Fumie Iwata

Neomaclafungins A-I: oligomycin-class macrolides from a marine-derived actinomycete.

Nine new 26-membered macrolides of the oligomycin subfamily, neomaclafungins A-I, were isolated from the fermentation broth of Actinoalloteichus sp. NPS702, which was isolated from marine sediment collected from Usa Bay, Kochi Prefecture, Japan. Their structures were identified through mass spectrometry and NMR experiments. They belong to the oligomycin class and have several distinct features including the presence of alkane or alkanol branches. Neomaclafungins A-I exhibited significant antifungal activity in vitro against Trichophyton mentagrophytes (ATCC 9533), showing MIC values between 1 and 3 μg/mL.

Usabamycins A-C: new anthramycin-type analogues from a marine-derived actinomycete.

New anthramycin-type analogues, designated usabamycin A-C (1, 2 and 3), have been isolated from cultures of Streptomyces sp. NPS853, a bacterium found in marine sediments. The structures of the new compounds were established on the basis of extensive spectroscopic analyses including 1D- and 2D-NMR ((1)H-(1)H COSY, HSQC, and HMBC) experiments. The usabamycins show weak inhibition of HeLa cell growth and selective inhibition of serotonin (5-hydroxytrypamine) 5-HT(2B) uptake.

Lorneic Acids, Trialkyl-Substituted Aromatic Acids from a Marine-Derived Actinomycete

A marine-derived actinomyces strain (NPS554) isolated from a marine sediment sample collected from Miyazaki Harbor, Japan, at a depth of 38 m yielded two trialkyl-substituted aromatic acids, lorneic acid A (1) and lorneic acid B (2). The structures of the lorneic acids, which were elucidated by spectroscopic analysis, differed only in the side-chain, which contained either a conjugated double bond or a benzylic alcohol. Their structural differences affected inhibition activities against phosphodiesterase 5.

3,6,7-tri-epi-invictolide, a diastereomer of queen recognition pheromone, and its analog from a marine-derived actinomycete

3,6,7-tri -epi -invictolide, a diastereomer of queen recognition pheromone, and its analog from a marine-derived actinomycete

Neomacquarimicin: a new macquarimicin analog from marine-derived actinomycete

During our screening program for a secondary metabolite with a polycyclic ring system from a bacterial species using LC-MS/UV-based chemical analysis, the production of a novel b-hydroxyl-d-lactone compound, neomacquarimicin (1), with a molecular ion at m/z 317.1756 and an absorption maximum at 279 nm, was observed in the culture extract of Micromonospora sp. NPS2077, which was isolated from an unidentified marine sponge collected at Uranouchi Bay, Kochi, Japan. Herein, we report the fermentation, isolation, structural elucidation, and biological properties of 1. The marine sponge was rinsed three times with sterile artificial seawater to remove the bacteria attached to the surface. The sample was then homogenized in a blender. The homogenized sample was resuspended in sterile seawater and was kept at 55 1C for 5 min in a separate glass container for pretreatment.1 Isolation of the actinomycetes from the homogenized samples was initially carried out by using serial dilution and spread plate technique on chitin agar plate, which consisted of 0.2% colloidal chitin (Sigma-Aldrich, St Louis, MO, USA), 0.15% KH2PO4 (Wako Pure Chemical Industries, Osaka, Japan), 0.21% K2HPO4 (Wako), 0.25% MgSO4 7H2O (Wako), 1.8% artificial seawater (Nihon Pharmaceutical, Tokyo, Japan) and 1.8% agar (Becton, Dickinson and Company, Sparks, MD, USA). The plates were incubated at 28 1C for 7 days. The 16S rDNA sequence of the NPS2077 strain (1387 base pairs) was deposited in the DDBJ Genbank (AB856417). This strain showed 100% 16S rDNA sequence identity with Micromonospora sp. A1-15.2 The strain was cultured on a rotary shaker (180 r.p.m.) at 28 1C for 3 days in 14 ml glass tube containing 3 ml of the seed medium. The seed medium consisted of 3% soytone (BD), 1.8% artificial seawater (Nihon Pharmaceutical). Strain NPS2077 was cultured in 500 ml baffled shake flasks containing 100 ml of the production medium (modified KG), which consisted of 0.8% glucose (Wako), 0.8% maltose monohydrate (Wako), 0.8% soluble starch (Wako), 1.5% soytone (BD), 0.2% yeast extract (BD), 1.8% artificial seawater (Nihon Pharmaceutical) and 1 ml seed culture. After 10 days of fermentation with shaking at 220 r.p.m. at 28.5 1C, the whole culture broth (900 ml) was extracted with an equal amount of EtOAc. Two MS and UV-guided chromatographic purification steps, reverse-phase chromatography (3.5 7 cm2, Wako gel C-50, Wako) with aqueous methanol solution (25–100% aq. MeOH in 25% stepwise increments), and partitioned TLC chromatography (0.5 mm, silica gel 60 F254; Merck, Darmstadt, Germany) with an EtOAc/methanol (19/1) solution were performed to afford a pure sample of neomacquarimicin (1, 4.8 mg) with an Rf value in EtOAc:MeOH (19:1) of 0.79. The molecular ion of m/z 317.1756 for neomacquarimicin was determined by HR-ESI-time-of-flight positive-ion MS. The 13C NMR and HSQC spectra of neomacquarimicin indicated 19 carbon atoms with 23 attached protons and suggested the presence of functional groups, including a ketone (dC 219.1, qC), an ester (dC 175.5, qC) and an olefin (dC 130.6, CH; dC 123.3, CH). Thus, the MW could represent a molecular formula of C19H24O4 with five rings. The 2D homonuclear and heteronuclear NMR experiments showed connectivities consistent with a structure possessing portions similar to macquarimicin C (2)3 but with desorption of the methyl ketone at C-9 and reduction of the ketone at C-19, as shown in Figure 1-I. The 1D (1H and 13C) NMR spectral data and 2D NMR correlations for 1 are summarized in Table 1. Key HMBC correlations were observed for the H-1 methine proton (dH 4.65) with the 13C NMR signals at dC 175.5 (C-3), 23.4 (C-16) and 68.9 (C-19) and for the H-6 methine proton (dH 2.43) with the 13C NMR signals at dC 28.4 (C-5), 38.5 (C-7), 46.2 (C-11), 130.6 (C-13) and 29.9 (C-14). The relative configuration of neomacquarimicin was determined by NOESY experiments and from the J values. The NOE correlations observed in these experiments are summarized in Figure 1-II. The coupling constant of J7, 8ab (6.8 Hz) and J8ab, 9 (7.3, 6.9 Hz) supported by the NOE correlations among 5-H, 7-H and 11-H confirmed that the AB ring junction was cis. The BC ring junction was also proved to be cis by the COSY correlation between H-14 and H-15a and the NOE network in H-6/Hb-8 and H-15a/H-13. The relative stereochemistry of the cyclopentane ring (A ring) and the cyclohexane rings (C and D rings) was determined by the NOE