• Korean Chemical Engineering Research
• /
• v.54 no.3
• /
• pp.310-314
• /
• 2016

The search for natural antioxidants as alternatives to synthetic products is growing. Microalgae have emerged as a source of natural antioxidants with significant and diverse health-promoting properties. In this study, the effects of hot-water extraction conditions on total polyphenol compounds (TPC) production were investigated for lipid extracted microalgae (LEA). In order to enhance the polyphenol productivity, the extraction variables including solvents, temperature, time and ethanol concentration were optimized. The results showed hot-water extraction provided a higher extraction efficiency than the organic solvents and extraction at high temperatures showed a better extraction efficiency. While hot-water extract showed a higher extraction efficiency compared to 98% ethanol extraction, the mixture of water and ethanol (40:60 v/v) showed the highest production of polyphenols. The maximum polyphenols of 3.35 mg GAE (gallic acid equivalent)/g DM were obtained at the optimized extraction time of 10 min, $100^{\circ}C$ and 40% ethanol, respectively. Although Tetraselmis KCTC 12236BP was preprocessed by hexane to remove lipid for bio-diesel production, the results showed LEA contains relatively high level of polyphenols compared to untreated microalgae which can be used in the production of value-added materials. The predictions obtained from the developed Peleg's model were compared with the experimental data under the same operating conditions. The predicted and experimental data were consistent, indicating the reliability of the model.

• Microbiology and Biotechnology Letters
• /
• v.49 no.4
• /
• pp.485-492
• /
• 2021

In this study, the whitening effect of Abelmoschus esculentus extract was investigated to confirm its applicability in cosmetics. To determine the whitening effect, the tyrosinase-inhibitory activity of Abelmoschus esculentus hot water extract (AEWE) and 70% ethanol extract (AEEE) was measured. At the final concentration of 1000 ㎍/ml, AEWE showed an inhibitory activity of 22.2% and AEEE of 32.8%. To determine the whitening effect at the cellular level, the viability of melanoma cells treated with AEWE and AEEE was evaluated using the MTT assay. At concentrations of 100 ㎍/ml or less, both AEWE- and AEEE-treated groups showed cell survival rates of >95%. Furthermore, in both AEWE- and AEEE-treated melanoma cells, the melanin content decreased in a concentration-dependent manner. The inhibitory effects of AEWE and AEEE used at 5, 10, 50, and 100 ㎍/ml on protein expression were measured by western blot, with β-actin as the positive control. At a concentration of 100 ㎍/ml, AEWE showed an inhibitory effect of 88.1%, 24.8%, 62.2%, and 42.9% on microphthalmia-associated transcription factors (MITF), tyrosinase, tyrosinase-related proteins (TRP)-1, and TRP-2 factors, respectively. At the same concentration, AEEE showed inhibitory effect of 65.3%, 58.3%, 66.2%, and 65.3% against MITF, tyrosinase, TRP-1, and TRP-2 factors, respectively. In conclusion, the whitening effects of AEWE and AEEE were verified, and their applicability as a natural ingredient in cosmetics was confirmed.

• Economic and Environmental Geology
• /
• v.52 no.6
• /
• pp.509-517
• /
• 2019

The birnessite (7Å manganate, δ-MnO₂) which is a manganese oxide and comprises manganese nodules, is a major manganese mineral on the earth surface and a precursor in the synthesis of todorokite. In this study birnessite was synthesized by three different methods: Feng et al. (2004) and Luo et al. (1998) based on redox reaction and Ma et al. (1999) based on reduction reaction. 12 birnessite samples were synthesized by different combinations of Na⁺ and K⁺ cations based on the base (OH^-) and permanganate (MnO₄^-) reagents in the synthesis. The mineral compositions of synthesized birnessite were identified by XRD, and the two cation ratio in the mineral was measured by ICP. The products obtained after hydrothermal treatment of Mg-buserite, by the precursor of birnessite, was examined by XRD, and then phase transition to todorokite and their characteristics were compared. Our results show that the byproducts and the characteristics of phase transition by each synthetic method have different trends. Hausmannite (γ-Mn₃O₄) and feitknechtite (β-MnOOH) were formed by both methods in the redox reaction mechanism. By Feng et al. (2004)'s method, manganite (γ-MnOOH) phase only appeared when cation was predominantly Na⁺. Two birnessite samples synthesized by redox reaction mechanism showed phase transition to todorokite (10Å manganate, OMS-1) when both NaOH and KMnO₄ were used together. However, single-phase birnessite was formed by Ma et al. (1999)'s method, and phase transition was confirmed only for the sample when the cation was only composed of Na⁺.

• Applied Chemistry for Engineering
• /
• v.31 no.6
• /
• pp.697-700
• /
• 2020

We report the synthesis and characterization of quartz nanocrystals (NCs). Quartz NCs were synthesized from the dissolution of amorphous silica nanoparticle precursors under the mild hydrothermal condition of ~250 ℃ and autogenic pressure. It was confirmed that the average size of the nanostructure with a highly crystalline phase of α-quartz can be tuned in a relatively narrow range from 407.5 to 826.2 nm with respect to the reaction time. α-Quartz NCs have potential uses for technological applications in optoelectronics, sensing, and rechargeable battery devices.

• Journal of the Mineralogical Society of Korea
• /
• v.20 no.1 s.51
• /
• pp.1-6
• /
• 2007

Hectorite was synthesized by a two-step hydrothermal process from $Mg(OH)_{2}$, water glass (${\sim}30\;wt%\;SiO_{2}$) and Li-compound at $90{\pm}5^{\circ}C$. The product shows excellent dispersion and swelling properties. The mixture of the starting materials was heated in a glass vessel for the first reaction with continuous stirring and the pH of the solution was adjusted to $6{\sim}8$, resulting in the formation of a precursor of hectorite. The excess salt components were washed out from the resulting slurry and then was matured in the glass vessel for the 2nd reaction. Li compound was added during the reaction. After a 10 h retention, the gel of hectorite was formed. The XRD pattern of the synthesized one was coincided with that of natural hectorite and SEM study revealed uniform grains 50 m in diameter. The d001 basal spacing of the product moved from 12 to $17.4\;{\AA}$ after glycolation treatment. The measured value of CEC and the swelling capacity was 90 cmol/kg and $60{\sim}70\;mL/2\;g$, respectively.

• Journal of Energy Engineering
• /
• v.19 no.3
• /
• pp.195-202
• /
• 2010

A third of primary energy is lost as a waste heat. To improve this inefficient use of energy, systems using chemical reaction have been suggested and studied. In this study, methanol decomposition/synthesis reaction as a chemical reaction was selected for long time heat storage and long distance heat transport system because of safe, cheap and gaseous product. The purpose of this study is to find the optimal conditions in the methanol decomposition and synthesis reactions for long distance heat transport. Several parameters such as reaction temperature, pressure, $H_2$/CO ratio, space velocity, catalyst particle size were tested to find the effects on the reaction rates for the methanol synthesis. And the reaction temperature, space velocity, catalyst particle size were tested to find the effects on the production concentration for the methanol decomposition.

• Journal of Life Science
• /
• v.22 no.6
• /
• pp.730-735
• /
• 2012

Existing pharmaceutical studies show that Magnolia biondii is effective in treating rhinitis and in reducing cholesterol, given its endogenous, volatile ingredients. The study herein seeks to assess the cosmeceutical activities and anti-inflammatory activities of Magnolia biondii extracts for possible application as cosmetic ingredients. The cosmeceutical and anti-inflammatory activities were investigated using hydroxyl radical scavenging, superoxide dismutase (SOD)-like activity, xanthine oxidase (XO) inhibition, cell viability, nitric oxide (NO) inhibition, and inducible nitric oxide synthase (iNOS) expression by Western blotting. Magnolia biondii extracts were identified to have antioxidant activities in hydroxyl free radical scavenging, SOD-like activity, and XO inhibition. In testing the anti-inflammatory activities of the extracts, NO production was inhibited in a dose-dependent manner. Additionally, in a dose-dependent manner, the Magnolia biondii extracts were able to suppress iNOS expression in LPS-stimulated RAW 264.7 macrophage cells. From these results, Magnolia biondii showed adequate potential for application in cosmetic production and related industries as well as a functional material.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.12
• /
• pp.1763-1770
• /
• 2015

The effects of root of Taraxacum coreanum Nakai (TC), on the suppression of inflammation and oxidative stress induced by lipopolysaccharide (LPS) in ICR mice were studied. LPS (10 mg/kg body weight) was injected into ICR mice in between two consecutive oral administrations. Hot water extract of fresh TC (HWETC) was administered to mice immediately before and 24 h after LPS injection. The animal groups used in this study were as follows: NOR group (PBS injection, DW administration), CON group (LPS injection, DW administration), and TC group (LPS injection, 1.4 g/kg bw of HWETC administration). Mice in the CON group lost weight due to inflammation induced by LPS, while the body weight of the TC group mice increased significantly, indicating that inflammation was inhibited by HWETC administration. Compare with the CON group, plasma and hepatic triglyceride, reactive oxygen species, peroxynitrite, and hepatic thiobarbituric acid reactive substances concentrations of the TC group decreased significantly (P<0.05). The protein expression of a pro-inflammatory transcription factor, nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) and its target enzyme, cyclooxygenase 2, increased in response to LPS injection, but was suppressed by HWETC administration (P<0.05). In conclusion, HWETC appears to ameliorate the oxidative stress and inflammatory responses induced by LPS via inhibition of $NF-{\kappa}B$ activation.

• Microbiology and Biotechnology Letters
• /
• v.50 no.1
• /
• pp.31-39
• /
• 2022

The purpose of this study was to investigate the whitening effects of hot water (AMPW) and ethanol (AMPE) extracts of Mangifera indica L. peel. To verify the whitening effects, tyrosinase inhibitory activity was measured. 9.51% inhibitory activity, and 35.98% inhibitory activity at 1,000 ㎍/ml. The effects of AMPW and AMPE on cell viability were measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in B16-F10 melanoma cells. Greater than 95% cell viability was observed at 100 ㎍/ml. Thus, subsequent experiments were performed at concentrations less than 100 ㎍/ml. The whitening effects were confirmed by measuring the protein and mRNA expression levels of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein 1 (TRP-1), and TRP-2, which are factors involved in melanin synthesis. Western blotting and reverse transcription-polymerase chain reaction results confirmed that 100 ㎍/ml AMPW and AMPE showed superior inhibitory effects than the control treatment (alpha-melanocyte stimulating hormone only). Therefore, Mangifera indica L. peel extract had a whitening effect, and thus, has potential as a natural material for use in cosmetics.

• Journal of Mushroom
• /
• v.14 no.4
• /
• pp.225-231
• /
• 2016

Hot water extracts from 16 domestic edible mushrooms including Pleurotus ferulae (Lanzi) X.L. Mao, Lentinula edodes (Berk.) Pegler, and Hypsizygus marmoreus (Peck) H.E. Bigelow, which are commercially available, were used for determining the cosmetic potential of these mushrooms. In this study, we carried out in vitro functional experiments to determine the inhibitory effects of these extracts on L-DOPA oxidation of tyrosinase and melanin synthesis. Based on the results of these experiments, H. marmoreus (Peck) H.E. Bigelow No. 10 and No. 15 were selected for further analysis. We analyzed the melanin synthesis inhibitory activity, TRP1 and MITF expression via real-time PCR, and Fontana Masson staining in artificial skin $Neoderm^{(R)}-ME$. Taken together, we observed that the hot water extract from H. marmoreus (Peck) H.E. Bigelow (No. 15) had better whitening effect than the extracts of other mushrooms. Thus, it can be a potential source of skin-whitening agent.