Acroamine A, a 2-Amino Adenine Alkaloid from the Marine Soft Coral and Its Semisynthetic Derivatives That Inhibit cAMP-Dependent Protein Kinase A Catalytic Subunit Alpha.

A high throughput screen performed to identify catalytic inhibitors of the oncogenic fusion form of cAMP-dependent protein kinase A catalytic subunit alpha (J-PKAcα) found an individual fraction from an organic extract of the marine soft coral as active. Bioassay-guided isolation led to the identification of a 2-amino adenine alkaloid acroamine A (), the first secondary metabolite discovered from this genus and previously reported as a synthetic product. As a naturally occurring protein kinase inhibitor, to unambiguously assign its chemical structure using modern spectroscopic and spectrometric techniques, five -methylated derivatives acroamines A-A (-) were semisynthesized.

Neopetrotaurines A-C, Isoquinoline Alkaloids with an Unprecedented Taurine Bridge from the Sponge sp.

Neopetrotaurines A-C (-), unusual alkaloids possessing two isoquinoline-derived moieties that are linked via a unique taurine bridge, were isolated from a sp. marine sponge. These new compounds have proton-deficient structural scaffolds that are difficult to unambiguously assign using only conventional 2- and 3-bond H-C and H-N heteronuclear correlation data.

Novel Cytotoxic Sesquiterpene Coumarin Ethers and Sulfur-Containing Compounds from the Roots of .

Six new sesquiterpene coumarin ethers, namely turcicanol A (), turcicanol A acetate (), turcicanol B (), turcica ketone (), 11'-dehydrokaratavicinol (), and galbanaldehyde (), and one new sulfur-containing compound, namely turcicasulphide (), along with thirty-two known secondary metabolites were isolated from the root of the endemic species Akalın, Miski, & Tuncay through a bioassay-guided isolation approach. The structures of the new compounds were elucidated by spectroscopic analysis and comparison with the literature. Cell growth inhibition of colon cancer cell lines (COLO205 and HCT116) and kidney cancer cell lines (UO31 and A498) was used to guide isolation.

Tolypocladamides A-G: Cytotoxic Peptaibols from .

Seven new peptaibols named tolypocladamides A-G have been isolated from an extract of the fungus , which inhibits the interaction between Raf and oncogenic Ras in a cell-based high-throughput screening assay. Each peptaibol contains 11 amino acid residues, an octanoyl or decanoyl fatty acid chain at the N-terminus, and a leucinol moiety at the C-terminus. The peptaibol sequences were elucidated on the basis of 2D NMR and mass spectral fragmentation analyses.

β-Triketone-Monoterpene Hybrids from the Flowers of the Australian Tree Corymbia intermedia.

Four new β-triketone monoterpene hybrids, intermediones A-D (1-4), have been identified from the flowers of the Australian eucalypt tree Corymbia intermedia. Intermediones A-D are β-triketones that incorporate a pinene moiety attached via a benzyl group to a syncarpic acid. The structures of 1-4, including relative configurations, were elucidated from the analysis of 1D/2D NMR and MS data.

Antiplasmodial β-Triketone-Flavanone Hybrids from the Flowers of the Australian Tree Corymbia torelliana.

The methanol extract of the flowers of the Australian eucalypt tree Corymbia torelliana yielded six new β-triketone-flavanone hybrids, torellianones A-F (1-6), the tetrahydroxycyclohexane torellianol A (7), and known β-triketones (4 S)-ficifolidione (8) and (4 R)-ficifolidione (9), and β-triketone-flavanones kunzeanone A (10) and kunzeanone B (11). Torellianones A and B, C and D, and E and F were each isolated as inseparable diastereomeric mixtures. Exchange correlations observed in a ROESY spectrum indicated that 5 and 6 also interconverted between stable conformers.

Antiplasmodial β-triketones from the flowers of the Australian tree Angophora woodsiana.

Chemical investigations of the MeOH extract of air dried flowers of the Australian tree Angophora woodsiana (Myrtaceae) yielded two new β-triketones, woodsianones A and B (1, 2) and nine known β-triketones (3-11). Woodsianone A is a β-triketone-sesquiterpene adduct and woodsianone B is a β-triketone epoxide derivative. The structures of the new and known compounds were elucidated from the analysis of 1D/2D NMR and MS data.

A novel tricyclic polyketide and its biosynthetic precursor azaphilone derivatives from the endophytic fungus Dothideomycete sp.

Azaphilone derivatives 1 and 2 and a novel tricyclic polyketide 3, together with a known azaphilone, austdiol (4), were isolated from the endophytic fungus Dothideomycete sp., which was isolated from a Thai medicinal plant, Tiliacora triandra. Compound 3 is the first polyketide having a tricyclic 6,6,6 ring system, which is similar to that of a terpenoid skeleton.

Antimycobacterial activity of bisbenzylisoquinoline alkaloids from Tiliacora triandra against multidrug-resistant isolates of Mycobacterium tuberculosis.

Bisbenzylisoquinoline alkaloids, tiliacorinine (1), 2'-nortiliacorinine (2), and tiliacorine (3), isolated from the edible plant, Tiliacora triandra, as well as a synthetic derivative, 13'-bromo-tiliacorinine (4), were tested against 59 clinical isolates of multidrug-resistant Mycobacterium tuberculosis (MDR-MTB). The alkaloids 1-4 showed MIC values ranging from 0.7 to 6.