• Journal of Microbiology and Biotechnology
• /
• 제9권6호
• /
• pp.709-715
• /
• 1999

A series of antifungal compounds were obtained from the methanol extract of the mycelium from marine actinomycetes M428 which was identified as a Stereptomyces species by fatty acid composition and biochemical characteristics. These compounds were purified by combined chromatographic techniques and the structures were characterized with spectroscopic methods including 1D and 2D NMR, and mass spectrometry as sn-l lysophosphatidyl inositols. The side chains were established by chemical degradation followed by GC analysis to be 14-methyl pentadecanoic acid (iso-palmitic acid, i-C16:0, compound A) and 13-methyl tetradecanoic acid (iso-pentadecanoic acid, i-C15:0, compound B). These compounds displayed highly selective antifungal activity against C. albicans with MIC values of $5{\;}\mu\textrm{g}/ml$ (compound A) and $2.5{\;}\mu\textrm{g}/ml$ (compound B), while it had almost negligible antibiotic activity against E. coli and P aerogenosa with MIC value higher than $50{\;}\mu\textrm{g}/ml$ and no cytotoxic activities against human myeloma leukemia K562 ($IC_{50}>100{\;}\mu\textrm{g}/ml$).

• Journal of Biosystems Engineering
• /
• 제40권1호
• /
• pp.47-60
• /
• 2015

Purpose: The purpose of this study was to non-destructively and quickly predict the capsaicinoid content of domestic red pepper powders from various areas of Korea using a pungency measurement system in combination with visible and near-infrared (VNIR) spectroscopic techniques. Methods: The reflectance spectra of 149 red pepper powder samples from 14 areas of Korea were obtained in the wavelength range of 450-950 nm and partial least squares regression (PLSR) models for the prediction of capsaicinoid content were developed using area models. Results: The determination coefficient of validation (RV2), standard error of prediction (SEP), and residual prediction deviation (RPD) for the capsaicinoid content prediction model for the Namyoungyang area were 0.985, ${\pm}2.17mg/100g$, and 7.94, respectively. Conclusions: These results show the possibility of VNIR spectroscopy combined with PLSR models in the non-destructive and facile prediction of capsaicinoid content of red pepper powders from Korea.

• Rapid Communication in Photoscience
• /
• 제4권1호
• /
• pp.1-8
• /
• 2015

For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

• Natural Product Sciences
• /
• 제21권4호
• /
• pp.231-236
• /
• 2015

Two new azaphilone derivatives containing 1,3-dioxolane moiety, penidioxolanes A (1) and B (2), were isolated from marine-derived fungus Penicillium sp. KCB12C078, together with four known compounds (3-6) by chemical investigation. Compounds 1 - 6 were isolated by combination of silica gel, ODS column chromatography and preparative HPLC. Their structures were determined by analysis of spectroscopic data including 1D-, 2D-NMR, and MS techniques. The isolates were evaluated against cancer cell growth inhibition effects and antimicrobial activity.

• Natural Product Sciences
• /
• 제20권3호
• /
• pp.152-159
• /
• 2014

A phytochemical investigation of Spergularia marina (L.) Griseb. growing in Egypt, has been carried out, which resulted in the isolation of seven compounds from the different extracts of the plant namely; ${\beta}$-sitosterol glucoside, tricin (1) dihydroferulic acid (2), vanillic acid (3), 4-hydroxybenzoic acid (4), uracil (5) and 8-hydroxy cuminoic acid (6) Structure elucidation of the isolated compounds was carried out using different spectroscopic techniques. This is the first report for the isolation of these compounds from genus Spergularia. Furthermore, 8-Hydroxy cuminoic acid and uracil were isolated for the first time from family Caryophyllaceae. The chemical composition of the volatile components present in the petroleum ether extract of Spergularia marina (L.) Griseb. using combined gas chromatography-mass spectrometry (GC-MS) is reported here for the first time. Of the 97 components present, 59 were identified including three sulfur containing compounds which represented about 1.8% of the volatiles of the total petroleum ether extract. This prompted us to study and report its possible antimicrobial activity. In addition, the antibacterial and antifungal screening of different extracts of Spergularia marina (L.) Griseb. as well as some isolates have been performed using agar diffusion method.

• Natural Product Sciences
• /
• 제20권2호
• /
• pp.80-85
• /
• 2014

In the course of screening for antioxidant compounds from natural plants in Korea by measuring the radical scavenging effect, a methanol extract of the flower buds of Daphne genkwa S. et Z. (Thymelaeaceae) was found to show a potent antioxidant activity. Subsequent activity-guided fractionation of methanol extract of D. genkwa led to the isolation of four compounds from the ethyl acetate soluble fraction. The chemical structures were elucidated as genkwanin (1), 3'-hydroxygenkwanin (2), apigenin (3), and tiliroside (4) by spectroscopic techniques. Among them, compound 2 showed the significant anti-oxidative effect on DPPH. And compound 2 showed the significant riboflavin-and xanthine-originated superoxide quenching activities. To verify the antioxidant enzymatic activities of compound 2, the SOD enzymatic activity was measured spectrophtometrically using prepared Caenorhabditis elegans homogenates. The results showed that compound 2 was able to elevate SOD activity of C. elegans in a dose dependent manner. Moreover, compound 2 decreased the intracellular ROS accumulation of worms.

• Natural Product Sciences
• /
• 제17권2호
• /
• pp.95-99
• /
• 2011

A monoterpene-neolignan, piperitylmagnolol (1), was isolated from the stem bark of Magnolia officinalis, together with syringaresinol (2), caffeic acid (3), and sinapaldehyde (4). The isolated compounds were established on the basis of spectroscopic and physicochemical analyses including 1D- and 2D-NMR techniques, as well as on comparing the spectral data with those in the literature and of authentic samples. Compounds 1 - 4 were tested for their cytotoxic activity against the HeLa, K562, A549, and HCT116 cancer cell lines in vitro. Of the isolates, piperitylmagnolol (1) exhibited cytotoxic activity against the tested cancer cell lines with $IC_{50}$ values of 7.7 - 9.5 ${\mu}g/ml$.

• The Plant Pathology Journal
• /
• 제29권1호
• /
• pp.105-109
• /
• 2013

Raman spectroscopy provides many advantages compared to other common analytical techniques due to its ability of rapid and accurate identification of unknown specimens as well as simple sample preparation. Here, we described potential of Raman spectroscopic technique as an efficient and high throughput method to detect plants infected by economically important viruses. To enhance the detection sensitivity of Raman measurement, surface enhanced Raman scattering (SERS) was employed. Spectra of extracts from healthy and Turnip yellow mosaic virus (TYMV) infected Chinese cabbage leaves were collected by mixing with gold (Au) nanoparticles. Our result showed that TYMV infected plants could be discriminated from non-infected healthy plants, suggesting the current method described here would be an alternative potential tool to screen virus-infection of plants in fields although it needs more studies to generalize the technique.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.187-187
• /
• 2011

Nowadays, the issue of solar cell durability in local weather and environment is a crucial issue. Above all, surface corrosion on solar cell multilayers is a major factor that determines the durability of commercial solar cells; corrosive chemical interactions between air, humidity and chemical species and solar cell multilayers can unfavorably affect the durability. Here, we study microscopic and spectroscopic surface techniques to investigate the corrosive interaction on the antireflective layers of solar cell multilayers under various conditions such as acid, base, constant temperature and humidity. Surface morphology and adhesion force were characterized with atomic force microscopy before and after chemical treatment. Chemical composition, and transmittance factors were studied with X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy, respectively. Based on these studies, we suggest the dominant factors in the corrosive chemical processes, and their influences on the structural, compositional, and optical properties of the antireflective layers.

• Journal of Microbiology
• /
• 제44권4호
• /
• pp.432-438
• /
• 2006

Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified. the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, $^1H$ NMR, $^{13}C$ NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of $C_{19}H_{29}NO_2$ and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.