• Korean Journal of Pharmacognosy
• /
• v.44 no.4
• /
• pp.336-343
• /
• 2013

In a continuation of investigation on Cordyceps militaris, thirteen compounds were isolated from the $CH_2Cl_2$ and n-BuOH-soluble fraction of C. militaris. They were identified as twelve diketopiperazines such as cyclo($\small{L}$-Gly-$\small{L}$-Pro) (1), cyclo($\small{L}$-Ala-$\small{L}$-Pro) (2), cyclo($\small{L}$-Ser-$\small{L}$-Pro) (3), cyclo($\small{L}$-Val-$\small{L}$-Pro) (4), cyclo($\small{L}$-Thr-$\small{L}$-Pro) (5), cyclo($\small{L}$-Pro-$\small{L}$-Pro) (6), cyclo($\small{L}$-Thr-$\small{L}$-Leu) (7), cyclo($\small{L}$-Tyr-$\small{L}$-Ala) (8), cyclo($\small{L}$-Phe-$\small{L}$-Ser) (9), cyclo($\small{L}$-Phe-$\small{L}$-Pro) (10), cyclo($\small{L}$-Tyr-$\small{L}$-Pro) (11) and brevianamide F (13), and an amino acid, tryptophan (12). Their structures were identified on the basis of chemical evidences and spectroscopic analysis including 1D-NMR ($^1H$, $^{13}C$), 2D-NMR (HSQC, HMBC) and MS spectral data. Among the isolated compounds, compounds 1, 2, 6-11 are first reported from C. militaris.

• Mycobiology
• /
• v.51 no.3
• /
• pp.148-156
• /
• 2023

Penicillium oxalicum strain can be isolated from the Bletilla striata (Thunb.) Reichb. f. tubers. Its solid-state fermentation products are concentrated by percolation extraction. Separation and purification have been conducted to the ethyl acetate extracts by preparative HPLC. Based on the use of spectrometry, we have determined 17 known compounds, 12,13-dihydroxy-fumitremorgin C (1), pseurotin A (2), tyrosol (3), cyclo-(L-Pro-L-Val) (4), cis-4-hydroxy-8-O-methylmellein (5), uracil (6), cyclo-(L-Pro-L-Ala) (7), 1,2,3,4-tetrahydro-4-hydroxy-4-quinolin carboxylic acid (8), cyclo-(Gly-L-Pro) (9), 2'-deoxyuridine (10), 1-(b-D-ribofuranosyl)thymine (11), cyclo-(L-Val-Gly) (12), 2'-deoxythymidine (13), cyclo-(Gly-D-Phe) (14), cyclo-L-(4-hydroxyprolinyl)-D-leucine (15), cyclo-(L)-4-hydroxy-Pro-(L)-Phe (16), uridine (17). Here, we report compounds 1-3, 5, 7-8, 11-12, 14-17 are first found and isolated from this endophyte.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.326-330
• /
• 2012

Antifungal metabolites were isolated from a culture of Pseudomonas aurantiaca IB5-10. Chemical structures of the metabolites were elucidated as phenazine-1-carboxylic acid (PCA; 1), 2-hydroxyphenazine (2-OH-PHZ; 2), and cyclo-(L-Pro-L-Val; 3), respectively, based on spectroscopic methods. Among them, 3 was isolated for the first time from this strain. The antifungal activities of 1-3 were evaluated against a variety of plant pathogens. To the best of our knowledge, the antifungal activities of 3 against plant fungal pathogens have been evaluated for the first time in this work. PCA (1) showed the most potent antifungal activities against Phytophthora capsici, Rhizoctonia solani AG-1(IA), and Pythium ultimum with MICs (${\mu}g/ml$) of less than 1.0, 1.3, and 2.0, respectively. On the other hand, 2-OH-PHZ (2) showed potent antifungal activity against R. solani AG-1(IA) with the MIC (${\mu}g/ml$) of 2.0, whereas it showed moderate antifungal activity against P. ultimum with the MIC (${\mu}g/ml$) of 50.0. In addition, 3 showed antifungal activity against only R. solani AG-1(IA).

• Journal of Microbiology and Biotechnology
• /
• v.27 no.7
• /
• pp.1249-1256
• /
• 2017

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Leu-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Phe-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Phe)$, and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

• Korean Journal of Pharmacognosy
• /
• v.50 no.2
• /
• pp.81-85
• /
• 2019

An endophytic fungus, Penicillium sp. JVF17, was isolated from a leaf of Vitex rotundifolia in coastal area of Jeju island. Chemical investigation of this fungal strain resulted in the isolation of four compounds, piceol (1), cyclo (${\text\tiny{L}}-Pro-{\text\tiny{L}}-Val$) (2), isochromophilone VI (3), and dicitrinin A (4). Their chemical structures were elucidated by comparison of their spectral data such as NMR and ESIMS with reported literature values.

• Natural Product Sciences
• /
• v.20 no.3
• /
• pp.202-205
• /
• 2014

Three compounds including 7,7-bis(3-indolyl)-p-cresol (1), cyclo-(S-Pro-R-Leu) (2) and cyclo-(S-Pro-R-Val) (3) were isolated from the strain of Bacillus megaterium LC derived from the marine sponge Haliclona oculata. All the isolated compounds showed antimicrobial activity at MIC values ranging from 0.005 to $5{\mu}g/mL$ against Gram-negative bacteria Vibrio vulnificus and V. parahaemolyticus, gram-positive bacteria Bacillus cereus and Micrococcus luteus, and the dermatophyte Trichophyton mentagrophytes. The results suggested that these compounds might have potential to be developed as agents treating dermatosis and controlling vibriosis in aquaculture.