Optimization of Sasa quelpaertensis Nakai Extract as a Natural Antioxidant and Whitening Product

다국어 초록 (Multilingual Abstract)

The medicinal properties of natural products are attributed to the presence of phytochemicals under various extraction conditions, such as the extraction method, type of solvent, extraction time, and temperature. In this study, optimization of extraction was performed using response surface methodology (RSM) to obtain materials with antioxidant activity and whitening effects from Sasa quelpaertensis Nakai. The central composite design, an RSM, was carried out to design an experimental model related to obtaining antioxidants by ethanol extraction and whitening effect materials by hydrothermal extraction from S. quelpaertensis Nakai. The optimal ethanol extraction conditions were determined as follows: ethanol concentration of 54%, extraction temperature of 52°C, and extraction time of 3 h. The optimal hydrothermal extraction conditions were as follow: total extraction time of 1 h, extraction temperature of 41°C, solid-liquid ratio of 1:19, and ultrasonic irradiation time of 8 min. Extraction was performed under the same predicted optimal conditions, and experiments using optimal extracts were carried out in triplicate to verify the significance of each optimum extraction condition. As a result, the actual activity value was confirmed to be similar to the predicted value. Moreover, quantitative analysis of indicator substances with antioxidant properties, such as tricin and p-coumaric acid, and whitening effects, such as p-coumaric acid and arbutin, was conducted using high-performance liquid chromatography analysis; the cell viability was measured to assess for toxicity by conducting a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay on extracts produced under optimized extraction conditions.
Therefore, the optimized extracts from S. quelpaertensis Nakai could be utilized for industrial applications.

국문 초록 (Abstract)

천연물의 의약적 특성은 추출방법, 용매의 종류, 추출시간, 추출온도 등 다양한 추출조건을 통한 식물 화학 물질에 따라 차이를 나타낸다. 본 연구에서는 제주조릿대 (Sasa quelpaertensis Nakai) 유래 항산화 및 미백 기능성 원료 생산 추출 공정 최적화를 위해 반응표면분석법 (RSM)을 적용하였다. 실험 조건 도출을 위해 중심 합성 계획법을
적용하였으며, 항산화 활성 및 미백 활성 물질 생산을 위해 각각 에탄올 추출공정과
열수추출공정을 적용하여 조건 최적화 및 검증을 수행하였다. 제주조릿대를 시료로 한 에탄올
추출공정의 최적조건은 에탄올 농도 54%, 추출온도 52℃, 추출시간 3 시간이며, 열수
추출공정의 최적조건은 총 추출시간 1 시간, 추출온도 41℃, 고액비 1:19, 초음파 조사시간
8 분으로 나타났다. 각각의 최적 추출조건의 유의성 검증을 위해 동일 조건에서 추출 및 3 반복
실험결과 활성예측 값과 실제 실험활성 값이 유사함을 확인하였다.
고성능 액체 크로마토그래피 분석을 통해 각 공정의 최적의 추출조건에서 생산된 에탄올 및
열수 추출물에서 각각 항산화 활성을 나타내는 지표성분 tricin, p-coumaric acid 과
미백활성을 나타내는 지표성분들 p-coumaric acid, arbutin 의 검출여부 및 수율 등을
확인하였다. 또한, 독성 테스트를 위해 세포 생존력 분석을 수행하였고, 미백활성을 나타낸
열수추출물에서는 멜라닌 합성 저해 분석을 수행하였다. 결과적으로, 최적추출 조건에서 생산된
제주조릿대 추출물은 항산화 및 미백의 기능성 화장품 소재로서의 활용이 가능한 것으로 판단된다.

목차 (Table of Contents)

• 1. Introduction 1
• 1.1. Background of this study 1
• 1.2. S. quelpaertensis Nakai 4
• 1.3. Ingredients derived from natural products with antioxidants and whitening effects 6
• 1.4. Optimization of extraction using response surface methodology 10
• 1.5. Objectives 13
• 2. Materials and Methods 14
• 2.1. Materials 14
• 2.2. Use of ethanol for extracting antioxidants and its evaluation 16
• 2.2.1 Method of extraction 16
• 2.2.2 DPPH radical scavenging assay 18
• 2.3. Hydrothermal extraction of whitening materials and its evaluation 19
• 2.3.1 Method of extraction 19
• 2.3.2 Tyrosinase inhibition assay 21
• 2.4. Optimizing extraction conditions and model validation 22
• 2.5. Quantitative analysis of indicator substances using HPLC 24
• 2.6. Cell-based assay 26
• 2.6.1 MTT cell viability assay 26
• 2.6.2 Melanin inhibition assay 27
• 3. Results and discussion 28
• 3.1. Establishment of independent variables for response surface analysis 28
• 3.2. Optimization of ethanol extraction for antioxidants 32
• 3.3. Optimization of hydrothermal extraction of substances with whitening effects 37
• 3.4. Quantitative analysis of indicator substances using HPLC 44
• 3.5. Cytotoxicity and melanin inhibition of optimized extracts 50
• 4. Conclusions 51
• References 53
• Abstract 63
• 국문초록 65