Prenylated Phenol and Benzofuran Derivatives from Aspergillus terreus EN-539, an Endophytic Fungus Derived from Marine Red Alga Laurencia okamurai

Three new prenylated phenol derivatives, terreprenphenols A–C (1–3), along with four known related compounds (4–7), were isolated from Aspergillus terreus EN-539, an endophytic fungus obtained from the marine red alga Laurencia okamurai. The structures of these compounds were established by extensive analysis of 1D/2D NMR data, mass spectrometric data, and optical rotation (OR). The corresponding relationship between absolute configuration and optical rotation for known compounds anodendroic acid (4) and asperterreusine C (5) was ambiguous in literature, and their absolute configurations were therefore discussed and confirmed for the first time by time-dependent density functional (TDDFT) ECD and OR calculations. Compounds 1–7 inhibited some common aquatic bacteria with MIC values ranging from 2 to 64 μg/mL.

Laurane-, Cyclolaurane-, and Cuparane-type Sesquiterpenes from the Marine Red Alga Laurencia okamurai

Chemical investigation of the secondary metabolites extracted from the marine red alga Laurencia okamurai has resulted in the isolation of one new (lauramurin, 1) and six known (2–7) sesquiterpenes. On the basis of the data obtained by our detailed spectroscopic analysis as well as by comparison with those reported, the structures of these compounds were elucidated as four laurane sesquiterpenes including lauramurin (1), laur-11-en-10-ol (2), aplysinol (3), and debromoaplysinol (4), two cyclolaurane sesquiterpenes laurequinone (5) and laurentristich-4-ol (6), and one cuparane ether sesquiterpene (7). The antibacterial activity against Staphylococcus aureus and brine shrimp ( Artemia salina) lethality for the isolated compounds were evaluated. Compounds 2 and 5–7 displayed moderate lethality against brine shrimp.