폴리벤즈이미다졸(polybenzimidazole, PBI)은 뛰어난 화학적 저항성, 열적 안정성, 그리고 기계적 강도를 지닌 고 성능 고분자로, 유기용매 나노여과(organic solvent nanofiltration, OSN) 분리막의 이상적인 소재로 잘 알려져 있다. 그러나 이 러한 이점에도 불구하고, 가교되지 않은 PBI는 강한 유기용매에 노출될 경우 상당한 팽윤, 제한적인 선택성, 그리고 장기 안 정성 저하를 보이는 경우가 많다. 이러한 문제를 극복하기 위해, PBI 분리막의 내구성과 분리 성능을 향상시키고자 다양한 가교 전략이 개발되어 왔다. 본 리뷰에서는 공유결합, 이온결합, 수소결합, 및 기타 가교 메커니즘으로 구분되는 PBI 기반 OSN 분리막의 가교에 관한 최근의 발전을 요약하였다. 특히 가교 화학과 분리 성능 간의 관계에 중점을 두었으며, 마지막으 로 견고하고 고성능인 OSN 분리막을 위한 향후 설계 전략에 대한 전망을 논의하였다.

The physiological activities of solvent fractions derived from the celtus methanol extract were measured. Following the extraction of celtus with methanol, the yields of the resulting fractions—methanol, hexane, chloroform, ethyl acetate, butanol, and water—were found to be 19.57%, 3.24%, 26.02%, 8.15%, 8.72%, and 63.57%, respectively. The total flavonoid contents of the celtus methanol extract were 13.76, 4.96, 8.20, 31.99, 28.33, and 5.02 mg CE/g, respectively. The DPPH radical scavenging activity (IC50%) was measured at 22.48, 6.14, 11.15, 24.20, 19.18, and 20.71 μg/mL, with the highest activity observed in the ethyl acetate layer. The hydroxyl radical scavenging activity (IC50%) results were 14.27, 2.97, 9.19, 13.93, 3.90, and 3.10 μg/mL, also showing the highest activity in the ethyl acetate layer. The SOD-like activity measurements for the solvent fractions yielded values of 22.07, 9.65, 16.24, 32.63, 39.64, and 32.76 units/mL, with the highest activity in the butanol layer. The α-glucosidase inhibitory activity results were 16.42%, 11.29%, 16.60%, 27.40%, 2.86%, and 36.19%. Correlation analysis of antioxidant components and antioxidant activity indicated a very high correlation between total flavonoid content and both DPPH and SOD-like activities, suggesting that the celtus methanol extract positively influences antioxidant activity.

In this study, domestic soybean cultivars were extracted using water, 70% ethanol, and 100% ethanol. The contents of polyphenols, flavonoids, and antioxidant activities of these extracts were measured. For the water extracts, the polyphenol content was significantly higher in the Daewon cultivar compared to the others. Ethanol extracts contained lower levels than the water extracts, and, unlike the water extracts, there was no significant difference between the cultivars. The flavonoid content in the Jinpung cultivar was the highest among the water extracts, and this content was greater in the water extract than in the ethanol extract. In terms of ABTS radical scavenging activity, Daewon and Taekwang exhibited significantly higher activity in the water extracts. The Jinpung cultivar showed the highest activity in the 70% ethanol extract, which was slightly lower than that of the water extract. DPPH radical scavenging activity was found to be higher in Taekwang than in the other cultivars. In the 70% ethanol extract, Taekwang demonstrated high antioxidant activity, similar to that of the water extract. A correlation analysis of antioxidant components and antioxidant activity in soybean cultivars revealed the highest r value of 0.9326 between the contents of flavonoid compounds and polyphenol compounds.

Gynura bicolor is a medicinal plant recognized for its antioxidant potential and natural pigments. This study aimed to evaluate antioxidant activities and bioactive compounds’ contents of G. bicolor extracts and solvent fractions prepared using different drying methods and solvent partitioning. Ethanol extracts were obtained from freeze-dried (FD) and hot-air-dried (HD) samples, followed by sequential partitioning with n-hexane (n-Hex), methylene chloride (MC), ethyl acetate (EA), and n-butanol (n-BuOH). Total polyphenol (TP) and flavonoid (TF) contents were measured. Antioxidant activities were assessed via DPPH and ABTS radical scavenging assays. The FD-EtOH extract showed the highest TP (100.8±0.29 mg TAE/mL) and TF (4.72±0.03 mg QE/mL) contents. EA and n-BuOH fractions exhibited significantly higher antioxidant activity than other fractions, suggesting that bioactive compounds were effectively concentrated through selective solvent extraction. These findings indicate that drying and solvent fractionation can significantly affect antioxidant functionality and phytochemical yield. G. bicolor may serve as a promising natural antioxidant and pigment source for functional food and beverage development.