• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.263-267
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• 2001

The changes of interfacial properties and microfailure degradation mechanisms of bioabsorbable composites with hydrolysis were investigated using micromechanical test and acoustic emission (AE). As hydrolysis time increased, the tensile strength, the modulus and the elongation of PEA and bioactive glass fibers decreased, whereas those of chitosan fiber changed little. Interfacial shear strength (IFSS) of bioactive glass fiber/poly-L-lactide (PLLA) composite was significantly higher than that two other systems. The decreasing rate of IFSS was the fastest in bioactive glass fiber/PLLA composite, whereas that of chitosan fiber/PLLA composite was the slowest. With increasing hydrolysis time, distribution of AE amplitude was narrow, and AE energy decreased gradually.

• 한국식품과학회지
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• 제52권5호
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• pp.503-509
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• 2020

The present study investigated the effects of dry and moist heat treatments on total phenols, total anthocyanins, and antioxidant activity levels in black chokeberry (Aronia melanocarpa) fruits. Lyophilized chokeberry powder samples were heated in a drying oven at 60, 100, 160, 180, and 200℃ for 20, 40, or 60 min. Finely ground fresh chokeberry fruits were heated in water at 60, 80, and 100℃ for 20 min, and bioactive compound and antioxidant activity levels were measured. The bioactive compounds and antioxidant activity decreased with increasing temperature and treatment duration. Antioxidant activity was preserved at 160℃ or lower without significant loss for dry heating, whereas moist heat treatment increased both bioactive compounds and antioxidant activity with increasing temperature.

• 분석과학
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• 제10권2호
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• pp.153-159
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• 1997

황련(C. japonica)의 추출물을 이용하여 사과겹무늬병, 사관탄저병 및 사과푸른곰팡이병에 대한 항균활성을 검정함과 동시에 활성물질을 분리하여 안정성이 있는 천연식물성 농약으로서의 개발 가능성을 검토하고자 시험했던 바, 그 결과를 요약하면 공시균에 대한 황련의 조추출액 $EC_{50}$은 $400{\sim}500{\mu}g/mL$이고 TLC, HPLC 분석을 통한 생리활성물질은 berberine으로 동정되었고 그 함유율은 81.14%였다.

• 분석과학
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• 제7권3호
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• pp.403-411
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• 1994

본 실험은 알팔파의 Allelopathy와 Autotoxicity에 관련되는 생리활성 물질의 분리, 정제, 동정하기 위하여 실시되었다. 알팔파 생잎 1kg을 80% MeOH로 추출하여 silica gel TLC와 DCCC의 분리와 정제과정을 거쳐 HPLC로 동정하였다. HLPC 분석결과 4개의 phenolic 물질(salicylic acid, rutin, quercetin, scopoletin) 등이 동정되었다. 이들 물질을 이용한 발아실험에서도 모두 알팔파의 발아와 생육에 억제적으로 작용하였으며, 이 중 quercetin의 처리가 가장 억제적이었다. 따라서 최소한 이들 물질이 알팔파의 Allelopathy와 Autotoxicity에 관련하는 것으로 생각되었다.

• 한국세라믹학회지
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• 제45권10호
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• pp.631-637
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• 2008

Self-standing mesoporous bioactive glass/poly($\varepsilon$-caprolactone) composite thin films with good molding capability, bioactivity, and biocompatibility in vitro, which may find potential applications in tissue engineering and drug storage, were prepared using a combination of the sol-gel, polymer templating, and water casting method. The thickness of self-standing films was affected by the difference of dielectric constant between distilled water and organic solvent.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권5호
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• pp.402-407
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• 2006

Vascular endothelial cells release proteinases that degrade the extracellular matrix (ECM), thus enabling cell migration during angiogenesis and vasculogenesis. Sildenafil citrate stimulates the nitric oxide-cyclic guanosine monophosphate pathway through inhibition of phosphodiesterase type V (PDE5). In this report, we examined the mechanisms underlying sildenafil citrate-induced cell migration using cultured mouse aortic endothelial cells (MAECs). Sildenafil citrate induced migration and proteinase secretion by murine endothelial cells. Sildenafil citrate induced the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9, which is inhibited by $NF-{\kappa}B$ inhibitors. Sildenafil citrate also induced the secretion of plasmin, which is inhibited by PI 3'-kinase inhibitors. It is suggested that sildenafil citrate-induced migrating activity in endothelial cells may be accomplished by increased secretion of proteinases.

• 셀메드
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• 제2권2호
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• pp.14.1-14.7
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• 2012

Cordycepin, a nucleoside derivative, was extracted from $Cordyceps$ $sinensis$, and then proved to be a bioactive compound present in traditional Chinese medicine Cordyceps. Early investigations revealed cordycepin possessed anti-microbial activity mainly by inhibiting nucleic acid synthesis. Although cordycepin is not used as antibacterial agents in clinic, its other pharmacological effects and possible mechanisms have gradually been deeply studied. This review serves to summarize the research progress of cordycepin.

• Natural Product Sciences
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• 제5권4호
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• pp.159-161
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• 1999

The effects of bioactive fractions containing protoberberine alkaloids from Coptis japonica on monoamine oxidase (MAO) activity were investigated. The MAO was obtained from the mitochondrial fraction of mouse brain. The butanol fraction from Coptis japonica was fractionated into separate bioactive fraction (Fr I-IV) by silica gel column chromatography. MAO activity was strongly inhibited by Fr III and IV, which mainly contain protoberberine alkaloids such as berberine, palmatine and coptisine. These results indicated that the protoberberine alkaloids from Coptis japonica had an inhibitory effect on MAO activity.

• Natural Product Sciences
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• 제10권4호
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• pp.152-167
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• 2004

Traditional Chinese Medicines (TCM) have attracted great interest in recent researchers as alternative medicines for incurable diseases. This review focuses on qualitative and quantitative analytical approaches for bioactive metabolites of components flavonoids and saponins of traditional Chinese medicines by TLC system, although various methods have been introduced. Emphasis will be put on the processes of metabolite extraction from intestinal bacterial cultures or urines, separation (mobile phase) and detection. The identified metabolites by selection of extraction solvent and detection methods are also discussed. In addition, metabolite determinations of flavonoids (baicalin, apiin, rutin, quercetin, quercitrin, kaempferol, diosmin, hesperidin, poncirin, naringin, puerarin, daidzin, daidzein, tectoridin) and saponins (ginsenosides, kalopanaxsaponins, glycyrrhizin, chiisanoside, saikosaponins, soyasaponins) in culture fluid, in urine and in some herbal formula extracts are summarized. These bioactive metabolites of these components by intestinal microflora should be connected to pharmacological actions.

• Natural Product Sciences
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• 제19권1호
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• pp.1-7
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• 2013

AMP-activated protein kinase (AMPK) is a major cellular energy sensor and master regulator of metabolic homeostasis. On activation, this cellular fuel sensing enzyme induces a series of metabolic changes to balance energy consumption via multiple downstream signaling pathways controlling nutrient uptake and energy metabolism. This pivotal role of AMPK has led to the development of numerous AMPK activators which might be used as novel drug candidates in the treatment of AMPK related disorders, diabetes, obesity, and other metabolic diseases. Consequently, a number of patents have been published on AMPK activators from natural products and other sources. This review covers the patented AMPK activators from natural products and their therapeutic potential in treatment or prevention of metabolic diseases including diabetes and obesity.