• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.188-192
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• 2009

New $\alpha$-pyrones (1 and 2) and cyclohexenones (13 and 14) were isolated along with known analogues (3, 5−12) from the ethyl acetate extract of the whole broth of the fungus Paecilomyces lilacinus, a strain derived from a marine sponge Petrosia sp. Their structures were established by interpretation of 1D and 2D NMR, and FABMS data. It is interesting to isolate cyclohexenone derivatives from the genus Paecilomyces (family Trichocomaceae, order Eurotiales), since these cyclohexenones were previously reported only from far distinct genera, Phoma and Alternaria (family Pleosporaceae, order Pleosporales). Compounds 6, 7, and 9 were evaluated for cytotoxicity against a small panel of human solid tumor cell lines. Their cytotoxicity was insignificant upto a concentration of 30 ${\mu}g/mL$.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1412-1423
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• 2019

The filamentous fungus Aspergillus tubingensis that belongs to the black Aspergillus section has the capacity to produce high-value metabolites, for instance, naphtho-gamma-pyrones (NGPs). For these fungal secondary metabolites, numerous biological properties of industrial interest have been demonstrated, such as antimicrobial, antioxidant and anti-cancer capacities. It has been observed that production of these secondary metabolites is linked with fungal sporulation. The aim of this research was to apply osmotic and oxidative environmental stresses to trigger the production of NGPs in liquid cultures with CYB (Czapek Dox Broth). In addition, numerous parameters were tested during the experiments, such as pH value, incubation time, container geometry, and static and agitation conditions. Results demonstrate that the produced amount of NGPs can be enhanced by decreasing the water activity ($a_w$) or by adding an oxidative stress factor. In conclusion, this study can contribute to our knowledge regarding A. tubingensis to present an effective method to increase NGP production, which may support the development of current industrial processes.

• Natural Product Sciences
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• v.21 no.4
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• pp.251-254
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• 2015

Recently, we reported violapyrones B, C, H and I, unusual 3, 4, 6-trisubstituted ${\alpha}-pyrones$ derivatives, from the culture broth of the marine Streptomyces sp. 112CH148. In previous studies, violapyrones have been shown to have antibacterial and antitumor activities. However, the anti-inflammatory effect of violapyrones has not been reported yet. As part of our ongoing study for the discovery of bioactive metabolites from marine microorganisms, we found that violapyrones also have anti-inflammatory activity. In this study, we investigated the effect of violapyrones on LPS-induced inflammatory responses in vitro. Violapyrones B and C did not affect the viability of RAW 264.7 cells at concentrations up to $25{\mu}M$. However, violapyrones B and C inhibited the production of NO compared to the LPS-induced control. In addition, violapyrones B and C down-regulated the expression of iNOS protein in LPS-stimulated RAW 264.7 cells. To the best of our knowledge, this is the first report on the anti-inflammatory activity of violapyrones B and C.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.108-114
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• 1993

A new strain of acidophilic, acetogenic bacterium, Acetobacter sp. strain HA was isolated by selective enrichment from the traditionally fermented rice wine vinegar in Korea. It was a gram-negative, non-motile short rod and oxidized acetate and lactate. The optimal temperature and pH for growth were $28^{\circ}C$ and 4.0, respectively. The strain HA differed from other Acetobacter species by growing well on methanol, xylitol, inositol, dulcitol, D-xylose, L-arabinose, and D-mannose as sole sources of carbon and energy. The isolated strain HA did not produce $\gamma$-pyrones from glucose and did not produce ketone bodies from glycerol. The quinone system used in this study was an ubiquinone-9 isoprene unit. The guanine-plus-cytosine content of the DNA was 50.7 mol%, and the major cellular fatty acids were $C_{18:1} and C_{16:0}$.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1796-1800
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• 2015

Sporopollenin is a poorly characterized mixed aliphatic and aromatic polymer with ester and ether linkages. Recent studies have reported that α-pyrone polyketide compounds generated by Arabidopsis thaliana, polyketide synthase A (PKSA) and tetraketide α-pyrone reductase 1 (TKPR1), are previously unknown sporopollenin precursors. Here, the yeast Saccharomyces cerevisiae was introduced to test potential sporopollenin biosynthetic pathways in vivo. A PKSA/TKPR1 dual expressor was generated and various chain-length alkyl α-pyrones were identified by GC-MS. The growth rate of the strain containing PKSA/TKPR1 appeared normal. These results indicate that PKSA/TKPR1-expressing yeast would be a starting platform to investigate in vivo sporopollenin metabolism.

• KSBB Journal
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• v.8 no.4
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• pp.397-404
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• 1993

Two strains were isolated from the vinegar of Korean traditional fermented rice wine and the vine gar of fermented persimmon, respectively. These strains, designated as KM and BPV, were identified as the genus Acetobacter with respect to morphological, physiological, and biochemical characteristics. The Isolates oxidized ethanol to acetate and over-oxidized acetate or lactate to CO2 and H2O. They were positive in catalase test, while being negative in oxidase, gelatin liquefaction, VP test, H2O production and indole formation tests. No ${\gamma}$-pyrones ware produced from glucose and fructose. KM was tolerant of 11% ethanol while BPV was relatively sensitive to ethanol at a higher concentration than 5%. The guanine-plus-cytosine contents of the DNA of KM and BPV strains were 53.8 and 56.6 mol%, respectively. The cellular fatty acid compositions contained in these isolates were saturated straightchain C14:0 and C16:0,, and unsaturated straight-chain C18:1. Major ubiquinone system of KM was Q-9, but that of BPV was Q-10. In morphophysiological and biochemical aspects, KM strain was similar to Acetobacter pasteurianus. However, BPV strain was different from other Acetobacter type strains.

• Food Science and Preservation
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• v.6 no.1
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• pp.121-135
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• 1999

Effective synthetic antioxidants such as butylated hydroxyanisole(BHA) and butylated hydroxytoluene(BHT) have been widely used in the food industry, but they are suspected to be toxic and carcinogenic effects. Therefore, the development of safely available natural antioxidants such as ascorbic acid, ${\alpha}$-tocopherol, ${\beta}$-carotene, flavonoids and selenium is essential. In particular, flavonoids, 2-phenyl-benzo-${\alpha}$-pyrones, are polyphenolic compounds that occur ubiquitously in food of plant origin. flavonoids occur in foods generally as O-glycosides with sugars bound usually at the C\ulcorner position. And variations in their heterocyclic ring gibes rise to flavones, flavonols, flavanones, flavanols, catechins, anthocyanidins, chalcone and isoflavones. Vegetables, fruits, and beverages are the main dietary sources of the flavonols, primarily as quercetin, kaempferol, and myricetin and the corresponding flavones, apigenin and luteolin. These flavonoids have biological activity such as antioxidant, anti-inflammatory, antithrombotic, antimutagenic, anticarcimogenic antiallergic and antimicrobial activity effects in vitro and in vivo. Flavonoids posses strong antioxidant activities acting as oxygen radicals scavenger, metal chelators and enzyme inhibitor. The antioxidant activity of flavonoids is determined by their molecular structure and more specially, by the position and degree of hydroxylation of the ring structure. All flavonoids with the 3`, 4`-dihydroxy(ortho-dihydroxy) posses marked antioxidant activity. And antioxidant activity increases with the number of hydroxyl groups substituted on the A-and B-rings. There is as yet no certainty about the effect of the presence of a double bond between C\ulcorner and C\ulcorner on the antioxidant activity of flavonoids.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.99-104
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• 1993

Two strains of the gram-negative acetic acid bacteria, Acetobacter sp. strain CS2- AND CS5, were isolated form the traditional raw rice wine vinegar of Haenam area. The strains oxidized ethanol to acetic acid and over-oxidized acetate and lactate to $CO^{2}$ and $H ^{2}$O. They produced 2-ketogluconic acid from glucose but did not produce .gamma.-pyrones from glucose and dihydroxyacetone from glycerol. The CS strains possessed ubiquinone-9 as a major isoprenoid quinone and contained straight-chain $C_{18 :1}$, $_C{16 : 0}$, and $C _{14 : 0}$ fatty acids. The DNA base composition of the CS2 and CS5 strains was 56.2 and 57.3 mole% G + C, respectively. The isolates were grown well on methanol, gluconate, erythritol, raffinose, dulcitol and xylitol as sole sources of carbon and energy which are different from those of other Acetobacter species and producedd acid from sucrose, glycerol, fructose, inositol, mannitol, and ribose.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.366-371
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• 2007

The volatile components in Eoyuk-jang, a traditional Korean fermented food, were isolated using solvent extraction, and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 36 components, including 11 aliphatic hydrocarbons, 4 acids, 2 ketones, 5 phenols, 7 alcohols, 1 pyrazines, 4 pyrones and furanones, and 2 miscellaneous components, were found in Eoyuk-jang; among them, butanoic acid was quantitatively dominant. In addition, the aroma-active compounds were determined by gas chromatography-olfactometry (GC-O) using aroma extract dilution analysis (AEDA). A total of 20 aroma-active compounds were detected by GC-O. Butanoic acid (rancid) and methional (cooked potato-like) were the most potent aroma-active compounds with the highest FD factors $(Log_3$, FD), followed by 2-methyl-2-butanol (soysauce-like), 3-hydroxy-2-butanone (buttery), and 2-furanmethanol (burnt sugar-like).