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Eriobotrya japonica (Thunb.) Lindl., commonly known as loquat, is a plant belonging to the Rosaceae family. While its fruit is widely consumed as food and used in traditional medicine, research on other parts of the plant remains insufficient. Therefore, the chemical constituents and biological activities of its leaves were investigated. Phytochemical analysis of E. japonica leaves identified 30 compounds, including flavonoids, phenolics, and megastigmanes. The flavonoids isolated from the leaves include flavones, flavans, flavolignans, flavonoid glycosides, and coumaroyl flavonoid glycosides. Coumaroyl flavonoid rhamnosides were characteristically present in E. japonica leaves, and the configurations of coumaric acids, as well as the binding position to the rhamnose in each compound, were identified through detailed NMR analysis. Notably, three of them were isolated from this plant for the first time. Phenolic compounds were found to be present as conjugates with organic acids, such as quinic acid, shikimic acid, and glucose. Flavonoid and phenolic compounds demonstrated significant antioxidant and α-glucosidase inhibitory effects, whereas megastigmanes showed little activity. Notably, coumaroyl flavonoid rhamnosides, which consist of flavonoids combined with the phenolic acid, coumaric acid, exhibited excellent anti-diabetic effects. Further molecular docking analysis confirmed that these compounds effectively bind to the α-glucosidase enzyme. In conclusion, the present study identified flavonoid and phenolic components with various structures in E. japonica leaves and clarified their anti-diabetic and antioxidant effects. These findings support the beneficial potential of E. japonica leaves for the treatment and/or prevention of metabolic diseases. [ABSTRACT FROM AUTHOR]

Cordycepin, also known as 3′-deoxyadenosine, is a major active ingredient of Cordyceps militaris with diverse pharmacological effects. Due to its limited supply, many attempts have been conducted to enhance the cordycepin content. As part of this study, eight medicinal plants were supplemented with cultivation substrates of Cordyceps to increase the cordycepin content. Cordyceps cultivated on brown rice supplemented with Mori Folium, Curcumae Rhizoma, Saururi Herba, and Angelicae Gigantis Radix exhibited increased cordycepin content compared to a brown rice control. Among them, the addition of 25% Mori Folium increased the cordycepin content up to 4 times. Adenosine deaminase (ADA) modulates the deamination of adenosine and deoxyadenosine, and the inhibitors have therapeutic potential with anti-proliferative and anti-inflammatory properties. As ADA is also known to be involved in converting cordycepin to 3′-deoxyinosine, the inhibitory activity of medicinal plants on ADA was measured by spectrophotometric analysis using cordycepin as a substrate. As expected, Mori Folium, Curcumae Rhizoma, Saururi Herba, and Angelicae Gigas Radix strongly inhibited ADA activity. Molecular docking analysis also showed the correlation between ADA and the major components of these medicinal plants. Conclusively, our research suggests a new strategy of using medicinal plants to enhance cordycepin production in C. militaris. [ABSTRACT FROM AUTHOR]

Cratoxylum formosum ssp. pruniflorum (Kurz.) Gogel (Guttiferae), called kuding tea, is widely distributed in Southeast Asia. In this study, the constituents and biological activity of C. formosum ssp. pruniflorum were investigated. Extract of its leaves, roots and stems showed antioxidant and α-glucosidase inhibitory activity. Interestingly, comparison of the metabolite profiles of leaves, roots and stems of C. formosum ssp. pruniflorum by LC-MS analysis showed a great difference between the roots and leaves, whereas the roots and stems were quite similar. Purification of the roots and leaves of C. formosum ssp. pruniflorum through various chromatographic techniques resulted in the isolation of 25 compounds. The structures of isolated compounds were elucidated on the basis of spectroscopic analysis as 18 xanthones, 5 flavonoids, a benzophenone and a phenolic compound. Among them, a xanthone (16) and a benzophenone (19) were first reported from nature. Evaluation of biological activity revealed that xanthones had a potent α-glucosidase inhibitory activity, while flavonoids were responsible for the antioxidant activity. To maximize the biological activity, yield and total phenolic content of C. formosum ssp. pruniflorum, extraction conditions such as extraction solvent, time and temperature were optimized using response surface methodology with Box–Behnken Design (BBD). Regression analysis showed a good fit of the experimental data, and the optimal condition was obtained as MeOH concentration in EtOAc, 88.1%; extraction time, 6.02 h; and extraction temperature 60.0 °C. α-Glucosidase inhibitory activity, yield and total phenolic content under the optimal condition were found to be 72.2% inhibition, 10.3% and 163.9 mg GAE/g extract, respectively. These results provide useful information about C. formosum ssp. pruniflorum as functional foods for oxidative stress–related metabolic diseases. [ABSTRACT FROM AUTHOR]

Ligustrum lucidum Aiton is a flowering plant of the Oleaceae family, and its fruits have been traditionally used for skin nourishment and the treatment of skin diseases. However, the anti-inflammatory constituents for skin disease are not well-characterized. Phytochemical investigation of L. lucidum fruits resulted in the isolation of a new secoiridoid, secoligulene (1), together with (E)-3-(1-oxobut-2-en-2-yl)pentanedioic acid (2) and trans-(E)-3-(1-oxobut-2-en-2-yl)glutaric acid (3). Secoligulene (1) displayed the potent inhibitory effect on NO production with an IC50 value of 12.0 μg/mL. Secoligulene (1) also downregulated mRNA transcriptional levels of pro-inflammatory cytokines such as IL-1 α, IL-1β, IL-6 and COX-2 in LPS-stimulated RAW264.7 cells. Further investigation showed that secoligulene (1) inhibited the phosphorylation of IκB and JNK activated by LPS. In addition, secoligulene (1) downregulated the expression of chemokines such as CXCL8 and CCL20 in the TNF-α/IL-17/IFN-γ induced HaCaT psoriasis model. Taken together, these findings support the beneficial effects of L. lucidum and its constituents on inflammation-related skin diseases and can be further developed as therapeutic treatments for related diseases. [ABSTRACT FROM AUTHOR]

As the leaf of Actinidia arguta has shown antioxidant activity, a study was conducted to identify the active ingredients. Forty-eight compounds were isolated from the leaves of A. arguta through various chromatographic techniques. Further characterization of the structures on the basis of 1D and 2D NMR and MS data identified several aromatic compounds, including phenylpropanoid derivatives, phenolics, coumarins, flavonoids and lignans. Among them, five compounds were newly reported, naturally occurring, and named argutosides A–D (1–4), which consist of phenylpropanoid glycosides that are conjugated with a phenolic moiety, and argutoside E (5), which is a coumarin glycoside that is conjugated with a phenylpropanoid unit. The isolated compounds showed good antioxidant and α-glucosidase inhibitory activity with differences in activity depending on the structures. Molecular docking analysis demonstrated the interaction between the hydroxyl and carbonyl groups of compounds 1 and 5 with α-glucosidase. Taken together, the leaves of A. arguta are rich in aromatic compounds with diverse structures. Therefore, the leaves of A. arguta and their aromatic components might be beneficial for oxidative stress and glucose-related diseases. [ABSTRACT FROM AUTHOR]

Recently, various studies for the use of Fe-based shape memory alloy (Fe-SMA) in the construction field have been widely conducted. However, most of the studies for using Fe-SMA are carried out for applying Fe-SMA for strengthening deteriorated structures. However, if Fe-SMA is used as a reinforcement for new structures, the disadvantages of conventional prestressed concrete can be effectively solved. Therefore, in this work, an experimental study was conducted to evaluate the flexural behavior of concrete beams in which Fe-SMA rebars were used as tensile reinforcement. For the study, ten specimens were constructed with the consideration of the cross-sectional area and activation of Fe-SMA rebars as experimental variable. Activation of the Fe-SMA rebars by electrical resistance heating applied an eccentric compressive force to the specimen to induce camber. The camber increased by an average of 0.093 mm as the cross-sectional area of the Fe-SMA rebar increased by 100 mm2. It was also confirmed through the four-point bending tests that the initial crack loads of the activated specimens were 47.6~112.8% greater than those of the nonactivated specimens. However, the ultimate strength of the activated specimens showed a slight difference of 3% to those of the nonactivated specimens. Therefore, it was confirmed that the effect of Fe-SMA activation on the ultimate strength of specimens was negligible. [ABSTRACT FROM AUTHOR]