No abstract

An isoflavone, 7,4'-dihydroxy-3',5'-dimethoxyisoflavone (1), and a chalcone, (+)-tephropurpurin (2), both novel compounds, as well as six constituents of known structure, (+)-purpurin (3), pongamol (4), lanceolatin B (5), (-)-maackiain (6), (-)-3-hydroxy-4-methoxy-8,9-methylene-dioxypterocarpan (7), and (-)-medicarpin (8), were obtained as active compounds from Tephrosia purpurea, using a bioassay based on the induction of quinone reductase (QR) activity with cultured Hepa 1c1c7 mouse hepatoma cells. Additionally, three inactive compounds of known structure, 3'-methoxydaidzein, desmoxyphyllin B, and 3,9-dihydroxy-8-methoxycoumestan, were isolated and identified. The structure elucidation of compounds 1 and 2 was carried out by spectral data interpretation.

A investigação do extrato orgânico produzido na fermentação microbiológica de Penicillium sp. H9318 conduziu ao isolamento de um novo alcaloide isoquinolínico, o composto (5S)-3,4,5,7-tetrametil-5,8-di-hidróxi-6(5H)-isoquinolinona (1), juntamente com quatro outros conhecidos compostos derivados da citrinina (2-5). Uma atividade inibitória significativa no ensaio da inibição da formação dos halos (HFI), foi exibida pela citrinina (2), semelhante àquela observada pelo Streptomyces 85E, enquanto os compostos 1, 3, 4 e 5 não mostraram atividade inibitória com respeito ao ensaio HFI quando testados com 20 mg/disco. Em relação ao ensaio de citotoxicidade, a citrinina (2) demonstrou uma atividade inibitória mais fraca quando comparada as linhagens de células cancerosas MCF-7 (IC 50 71,93 µmol L -1 ), LNCaP (IC 50 77,92 µmol L -1 ), LU-1 (147,85 µmol L -1 ) e KB (IC 50 65,93 µmol L -1 ).Investigation of a microbial fermentation organic extract of Penicillium sp. H9318 led to the isolation of a new isoquinolinone alkaloid, (5S)-3,4,5,7-tetramethyl-5,8-dihydroxyl-6(5H)-isoquinolinone (1), along with four known citrinin derivatives (2-5). Citrinin (2) exhibited significant inhibitory activity against Streptomyces 85E in the hyphae formation inhibition (HFI) assay, while compounds 1, 3-5 were not active when tested at 20 mg/disk in the HFI assay. Citrinin (2) further demonstrated a weak inhibitory activity against MCF-7 (IC 50 71.93 µmol L -1 ), LNCaP (IC 50 77.92 µmol L -1 ), LU-1 (147.85 µmol L -1 ) and KB (IC 50 65.93 µmol L -1 ) cell lines, respectively, in the cytotoxicity assay.

Seven norsesterterpene peroxides: epimuqubilin A (1), muqubilone B (2), unnamed cyclic peroxide ester (3), epimuqubilin B (4), sigmosceptrellin A methyl ester (5), sigmosceptrellin A (6), and sigmosceptrellin B methyl ester (7), isolated from the marine sponge Latrunculia sp., were examined with regard to their effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. The results indicated epimuqubilin A (1) possessed potent NO inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide release with an IC50 value of 7.4 μM, a level three times greater than the positive control, L-NG-monomethyl arginine citrate, followed by 6 (sigmosceptrellin A, IC50 = 9.9 μM), whereas other compounds exhibited only modest activity (Table 1). These compounds did not show appreciable cytotoxicity at their IC50 values for NO–inhibitory activity. The structure–activity upon NO inhibition could be summarized as follows: (1) a monocyclic carbon skeleton framework was essential for activity, (2) free acids gave higher activity, (3) the orientation of H3-22 with an equatorial position increased activity, and (4) a bicyclic structure reduced activity. This is the first report of a norsesterterpene peroxide with NO–inhibitory activity. In addition, compounds 1–7 were also evaluated for their inhibitory activities in the yeast glycogen synthase kinase-3β assay. In summary, several norsesterterpene peroxides showed novel biological activities of inhibition in NO production, suggesting that these might provide leads for anti-inflammatory or cancer chemopreventive agents.

Two new pyrroloquinoline alkaloids, isobatzelline E (1) and batzelline D (2), together with the known compounds batzelline C (3), isobatzelline C (4), and makaluvamine D (5), were isolated from an Indopacific collection of the marine sponge Zyzzya fuliginosa; the known compounds makaluvamines A (9), H (10), J (7), K (8), and P (6) were obtained from Z. fuliginosa collected in Papua New Guinea. The structures were elucidated by interpretation of 1D (1)H and (13)C NMR spectra and 2D HSQC and HSQC-LR spectra. Compounds 1-10 were isolated because the crude extracts of both Zyzzya species inhibited HIV-1 envelope-mediated cell fusion. However, the inhibition profile observed for the pure compounds 1-10 mirrors that reported for the inhibition of topoisomerase II by other pyrroloquinolines, leaving open the possibility that the activity results from interactions with DNA-modifying enzymes.