Marine lipids
Jayatilake et al., 1996), have allowed isolation of antimicrobial
compounds, which suggests that these bacteria may play a role in the
defence mechanism ot these invertebrates. Furthermore, metabolites
previously ascribed to invertebrates were lately demonstrated to be
biosynthesized by bacteria (Stierle et al., 1988; Unson & Faulkner, 1993;
Unson et al., 1994). However, studies of sponge-associated prokariotes
are difficult considering that only a small fraction of species can
actually be cultured from natural samples (Amman et al., 1991 ; Schmidt
et al., 1991).
In a program devoted to the search of bioactive compounds biosynthesized by marine invertebrate associated bacteria collected in New
Caledonia, a large screening of bacteria gathered at the surface of 19
species of sponges has allowed to isolate 54 antimicrobial species.
However, preliminary analysis using Biolog showed that a same strain
could be found in different sponges. Moreover, some strains were impossible to cultivate and ultimately we can estimate to have isolated about
twenty exploitable strains for chemical analysis. We present here the
preliminary results ol our study.
Materials and methods
HRFABMS (positive mode) of compounds 2 and 7 was measured on a
ZAB-SEQ spectrometer in a thioglycerine matrix at the Service central
d’analyses du CNRS (Lyon), and EIMS of other compounds on a Nermag
R10-10. UV spectra were obtained in MeOH, using a Kontron type
Uvikon 930 spectrophotometer, and IR spectra were recorded on a
Nicolet (Impact 400D) FT-IR spectrophotometer. Optical rotations
were measured with a Perkm-Elmer 141 polarimeter with a sodium lamp
(589 nm) in a 10 cm microcell. Melting points were determined on a
hot plate fitting light microscope (Reichert).
1 H NMR and
13 C NMR spectra were obtained on a Bruker AC 300
spectrometer with standard pulse sequences operating at 300.13 MHz
and 75.47 MHz, respectively. The chemical shift values are reported as
ppm units and the coupling constants in hertz.
Silica gel column chromatographies were carried out using Kiesel gel
60 (230-400 mesh, Merck). Fractionations were monitored by TLC
using aluminium-backed sheets (Silica gel 60 F-254, 0.25 mm thick)
with visualization uncler UV (254 and 366 nm). All the solvents were
distilled prior to use.
GC-MS expenments were carried on a Hewlet-Packard 6890 chromatograph, carrier gaz helium (flow rate 1 ml/mn), CPsil8 column (Chrompack 0.25 mm by 50 m). The column was operated at 80°C during one
minute and increased at 5°C/min to 290 ’C. Methylated acids were
analysed on a Nermag R10-10 mass spectrometer.
194
Jayatilake et al., 1996), have allowed isolation of antimicrobial
compounds, which suggests that these bacteria may play a role in the
defence mechanism ot these invertebrates. Furthermore, metabolites
previously ascribed to invertebrates were lately demonstrated to be
biosynthesized by bacteria (Stierle et al., 1988; Unson & Faulkner, 1993;
Unson et al., 1994). However, studies of sponge-associated prokariotes
are difficult considering that only a small fraction of species can
actually be cultured from natural samples (Amman et al., 1991 ; Schmidt
et al., 1991).
In a program devoted to the search of bioactive compounds biosynthesized by marine invertebrate associated bacteria collected in New
Caledonia, a large screening of bacteria gathered at the surface of 19
species of sponges has allowed to isolate 54 antimicrobial species.
However, preliminary analysis using Biolog showed that a same strain
could be found in different sponges. Moreover, some strains were impossible to cultivate and ultimately we can estimate to have isolated about
twenty exploitable strains for chemical analysis. We present here the
preliminary results ol our study.
Materials and methods
HRFABMS (positive mode) of compounds 2 and 7 was measured on a
ZAB-SEQ spectrometer in a thioglycerine matrix at the Service central
d’analyses du CNRS (Lyon), and EIMS of other compounds on a Nermag
R10-10. UV spectra were obtained in MeOH, using a Kontron type
Uvikon 930 spectrophotometer, and IR spectra were recorded on a
Nicolet (Impact 400D) FT-IR spectrophotometer. Optical rotations
were measured with a Perkm-Elmer 141 polarimeter with a sodium lamp
(589 nm) in a 10 cm microcell. Melting points were determined on a
hot plate fitting light microscope (Reichert).
1 H NMR and
13 C NMR spectra were obtained on a Bruker AC 300
spectrometer with standard pulse sequences operating at 300.13 MHz
and 75.47 MHz, respectively. The chemical shift values are reported as
ppm units and the coupling constants in hertz.
Silica gel column chromatographies were carried out using Kiesel gel
60 (230-400 mesh, Merck). Fractionations were monitored by TLC
using aluminium-backed sheets (Silica gel 60 F-254, 0.25 mm thick)
with visualization uncler UV (254 and 366 nm). All the solvents were
distilled prior to use.
GC-MS expenments were carried on a Hewlet-Packard 6890 chromatograph, carrier gaz helium (flow rate 1 ml/mn), CPsil8 column (Chrompack 0.25 mm by 50 m). The column was operated at 80°C during one
minute and increased at 5°C/min to 290 ’C. Methylated acids were
analysed on a Nermag R10-10 mass spectrometer.
194