naphthoquinones and 2-methylanthraquinone

Barleria alluaudii and Diospyros maritima were both investigated as part of an ongoing search for synergistic TRAIL (tumor necrosis factor-α-related apoptosis-inducing ligand) sensitizers. As a result of this study, two naphthoquinone epoxides, 2,3-epoxy-2,3-dihydrolapachol (1) and 2,3-epoxy-2,3-dihydro-8-hydroxylapachol (2), both not previously isolated from natural sources, and the known 2-methylanthraquinone (3) were identified from B. alluaudii. Time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra were utilized to establish the absolute configuration of 1 and 2. Additionally, five known naphthoquinone derivatives, maritinone (4), elliptinone (5), plumbagin (6), (+)-cis-isoshinanolone (7), and ethylidene-6,6'-biplumbagin (8), were isolated from D. maritima. Compounds 1, 2, and 4-6 showed varying levels of synergy with TRAIL. Maritinone (4) and elliptinone (5) showed the highest synergistic effect, with more than a 3-fold increase in activity observed with TRAIL than with compound alone.

Topics: Acanthaceae; Anthraquinones; Diospyros; Madagascar; Molecular Structure; Naphthoquinones; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

Two new furanonaphthoquinones, (3R)-7-methoxy-α-dunnione (5) and (3R)-6-hydroxy-7-methoxy-α-dunnione (6), along with the known (3R)-dunnione (1), (3R)-α-dunnione (2), (3R)-7-hydroxy-α-dunnione (3), and 1-hydroxy-2-methylanthraquinone (4), were isolated from in vitro cultures of Streptocarpus dunnii. The structures of compounds 5 and 6 were established by spectroscopic means. This is the first report of hydroxylated furanonaphthoquinones in a Streptocarpus species. Compounds 1-3 demonstrated cytotoxic activity against a range of breast cancer and pancreatic tumor cell lines.

Topics: Anthraquinones; Antineoplastic Agents, Phytogenic; Drug Screening Assays, Antitumor; Female; Furans; Humans; Magnoliopsida; Molecular Structure; Naphthoquinones; Nuclear Magnetic Resonance, Biomolecular; Seedlings; Seeds; South Africa; Structure-Activity Relationship

Three new aromatic epsilon-lactones, aggregatins A (1), B (2), and C (3), a new naphthoquinone derivative, aggregatin D (4), and three known anthraquinones, 2-methylanthraquinone, 7-methoxy-2-methylanthraquinone, and 7-hydroxy-2-methylanthraquinone, were isolated from the tubers of Sinningia aggregata (Gesneriaceae). Compounds 1 and 4 and the anthraquinones showed marginal antimicrobial activity.

Topics: Anthraquinones; Anti-Infective Agents; Brazil; Escherichia coli; Lactones; Magnoliopsida; Microbial Sensitivity Tests; Molecular Structure; Naphthoquinones; Nuclear Magnetic Resonance, Biomolecular; Pseudomonas aeruginosa; Staphylococcus; Yeasts