• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.599-603
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• 2011

A new geldanamycin (GDM) derivative was discovered and isolated from the fermentation broth of Streptomyces hygroscopicus 17997. Its chemical structure was elucidated as thiazinogeldanamycin by LC-MS, sulfur analysis, and NMR. The addition of cysteine to the fermentation medium significantly stimulated the production level of thiazinogeldanamycin, suggesting cysteine as a precursor of thiazinogeldanamycin production. Although showing a decreased cytotoxicity against HepG2 cancer cells, thiazinogeldanamycin exhibited an improved water solubility and photostability. Thiazinogeldanamycin may represent the first natural GDM derivative characterized so far that uses GDM as its precursor. Its appearance also clearly indicates that an appropriate end-point of fermentation is of critical importance for the maximal production of GDM by Streptomyces hygroscopicus 17997.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.66.1-66.1
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• 2015

Plasma medicine is an upcoming research area that has attracted the scientists to explore more deeply the utility of plasma. So, apart from the treating biomaterials and tissues with plasma, we have studied the effect of plasma with different feeding gases on modification of biomolecules. Additionally, we have checked the action of nanosecond pulsed plasma on the biomolecules. We have checked the plasma action on proteins ((Hemoglobin (Hb) Myoglobin (Mb) and lysoenzyme), calf thymus DNA and amino acids. The structural changes or structural modification of proteins and DNA have been studied using circular dichroism (CD), dynamic light scattering (DLS), gel electrophoresis, protein oxidation test, UV-vis spectroscopy and 1D NMR, while Liquid Chromatograph/Capillary Electrophoresis-Mass Spectrometer(LC/CE-MS) based qualitative bio-analysis have been used to study the modification of amino acids. We have also shown the effect of NaCl and ionic liquid on the formation of OH radicals using electron spin resonance and fluorescence techinques.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.348-351
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• 2007

The stem barks of Fraxinus rhynchophylla was extracted with 95% EtOH, and the concentrated extract was successively partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$ in order to investigate the major phytochemicals. From the $CH_2Cl_2$ soluble fraction, a sterol (1) was isolated through the repeated silica gel column chromatographies. Three additional compounds (2-4) were isolated from the n-BuOH soluble fraction through silica gel, RP-18, and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as daucosterol $(1;{\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside)$, caffeic acid (2), 6,8-dihydroxy-7-methoxycoumarin (3), and coniferaldehyde glucoside (4) by comparing their spectral data with those in the literatures. All isolates (1-4) were the first to be isolated from F. rhynchophylla.

• Natural Product Sciences
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• v.26 no.3
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• pp.230-235
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• 2020

A pregnane steroid, 3α-hydroxy-pregn-7-ene-6,20-dione (1), was isolated from a Hydractinia-associated Cladosporium sphaerospermum SW67 by repetitive column chromatographic separation and high-performance liquid chromatography (HPLC) purification. The planar structure of 1 was elucidated from the analysis of the spectroscopic data (1D and 2D NMR spectra) and LC-MS data. The absolute configuration of 1 was determined by interpretation of ROESY spectrum of 1, together with the comparison of reported spectroscopic values in previous studies. To the best of our knowledge, this is the first report of the identification of the pregnane scaffold from C. sphaerospermum, a natural source. Compound 1 was evaluated for its effects on lipid metabolism and adipogenesis during adipocyte maturation and showed that compound 1 substantially inhibited lipid accumulation compared to the control. Consistently, the expression of the adipocyte marker gene (Adipsin) was reduced upon incubation with 1. Further, we evaluated the effects of 1 on lipid metabolism by measuring the transcription of lipolytic and lipogenic genes. The expression of the lipolytic gene ATGL was significantly elevated upon exposure to 1 during adipogenesis, whereas the expression of lipogenic genes FASN and SREBP1 was significantly reduced upon treatment with 1. Thus, our findings provide experimental evidence that the steroid derived from Hydractinia-associated C. sphaerospermum SW67 is a potential therapeutic agent for obesity.

• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.988-994
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• 2010

The EtOAc fraction of Lespedeza cyrtobotrya showed mushroom tyrosinase inhibitory and radical scavenging activities. Four active compounds were isolated based on Sephadex LH-20 chromatography and HPLC, and the structures were elucidated, on the basis of their LC-MS and NMR spectral data, as 2-(2,4-dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4), respectively. Compound (1) showed mushroom tyrosinase inhibitory activity with an $IC_{50}$ value of $5.2\;{\mu}M$ and acted as a competitive inhibitor. Furthermore, $37.3\;{\mu}M$ of compound 1 reduced 50% of the melanin content on human melanoma (MNT-1) cells. The radical scavenging activities of compounds 1, 2, 3, and 4 were shown to have $IC_{50}$ values of 11.0, 24.5, 9.0, and $36.5\;{\mu}M$, respectively, in an ABTS system and $IC_{50}$ values of 42.7, 36.0, 37.7, and $61.7\;{\mu}M$, respectively, in a DPPH system. The mushroom tyrosinase inhibitory activity of the EtOAc fraction of Lespedeza cyrtobotrya was contributed by compounds 1, 3, and 4, and its radical scavenging activity was contributed by compounds 1-4.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.1-6
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• 2006

Harmful algal blooms (HABs or red tides), caused by uncontrolled proliferation of marine phytoplankton, impose a severe environmental problem and occasionally threaten even public health. We sequenced the genome of an EPS-producing marine bacterium Hahella chejuensis that produces a red pigment with the lytic activity against red-tide dinoflagellates at parts per billion level. H. chejuensis is the first sequenced species among algicidal bacteria as well as in the order Oceanospirillales. Sequence analysis indicated a distant relationship to the Pseudomonas group. Its 7.2-megabase genome encodes basic metabolic functions and a large number of proteins involved in regulation or transport. One of the prominent features of the H. chejuensis genome is a multitude of genes of functional equivalence or of possible foreign origin. A significant proportion (${\sim}23%$) of the genome appears to be of foreign origin, i.e. genomic islands, which encode genes for biosynthesis of exopolysaccharides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigment production. Molecular structure of the algicidal pigment was determined to be prodigiosin by LC-ESI-MS/MS and NMR analyses. The genomics-based research on H. chejuensis opens a new possibility for controlling algal blooms by exploiting biotic interactions in the natural environment and provides a model in marine bioprospecting through genome research.

• Food Industry
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• s.99
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• pp.32-37
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• 1989

양질의 국산 생강엑기스 제조기술 개발을 위한 본 연구결과를 요약하면 다음과 같다. 1) 본 연구에서 시료로 사용한 생강은 전라북도 봉동산과 충청남도 서산산이며, 이들 건강은 수분이 약$10\%$, 회분 $8\~9\%$, 조지방 $4\~5\%$이다. 2) 생강엑기스의 유효성분들은 건강입자에 내포되어 있는 상태에서 추출 속도는 반응층을 통한 확산모델로 설명된다. 침출 효율을 개선하기위해서는 다음과 같은 조건이 필수적이다. 3) 건강의 입자는 $10\~20{\mu}m$정도의 전분입자가 될수록 많이 노출되도록 160목을 통과하는 작은 입자로 분쇄하면 추출효율은 최대화 할 수 있다. - 추출온도는 엑기스의 주요성분의 손실이 무시되는 최대온도, $40^{\circ}C$가 최적이다. - 160목, $40^{\circ}C$에서 추출시간 3-4시간이 최적이다. - 이같은 조건에서의 엑기스 회수율은 약 $8\%$이다. 4) 엑기스내의 비자극성 성분은 회분 $0.5\~0.8\%$, 조지방 $1.2\~1.8\%$, 조단백 $2.8\~3.5\%$이고, 유리당은 거의 침출되지 않는다. 엑기스내의 주요 지방산은 Linoleic acid가 가장 많이 함유되어 있다. 5) 기계건조보다 일광건조에 의한 건강에서 추출된 엑기스의 품질이 양호하며, 외국산 고급 엑기스와 품질면에서 대등한 것이다. 6) 위와 같은 결과는 TLC로 분리하고 분리된 각 Spot를 HPLS로 분석, IR, NMR, LC/MS를 사용하여 주요성분을 확인 및 정량화하였다. 이로부터 엑기스내의 주요성분은 gingerol이 약 0.38, Shogaol이 약 0.027, 그리고 Paradol이 0.03의 농도분율을 가지고 있음을 알았다. 7) 기계건조 건강으로부터 얻은 엑기스는 상온 $\~100^{\circ}C$ 범위에서 휘발 및 열분해에 의한 무게감량이 양건강에 비해 약 2.7배나 높다. 그러므로 생강엑기스를 사용하여 제조되는 생강차 제조시 열풍건조($60^{\circ}C$, 30분)는 품질에 지대한 영향을 미친다는 것을 발견하였다. 8) 생강엑기스 제조는 건강 재배방법 저장기간과 방법, 건조방법이 건강특성을 좌우한다. 9) 본 연구에서 제시된 열분석(DSC와 TGA)방법을 도입한다면 신속하고 경제적으로 생강 엑기스 품질을 평가하는 데에 큰 기여가 있을 것으로 생각된다. 10) 양호한 생강차를 만들 수 있다고 선정된 엑기스는 수입 엑기스와 함께 양건강의 제품이다.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1237-1244
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• 2012

Agarase genes of non-marine agarolytic bacterium Cellvibrio sp. were cloned into Escherichia coli and one of the genes obtained using HindIII was sequenced. From nucleotide and putative amino acid sequences (713 aa, molecular mass; 78,771 Da) of the gene, designated as agarase AgaA, the gene was found to have closest homology to the Saccharophagus degradans (formerly, Microbulbifer degradans) 2-40 aga86 gene, belonging to glycoside hydrolase family 86 (GH86). The putative protein appears to be a non-secreted protein because of the absence of a signal sequence. The recombinant protein was purified with anion exchange and gel filtration columns after ammonium sulfate precipitation and the molecular mass (79 kDa) determined by SDS-PAGE and subsequent enzymography agreed with the estimated value, suggesting that the enzyme is monomeric. The optimal pH and temperature for enzymatic hydrolysis of agarose were 6.5 and $42.5^{\circ}C$, and the enzyme was stable under $40^{\circ}C$. LC-MS and NMR analyses revealed production of a neoagarobiose and a neoagarotetraose with a small amount of a neoagarohexaose during hydrolysis of agarose, indicating that the enzyme is a ${\beta}$-agarase.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1224-1229
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• 2012

Puerarin (P), an isoflavone derived from kudzu roots, has strong biological activities, but its bioavailability is often limited by its low water solubility. To increase its solubility, P was glucosylated by three dextransucrases from Leuconostoc or Streptococcus species. Leuconostoc lactis EG001 dextransucrase exhibited the highest productivity of puerarin glucosides (P-Gs) among the three tested enzymes, and it primarily produced two P-Gs with a 53% yield. Their structures were identified as ${\alpha}$-$_D$-glucosyl-($1{\rightarrow}6$)-P (P-G) by using LC-MS or $^1H$- or $^{13}C$-NMR spectroscopies and ${\alpha}$-$_D$-isomaltosyl-($1{\rightarrow}6$)-P (P-IG2) by using specific enzymatic hydrolysis, and their solubilities were 15- and 202-fold higher than that of P, respectively. P-G and P-IG2 are easily applicable in the food and pharmaceutical industries as alternative functional materials.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1359-1366
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• 2010

A search of the Streptomyces avermitilis genome reveals that its closest homologs are several O-methyltransferases. Among them, one gene (viz., saomt5) was cloned into the pET-15b expression vector by polymerase chain reaction using sequence-specific oligonucleotide primers. Biochemical characterization with the recombinant protein showed that SaOMT5 was S-adenosyl-L-methionine-dependent Omethyltransferase. Several compounds were tested as substrates of SaOMT5. As a result, SaOMT5 catalyzed O-methylation of flavonoids such as 6,7-dihydroxyflavone, 2',3'-dihydroxyflavone, 3',4'-dihydroxyflavone, quercetin, and 7,8-dihydroxyflavone, and phenolic compounds such as caffeic acid and caffeoyl Co-A. These reaction products were analyzed by TLC, HPLC, LC/MS, and NMR spectroscopy. In addition, SaOMT5 could convert phenolic compounds containing ortho-dihydroxy groups into O-methylated compounds, and 6,7-dihydroxyflavone was known to be the best substrate. SaOMT5 converted 6,7-dihydroxyflavone into 6-hydroxy-7-methoxyflavone and 7-hydroxy-6-methoxyflavone, and caffeic acid into ferulic acid and isoferulic acid, respectively. Moreover, SaOMT5 turned out to be a $Mg^{2+}$-dependent OMT, and the effect of $Mg^{2+}$ ion on its activity was five times greater than those of $Ca^{2+}$, $Fe^{2+}$, and $Cu^{2+}$ ions, EDTA, and metal-free medium.