• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.162-165
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• 2005

A series of fluorine and hydroxyl containing jasmonate derivatives, which were chemically synthesized in our institute, were investigated for their effects on the biosynthesis and heterogeneity of ginsenosides in suspension cultures of Panax notoginseng cells. Com-pared to the control (without addition of elicitors), $100{\mu}M$ of each of the jasmonate was added on day 4 to the suspension cultures of P. notoginseng cells. It was observed that, jasmonates greatly enhanced the ginsenoside content and the ratio of Rb group to Rg group (i.e. $(Rb_1\;+\;Rd)/(Rg_1\;+\;Re)$ in the P. notoginseng cells. Some of the synthetic jasmonates, such as pentafluoropropyl jasmonate (PFPJA), 2-hydroxyethyl jasmonate (HEJA) and 2-hydroxye-thoxyethyl jasmonate (HEEJA), could promote the ginsenoside content to $2.55\;\pm\;0.11,\;3.65\;\pm\;0.13\;and\;2.94\;\pm\;0.06$mg/100 mg DW, respectively, compared to that of $0.64\;\pm\;0.06$mg/100 mg DW for the control and $2.17\;\pm\;0.04$ mg/100 mg DW by the commercially available methyl jasmonate (MJA); and they could change the respective Rb:Rg ratio to $1.60\;\pm\;0.04,\;1.87\;\pm\;0.01\;and\;1.56\;\pm\;0.05$, compared to that of $0.47\;\pm\;0.01$ for the control and $1.42\;\pm\;0.06$ by MJA. The results suggest that suitable esterification of MJA with fluorine or hydroxyl group could in-crease the elicitation activity to induce plant secondary metabolism. The information obtained from this study is useful for hyper-production of heterogeneous products by plant cell cultures.

• KSBB Journal
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• 제26권5호
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• pp.471-476
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• 2011

Nowadays biodiesel (fatty acid methyl ester, FAME) has been becoming an important issue as a desired alternative of energy products because of non-toxic, biodegradable properties, and lower exhaust emissions. During esterification of fatty acids or transesterification of oils and fats with short chain alcohols by the alkali-catalyzed methanolysis, FAME and unrefined glycerol are generated. Quantification of glycerol as a by-product is important because of a determinant of biodiesel quality. However, the glycerol analysis by gas chromatography (GC) method has laborious works with sample preparation, long time and cost of sample analysis. Thus, there is a need to analyze glycerol more simply. Herein we demonstrate that the colorimetric assay for glycerol analysis conducted by UV-vis spectrophotometer at the wavelength 617 nm whose peak is maximum intensity of malachite green, resulting in the red-shift occurred proportionally as a function of glycerol amount. Thus, it is considered the solvent media for malachite green fading for biodiesel production: (1) water, (2) MeOH, and (3) EtOH. The resulting findings show that the peak intensity at 617 nm in glycerol-malachite green mixture had a relationship between glycerol concentration and degree of peak shift as increase in pure glycerol concentration approximately at pH 7.0. However, when it was measured the unrefined glycerol concentration by diluting and adjusting with water to buffer (pH 7.0), it was not observed the absorption peak at 617 nm because of impurities and OH ions. In case of glycerol from biodiesel production factories, glycerol concentration could be successfully measured.

• Tribology and Lubricants
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• 제32권3호
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• pp.95-100
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• 2016

As an alternative fuel, biodiesel has excellent lubricating property. Previously, our research group reported that the properties of biodiesels depended on their composed molecular structure. In this study, we investigate lubricity and the mechanism of lubricity improvement of synthesized biodiesel molecules. We synthesize four types of biodiesel components from fatty acid via fisher esterification and soybean biodiesel from soybean oil via transesterification in high yield (92-96%). We analyze the lubricity of the five 5 types of biodiesel using HFRR (high frequency reciprocating rig). We estimate that the mechanism of lubricity is relevant to the molecular structure and structure conversion of biodiesel. The test results indicate that the longer the length of molecules and the higher the content of olefin, the better the lubricity of the biodiesel molecules. However, the wear scar size of the first test samples’ do not show a regular pattern with the wear scar size of the second test samples’. Moreover, we investigated the structure conversion of the biodiesels by using GC-MS for the recovered biodiesel samples from the HFRR test. However, we do not detect structure conversion. Thus, we conclude that the lubricity of biodiesel depends on how effectively solid adsorption and boundary lubrication occurs based on the size of the molecule and the content of olefin in the molecule. In addition, HFRR test condition in not sufficient for Diels-Alder cyclization of biodiesel components.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1048-1056
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• 2018

비식용 원료인 Palm Acid Oil, 동물성 폐유지 등은 상대적으로 자유 지방산 함량이 높기 때문에 일반적인 염기 촉매를 이용한 전이에스테르화 반응에 적합하지 않다. 효소 촉매를 이용하면 염기 촉매에서 해결할 수 없는 몇 가지 문제를 해결할 수 있으며, 에너지 소비가 작고, 바이오디젤 부산물인 글리세롤 회수가 쉬우며, 자유 지방산 함량이 높은 트리글리세라이드에 대한 전이에스테르화 반응이 가능하다. 본 연구에서는 고정화 효소 촉매를 이용하여 1 ton/day 용량의 반응기에서 비식용 폐유지를 바이오디젤로 합성하였으며, 반응 공정의 변수를 최적화하였다.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.491-505
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• 2020

A newly isolated strain, Proteus vulgaris OR34, from olive mill waste was found to secrete an alkaline extracellular lipase at 11 U·ml-1 when cultivated on an optimized liquid medium. This lipase was purified 94.64-fold with a total yield of 9.11% and its maximal specific activity was shown to be 3232.58 and 1777.92 U·mg-1 when evaluated using the pH-stat technique at 55℃ and pH 9 and Tributyrin TC4 or olive oil as the substrate. The molecular mass of the pure OR34 lipase was estimated to be around 31 kDa, as revealed by SDS-PAGE and its substrate specificity was investigated using a variety of triglycerides. This assay revealed that OR34 lipase preferred short and medium chain fatty acids. In addition, this lipase was stable in the presence of high concentrations of bile salt (NaDC) and calcium ions appear not to be necessary for its activity. This lipase was inhibited by THL (Orlistat) which confirmed its identity as a serine enzyme. In addition, the immobilization of OR34 lipase by adsorption onto calcium carbonate increased its stability at higher temperatures and within a larger pH range. The immobilized lipase exhibited a high tolerance to organic solvents and retained 60% of its activity after 10 months of storage at 4℃. Finally, the OR34 lipase was applied in biodiesel synthesis via oleic acid mediated esterification of methanol when using hexane as solvent. The best conversion yield (67%) was obtained at 12 h and 40℃ using the immobilized enzyme and this enzyme could be reused for six cycles with the same efficiency.

• Journal of Plant Biotechnology
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• 제49권4호
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• pp.271-291
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• 2022

Pectin methylesterase (PME) plays an important role in vegetative and reproductive development and biotic/abiotic stress responses by regulating the degree of methyl-esterification of pectic polysaccharides in the plant cell wall. PMEs are encoded by a large multigene family in higher land plant genomes. In general, the expression of plant PME genes shows tissue- or cell-specific patterns and is induced by endogenous and exogenous stimuli. In this study, we identified PME multigene family members (CsPMEs) from the sweet orange genome and report detailed molecular characterization and expression profiling in different citrus tissues and two fruit developmental stages. We also discussed the possible functional roles of some CsPME genes by comparing them with the known functions of PMEs from other plant species. We identified 48 CsPME genes from the citrus genome. A phylogenetic tree analysis revealed that the identified CsPMEs were divided into two groups/types. Some CsPMEs showed very close phylogenetic relationships with the PMEs whose functions were formerly addressed in Arabidopsis, tomato, and maize. Expression profiling showed that some CsPME genes are highly or specifically expressed in the leaf, root, flower, or fruit. Based on the phylogenetic relationships and gene expression profiling results, we suggest that some CsPMEs could play functional roles in pollen development, pollen tube growth, cross incompatibility, root development, embryo/seed development, stomata movement, and biotic/abiotic stress responses. Our results shed light on the biological roles of individual CsPME isoforms and contribute to the search for genetic variations in citrus genetic resources.

• 청정기술
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• 제30권1호
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• pp.47-54
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• 2024

비식용 작물인 네팔산 Jatropha 씨앗으로부터 추출한 식물성 오일을 원료로 사용하고, 에스테르화 반응과 전이에스테르화 반응으로 구성된 2-step 공정을 거쳐서 바이오디젤로 전환하였다. Jatropha 오일에 함유되어 있는 유리지방산과 메탄올과의 에스테르화 반응에 Amberlyst-15 촉매를 적용하였으며, 자트로파 오일의 산가를 11.0으로부터 0.26 mgKOH/g까지 낮추었다. 산가가 0.26 mgKOH/g인 Jatropha 오일과 메탄올을 원료로 사용하고 NaOH/γ-Al₂O₃ 촉매를 사용하여 전이에스테르화 반응을 통해서 바이오디젤을 제조하였다. NaOH 담지량이 3 wt%에서 25 wt%로 증가함에 따라 비표면적은 129 m²/g에서 28 m²/g으로, 기공 부피는 0.249 m³/g에서 0.129 cm³/g으로 감소하였다. 또한, NaOH의 담지량이 증가할수록 NaOH/γ-Al₂O₃ 촉매의 염기점의 양과 세기가 동시에 증가하였다. NaOH/γ-Al₂O₃ 촉매의 최적 NaOH 담지량은 12 wt%인 것을 확인하였다. NaOH/γ-Al₂O₃ 촉매를 이용한 Jatropha oil의 전이에스테르화 반응에서 최적 온도를 65 ℃로 선정하였다. 교반속도가 150 RPM 이하의 조건에서는 전이에스테르화 반응 속도가 외부 물질 전달의 영향을 받았으나, 그 이상의 교반속도에서는 외부 물질 전달의 영향이 크지 않았다.

• 한국환경농학회지
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• 제13권2호
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• pp.199-208
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• 1994

토양 침투수중에 잔류하는 제초제 MCPP를 추출, 유도체를 합성하여 GC-MS로 확인하고 capillary GC-ECD로 잔류분석하였다. Diazomethane과 $BF_3$/MeOH 등을 이용하여 합성한 MCPP의 methyl 유도체, 황산을 촉매로 이용하여 합성한 MCPP의 2,2,2-trifluoroethyl(TFE) 및 2,2,2-trichloroethyl(TCE) 유도체, 그리고 MCPP의 pentafluorobenzyl(PFB) 유도체간의 잔류분석법을 비교한 결과 이 연구에서 개발된 MCPP-TFE 유도체화가 간편하고 신속, 안전한 유도체화 기술로서 GC-ECD에서 비교적 감도가 우수한 편이었다. MCPP의 methyl 유도체는 GC-ECD에서 그 감도가 너무 낮아 시료가 소량인 경우 ppb 수준의 잔류분석이 불가능하였고 MCPP-TCE 및 MCPP-PFB 유도체는 그 감도는 우수하였으나 크로마토그람상의 방해물질이 많아 액액분리에 의한 정제만으로는 잔류분석이 곤란하였다. MCPP-TFE 유도체화에 의하면 토양침투수 100ml중 $0.1{\mu}g$ 미만의 농도를 가진 MCPP의 잔류분석이 액액분리에 의한 정제만으로 가능하였다.

• 생명과학회지
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• 제17권7호통권87호
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• pp.910-914
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• 2007

본 연구는 MRI 조영제나 새로운 생리활성 물질을 개발키 위해 paraformaldehyde와 hypophosphorous acid를 아미노산인 glycine 혹은 glutamic acid와 함께 반응시켜 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphos-phocme-1,5-diacetic acid 1 와 3,7-dihydrexy-3,7-dioxoperhydre-1,5,3,7-diazadiphos-phocme-1,5-di- (2-glutaric acid)3을 합성하였다. 그러나 aspartic acid에 의한 2-[5-(1,2-dicarboxy-ethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7]diazadiphosphocan-1-yl]-succinic acid 2는 얻지 못했다. 합성 된 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-dia-zadiphosphocine-1,5-diacetic acid 1을 산 촉매에 의한 에스테르화반응시켜 화합물 3,7-dihydroxy-3,7-dioxoper-hydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-dia-zadiphosphocine-1,5-diacetic acid ethyl ester 5, 그리고 3,7-dihyoxy-3,74dioxoperhyo-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6을 합성하였다. 계속해서 다양한 반응을 통해 새로운 화합물을 합성할 것이며 생리활성검색도 실시할 예정이다.

• Korean Chemical Engineering Research
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• 제46권4호
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• pp.739-746
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• 2008

반응증류 공정은 전형적인 반응공정과 증류공정을 통합하여 증류탑에서 반응과 동시에 분리를 수행하는 공정이다. 반응증류 공정의 가장 큰 장점은 반응 전환율의 제약과 공비점으로 인한 제약을 효율적으로 극복할 수 있다는 데 있다. 본 연구에서는 에스테르화반응으로 얻어지는 대표적인 물질인 메틸 아세테이트를 합성, 생산하는 연속 반응증류 공정의 상세한 수학적 모델을 구성하여 동적 모사 및 동적 최적화를 수행하였다. 상평형을 가정한 평형단 모델에 반응속도 식을 적용하여 분리와 반응이 함께 일어나는 증류탑과 재비기 및 응축기를 수학적 모델로 구성하여 동적모사를 수행하여 실제 공정이 운전되는 시나리오대로 공정전체를 모사함으로써 공정 개시부터의 공정의 동적 특성을 살펴보았다. 이 동적 모델과 연계되어, 반응증류 공정으로 얻어지는 메틸 아세테이트의 순도를 목적함수로 하는 최적화 문제를 구성하여 그 결과로 최적의 원료주입 분율 및 재비기의 열량 및 환류비 등을 구할 수 있었다. 또한 여기서 얻어진 운전 변수의 값을 변화시킬 때 반응 전환율의 변화를 살펴봄으로써, 최적화 문제의 해로 구해진 운전 변수의 값의 타당성을 증명하였다.