Chemistry and Bioactivity of Briaranes from the South China Sea Gorgonian Dichotella gemmacea.

Seven new briarane diterpenoids, gemmacolides AZ-BF (1-7), were isolated together with eight known analogues (8-15) from the South China gorgonian Dichotella gemmacea. Their structures were elucidated based on detailed spectroscopic analysis and a comparison with reported data. In an in vitro bioassay, these compounds exhibited different levels of growth inhibition activity against A549 and MG63 cells, giving continuous evidences about the biological contribution of functional groups at C-2, C-12, C-13, and C-16. These compounds were also evaluated for their antibacterial and antifungal activities. Compound 8 exhibited a potential antibacterial activity against both Gram-positive bacterium Bacillus megaterium and Gram-negative bacterium Escherichia coli.

Crystal structures of (1,4,7,10-tetra-aza-cyclo-dodecane-κ(4) N)bis-(tri-cyano-methanido-κN)nickel and (1,4,7,10-tetra-aza-cyclo-dodecane-κ(4) N)(tri-cyano-methanido-κN)copper tri-cyano-methanide.

The structures of two mononuclear transition-metal complexes with tri-cyano-methanide (tcm(-)) and 1,4,7,10-tetra-aza-cyclo-dodecane (cyclen) ligands, [Ni(C4N3)2(C8H20N4)], (I), and [Cu(C4N3)(C8H20N4)](C4N3), (II), are reported. In the neutral complex (I), the nickel cation is coordinated by one cyclen ligand and two monodentate N-bound tcm(-) anions in a distorted octa-hedral geometry. The tcm(-) ligands are mutually cis. The Cu(II) atom in (II) displays a distorted tetra-gonal-pyramidal geometry, with the four N-donor atoms of the cyclen ligand in the equatorial plane, and one tcm(-) anion bound through a single N atom in an axial site, forming a monocation. The second tcm(-) molecule acts as a counter-ion not directly coordinating to the copper cation. In both (I) and (II), extensive series of N-H⋯N and C-H⋯N hydrogen bonds generate three-dimensional network structures.

Briarane diterpenoids from the gorgonian Dichotella gemmacea.

Seven new briarane diterpenoids, gemmacolides AS-AY (1-7), were isolated together with ten known analogues (8-17) from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by the detailed analysis of spectroscopic data and comparison with reported data. The absolute configuration of compounds was determined based on electronic circular dichroism (ECD) experiments and genetic correlations as well. Compounds 15 and 16 were reported for the first time for the gorgonian. In the preliminary in vitro bioassays, compound 5 showed potential growth inhibitory activity against MG63 cells.

Briarane diterpenes from the South China Sea gorgonian coral, Junceella gemmacea.

Four new briarane diterpenoids, junceellolides M-P (1-4), were isolated together with seven known analogs (5-11) from the South China Sea gorgonian, Junceella gemmacea. The structures of these compounds were elucidated by detailed spectroscopic analysis and comparison with the reported data. The absolute configuration of compounds 1-3 were determined based on an ECD experiment, while the absolute configuration of compound 4 was genetically determined. All the compounds were isolated for the first time from J. gemmacea. These compounds showed no growth inhibitory activity against A549, MG63 and SMMC-7721 cell lines in an in vitro bioassay.

Bis(dicyanamido-κN)[tris-(3-amino-propyl)amine-κ(4) N]nickel(II).

In the title complex, [Ni(C2N3)2(C9H24N4)], the Ni(II) atom is coordinated in a distorted octa-hedral geometry by one tris-(3-amino-prop-yl)amine (tris-apa) ligand and two dicyanamide (dca) ligands [one of them disordered in a 0.681 (19):0319 (19) ratio]. Inter-molecular N-H⋯N hydrogen bonds involving the N atoms of the dca anions and the tris-apa amine H atoms result in the formation of a three-dimensional network.

Tumor cell growth inhibitory activity and structure-activity relationship of polyoxygenated steroids from the gorgonian Menella kanisa.

Fourteen new polyoxygenated steroids (6, 9, 14-18, 20-23, 25-27) having carbon skeletons of cholestane, ergostane, and 24-norcholestane, were isolated together with thirteen known analogues (1-5, 7, 8, 10-13, 19, 24) from the South China Sea gorgonian Menella kanisa. The structures of the new compounds were elucidated by detailed analysis of spectroscopic data and comparisons with reported data. This is the first report of chemical investigation on the title gorgonian. Compounds 12 and 13 were reported for the first time from natural sources. These compounds exhibited different levels of growth inhibition activity against A549 and MG-63 cell lines in bioassay in vitro. Preliminary structure-activity analysis revealed an important role of side chain in the activity. A substitution of a 5α-hydroxy or an oxidation of 6ß-hydroxy to a ketone carbonyl group may decrease the activity whereas the contribution of the 1-ketone group remains uncertain.

Chemistry and tumor cell growth inhibitory activity of 11,20-epoxy-3Z,5(6)E-diene briaranes from the South China Sea gorgonian Dichotella gemmacea.

Eighteen new 11,20-epoxy-3Z,5E-dien briaranes, gemmacolides AA-AR (1-18), were isolated together with three known analogs, dichotellides F (19) and I (20), and juncenolide C (21), from the South China Sea gorgonian Dichotella gemmacea. The structures of the compounds were elucidated by detailed spectroscopic analysis and comparison with reported data. The absolute configuration was determined based on the ECD experiment. In the in vitro bioassay, compounds 1-3, 5, 6, 8-12, and 14-19 exhibited different levels of growth inhibition activity against A549 and MG63 cell lines. Preliminary structure-activity analysis suggests that 12-O-isovalerate may increase the activity whereas 13- or 14-O-isovalerate may decrease the activity. Contribution of substitutions at C-2 and C-16 remains uncertain.

Steroids glycosylated with both D- and L-arabinoses from the South China Sea gorgonian Dichotella gemmacea.

Three new 19-hydroxy steroidal glycosides, namely, junceellosides E-G (2-4), were isolated together with the known analogue junceelloside C (1) from the South China Sea gorgonian Dichotella gemmacea. The structures of these compounds were elucidated by a combination of detailed spectroscopic analyses, chemical methods, and comparison with reported data. These glycosides are found to have sugar moieties of both ß-l- and ß-d-arabinopyranoses by HPLC analysis of their thiocarbamoyl-thiazolidine derivatives and those of authentic d- and l-arabinoses, leading to the structure revision of junceelloside C (1). This is the first report of steroidal glycosides from the gorgonian D. gemmacea and the first report of glycosides with ß-l-arabinopyranose from marine sources.

Sinularosides A and B, bioactive 9,11-secosteroidal glycosides from the South China Sea soft coral Sinularia humilis Ofwegen.

Two new 9,11-secosteroidal glycosides, namely, sinularosides A and B (1, 2), together with the known pregnene glycoside 3ß-(ß-xylopyranosyloxy)-5α-pregna-20-ene (3), were isolated from the South China Sea soft coral Sinularia humilis Ofwegen. The structures of these compounds were elucidated by a combination of detailed spectroscopic analyses, chemical methods, and comparison with reported data. This is the first report of 9,11-secosteroidal glycosides from a soft coral and from nature. In in vitro bioassays, the new compounds exhibited potent antimicrobial activities and showed no growth inhibition activity against the tumor cells HepG2 and Caco-2.

New bioactive sulfated alkenes from the sea cucumber Apostichopus japonicus.

Two new alkene sulfates, (5Z)-dec-5-en-1-yl sulfate (4) and (3E)-dec-3-en-1-yl sulfate (5), together with three known sulfated alkanes, 2,6-dimethylheptyl sulfate (1), octyl sulfate (2), and decyl sulfate (3), were isolated from the sea cucumber Apostichopus japonicus. The structures of the new compounds 4 and 5 were elucidated by spectroscopic analysis, including ¹H-, ¹³C-, and 2D-NMR, ESI-MS, and HR-ESI-MS. Compounds 2 and 3 were isolated from natural sources for the first time. In preliminary bioassays in vitro, compounds 4 and 5 showed antibacterial, antifungal, and cytotoxic activities.

Bioactive (3Z,5E)-11,20-epoxybriara-3,5-dien-7,18-olide diterpenoids from the South China Sea gorgonian Dichotella gemmacea.

Six new (3Z,5E)-11,20-epoxybriara-3,5-dien-7,18-olide diterpenoids, gemmacolides N-S (1-6), were isolated together with four known analogues, juncenolide D, and juncins R, S and U (7-10), from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by the detailed analysis of spectroscopic data in combination with the comparison with reported data. The absolute configuration of 1 was determined by a TDDFT calculation of its solution ECD spectrum, affording the determination of absolute configuration of other analogues by simply comparing their ECD spectra with that of 1. The cytotoxic and antimicrobial activities of these compounds were evaluated. In preliminary in vitro bioassays, compounds 4, 5, 6, 8 and 9 showed cytotoxicity against A549 and MG63, while compounds 1, 2, 4, 7-10 showed antimicrobial activity against the fungus Septoria tritici and the bacterium Escherichia coli.

Bioactive 11,20-epoxy-3,5(16)-diene briarane diterpenoids from the South China Sea gorgonian Dichotella gemmacea.

Seven new briarane diterpenoids, gemmacolides G-M (1-7), were isolated together with two known analogues, juncin O and junceellolide C, from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by detailed analysis of spectroscopic data and comparison with reported data. In an in vitro bioassay, these compounds exhibited different levels of growth inhibition activity against A549 and MG63 cells. In particular, compound 4 was more active than the positive control adriamycin against A549 cells. Compounds 4 and 7 also exhibited weak antimicrobial activity against the bacterium Bacillus megaterium and the fungus Septoria tritici, respectively.

Solubility of disodium 5'-guanylate heptahydrate in aqueous methanol mixtures.

The solubility of disodium 5'-guanylate heptahydrate (5'-GMPNa2) in binary aqueous methanol solvent mixtures with the temperature ranging from 278.15 to 323.15K was measured by a dynamic method with a laser monitoring observation technique. The solubility data were correlated with the Combined Nearly Ideal Binary Solvent/Redlich-Kister (CNIBS/R-K) model and the modified Jouyban-Acree model, respectively. For the ten groups of data studied, the CNIBS/R-K model was found to provide a more accurate mathematical representation of the experimental data, while the modified Jouyban-Acree model containing provisions for correlating both the solvent composition and temperature.

A novel sulfated holostane glycoside from sea cucumber Holothuria leucospilota.

A new sulfated holostane glycoside, leucospilotaside B (1), together with the two related structurally known compounds holothurin B(2) (2) and holothurin B (3), was isolated from sea cucumber Holothuria leucospilota collected from the South China Sea. The structure of 1 was elucidated by spectral analysis (1H-, 13C-, and 2D-NMR, ESI-MS, and HR-ESI-MS) and chemical methods. The compounds 1-3 possess the same disaccharide moiety, but were different in the side chains of the triterpene aglycone. Compound 1 showed significant cytotoxicities against four human tumor cell lines, HL-60, MOLT-4, A-549, and BEL-7402.

Bis(2,2'-bipyridyl dioxide-κN,N')bis-(tricyano-methanido)cobalt(II) dihydrate.

In the title compound, [Co(C(4)N(3))(2)(C(10)H(8)N(2)O(2))]·2H(2)O, a novel tricyano-methanide complex, the Co(II) atom is located on an inversion center and has a distorted octa-hedral coordination with two 2,2'-bipyridyl dioxide (dpdo) mol-ecules and two trans tricyano-methanide (tcm) anions. The equatorial plane is formed by the four O atoms of the two chelating dpdo ligands, with one N atom of each of the two tcm ligands occupying an apical position. There is a disordered solvent water mol-ecule in the asymmetric unit (occupancy ratio 0.63:0.37). These water mol-ecules result in the formation of O-H⋯O and O-H⋯N hydrogen bonds, building a layer parallel to (100). The layers are linked by C-H⋯N hydrogen-bonding inter-actions, leading to a three-dimensional network.

Antifungal active triterpene glycosides from sea cucumber Holothuria scabra.

To study the new antifungal active triterpene glycosides of sea cucumber Holothuria scabra. Triterpene glycosides from Holothuria scabra were separated and purified by silica gel chromatography, reversed-phase silica gel chromatography and RP-HPLC. Their structures were elucidated on the basis of spectral data and chemical evidence. Three triterpene glycosides were identified as scabraside A (1), echinoidea A (2) and holothurin A1 (3). Scabraside A (1) is a new triterpene glycoside, and compounds 2 and 3 were isolated from Holothuria scabra for the first time. They showed antifungal activities (1 < or = MIC80 < or = 16 microg mL(-1)).

Antifungal triterpene glycosides from the sea cucumber Bohadschia marmorata.

Four new holostan-type triterpene glycosides, marmoratoside A ( 1), 17 alpha-hydroxy impatienside A ( 2), marmoratoside B ( 3), 25-acetoxy bivittoside D ( 4), together with two known triterpene glycosides, impatienside A ( 5) and bivittoside D ( 6), were isolated from the sea cucumber Bohadschia Marmorata Jaeger. On the basis of spectroscopic analyses, including two-dimensional NMR techniques, and chemical reactions, the structures of the new triterpene glycosides were elucidated. Compounds 1, 2, 5, and 6 exhibited significant antifungal activity against six strains (0.70 < or = MIC (80) < or = 2.81 microM).

Bis(2,2':6',2''-terpyridine)cobalt(II) bis-(tricyano-methanide).

The title complex, [Co(C(15)H(11)N(3))(2)](C(4)N(3))(2), is built up from discrete [Co(terpy)(2)](2+) cations (terpy is 2,2':6',2''-terpyridine) and [C(CN)(3)](-) anions. In the cation, the Co(II) atom is coordinated by two terpy mol-ecules, giving a distorted octa-hedral geometry. The tricyano-methanide anions are not directly coordinated to the Co(II) atom, but some weak C-H⋯N hydrogen bonds involving the terminal N atoms of the tricyaomethanide ions and the terpyridine H atoms link anions and cations building a three-dimensional network.

Bis(2,2'-bipyridine N,N'-dioxide)bis-(tri-cyano-methanido)manganese(II).

In the title complex, [Mn(C(4)N(3))(2)(C(10)H(8)N(2)O(2))(2)], the Mn(II) atom lies on an inversion center and is coordinated by two 2,2'-bipyridine N,N'-dioxide (dpdo) mol-ecules and two tricyano-methanide (tcm) ligands to form a distorted octa-hedral geometry. Weak inter-molecular C-H⋯O or C-H⋯N hydrogen bonds, involving either the O atom of the dpdo mol-ecule and the pyridyl H atom, or the N atom of the tcm anion and the pyridyl H atom, result in the formation of a three-dimensional network structure.

Argusides D and E, two new cytotoxic triterpene glycosides from the sea cucumber Bohadschia argus Jaeger.

Two new triterpene glycosides, argusides D and E (1 and 2, resp.), have been isolated from the sea cucumber Bohadschia argus Jaeger collected in the South China Sea. Their structures have been established by spectral analysis (ESI-MS, and 1D- and 2D-NMR) and chemical evidence. Compounds 1 and 2 both possess an holostane-type triterpene aglycone with a C(9)=C(11) bond, an OH group at C(12), and tetrasaccharide moieties, but differ in the side chains. The two glycosides exhibited significant cytotoxicities against four human tumor cell lines, A549, HCT-116, HepG2, and MCF-7.