The objective of this study was to determine the ultrasonication-assisted extraction conditions that maximize the DPPH radical scavenging activity of extracts obtained from the stems of Lespedeza bicolor Turcz through the application of the Response Surface Methodology (RSM). Before delving into the analysis of extraction conditions using the RSM model, we conducted efficiency validation of ultrasonication-assisted extraction and executed single-factor experiments for ethanol concentration, extraction time, and extraction temperature. The data obtained from these single-factor experiments were employed to construct the Box-Behnken Design (BBD). In these results, in the single-factor experiments, it was evident that the parameters for ethanol concentration, extraction time, and extraction temperature exhibited quadratic trends. The single-factor experiments allowed us to discern the trends for each parameter leading to the maximum antioxidant capacity, and this data was subsequently applied to the BBD. Following the completion of initial experiments, a Response Surface Methodology (RSM) model was constructed based on Box-Behnken Design (BBD). According to the predictive model developed in this study, it was anticipated that performing ultrasonic-assisted extraction for 85.0412 minutes at an ethanol concentration of 32.573% and an extraction temperature of 51.5608°C will result in a DPPH radical scavenging activity of 79.7146%. The predictive results were statistically verified through a comparative analysis with actual measurements and ANOVA analysis, confirming the statistical significance of the model. The finding of this study underscore the significance of optimizing extraction conditions in the precise quantification of the antioxidant potential for economic advantages in both experimental and industrial contexts.

본 연구에서는 다른 광환경에서 자란 긴산개나리(Forsythia saxatilis var. lanceolata) 줄기와 잎의 항산화물질 함량 및 활성을 분석하여 기능성 신소재로 활용하기 위한 기초자료를 마련 하고자 수행하였다. 삽목 후 3년생인 긴산개나리를 무작위로 채취하여 부위별로 분석한 결과, 긴산개나리 잎의 항산화물질 함량은 총 안토시아닌 함량과 총 플라보노이드 함량, 총 페놀 함량이 각각 68.8mg CGE/100g FW, 7405.0mg CE/100g FW, 4231.2mg GAE/100g FW로 줄기보다 높았으며, 항산화 활성 또한 294.3mg VCE/100g FW로 줄기보다 높은 것으로 조사되 었다. 이에 따라 긴산개나리의 항산화물질 함량과 활성간의 상관관계를 분석한 결과, 총 안토시아닌은 다른 요인 간의 상관관계가 없는 것으로 나타났으나 총 플라보노이드와 총 페놀은 서로 간에 0.05 유의수준 내에서 r=0.753으로 양의 높은 상관관계를 가지며, 총 플라보노이드와 총 페놀은 항산화 활성인 DPPH radical 소거활성과 0.05 유의수준 내에서 각각 r=0.753, 0.698 로 높은 양의 상관관계를 갖는 것으로 조사되었다. 이를 통해 긴산개나리의 총 페놀은 대부분 총 안토시아닌보다 총 플라보 노이드로 구성된 것으로 판단되고, 이러한 총 플라보노이드와 총 페놀이 항산화 활성에 기여하는 것으로 판단된다. 서로 다른 광환경에서 삽목 후 3년동안 생육한 긴산개나리의 부위별 항산 화물질 함량 및 활성을 분석한 결과, 총 안토시아닌, 총 플라보 노이드, 총 페놀은 반음지(42.83μmol･m-2 ･s-1 PPFD)보다 양지 (788.39μmol･m-2 ･s-1 PPFD)에서 생육한 긴산개나리의 잎에서 함량이 높은 것으로 조사되었으며, 항산화 활성도 반음지보다 양지에서 생육한 긴산개나리의 잎에서 높은 것으로 나타났다. 광환경에 따라 긴산개나리의 엽록소 함량을 조사한 결과, 엽록소 함량 또한 양지에서 생육한 긴산개나리 잎에서 높은 것으로 조사되었다. 이를 통해, 페놀화합물과 vitamin C 는 광합성 과정 중 합성되는 물질이기 때문에 반음지보다 광량이 많은 양지에서 생육한 긴산개나리의 잎이 항산화물질 함량과 활성이 높은 것으로 판단된다. 따라서, 긴산개나리는 줄기보다 잎에 항산화물질 함량 및 활성이 높아 천연항산화제로서 가능성이 있는 것으로 판단되며, 특히, 양지에서 생육한 긴산개나리의 잎이 반 음지에서 생육한 것보다 항산화물질 및 활성이 높기 때문에 기능성 소재로서 잠재적 활용 가능성이 높을 것으로 판단된다.

국내 자생하는 야생버섯의 생리활성 및 항염 활성을 분석하기 위하여 버섯추출물에 대한 DPPH 라디컬 소거능, 아질산염소거능, 총 폴리페놀 함량, NO 생성저해도 및 세포독성을 분석하였다. 국내 수집 야생버섯 중에서 DPPH 라디컬 소거능이 높은 버섯은 64.2%를 나타낸 박막깔때기버섯(OK825)과 69.7%를 보인 흰우단버섯(OK829)이었다. 아질산염 소거능은 흰우단버섯(OK811)이 64.1%로 가장 높았다. 야생수집 버섯류 중에서 가장 높은 총 폴리페놀 함량을 나타낸 것은 젖비단버섯(OK804), 흰우단버섯 (OK829) 및 큰밤갈색광대버섯(OK944)으로 각각 19.7 mg GAE/g, 20.2 mg GAE/g, 22.3 mg GAE/g의 값을 보였다. NO 생성저해도의 경우, 박막깔때기버섯(OK825)과 노란다발버섯(OK826)은 각각 11.8%와 11.2%로 가장 낮은 NO를 생성하는 것으로 나타나 수집 버섯 추출물 중에서 가장 높은 항염증 효능을 보였다. MTT를 이용한 세포 생존율(%)을 측정한 결과 젖비단그물버섯(OK804), 흰우단버섯(OK811), 노란젖버섯(OK904)의 추출물에서는 각각 40.3%, 48.3%, 43.2%로 가장 높은 생존율을 나타내었다. 본 연구결과는 국내 버섯산업의 확대를 위하여 우수 버섯자원을 발굴함과 동시에 토종 버섯자원을 이용한 새로운 천연물 유래 생리활성 물질로 활용하기 위한 기초자료로 활용도가 높으리라 기대된다.

양파의 이용 다변화를 위하여 껍질과 육질을 각각 100∼300℃의 조건에서 아임계수로 추출하여 그 특성을 조사하였다. 양파 껍질과 육질 모두 추출 온도가 상승함에 따라 아임계수 추출물의 페놀 함량이 증가하였다. 양파 껍질 추출물은 250℃에서 quercetin, quercetin 3,4'-diglycoside, quercetin-3- glucoside의 함량이 가장 높았고, 육질 추출물은 quercetin 3,4'-diglycoside 의 함량이 200℃에서 가 장 높았으나 quercetin 및 quercetin-3-glucoside의 함량은 상대적으로 미미하였다. 양파 껍질과 육질 추출물의 quercetin및 그 배당체 함량은 300℃에서 급격히 감소하였다. 양파 껍질과 육질 모두 추출 온도가 증가할수록 아임계수 추출물들의 DPPH 라디칼 소거능과 alcohol dehydrogenase 활성을 향상시 켰다. 이상의 결과는 적절한 아임계수 조건이 양파 추출물의 생리활성을 향상시킬 수 있음을 시사한다.

This study was conducted to investigate the total phenol contents, antioxidative activities and antibacterial activities of twenty species of entomopathogenic fungi. The total phenol content was highest in Aspergillus flavus (553.0±52.15 ㎍/g) and A. parasiticus (529.9±60.10 ㎍/g). On the other hand those in other strains were within the range of 26.6～121.9 ㎍/g. The antioxdative activity was shown in the most of strains and the highest DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging activity was observed in A. flavus (90.9±2.90%) and A. parasiticus (77.9±4.13%). This result indicated that the antioxidative activities were very correlated with the total phenol contents. The antibacterial activitiy was found in the every tested pathogenic bacteria. Especially, the antibacterial activity was strongest against Listeria monocytogenes and Escherchia coli.

Lactic Acid Bacteria (LAB) are among the representative probiotics that have been used for a long time in fermented food. Although there are many studies on detecting the radical scavenging activity of LAB, few studies have been conducted on the environmental factors that improve scavenging activity. This study investigated the environmental factors affecting the DPPH radical scavenging and various antioxidant activities of Kimchi-derived Lactobacillus plantarum K-21 with antihypertensive and radical scavenging activities. The optimal conditions for scavenging DPPH radicals were glucose 2%, bactopeptone 0.5%, Tween 80 0.05%, L-cysteine 0.05%, and an initial pH 6.5 at 35℃. Under optimal conditions, the DPPH radical scavenging activity was 94.8±2.2%, which was 1.5 times higher than that of the basic medium. In addition, L. plantarum K-21 had other antioxidant activities; ABTS radical scavenging (93.6±1.5%), hydroxyl radical scavenging (8.5±0.9%), metal chelating (65.9±0.5%), NO scavenging (53.1±19%), SOD-like (25.1±1.5%), and reducing power (11.7±1.4%) activities were detected. Therefore, L. plantarum K-21 may act not only as a starter for lactic acid-fermented foods with improved functionality but also as a drug for various diseases caused by oxidative stress.

This study is conducted to investigate the effects of growth characteristics (GC) and DPPH radical scavenging activity (DRSA) of the heading lettuce ‘Fidel’ depending on four concentrations of activated mineral groups (AMG: 1.6% active minerals and 0.03% CaO) added to basic nutrient solutions (diluted by 0, 0.05, 0.1, and 0.2%) and on four different light-emitting diodes (LED; B:R:W ratio = 0:1:12, 0:1:9, 0:5:5, and 2:3:5). Both 0.1 and 0.2% AMG showed better GC of lettuce in plant width, plant length, leaf width, leaf length, and the number of leaves than those of other AMG, while leaf thickness and chlorophyll value did not show significant difference among all AMG. Moreover, 0.1 and 0.2% AMG showed heavier shoot fresh weights than those of other AMG. As for the combinations of AMG and LED, B0:R5:W5 showed the best lettuce GC regardless of AMG compared to other AMG and LED combinations. As shown in the above results of LED, although there was a difference in lettuce growth by LED, the differences of lettuce growth by AMG were statistically significant. The DRSA was the highest at 82.8% in B2:R3:W5, followed by B0:R5:W5 at 77.8%. LED showed differences but AMG did not affect DRSA. Therefore, the optimal conditions in plant factory for GC and DRSA of the lettuce were 0.1% AMG and B0:R5:W5.

항산화 및 항균활성을 가진 천연물을 활용해 합성보존료를 대체하고자 하는 연구가 활발한 가운데 국내 자생 식물 중 135종을 대상으로 DPPH radical 소거활성을 측정하였다. 이중 항산화 활성이 10%대로 낮게 나타난 식물 8종에 대해 항균효과를 조사하였다. 식물 추출물의 DPPH radical 소거활성은 0.41~94.84%로 다양하였으며, 가장 효과가 좋은 식물은 꽃향유와 우엉으로 각각 94.84, 80.55%를 나타내었다. 우엉은 잎의 경우 26.87, 뿌리 19.29%의 활성을 나타내 동일 식물이라도 추출부위에 따라 활성의 차이가 있을 것으로 보인다. 선이질풀과 비쭈기나무는 각각 그람양성균인 B. subtilis, 그람음성균인 E. coli 및 Candida속인 C. albicans에 대해 2.2~10.8 mm 수준의 항균활성을 나타내었다. 각 식물에 대한 다양한 추출법을 적용하여 기능성을 확인하고 이들 항산화성 물질에 대한 추가 연구가 진행되어야 할 것으로 사료된다.

국내 자생식물인 꿀풀(Prunella vulgaris)과 섬초롱꽃(Campanula takesimana)을 이용하여 질소비료의 형태에 따라 생육반응, 항산화 물질 함량 및 항산화 활성을 조사하였다. 질소비료처리는 NO3-N 처리구와 NH4-N 처리구 및 이들의 혼용구로 구분하여 수경재배를 실시하였다. 꿀풀과 섬초롱꽃의 생육은 NO3-N과 NH4-N 혼합처리구에서 좋았다. 총 플라보노이드 함량은 꿀풀의 경우 NO3-N과 NH4-N 혼합처리구가 좋았다. 총 폴리페놀 함량과 DPPH 라디칼 소거능 및 NO 소거 활성 등의 항산화 활성은 NH4-N 처리구에서 높게 나타났다. NO3-N 처리구의 경우 총 플라보노이드 및 총 폴리페놀 함량이 낮고, 항산화 활성도 낮은 경향이었다.

Changes in the contents of total phenolic compounds in as Agrimonia pilosa well as their antioxidant capacity according to the havest time and positions were examined. The contents of the total phenolic compounds were determined by extraction with MeOH. Among havest times harvestry in July showed highest contents of the total phenolic compounds and harvestry in May showed lowest contents of the phenolic compounds. Among the 4 positions (root, branch, leaf, flower) of Agrimonia pilosa the root contained highest contents of the phenolic compounds. The antioxidant capacities of Agrimonia pilosa were increased roughly with increasing level of contents of phenolic compounds according to positions.

A series of methanol extracts from leaf and root parts in spring- and winter-barley plants were assayed to determine their allelopathy and antioxidant activity. The methanol extracts applied on filter paper in a Petri-dish significantly inhibited root growth of Chinese milkvetch (Astragalus sinicus L.) seedlings. Leaf extracts at 25 and 50 g L-1 inhibited root growth of Chinese milkvetch seedlings more than root extracts. No difference in phytotoxic effects of spring- and winter-barley seedlings extracts on root growth of Chinese milkvetch was observed. Methanol extracts dose-dependently increased DPPH free radical scavenging activity in vitro. DPPH free radical scavenging activity was higher in the methanol extracts from winter-barley seedlings than in those from spring-barley seedlings, and from leaf extracts than from root extracts. The antioxidant potential of the individual fraction from the methanol extracts of spring-barley seedlings was in order of n-butanol>ethyl acetate>water>chloroform>n-hexane fraction. By means of HPLC analysis, spring-barley (200.62 mg 100g-1 ) had more amount of total phenol acid than winter-barley (114.08 mg 100g-1 ). Especially, ferulic acid was detected in spring-barley extract (183.46 mg 100g-1 ) as the greatest amount. These results suggest that early seedlings of barley plants had potent allelopathy and antioxidant activity, and their activities were differently exhibited depending on plant parts and growing condition.

A series of aqueous or methanol extracts from four different Korean salad plants were assayed to determine their allelopathy and antioxidant activity. The extracts applied on filter paper in a Petri-dish bioassay significantly inhibited root growth of against alfalfa (Medicago sativa) seedlings. Leaf extracts from 40 g dry tissue L-1 of Aster yomena was most phytotoxic to alfalfa root growth, and followed by that of Cirsium japonicum, Taraxacum officinale, and Ixeris dentate. Methanol extracts of plants dose-dependently increased DPPH free radical scavenging activity in vitro. Antioxidant activity of methanol extracts from the same plant species was investigated, and the result showed high DPPH free radical scavenging activity in Cirsium japonicum, Aster yomena, and Ixeris dentate, however, in Taraxacum officinale was least activity. By means of HPLC analysis, chlorogenic acid, p-coumaric acid, and total phenolics with 7.68, 17.47 and 18.64 mg, 100g-1, respectively, showed the highest amounts in methanol extracts from Cirsium japonicum leaves. These results suggest that Compositae salad plants contain water-soluble substances with allelopathic potential as well as antioxidant activity.