Marine Natural Products. XXXII. Absolute Configurations of C-4 of the Manoalide Family, Biologically Active Sestertepenes from the Marine Sponge Hyrtios erecta.

Reduktion cyclischer Maleinsäurederivate/Reduction of Cyclic Maleic Acid Derivatives

“…Zahlreiche natürlich vorkom m ende Verbindun gen m it cytotoxischen oder antibakteriellen W ir kungen wie C yclopaldsäure [3], Cinnolid, Rubratoxin [4] oder die M annoalide [5] enthalten das Struk turelem ent eines 7 -L actols oder 7 -H ydroxylactam s der allgem einen Form el 1. B esonders einfache Ver bindungen diesen Typs sind die N aturstoffe N arthigenin 2 [6] und Jatropham 3 [7], Bei der erstgenann ten Verbindung, einem Inhaltsstoff des Beinbrech (N arthecium ossifragu m Hud., Liliaceae) konnte Tschesche [6 ] eine antibiotische A ktivität gegen B a cillu s su b tilis sow ie eine W achstum shem m ung bei P ythium d ebaryan u m nachw eisen.…”

Secondary metabolites from marine microorganisms

“…These metabolites that are endowed of cytotoxic, antileukemic and antineoplasic properties, have never been observed in the brown alga the which affords chromenol meroditerpenes (Kikuchi et al 1983;Numata et al 1991). Similarly, sponges of the genus Hyrtios have furnished a potent cytotoxic macrolide, altohyrtine A (23) , and several terpenoids, one of them, manoalide (24), is an interesting anti-inflammatory agent (Kobayashi et al 1994) first isolated from the sponge Luffariella variabilis (Silva and Scheuer, 1980). Again, none of these compounds was obtained from the fungus Aspergillus niger isolated from a Hyrtios species.…”

Deoxymanoalides from the Nudibranch Chromodoris willani

“…The fourth fraction (1.33 g) was purified on HPLC (silica, nhexane-EtOAc, 1-2) to give manoalide (3, 350.0 mg) and secomanoalide (4, 46.8 mg), both of which showed identical NMR data to those reported. 5,7) Deoxymanoalide (1) NaBH 4 Reduction of Compounds 1 and 3 A solution of 1 (9.3 mg) in MeOH (2 ml) was treated with NaBH 4 (1.6 mg) and the whole mixture was stirred under N 2 atmosphere for 2 h. The reaction mixture was partitioned between EtOAc and water, and the organic layer was taken. After drying and concentration, the crude product was separated on HPLC (RP-18, MeOH-H 2 O, 9-1) to give diol (5) in the amount of 5.3 mg (57%).…”

“…5) Manoalide was first discovered as an antimicrobial constituent of the sponge Luffariella variabilis 5) and later shown to have anti-inflammatory activity against phospholipase A2 (PLA2) 6) in addition to cytotoxicity. 7) In this note, we report the structures and biological activities of two manoalide analogs isolated from C. willani.…”