A rare diketopiperazine glycoside from marine-sourced Streptomyces sp. ZZ446

Abstract

Two diketopiperazines were isolated from a culture of the marine-derived actinomycete Streptomyces sp. ZZ446. Their structures were elucidated as maculosin (1) and maculosin-O-α-L-rhamnopyranoside (2) based on their NMR and HRESIMS data, specific rotation, and chemical degradation. Maculosin-O-α-L-rhamnopyranoside (2) is a new diketopiperazine glycoside, a structural class not reported previously from the natural sources. Both compounds showed antimicrobial activity against methicillin-resistant Staphylococcus aureus, Escherichia coli, and Candida albicans with MIC values in a range from 26.0 to 37.0?μg/mL.

     

Novel Polyketides Isolated from Streptomyces sp.

From the endophytic strain Streptomyces sp. CS of Maytenus hookeri, five novel type III polyketides, compounds 1 – 5 , were isolated. Their structures were elucidated by spectroscopic analyses including 1D‐ and 2D‐NMR experiments, and by HR‐ESI‐MS.     

Four new anthraquinones from a soil actinomycete Streptomyces sp. WS-13394 and their bioactivities

Further chemical study of secondary metabolites from the soil actinomycete Streptomyces sp. WS-13394 resulted in the isolation of four new alkylated anthraquinone analogues (5–8). Their structures were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. The new compounds, together with analogues obtained before (1–4), were tested for their in vitro cytotoxicity against Huh-7 and SGC-7901.     

Antiglioma Natural Products from the Marine-Associated Fungus Penicillium sp. ZZ1750

Marine-derived Penicillium fungi are one of the most important sources for the discovery of new bioactive natural products. This study characterized the isolation, structures, and antiglioma activities of twelve compounds, including three novel ones—penipyridinone B (1), 11S-(−)-penilloid A (2), and 11R,14E-(+)-penilloid A (3)—from the marine fungus Penicillium sp. ZZ1750. The structures of the novel compounds were determined via extensive nuclear magnetic resonance (NMR) spectroscopic analyses, high-resolution electrospray ionization mass spectroscopy (HRESIMS) data, Mosher’s method, optical rotation (OR) calculations, and electronic circular dichroism (ECD) calculations. Penipyridinone B represents the first example of its structural type and showed potent antiglioma activity, with IC₅₀ values of 2.45 μM for U87MG cells and 11.40 μM for U251 cells. The known compounds of questiomycin A (9) and xanthocillin X (10) also showed antiproliferative activity against both U87MG and U251 cells, with IC₅₀ values of 13.65 μM to 22.56 μM. The antiglioma activity of questiomycin A and xanthocillin X may be related to the promotion of reactive oxygen species (ROS) production, the reduction of mitochondrial membrane potential (MMP), and the enhancement of caspase-3 enzyme activity.     

Antimicrobial and antioxidant activities of a new benzamide from endophytic Streptomyces sp. YIM 67086

A new benzamide (1) and four known compounds (2–5) were isolated from endophytic Streptomyces YIM67086, and their structures were determined as 2-amino-3,4-dihydroxy-5-methoxybenzamide (1), 4-hydroxy-3-methoxybenzoic acid (2), phenylacetic acid (3), N-acetyltyramine (4) and p-hydroxytruxinic acid (5). Compound 5 was first found in the microorganism. The antimicrobial activities of compounds 1–5 and antioxidant activity of compound 1 were investigated.     

Angucycline antibiotics and its derivatives from marine-derived actinomycete Streptomyces sp. A6H

Vineomycin A₁ (1) and B₂ (2) were isolated from the culture broth of marine actinomycete Streptomyces sp. A6H. Five hydrolysis products were obtained by rational hydrolysis and methanolysis of the fermentation extract. Their structures were characterised as aquayamycin (3), vineomycinone B₂ (4), 9-C-_D-olivosyltetrangulol (5), 7-O-methylgaltamycinone (6) and vineomycinone B₂ methyl ester (7). In addition to these compounds, two ester derivatives, vineolactone A (8) and vineomycinone B₂ benzyl ester (9) of compound 4 were generated semisynthetically. Compound 6 is a new analogue of galtamycinone, while compounds 8 and 9 are new members of vineomycins. Cytotoxic activities and antimicrobial activities were determined for all compounds. The results indicate that only compound 1 showed significant activities with IC₅₀ value of 0.34 μM against H1975 and MIC value of 4 μg/mL against Staphylococcus aureus.     

Bandunamide, a Novel Cyclopeptide from the Streptomyces Griseovariabilis bandungensis

A new cyclic octapeptide, bandunamide, was isolated from the acetone extracts of streptomyces griseovariabilis bandungensis. This cyclic octapeptide exhibits strong antimicrobial activity against Phytophthora drechsleri (IC50=15 ng/mL), Colletotrchum higginsiannum(IC50=15.6 ng/mL), Piricularia oxyzae (IC50=0.2 μg/mL), and Fusarium oxysporum f. Sp.(IC50= 100μg/mL). The structure elucidation of bandunamide is herein reported.     

A new diketopiperazine derivative from a deep sea-derived Streptomyces sp. SCSIO 04496

A new diketopiperazine (DKP) derivative, (6R,3Z)-3-benzylidene-6-isobutyl-1-methyl piperazine-2,5-dione (1), as well as five known DKPs 2–6 was isolated from a deep sea-derived Streptomyces sp. SCSIO 04496. The structure of 1 was elucidated using a combination of 1D and 2D NMR, HR-ESI-MS and chiral-phase HPLC techniques. Compounds 1–6 did not show cytotoxic activity at a concentration of 100 μM in bioactivity assay.     

A New Virginae Butanolide from Streptomyces sp.

A novel butanolide, named virginaebutanolide F (1), was isolated from the lyophilized culture broth of Slreptomyces sp., along with a known compound virginaebutanolide C (2). Their structures including the stereochemistry were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS and CD spectroscopic analysis.     

海洋放线菌Streptomyces sp. V5产生的一个新的八元环内酯

海洋放线菌Streptomyces sp. V5分离自南中国海红树根部土壤, 从其培养液分离获得一个新的八元环内酯octalactin C (A), 以及四个已知化合物2-甲基-3-呋喃甲酸(B)、环(脯-亮)二肽(C)、环(丙-缬)二肽(D)和尿嘧啶(E). 通过完整的波谱数据解析了它们的结构.     

A new O-cinnamoyl threonine derivative from gene adpA overexpression strain Streptomyces sp. HS-NF-1222A

Abstract

A new O-cinnamoyl threonine derivative, O-(2-(3-methyloxiranyl) cinnamoyl) threonine (1), was isolated from the gene adpA overexpression strain Streptomyces sp. HS-NF-1222A. The structure of 1 was determined based on HRESIMS and extensive NMR analysis.     

Microbial transformation of resveratrol by endophyte Streptomyces sp. A12 isolated from Polygonum cuspidatum

Resveratrol (1) undergoes microbial transformation when fermented with Streptomyces sp. A12 to yield 3, 5, 4′-trimethoxy-trans-stilbene (2). The structure of the compound 2 was elucidated using the modern spectroscopic techniques. This is the first report of the microbial transformation of resveratrol to compound 2 using the endophyte isolated from Polygonum cuspidatum.     

Bisamides and rhamnosides from mangrove actinomycete Streptomyces sp. SZ-A15

Four new bisamides 1–4, and two new rhamnosides (5, 6), along with four known compounds 7–10, were isolated from a scale culture of the mangrove-derived actinomycete Streptomyces sp. SZ-A15. All structures were determined through analysis of the UV, IR, HRESIMS, 1D and 2D NMR spectra as well as by comparison with literature data. BRD4 inhibition of all isolated compounds was evaluated. As for the ability to inhibit protein BRD4, compound 9 exhibited moderate activity with the value of 78.4 ± 2.2% at 10 μM.     

Structure elucidation of four prenylindole derivatives from Streptomyces sp. isolated from Ailuropoda melanoleuca feces

Four new prenylindole derivatives, (R)‐6‐(2,3‐dihydroxy‐3‐methylbutyl)indole (1), (R)‐6‐(2,3‐dihydroxy‐3‐methylbutyl)indolin‐2‐one (2), and an unseparated mixture of (Z)‐6‐(4‐hydroxy‐3‐methylbut‐2‐en‐1‐yl)indolin‐2‐one (3a) and (E)‐6‐(4‐hydroxy‐3‐methylbut‐2‐en‐1‐yl)indolin‐2‐one (3b) with a ratio of 3 : 2, were isolated from the culture broth of a streptomycete isolated from Ailuropoda melanoleuca feces. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic techniques. The absolute configuration of 1 was determined by Mosher's method. Copyright © 2013 John Wiley & Sons, Ltd.     

Two new macrosporin dimers from the fungus Alternaria sp. XZSBG-1

Two new macrosporin dimers (1–2) along with four known compounds (3–6) were isolated from the extracts of the fungal strain Alternaria sp. XZSBG-1 from the sediment of the salt lake in the Bange, Tibetan, China. Their structures were determined by spectroscopic methods, mainly by 2D NMR spectra. Compounds 1 and 2 are new macrosporin dimers with symmetric chemical structures. In the cytotoxicity assay and inhibited alpha-glucosidase activity assay, all these compounds showed no notable inhibitory activity.     

Neopeapyran,an unusual furo[2,3b]pyran analogue and turnagainolide C from a soil Streptomyces sp. S2236

Neopeapyran (1), an unusual furo[2,3b]pyran analogue, together with a new cyclopeptide, turnagainolide C (2), were isolated from Streptomyces sp. S2236 associated with the rhizosphere soil of Panax notoginseng. The planar structure and relative configuration of neopeapyran (1)) were elucidated on the basis of spectroscopic techniques, while the absolute configuration was determined by TDDFT calculation. The absolute configuration of turnagainolide C (2) was determined by partial hydrolysis, together with the advanced Marfey's method and spectroscopic analysis. The antimicrobial activities of these two compounds were also investigated.     

Spirodionic acid, a novel metabolite from Streptomyces sp., part 1: structure elucidation and Diels-Alder-type biosynthesis

Spirodionic acid (1), a novel microbial metabolite with a spiro[4.5]decene skeleton, the 6-ethyl-2H-pyrone 5, dihydrosarkomycin (6), and other metabolites were isolated from the strain Streptomyces sp. Tü 6077. Structural elucidation was accomplished by NMR spectroscopic and mass-spectrometric studies, and the biosyntheses of compounds 1, 5, and 6 were investigated by feeding experiments with (13)C-labeled precursors. All results indicate a biogenetic sequence with metabolite 5 and sarkomycin (7) as precursors in the formation of spirocyclus 1 through an intermolecular Diels-Alder-type reaction.     

Novel antifungal janthinopolyenemycins A and B from a co-culture of marine-associated Janthinobacterium spp. ZZ145 and ZZ148

Two rare polyketides, named as janthinopolyenemycins A (1) and B (2), were isolated from a co-culture of two marine-sourced bacteria Janthinobacterium spp. ZZ145 and ZZ148. Their structures were established by a combination of extensive NMR spectroscopic analyses, HRESIMS data, and ECD calculation. Both janthinopolyenemycins A and B showed activity in inhibiting the growth of Candida albicans with a MIC value of 15.6?μg/mL and a MBC value of 31. 25?μg/mL.     

MDN-0171, a new medermycin analogue from Streptomyces albolongus CA-186053

A new medermycin derivative, MDN-0171 (1), and two known structurally related compounds, medermycin (2) and antibiotic G15-F (3) were isolated from the acetone extract of culture broths of the marine-derived Streptomyces albolongus strain CA-186053. Their structures were determined using a combination of spectroscopic techniques, including 1D and 2D NMR and electrospray-time of flight mass spectrometry (ESI-TOF MS). Compounds 2 and 3 accounted for the antimicrobial activity (against methicillin-resistant Staphylococcus aureus and Escherichia coli) previously detected in the crude extract of this actinomycete.     

Diphenyl ethers from a marine-derived isolate of Aspergillus sp. CUGB-F046

One new diphenyl ether, diorcinol K (1), along with three known compounds, diorcinols D (2), F (3) and I (4) were isolated from the fermentation media of a marine-derived fungus Aspergillus sp. CUGB-F046 which was isolated from a sediment sample collected from the Bohai Sea, China. Their structures were elucidated by detailed spectroscopic methods. Compounds 1, 2 and 4 displayed significant antibacterial activities against Staphylococcus aureus and methicillin-resistant S. aureus with MIC values of 3.125, 6.25 and 6.25 μg/mL, respectively.