8-8--biplumbagin and plumbagin

Study of the chemical constituents of the roots of Plumbago zeylanica L. collected in Taiwan led to the isolation and identification of a new naphthoquinone dimer, plumzeylanone (1), along with eight known compounds (2-9). Nine naphthoquinones isolated from this plant were assayed for cell growth inhibition activity using NALM-6 (human B cell precursor leukaemia), A549 (human lung adenocarcinoma), Colo205 (human colorectal adenocarcinoma) and KB (human epidermoid carcinoma). Plumzeylanone (1), a novel plumbagin dimer, suppressed cell proliferation in only NALM-6 cells (IC

Topics: Antineoplastic Agents; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Dimerization; Humans; Naphthoquinones; Plant Roots; Plumbaginaceae; Taiwan

A phytochemical investigation of the stem bark of Diospyros cuneata (Ebenaceae) together with in vitro cytotoxic evaluation of the pure compounds in four human cancer cell lines KB, Hep-2, HeLa and SiHa led to the isolation of plumbagin, elliptinone, lupeol, atraric acid methyl ester, maritinone, betulin and betulinaldehyde. The structural determination of the compounds was established by nuclear magnetic resonance, electron ionisation mass spectrometric analysis as well as comparison with data from the literature. Plumbagin exhibited a potent cytotoxic activity (CC50 = 3.56 µg mL(-1)) against KB cell lines whereas maritinone displayed cytotoxic activity against Hep-2 (CC50 = 17.30 µg mL(-1)), cervical cancer (CC50 = 21.10 µg mL(-1)) and the KB cell lines (CC50 = 20.30 µg mL(-1)). This is the first report on a phytochemical and biological evaluation of D. cuneata.

Topics: Cell Line, Tumor; Cell Survival; Diospyros; Humans; Naphthoquinones; Pentacyclic Triterpenes; Plant Bark; Plant Extracts; Plant Stems; Triterpenes

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

Bioactivity-directed fractionation of extracts of two Diospyros maritima bark samples from Indonesia,one collected at sea level in a beach forest in Java and the other collected at a slight elevation away from the sea shore on the island of Lombok, yielded a diverse set of secondary metabolites. The naphthoquinone plumbagin (1), although found in extracts of both specimens, constituted a much larger percentage of the former sample, which also yielded a series of plumbagin dimers, maritinone (2), chitranone (3), and zeylanone (4). The latter sample yielded a new naphthoquinone derivative, (4S)-shinanolone (5), and a new natural product coumarin, 7,8-dimethoxy-6-hydroxycoumarin (6), along with three other analogues of plumbagin, 2-methoxy-7-methyljuglone (7), 3-methoxy-7-methyljuglone (8), and 7-methyljuglone (9). The structures of compounds 5 and 6 were elaborated by physical, spectral, and chemical methods. All of the isolates were evaluated in both cytotoxicity and antimicrobial assays, and structure-activity relationships of these naphthoquinones are proposed. Plumbagin (1) and maritinone (2) were evaluated also for in vivo antitumor activity in the hollow fiber assay, but both were found to be inactive.

Topics: Aspergillus niger; Bacteria; Candida albicans; Coumarins; Diospyros; Drug Screening Assays, Antitumor; Humans; Indonesia; KB Cells; Microbial Sensitivity Tests; Naphthoquinones; Plant Bark; Plants, Medicinal; Saccharomyces cerevisiae

Plumbagin, 3,3'-biplumbagin and 8,8'-biplumbagin are naphthoquinones isolated by activity-directed fractionation from a Bolivian plant, Pera benensis, used in folk medicine as treatment of cutaneous leishmaniasis caused by Leishmania braziliensis. BALB/c mice were infected with L. mexicana or L. venezuelensis and treated 24 h after the parasitic infection with plumbagin (5 or 2.5 mg/kg/day), 3,3'-biplumbagin, 8,8'-biplumbagin (25 mg/kg/d) or Glucantime (200 mg/kg/d). Lesion development was the criteria employed to evaluate the inhibitory effect. The bis-naphthoquinones were less potent than Glucantime against L. amazonensis and L. venezuelensis. Plubagin and Glucantime delayed the development of L. amazonensis and L. venezuelensis. Assays of a single local treatment on foot-pad infection two weeks after the parasitic inoculation with L. amazonensis showed that 8,8'-biplumbagin (50 mg/kg/d) was as potent as Glucantime (400 mg/kg/d).

Topics: Animals; Antiprotozoal Agents; Disease Models, Animal; Female; Leishmaniasis, Cutaneous; Leishmaniasis, Mucocutaneous; Male; Meglumine; Meglumine Antimoniate; Mice; Mice, Inbred BALB C; Naphthoquinones; Organometallic Compounds; Plant Extracts