Nazumazoles A–C, Cyclic Pentapeptides Dimerized through a Disulfide Bond from the Marine Sponge <i>Theonella swinhoei</i>

A mixture of nazumazoles A–C (<b>1</b>–<b>3</b>) was purified from the extract of the marine sponge <i>Theonella swinhoei</i>. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation of the NMR data and chemical degradations. Nazumazoles contain one residue each of alanine-derived oxazole and α-keto-β-amino acid residue. Nazumazoles exhibited cytotoxicity against P388 cells

Specific growth rate (μ/day) of algae cultured in modified Chu13 medium and 1/4 ASWM.

<p>Data represents an average of three lots. Bars indicate mean ± SD.</p

Hydrocarbon content (%) in dry biomass weight for algae.

<p>Algae was cultured in the modified Chu13 medium and 1/4 ASWM. Data represents an average of three lots. Bars indicate mean ± SD.</p

Changes in hydrocarbon recovery rate during culture in the 1/4 ASWM.

<p>The alga was cultured in 1/4 ASWM and the subculture was run three times. Different symbols represent different culture lots.</p

Changes in hydrocarbon recovery rate during culture in the 1/4 NSWM or the NaCl medium.

<p>Each alga was cultured in 1/4 NSWM or NaCl medium and the subculture was run three times.</p

Nazumazoles D–F, Cyclic Pentapeptides That Inhibit Chymotrypsin, from the Marine Sponge <i>Theonella swinhoei</i>

Nazumazoles D–F (<b>1</b>–<b>3</b>) were isolated from the marine sponge <i>Theonella swinhoei.</i> The compounds gave extremely broad peaks by reversed-phase HPLC using an ODS column. HPLC using a gel permeation column was instrumental for the separation of the three compounds. Their planar structures were determined by interpretation of NMR data to be cyclic pentapeptides. Nazumazoles D–F contained one residue each of α-keto-l-norvaline (l-Knv) {or α-keto-d-leucine (l-Kle)}, l-alanyloxazole (l-Aox), d-Abu (or d-Ser), <i>N</i>-α-CHO-β-l-Dpr, and <i>cis</i>-4-methyl-l-proline. The absolute configuration of each amino acid residue was determined by Marfey’s method in combination with conversion of the α-keto-β-amino acid to the α-amino acid by oxidation. Nazumazoles D–F are not cytotoxic against P388 cells at 50 μM, but inhibit chymotrypsin

Composition of each type of medium applied in this study.

a<p>Added to offset differences compared with the modified Chu13 medium.</p>b<p>Two hundred and fifty milliliters of natural seawater taken directly from the open sea.</p

Difference in appearance of freeze-dried alga sample.

<p>Each sample was cultured in (A) the modified Chu13 medium and (B) 1/4 ASWM after three culture period. Dried algal samples cultured in the modified Chu 13 medium are usually covered with white furry matters (arrow) that can not be seen in one cultured in 1/4 ASWM.</p

Isolation and Characterization of Cyclic C₃₃ Botryococcenes and a Trimethylsqualene Isomer from <i>Botryococcus braunii</i> Race B

Three cyclic C₃₃ botryococcenes and one new trimethylsqualene isomer were isolated from the B race, Showa (Berkeley) strain of <i>Botryococcus braunii</i>, which is known to produce large amounts of isoprenoid hydrocarbons ranging in carbon number from 30 to 34. Their purity was determined by GC-MS, and structures were characterized by 1D and 2D NMR. One of these molecules, cyclic C₃₃-1 botryococcene (<b>5</b>), has an unusual connection of a methylenecyclohexane ring to the molecule backbone not seen before in botryococcenes. This report further adds to our knowledge of the wide range of isoprenoid hydrocarbon structures produced by <i>B. braunii</i>

Miuramides A and B, Trisoxazole Macrolides from a <i>Mycale</i> sp. Marine Sponge That Induce a Protrusion Phenotype in Cultured Mammalian Cells

Morphology-guided cell-based screening of the extract of a <i>Mycale</i> sp. marine sponge led to the isolation of two trisoxazole macrolides, miuramides A (<b>1</b>) and B (<b>2</b>), which induced characteristic morphological changes in 3Y1 cells. The structure of <b>1</b> including absolute configuration was elucidated by a combination of the analysis of spectroscopic data, derivatization, and degradation. Both compounds exhibit potent cytotoxicity against 3Y1 cells