Ethnobotany of Tuberculosis in Laos

XX, 109 p. 90 illus., 89 illus. in color.online r

Bioactive Constituents of <i>Indigofera spicata</i>

Four new flavanones, designated as (+)-5″-deacetylpurpurin (<b>1</b>), (+)-5-methoxypurpurin (<b>2</b>), (2<i>S</i>)-2,3-dihydrotephroglabrin (<b>3</b>), and (2<i>S</i>)-2,3-dihydrotephroapollin C (<b>4</b>), together with two known flavanones (<b>5</b> and <b>6</b>), three known rotenoids (<b>7</b>–<b>9</b>), and one known chalcone (<b>10</b>) were isolated from a chloroform-soluble partition of a methanol extract from the combined flowers, fruits, leaves, and twigs of <i>Indigofera spicata</i>, collected in Vietnam. The compounds were obtained by bioactivity-guided isolation using the HT-29 human colon cancer, 697 human acute lymphoblastic leukemia, and Raji human Burkitt’s lymphoma cell lines. The structures of <b>1</b>–<b>4</b> were established by extensive 1D- and 2D-NMR experiments, and the absolute configurations were determined by the measurement of specific rotations and CD spectra. The cytotoxic activities of the isolated compounds were tested against the HT-29, 697, Raji, and CCD-112CoN human normal colon cells. Also, the quinone reductase induction activities of the isolates were determined using the Hepa 1c1c7 murine hepatoma cell line. In addition, <i>cis</i>-(6aβ,12aβ)-hydroxyrotenone (<b>7</b>) was evaluated in an in vivo hollow fiber bioassay using HT-29, MCF-7 human breast cancer, and MDA-MB-435 human melanoma cells

Alkaloids from <i>Microcos paniculata</i> with Cytotoxic and Nicotinic Receptor Antagonistic Activities

<i>Microcos paniculata</i> is a large shrub or small tree that grows in several countries in South and Southeast Asia. In the present study, three new piperidine alkaloids, microgrewiapines A–C (<b>1</b>–<b>3</b>), as well as three known compounds, inclusive of microcosamine A (<b>4</b>), 7′-(3′,4′-dihydroxyphenyl)-<i>N</i>-[4-methoxyphenyl)­ethyl]­propenamide (<b>5</b>), and liriodenine (<b>6</b>), were isolated from cytotoxic fractions of the separate chloroform-soluble extracts of the stem bark, branches, and leaves of <i>M. paniculata</i>. Compounds <b>1</b>–<b>6</b> and <b>1a</b> (microgrewiapine A 3-acetate) showed a range of cytotoxicity values against the HT-29 human colon cancer cell line. When evaluated for their effects on human α3β4 or α4β2 nicotinic acetylcholine receptors (nAChRs), several of these compounds were shown to be active as nAChR antagonists. As a result of this study, microgrewiapine A (<b>1</b>) was found to be a selective cytotoxic agent for colon cancer cells over normal colon cells and to exhibit nicotinic receptor antagonistic activity for both the hα3β4 and hα4β2 receptor subtypes