrazine-2-carboxyl-ate ligands. The structure is isotypic with the manganese analog.

A monoclinic modification of propane-1,3-diyl bis-(pyridine-3-carboxyl-ate).

In the title compound, C(15)H(14)N(2)O(4), (I), the mol-ecule lies on a twofold rotation axis which passes through the central C atom of the aliphatic chain, giving one half-mol-ecule per asymmetric unit. The structure is a monoclinic polymorph of the triclinic structure previously reported [Brito, Vallejos, Bolte & López-Rodríguez (2010). Acta Cryst. E66, o792], (II). The most obvious difference between them is the O/C/C/C-O/C/C/C torsion angle [58.2 (7)° in (I) and 173.4 (3)/70.2 (3)° in (II) for GG and TG conformations, respectively]. Another important difference is observed in the dihedral angle between the planes of the aromatic rings [86.49 (7)° for (I) and 76.4 (3)° for (II)]. The crystal structure features a weak π-π inter-action [centroid-centroid distance = 4.1397 (10)Å]; this latter kind of inter-action is not evident in the triclinic polymorph.

1-[2-(4-Nitrophenyl)-5-(5-phenyl-1,2-oxazol-3-yl)-1,2,3,4-tetrahydroquinolin-4-yl]pyrrolidin-2-one.

The title compound, (I) C(28)H(24)N(4)O(4), is the trans diastereo-isomer of the compound 1-[2-(4-nitro-phen-yl)-6-(5-phenyl-3-isoxazol-yl)-1,2,3,4-tetra-hydro-4-quinolin-yl]-2-pyrrolidinone monohydrate, (II) [Gutierrez et al. (2011 ▶). Acta Cryst. E67, o175-o176]. The most obvious differences between the diastereo-isomers are the dihedral angles between the isoxazole ring and the benzene and phenyl rings [47.0 (2); 56.4 (2) and 33.3 (2); 11.0 (2)°, respectively, for (II) 75.4 (2) and 5.8 (3), respectively, for (I)]. In the crystal of (I), the mol-ecules are linked by N-H⋯O inter-actions into a chain along [001] with graph-set notation C(8).

Nonterpenoid C15 acetogenins from Laurencia marilzae.

Eight new halogenated C(15) acetogenins, 1-8, were isolated from the organic extract of the red alga Laurencia marilzae. The structure elucidation and the assignments of the relative configurations were established by extensive use of spectroscopic studies, particularly 1D and 2D NMR data, while the absolute configurations of compounds 1 and 5 were determined by single-crystal X-ray diffraction analysis. Compounds 1, 2, 4, 5, and 7, along with the previously reported related cyclic ether obtusallene IV (9), were evaluated against six human solid tumor cell lines. All compounds were found to be essentially inactive (GI(50) > 10 µg/mL).

Propane-1,3-diyl bis-(pyridine-4-carboxyl-ate).

The title compound. C(15)H(14)N(2)O(4), (I), has a gauche-gauche (O/C/C/C-O/C/C/C or GG) conformation and is a positional isomer of propane-1,3-diyl bis-(pyridine-3-carboxyl-ate), (II). The mol-ecule of (I) lies on a twofold rotation axis, which passes through the central C atom of the aliphatic chain, giving one half-mol-ecule per asymmetric unit. There is excellent agreement of the geometric parameters of (I) and (II). The most obvious differences between them are the O/C/C/C-O/C/C/C torsion angles [56.6 (2)° in (I) and 174.0 (3)/70.2 (3)° in (II) for GG and TG conformations, respectively] and the dihedral angle between the planes of the aromatic rings [80.3 (10)° in (I) and 76.5 (3)° in (II)]. The crystal structure is stabilized by weak C-H⋯ N and C-H⋯ O hydrogen bonding.

An orthorhombic polymorph of mulinic acid.

THE TITLE COMPOUND [SYSTEMATIC NAME: (3S,3aS,10bR)-3-isopropyl-5a,8-dimethyl-2,3,4,5,5a,6,7,10,10a,10b-deca-hydro-endo-epidioxy-cyclo-hepta-[e]indene-3a(1H)-carboxylic acid], C(20)H(30)O(4), is a polymorphic form of a previously reported structure [Loyola et al. (1990 ▶). Tetra-hedron, 46, 5413-5420]. The newly found ortho-rhom-bic polymorph crystallizes in P2(1)2(1)2(1) with two mol-ecules in the asymmetric unit. The mol-ecules are linked into discrete D(2) chains by simple O-H⋯O inter-actions. There are only slight variations in the mol-ecular geometry and supra-molecular organization in the crystal structures of the two polymorphs. The densities are 1.145 (monoclinic, P2(1)) and 1.155 Mg m(-3) (ortho-rhom-bic, P2(1)2(1)2(1)).

Propane-1,3-diyl bis-(pyridine-3-carboxyl-ate).

The title compound, C(15)H(14)N(2)O(4), has a trans-gauche [O/C/C/C-O/C/C/C] (TG) conformation. The angle between the planes of aromatic rings is 76.4 (3)°. The crystal structure is stabilized by van der Waals inter-actions and C-H⋯O hydrogen bonds. The crystal used was a non-merohedral twin with a fractional contribution of the minor component of 0.443 (5).

(-)-istanbulin a.

THE TITLE COMPOUND (SYSTEMATIC NAME: 9a-hydr-oxy-3,4a,5-trimethyl-4a,6,7,8a,9,9a-hexa-hydro-4H,5H-naphtho[2,3-b]furan-2,8-dione), C(15)H(20)O(4), is a sesquiterpene lactone showing the typical eremophilanolide skeleton, which has been isolated from the plant Senecio candidans collected in the Chilean Magallanes region. The present study confirms the atomic connectivity assigned on the basis of (1)H and (13)C NMR spectroscopy, as well as the relative stereochemistry of the 4α-methyl,5α-methyl,8ß-hydr-oxy,10ß-H unit. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds involving the hydr-oxy group as donor and the oxo group as acceptor, giving chains along the a axis. The absolute structure was not determined because of the lack of suitable anomalous scatters.

Dimethyl 2,2'-[butane-1,4-diylbis(sul-fanediyl)]dibenzoate.

The title compound, C(20)H(22)O(4)S(2), was synthesized by the reaction of 1,4-dibromo-butene with methyl thio-salicylate. The aliphatic segment of this ligand is in an all-trans conformation. The bridging chain, -S-(CH(2))(4)-S-, is almost planar (r.m.s. deviation for all non-H atoms: 0.056 Å) and its mean plane forms dihedral angles of 16.60 (7) and 5.80 (2)° with the aromatic rings. In the crystal, the mol-ecules are linked by weak C-H⋯O inter-actions into chains with graph-set notation C(14) along [0 0 1]. The crystal studied was a racemic twin, the ratio of the twin components being 0.27 (9):0.73 (9).