Secondary metabolites from marine microorganisms: bacteria, protozoa, algae and fungi. Achievements and prospects

Pietra, Francesco

doi:10.1039/np9971400453

Cited by 186 publications

(103 citation statements)

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“…Comparison of the 13 C-NMR data of essramycin with values of related synthetic compounds of type 1 delivered, however, a much better agreement with the experimental values than with compounds of type 2, confirming the skeleton of 1 [15,16]: A C-2 substituent affects the ipso C atom of 1,2,4-triazolo[1,5-a]pyrimidines, however, the influence on the 13 C shifts of the other ring atoms is negligible (Table 4). [1,2,4]Triazolo[1,5-a]pyrimidines have found a broad interest as fungicides [17], herbicide safener [18,19], kinase inhibitors [20,21], antiparasitic [22] and plant protecting agents [23]. Thousands of compounds of this type have been described, however, to the best of our knowledge, not a single natural product is amongst them [6,24,25].…”

Section: Resultsmentioning

confidence: 99%

Essramycin: A First Triazolopyrimidine Antibiotic Isolated from Nature†

et al. 2008

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In the course of our screening program for new bio-active compounds, a novel triazolopyrimidine antibiotic, essramycin (1), was obtained from the culture broth of the marine Streptomyces sp., isolate Merv8102. Structure 1 was established by intensive NMR studies and by mass spectra. The compound is antibacterially active with MIC of 2 to 8 mg/ml against Gram-positive and Gramnegative bacteria, while it showed no antifungal activity. The fermentation and isolation, as well as the structure elucidation and biological activity of 1 are described.

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Section: Resultsmentioning

confidence: 99%

Essramycin: A First Triazolopyrimidine Antibiotic Isolated from Nature†

et al. 2008

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“…In recent years, marine microorganisms have been paid much attention as a significant source for new drug leads [1,2]. During course of our search for anticancer agent from marine-derived microbe, three novel cytotoxic substances named prenylterphenyllin (1), 4Љ-deoxyprenylterphenyllin (2), and 4Љ-deoxyisoterprenin (3) were isolated from a cultured marine-derived fungus of Aspergillus candidus IF10 together with 4Љ-deoxyterprenin (4) (Fig.…”

Section: Abstract Prenylterphenyllin Cytotoxic Marine-derived Fungumentioning

confidence: 99%

Prenylterphenyllin and Its Dehydroxyl Analogs, New Cytotoxic Substances from a Marine-derived Fungus Aspergillus candidus IF10

et al. 2007

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Three novel cytotoxic substances named prenylterphenyllin (1), 4Љ-deoxyprenylterphenyllin (2), and 4Љ-deoxyisoterprenin (3) were isolated from a cultured marine-derived fungus of Aspergillus candidus IF10 together with 4Љ-deoxyterprenin (4). Their chemical structures were elucidated on the basis of 2D NMR analysis. These compounds 1ϳ4 showed cytotoxic activity against human epidermoid carcinoma KB cells (KB3-1) with IC 50 of 8.5, 3.0, 2.5, and 4.5 mg/ml, respectively. Keywords prenylterphenyllin, cytotoxic, marine-derived fungus, Aspergillus candidusIn recent years, marine microorganisms have been paid much attention as a significant source for new drug leads [1,2]. During course of our search for anticancer agent from marine-derived microbe, three novel cytotoxic substances named prenylterphenyllin (1), 4Љ-deoxyprenylterphenyllin (2), and 4Љ-deoxyisoterprenin (3) were isolated from a cultured marine-derived fungus of Aspergillus candidus IF10 together with 4Љ-deoxyterprenin (4) (Fig. 1). In this paper, the fermentation, isolation, and structure elucidation of these compounds are presented.The fungal strain IF10 was isolated from the marine sediment collected from a depth of 50 m off Gokasyo Gulf, Mie Prefecture, Japan, and identified as The slant culture of the strain A. candidus IF10 was inoculated into a 500-ml Erlenmeyer flask containing 200 ml of MG medium [consisting of 2.0% malt extract (Difco, NJ, USA), 2.0% glucose, 0.1% bact peptone (Difco, NJ, USA) in artificial seawater (Yashima Pure Chemicals, Osaka, Japan)] at 30°C for 3 days. Then, 40 ml aliquots of the culture were transferred into 5-liter Erlenmeyer flasks containing 1.0 liter of MG medium and cultured under static conditions at 30°C for 2 weeks. A typical time course of the fermentation is shown in Fig. 3. 1 was detected in the culture broth at day 10 after inoculation, and its concentration reached level of 4.5 mg/liter at day 14. The 2 weeks old culture was extracted with 2-butanone, and the 2-butanone-soluble portion was further partitioned into an n-hexane -90% aq MeOH mixture to furnish a MeOH extract (3.8 g). The MeOH extract (2.1 g) was fractionated by SiO 2 gel column chromatography (n-hexane -EtOAc) to give eight fractions (AϳH) on the guidance of bioassay. Fraction C (73 mg) was then subjected to SiO 2 gel column chromatography (n-hexane -CHCl 3 -EtOAcϭ4 : 1 : 1) to afford 1 (14 mg). Fraction A (50 mg) was separated by SiO 2 gel column chromatography (n-hexane -CHCl 3 -EtOAcϭ10 : 10 : 1) to give four fractions (A-1 to A-4). Fraction A-4 (14 mg) was purified by HPLC (Cosmosil 5SL-II, n-hexane -CHCl 3 -EtOAcϭ4 : 4 : 1) to furnish 2 (2.5 mg). Then, fraction A-3 (20 mg) was separated by HPLC (Cosmosil 5SL-II, n-hexane -CHCl 3 -EtOAcϭ 5 : 5 : 1) to obtain an active fraction A-3-1 (8.0 mg), which was further purified by reversed phase HPLC (Cosmosil 5C 18 -MS-II, CH 3 CN -H 2 Oϭ55 : 45) to afford 3 (1.0 mg) and 4 (4.5 mg).The COSY, HMQC, and HMBC spectra of 1 clarified the presence of three phenyl rings and an isopentenyl moiety a...

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“…The diversity of sponges species is superior in the tropical coral reef environments. The sponges are also very important resources for searching the biologically active substances, which are useful to develop pharmaceuticals, agrochemicals and biochemical reagents and their lead compounds [1] . The origins of these biologically active substances are recently thought to be the metabolites produced by the microorganisms associated with the sponges.…”

Section: Introductionmentioning

confidence: 99%