Marine Drugs

252 KiB

Open AccessArticle

Two Antimycin A Analogues from Marine-Derived Actinomycete Streptomyces lusitanus

by Zhuang Han, Ying Xu, Oliver McConnell, Lingli Liu, Yongxin Li, Shuhua Qi, Xiangzhong Huang and Peiyuan Qian

Mar. Drugs 2012, 10(3), 668-676; https://doi.org/10.3390/md10030668 - 22 Mar 2012

Cited by 36 | Viewed by 8043

Abstract

Two new antimycin A analogues, antimycin B1 and B2 (1–2), were isolated from a spent broth of a marine-derived bacterium, Streptomyces lusitanus. The structures of 1 and 2 were established on the basis of spectroscopic analyses and chemical [...] Read more.

Two new antimycin A analogues, antimycin B1 and B2 (1–2), were isolated from a spent broth of a marine-derived bacterium, Streptomyces lusitanus. The structures of 1 and 2 were established on the basis of spectroscopic analyses and chemical methods. The isolated compounds were tested for their anti-bacterial potency. Compound 1 was found to be inactive against the bacteria Bacillus subtilis, Staphyloccocus aureus, and Loktanella hongkongensis. Compound 2 showed antibacterial activities against S. aureus and L. hongkongensis with MIC values of 32.0 and 8.0 μg/mL, respectively. Full article

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477 KiB

Open AccessArticle

Isolation and Structural Determination of the First 8-epi-type Tetrodotoxin Analogs from the Newt, Cynops ensicauda popei, and Comparison of Tetrodotoxin Analogs Profiles of This Newt and the Puffer Fish, Fugu poecilonotus

by Yuta Kudo, Takeshi Yasumoto, Keiichi Konoki, Yuko Cho and Mari Yotsu-Yamashita

Mar. Drugs 2012, 10(3), 655-667; https://doi.org/10.3390/md10030655 - 22 Mar 2012

Cited by 52 | Viewed by 8216

Abstract

Identification of new tetrodotoxin (TTX) analogs from TTX-possessing animals might provide insight into its biosynthesis and metabolism. In this study, four new analogs, 8-epi-5,6,11-trideoxyTTX, 4,9-anhydro-8-epi-5,6,11-trideoxyTTX, 1-hydroxy-8-epi-5,6,11-trideoxyTTX, and 1-hydroxy-4,4a-anhydro-8-epi-5,6,11-trideoxyTTX, were isolated from the newt, Cynops ensicauda [...] Read more.

Identification of new tetrodotoxin (TTX) analogs from TTX-possessing animals might provide insight into its biosynthesis and metabolism. In this study, four new analogs, 8-epi-5,6,11-trideoxyTTX, 4,9-anhydro-8-epi-5,6,11-trideoxyTTX, 1-hydroxy-8-epi-5,6,11-trideoxyTTX, and 1-hydroxy-4,4a-anhydro-8-epi-5,6,11-trideoxyTTX, were isolated from the newt, Cynops ensicauda popei, and their structures were determined using spectroscopic methods. These are the first 8-epi-type analogs of TTX that have been found in a natural source. Furthermore, we examined the composition of the TTX analogs in this newt and in the ovary of the puffer fish, Fugu poecilonotus, using LC/MS. The results indicate that TTX and 11-deoxyTTX were present in both sources. However, 6-epiTTX and 8-epi-type analogs were detected only in the newt, while 5,6,11-trideoxyTTX was a specific and major analog in the puffer fish. Such considerable differences among analog compositions might reflect differences in the biosynthesis or metabolism of TTX between these animals. Full article

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345 KiB

Open AccessArticle

Identification and Characterization of an Anti-Fibrotic Benzopyran Compound Isolated from Mangrove-Derived Streptomyces xiamenensis

by Min-Juan Xu, Xiao-Jin Liu, Yi-Lei Zhao, Dong Liu, Zhen-Hao Xu, Xiao-Meng Lang, Ping Ao, Wen-Han Lin, Song-Lin Yang, Zhi-Gang Zhang and Jun Xu

Mar. Drugs 2012, 10(3), 639-654; https://doi.org/10.3390/md10030639 - 15 Mar 2012

Cited by 33 | Viewed by 10185

Abstract

An anti-fibrotic compound produced by Streptomyces xiamenensis, found in mangrove sediments, was investigated for possible therapeutic effects against fibrosis. The compound, N-[[3,4-dihydro-3S-hydroxy-2S-methyl-2-(4¢R-methyl-3¢S-pentenyl)-2H-1-benzopyran-6-yl]carbonyl]-threonine (1), was isolated from crude extracts and its [...] Read more.

An anti-fibrotic compound produced by Streptomyces xiamenensis, found in mangrove sediments, was investigated for possible therapeutic effects against fibrosis. The compound, N-[[3,4-dihydro-3S-hydroxy-2S-methyl-2-(4¢R-methyl-3¢S-pentenyl)-2H-1-benzopyran-6-yl]carbonyl]-threonine (1), was isolated from crude extracts and its structure, including the absolute configuration was determined by extensive spectroscopic data analyses, Mosher’s method, Marfey’s reagent and quantum mechanical calculations. In terms of biological effects, this compound inhibits the proliferation of human lung fibroblasts (WI26), blocks adhesion of human acute monocytic leukemia cells (THP-1) to a monolayer of WI26 cells, and reduces the contractile capacity of WI26 cells in three-dimensional free-floating collagen gels. Altogether, these data indicate that we have identified a bioactive alkaloid (1) with multiple inhibitory biological effects on lung excessive fibrotic characteristics, that are likely involved in fibrosis, suggesting that this molecule might indeed have therapeutic potential against fibrosis. Full article

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738 KiB

Open AccessArticle

Chondrosterins A–E, Triquinane-Type Sesquiterpenoids from Soft Coral-Associated Fungus Chondrostereum sp.

by Hou-Jin Li, Ying-Lu Xie, Zhong-Liang Xie, Ying Chen, Chi-Keung Lam and Wen-Jian Lan

Mar. Drugs 2012, 10(3), 627-638; https://doi.org/10.3390/md10030627 - 13 Mar 2012

Cited by 55 | Viewed by 8273

Abstract

The marine fungus Chondrostereum sp. was collected from a soft coral Sarcophyton tortuosum from the South China Sea. This fungus was cultured in potato dextrose broth medium and the culture broth was extracted with EtOAc. Five new triquinane-type sesquiterpenoids, chondrosterins A–E (1 [...] Read more.

The marine fungus Chondrostereum sp. was collected from a soft coral Sarcophyton tortuosum from the South China Sea. This fungus was cultured in potato dextrose broth medium and the culture broth was extracted with EtOAc. Five new triquinane-type sesquiterpenoids, chondrosterins A–E (1–5), and the known sesquiterpenoid hirsutanol C (6), were isolated. The structures were elucidated mainly on the basis of NMR, MS, and X-ray single-crystal diffraction data. Chondrosterin A (1) showed significant cytotoxic activities against cancer lines A549, CNE2, and LoVo with IC₅₀ values of 2.45, 4.95, and 5.47 μM, respectively. Full article

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457 KiB

Open AccessArticle

Sarcocrassocolides M–O, Bioactive Cembranoids from the Dongsha Atoll Soft Coral Sarcophyton crassocaule

by Wan-Yu Lin, Yi Lu, Bo-Wei Chen, Chiung-Yao Huang, Jui-Hsin Su, Zhi-Hong Wen, Chang-Feng Dai, Yao-Haur Kuo and Jyh-Horng Sheu

Mar. Drugs 2012, 10(3), 617-626; https://doi.org/10.3390/md10030617 - 8 Mar 2012

Cited by 24 | Viewed by 7356

Abstract

Three new cembranoids, sarcocrassocolides M–O (1–3), have been isolated from the soft coral Sarcophyton crassocaule. The structures of the metabolites were determined by extensive spectroscopic analysis. Compounds 1–3 were shown to exhibit moderate cytotoxicity toward a limited panel of cancer cell lines and [...] Read more.

Three new cembranoids, sarcocrassocolides M–O (1–3), have been isolated from the soft coral Sarcophyton crassocaule. The structures of the metabolites were determined by extensive spectroscopic analysis. Compounds 1–3 were shown to exhibit moderate cytotoxicity toward a limited panel of cancer cell lines and display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Full article

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183 KiB

Open AccessReview

Fucoxantin: A Treasure from the Sea

by Nicolantonio D’Orazio, Eugenio Gemello, Maria Alessandra Gammone, Massimo De Girolamo, Cristiana Ficoneri and Graziano Riccioni

Mar. Drugs 2012, 10(3), 604-616; https://doi.org/10.3390/md10030604 - 7 Mar 2012

Cited by 253 | Viewed by 16578

Abstract

The World Health Organization (WHO) estimates that 2.3 billion people will be overweight and 700 million obese in 2015. The reasons for this disastrous trend are attributed to the global tendency toward the reduced magnitude of exercise and physical activity and the increased [...] Read more.

The World Health Organization (WHO) estimates that 2.3 billion people will be overweight and 700 million obese in 2015. The reasons for this disastrous trend are attributed to the global tendency toward the reduced magnitude of exercise and physical activity and the increased dietary intake of fats, sugars and calories with reduced amount of vitamins and minerals. To prevent life-style-related diseases, like Metabolic Syndrome (MS), researchers’ attention is increasingly focusing on some of the so called “functional foods” which may be useful for their prevention and treatment. One of these functional ingredients is fucoxanthin (FX), a characteristic carotenoid present in edible brown seaweeds, such as Undaria pinnatifida (Wakame), Hijikia fusiformis (Hijiki), Laminaria japonica (Ma-Kombu) and Sargassum fulvellum. The increasing popularity of this molecule is certainly due to its anti-obesity effect, primarily detected by murine studies. These works revealed FX mediated induction of uncoupling protein-1 (UCP-1) in abdominal white adipose tissue (WAT) mitochondria, leading to the oxidation of fatty acids and heat production in WAT. Beyond this important role, in recent studies FX has shown a great antioxidant activity, anti-cancer, anti-diabetic and anti-photoaging properties. The aim of this review is to highlight the main effects of FX on human health. Full article

(This article belongs to the Special Issue Marine Carotenoids and Oxidative Stress)

184 KiB

Open AccessArticle

A Fatty Acid Glycoside from a Marine-Derived Fungus Isolated from Mangrove Plant Scyphiphora hydrophyllacea

by Yan-Bo Zeng, Hui Wang, Wen-Jian Zuo, Bo Zheng, Tao Yang, Hao-Fu Dai and Wen-Li Mei

Mar. Drugs 2012, 10(3), 598-603; https://doi.org/10.3390/md10030598 - 6 Mar 2012

Cited by 35 | Viewed by 7864

Abstract

To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic [...] Read more.

To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, ¹H-¹H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method. Full article

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220 KiB

Open AccessArticle

Cellular and Transcriptional Responses of Crassostrea gigas Hemocytes Exposed in Vitro to Brevetoxin (PbTx-2)

by Danielle F. Mello, Eliza S. De Oliveira, Renato C. Vieira, Erik Simoes, Rafael Trevisan, Alcir Luiz Dafre and Margherita Anna Barracco

Mar. Drugs 2012, 10(3), 583-597; https://doi.org/10.3390/md10030583 - 5 Mar 2012

Cited by 56 | Viewed by 8942

Abstract

Hemocytes mediate a series of immune reactions essential for bivalve survival in the environment, however, the impact of harmful algal species and their associated phycotoxins upon bivalve immune system is under debate. To better understand the possible toxic effects of these toxins, Crassostrea [...] Read more.

Hemocytes mediate a series of immune reactions essential for bivalve survival in the environment, however, the impact of harmful algal species and their associated phycotoxins upon bivalve immune system is under debate. To better understand the possible toxic effects of these toxins, Crassostrea gigas hemocytes were exposed to brevetoxin (PbTx-2). Hemocyte viability, monitored through the neutral red retention and MTT reduction assays, and apoptosis (Hoechst staining) remained unchanged during 12 h of exposure to PbTx-2 in concentrations up to 1000 µg/L. Despite cell viability and apoptosis remained stable, hemocytes incubated for 4 h with 1000 µg/L of PbTx-2 revealed higher expression levels of Hsp70 (p < 0.01) and CYP356A1 ( p < 0.05) transcripts and a tendency to increase FABP expression, as evaluated by Real-Time quantitative PCR. The expression of other studied genes (BPI, IL-17, GSTO, EcSOD, Prx6, SOD and GPx) remained unchanged. The results suggest that the absence of cytotoxic effects of PbTx-2 in Crassostrea gigas hemocytes, even at high concentrations, allow early defense responses to be produced by activating protective mechanisms associated to detoxification (CYP356A1 and possibly FABP) and stress (Hsp70), but not to immune or to antioxidant (BPI, IL-17, EcSOD, Prx6, GPx and SOD) related genes. Full article

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1162 KiB

Open AccessArticle

Activation of the Dormant Secondary Metabolite Production by Introducing Gentamicin-Resistance in a Marine-Derived Penicillium purpurogenum G59

by Yun-Jing Chai, Cheng-Bin Cui, Chang-Wei Li, Chang-Jing Wu, Cong-Kui Tian and Wei Hua

Mar. Drugs 2012, 10(3), 559-582; https://doi.org/10.3390/md10030559 - 2 Mar 2012

Cited by 71 | Viewed by 10557

Abstract

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous [...] Read more.

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1–4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites. Full article

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200 KiB

Open AccessArticle

Kiamycin, a Unique Cytotoxic Angucyclinone Derivative from a Marine Streptomyces sp.

by Zeping Xie, Bing Liu, Hongpeng Wang, Shengxiang Yang, Hongyu Zhang, Yipeng Wang, Naiyun Ji, Song Qin and Hartmut Laatsch

Mar. Drugs 2012, 10(3), 551-558; https://doi.org/10.3390/md10030551 - 27 Feb 2012

Cited by 28 | Viewed by 7696

Abstract

Kiamycin (1), a new angucyclinone derivative possessing an 1,12-epoxybenz[a]anthracene ring system, was isolated from the marine Streptomyces sp. strain M268 along with the known compounds 8-O-methyltetrangomycin (3) and 8-O-methylrabelomycin (4). Their structures were [...] Read more.

Kiamycin (1), a new angucyclinone derivative possessing an 1,12-epoxybenz[a]anthracene ring system, was isolated from the marine Streptomyces sp. strain M268 along with the known compounds 8-O-methyltetrangomycin (3) and 8-O-methylrabelomycin (4). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. The new angucyclinone derivative showed inhibitory activities against the human cell lines HL-60 (leukemia), A549 (lung adenocarcinoma), and BEL-7402 (hepatoma) with inhibition rates of 68.2%, 55.9%, and 31.7%, respectively, at 100 µM. It appears to have potential as an anticancer agent with selective activity. Full article

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447 KiB

Open AccessArticle

Scopararanes C–G: New Oxygenated Pimarane Diterpenes from the Marine Sediment-Derived Fungus Eutypella scoparia FS26

by Li Sun, Dongli Li, Meihua Tao, Yuchan Chen, Feijun Dan and Weimin Zhang

Mar. Drugs 2012, 10(3), 539-550; https://doi.org/10.3390/md10030539 - 27 Feb 2012

Cited by 51 | Viewed by 8865

Abstract

Five new oxygenated pimarane diterpenes, named scopararanes C–G (1–5) were isolated from the culture of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from the South China Sea. The structures of these compounds were established on the basis of [...] Read more.

Five new oxygenated pimarane diterpenes, named scopararanes C–G (1–5) were isolated from the culture of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from the South China Sea. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configurations of compounds 1–5, were determined by CD spectroscopic analysis and comparison with literature data. All isolated compounds (1–5) were evaluated for their cytotoxic activities against MCF-7, NCI-H460, and SF-268 tumor cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method. Full article

(This article belongs to the Special Issue Terpenoids of Marine Origin)

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973 KiB

Open AccessArticle

Antiviral Activities and Putative Identification of Compounds in Microbial Extracts from the Hawaiian Coastal Waters

by Jing Tong, Hank Trapido-Rosenthal, Jun Wang, Youwei Wang, Qing X. Li and Yuanan Lu

Mar. Drugs 2012, 10(3), 521-538; https://doi.org/10.3390/md10030521 - 24 Feb 2012

Cited by 14 | Viewed by 9254

Abstract

Marine environments are a rich source of significant bioactive compounds. The Hawaiian archipelago, located in the middle of the Pacific Ocean, hosts diverse microorganisms, including many endemic species. Thirty-eight microbial extracts from Hawaiian coastal waters were evaluated for their antiviral activity against four [...] Read more.

Marine environments are a rich source of significant bioactive compounds. The Hawaiian archipelago, located in the middle of the Pacific Ocean, hosts diverse microorganisms, including many endemic species. Thirty-eight microbial extracts from Hawaiian coastal waters were evaluated for their antiviral activity against four mammalian viruses including herpes simplex virus type one (HSV-1), vesicular stomatitis virus (VSV), vaccinia virus and poliovirus type one (poliovirus-1) using in vitro cell culture assay. Nine of the 38 microbial crude extracts showed antiviral potencies and three of these nine microbial extracts exhibited significant activity against the enveloped viruses. A secosteroid, 5α(H),17α(H),(20R)-beta-acetoxyergost-8(14)-ene was putatively identified and confirmed to be the active compound in these marine microbial extracts. These results warrant future in-depth tests on the isolation of these active elements in order to explore and validate their antiviral potential as important therapeutic remedies. Full article

(This article belongs to the Special Issue Marine Anti-infective Agents)

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Mar. Drugs, Volume 10, Issue 3 (March 2012) – 12 articles , Pages 521-676

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