Cellulose, the most abundant natural polymer on earth, has recently gained attention for a large spectrum of applications. At a nanoscale, nanocelluloses (mainly involving cellulose nanocrystals or ...cellulose nanofibrils) possess many predominant features, such as highly thermal and mechanical stability, renewability, biodegradability and non-toxicity. More importantly, the surface modification of such nanocelluloses can be efficiently obtained based on the native surface hydroxyl groups, acting as metal ions chelators. Taking into account this fact, in the present work, the sequential process involving chemical hydrolysis of cellulose and autocatalytic esterification using thioglycolic acid was performed to obtain thiol-functionalized cellulose nanocrystals. The change in chemical compositions was attributed to thiol-functionalized groups and explored via the degree of substitution using a back titration method, X-ray powder diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Cellulose nanocrystals were spherical in shape and ca. 50 nm in diameter as observed via transmission electron microscopy. The adsorption behavior of such a nanomaterial toward divalent copper ions from an aqueous solution was also assessed via isotherm and kinetic studies, elucidating a chemisorption mechanism (ion exchange, metal chelation and electrostatic force) and processing its operational parameters. In contrast to an inactive configure of unmodified cellulose, the maximum adsorption capacity of thiol-functionalized cellulose nanocrystals toward divalent copper ions from an aqueous solution was 4.244 mg g
at a pH of 5 and at room temperature.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Globally, hydrometeorological hazards have large impacts to agriculture output, as well as human well-being. With climate change derived increasing frequency of extreme weather conditions, the ...situation has becoming more severe. This study strives to evaluate both dry and wet conditions in the Vietnamese Mekong Delta (VMD), also known as the rice basket of the Southeast Asian region. Different meteorological parameters from the last three decades were used to develop drought indices for Ca Mau province to investigate their impact on agricultural output. For this purpose, the standard precipitation index (SPI), the agricultural rainfall index (ARI), and the standardized precipitation evapotranspiration index (SPEI) were used in this study. Results highlight that Ca Mau has a peculiar characteristic of the whole VMD in that dry periods persist well into the wet season extending the duration of drought events. The role of storms, including tropical storms, and El Niño cannot be ignored as extreme events, which both change humidity, as well as rainfall. It is also found that the drought situation has caused significant damage to both rice and shrimp outputs in almost 6000 hectares. The assessment contributes to an improved understanding of the pattern of unpredictable rainfall and meteorological anomaly conditions in Ca Mau. The findings of this paper are important for both policymakers and practitioners in designing more robust plans for water resource management.
Artemisia keiskeana and A. stolonifera are plants of the genus Artemisia, distributed in various regions, especially China and Korea. They are renowned as medicinal plants with biological and ...pharmacological activities. Fraxidin, isofraxidin, and daphnoretin are coumarins present in Artemisia spp.; however, research on them is limited. Therefore, this study was carried out to quantify the content of these compounds in the aerial parts of A. keiskeana and A. stolonifera in different regions in Korea. High-performance liquid chromatography was performed with a photodiode array detector and a reverse-phase INNO column. A. stolonifera only contained fraxidin with the highest amount found in Yongmun commune. A. keiskeana cultivation in Soyang commune gave the highest fraxidin and daphnoretin content. However, isofraxidin was not present in all samples. The findings suggest that the concentrations of the three compounds may differ depending on the growth site and provide a foundation for future studies. KCI Citation Count: 0
The constituents and antioxidant activities of
Cyperus exaltatus
var.
iwasakii
(CE) have not been studied to date. In this study, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ...2,2′-azino-bis(3-ethylbenzothiazoline-6 sulfonic acid) (ABTS) assays were used to evaluate the radical-scavenging activities of the ethanol extract, four fractions, and isolated compounds of CE. In addition, phenolic acids and flavonoids were isolated from the ethanol extract of CE using column chromatography. The compounds identified by spectroscopy were gallic acid, protocatechuic acid, vanillic acid,
p
-coumaric acid, rutin, ferulic acid, isoquercitrin, astragalin, quercetin, luteolin, apigenin, tricin, and kaempferol. Quantitative analysis using high-performance liquid chromatography (HPLC) revealed that the major flavonoids of CE were astragalin and tricin and that the major phenolic acid was
p
-coumaric acid. In addition, comparative analysis of CE from Ganghwa and Hampyeong habitats using HPLC showed that the Hampyeong CE had a higher phytochemical content. Comparative analyses of the isolated compounds were also conducted among five
Cyperus
species. The highest antioxidant activities were found in the ethyl acetate (EtOAc) fraction, and among the compounds isolated from CE, vanillic acid and quercetin showed remarkable antioxidant activity even when compared with ascorbic acid. The results demonstrate the usefulness of CE, which has not been sufficiently studied previously, and will facilitate the evaluation of its potential effectiveness as antioxidant functional plant material.
Total polyphenol and total flavonoid assays were performed to characterize the relationships between the color of Peucedanum japonicum (PJ) seed coat and stem and the content of phytochemical ...compounds. The samples were divided into two groups based on their stem and seed coat color, with each group containing 23 samples. The stem color group was subdivided into green, light red, and red, whereas the seed coat color group was divided into light brown, brown, and dark brown. In the stem color group, the light red stems exhibited the highest content of phytochemical compounds, with levels over 10% higher than those of the stems of the other colors. Moreover, among the top ten samples with the highest total polyphenol content, eight samples were light red, and the light red group also exhibited the highest total flavonoid content among the examined color groups. In terms of the seed coat color, the plants grown from dark brown seeds exhibited the highest contents of both total polyphenols and total flavonoids. In conclusion, PJ plants with dark brown seeds and light red stems contained the highest levels of phytochemical compounds. Collectively, our findings provide a valuable basis for future seed selection of PJ for pharmaceutical purposes.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Adlay is an annual plant known for its abundant bioactive compounds and diverse pharmacological activities. Coixol, a key component found in various parts of adlay, significantly contributes to its ...biological activity. This study was conducted to extract adlay sprouts and seeds using different solvents (methanol and ethanol) and extraction methods (reflux and ultrasonic extraction). The extracts were then evaluated for their total polyphenol and flavonoid contents, as well as antioxidant ability (DPPH and ABTS+). Additionally, the coixol content of these extracts was analyzed using HPLC/DAD analysis. The results showed that the extraction methods and solvents used impacted the bioactive compounds and their activities in the samples. Adlay sprouts exhibited a higher compound content and stronger antioxidant capacity than adlay seeds. Moreover, a substantial amount of coixol was found in the sprouts, while it was not detected in the seeds. This study emphasizes the importance of selecting appropriate extraction methods to optimize the biological activities of adlay sprouts and seeds. Adlay sprouts, with their enriched phytochemical compounds and enhanced antioxidant ability, could serve as a valuable material for health product applications.
Socioeconomic development and population growth have led to canal pollution, a challenge in Ho Chi Minh City (HCMC), Vietnam. In HCMC, diffuse pollution of rivers and canals makes applying pollution ...control measures at the source challenging. Poor sanitation, insufficient safe drinking water, and poor hygiene practices are the leading causes of the emergence of waterborne diseases.
A cross-sectional survey was done to investigate the knowledge, behavior, and factors associated with sanitation and hygiene of residents living along the side of canals in HCMC. This study also investigated the pollution of canal water in the primary canal systems in HCMC.
The canal water systems at Ho Chi Minh City exceeded the permissible thresholds of Vietnam's discharge limit standards of total coliforms and E. coli. Among the 640 households interviewed, 60% of residents perceived that the polluted canal environment affected their lives. Most residents (99%) used tap water for daily activities, but 25% of households did not filter water before drinking. The hygiene behavior is uneven; more than 30% of households discharged wastewater into the canal, and nearly 60% of children have the conditions to contact flood water on the street. The causes of water pollution in canals are people's low awareness, with only 38.4% of respondents interested in canal-environmental protection activities, inadequate infrastructure (59%), and the ineffective management of surface water resources (57.8%).
The study indicated incorrect knowledge and behavior toward sanitation and protecting the canal environment of the local people caused increasing pollution of canal water. Hence, measures must be implemented to protect the canal water environment and the community's health, such as training about sanitation and hygiene for local people.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In contrast to other natural disasters, droughts may develop gradually and last for extended periods of time. The World Meteorological Organization advises using the Standardized Precipitation Index ...(SPI) for the early identification of drought and understanding of its characteristics over various geographical areas. In this study, we use long-term rainfall data from 14 rain gauge stations in the Vietnamese Mekong Delta (1979–2020) to examine correlations with changes in rice yields. Results indicate that in the winter–spring rice cropping season in both 2016 and 2017, yields declined, corresponding with high humidity levels. Excessive rainfall during these years may have contributed to waterlogging, which in turn adversely affected yields. The results highlight that not only drought, but also humidity has the potential to adversely affect rice yield.
is a valuable plant that contains a wide range of phytochemical compounds and exhibits various biological activities. Ethanol extracts from both the leaves and flowers of 17 different cultivars of
...were tested for antioxidant activities using the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays and were quantitatively analyzed for 12 phenolic compounds using high-performance liquid chromatography with diode-array detection. We found that the 'Ford' and 'Raina' cultivars demonstrated strong antioxidant abilities and high phenolic compound contents compared to other cultivars, while the flowers of 'Cielo' and the leaves of 'White Cap' exhibited low antioxidant capacity in both assays. The 'Cielo' cultivar also displayed the lowest compound contents. Additionally, in most samples, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid stood out as high-content compounds in the extracts. This study provides foundational knowledge that can be used for selecting appropriate
cultivars for further research. Moreover, the 'Ford' and 'Raina' cultivars, containing high amounts of bioactive compounds and showing superior antioxidant ability, could be applied to produce health-beneficial products.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Y. N. Lee (OMY) is an endemic Korean plant in the family Crassulaceae that is known to contain a variety of bioactive compounds. To assess the physiological activities of an OMY ethanol extract, ABTS
...and DPPH radical scavenging assays and a nitric oxide (NO) inhibition assay were conducted. The phytochemical makeup of the extract was profiled via liquid chromatography-mass spectrometry (LC-ESI/MS) and high-performance liquid chromatography with a photodiode array detector (HPLC/PDA). The OMY extract was found to have weaker ABTS
and DPPH radical scavenging activities than the control group (green tea). In the NO inhibition assay, the OMY extract induced a significant increase in macrophage cell viability but showed a lower NO inhibitory activity than l-NAME, producing an IC
value of 202.6 μg/mL. The LC-ESI/MS and HPLC/PDA analyses identified isoquercitrin and astragalin in the OMY extract, quantifying their contents at 3.74 mg/g and 3.19 mg/g, respectively. The study revealed possibilities for the utilization of OMY as a future source of drugs for alleviating inflammation and diseases related to reactive oxygen species.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
