• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.1
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• pp.89-94
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• 2014

Stem bark extracts of Fraxinus rhynchophylla Hance were found to contain two major bioactive components, esculetin and esculin. Esculetin substantially inhibited melanogenesis in B16F10 melanoma cells, with an $IC_{50}$ value of $2.8{\mu}M$, and reduced melanin synthesis in Melan-A cells. Moreover, esculetin suppressed melanin biosynthesis by inhibiting mushroom tyrosinase activity, with an $IC_{50}$ value of $40{\mu}M$. Taken together, these results suggest that esculetin could serve as an effective skin-lightening agent that inhibits melanin production by regulating the activity of melanogenic enzymes.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.7-19
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• 2013

This study was carried out to select new pelleting binder and material for seeds from Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. The optimum treatments of the various concentrations and species of priming agents to improve seed germination of both woody medicinal plants were also estimated. Germinability was increased when the seeds of Fraxinus rhynchophylla Hance was soaked in -1.0 MPa of PEG6000 solution at $15^{\circ}C$ for 4 days significantly, the optimum treatment for improving germination of Alnus sibirica Fisch. ex Turcz was observed when the tested seeds was soaked in 100 mM of KCl at $15^{\circ}C$ for 4 days. The influence of physical and chemical properties of pelleting solid materials, the mixture of gypsum, diatomaceous earth, dalma ceramic and vermicuolite (6:1:1:1 ratio) were found as the best pelleting materials for Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. seeds. To satisfy the requirements of absorption and compatibility for multi-layer seed pelleting, SGPA (Starch-grafted cross-linked polyacrylates) hydrogel was prepared using starch, acrylonitrile, ceric ammonium nitrate, nitric acid, methyl alcohol and potassium hydroxide. The resulting SGPA hydrogel showed high water absorption but not plant compatibility. It suggested that seed pelleting using pelleting materials and SGPA hydrogel (multi-layer coating) after priming agent treatment is to increase germinability and seedling growth and it can reduced irrigation labours and can also save seed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.277-283
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• 2023

Fraxinus rhynchophylla Hance (F. rhynchophylla) is a traditional medicinal plant that has been widely used in East Asia and has been used for chronic bronchitis, bacterial dysentery and improved eyesight. F. rhynchophylla contains various type of coumarins such as esculin, esculetin, fraxin and fraxetin. Esculetin possesses versatile activities including antioxidant, anti-inflammatory, antimicrobial, anticancer properties and improvement of atopic dermatitis. However, there is no research on the process of increasing active components in F. rhynchophylla. The objectives of the present study were to apply biotransformation technology to F. rhynchophylla for increasing the content of esculetin, and enhancing anti-inflammatory and antioxidant activities. F. rhynchophylla extract (FRE) treated with viscozyme L (FRE-VL) showed 3.1 times higher content of esculetin than FRE, and exhibited effects such as increased anti-inflammatory activity and DPPH radical scavenging activity. Based on the these results, it is concluded that biotransformed FRE-VL could be potentially applicable as a new active ingredient in the cosmetic field.

• Journal of the Korean Wood Science and Technology
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• v.16 no.3
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• pp.48-64
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• 1988

This study was carried out to investigate the free vibrational properties of traditional and replaceable species for sounding board, using piezoelectrical accelerometer and signal analyzer. In the study, the frequency equations of free-free beam carrying a concentrated mass in the transverse vibration and of free-mass beam in the longitudinal vibration were used. The results obtained were as follows. 1. Average values of dynamic modulus of rigidity of Korean commercial species measured were as follows. Paulownia tomatosa (Thunb.) Steudel: $5.590\times10^9\;dyne/cm^2$ Tilia amurensis Rupr.: $5.414\times10^9\;dyne/cm^2$ Macckia amurensis Rupr.: $10.044\times10^9\;dyne/cm^2$ Fraxinus mandshurica Rupr.: $8.876\times10^9\;dyne/cm^2$ Ulmus davidiana var.japonica Nakai: $8.677\times10^9\;dyne/cm^2$ Pinus rigida Miller: $6.33\times10^9\;dyne/cm^2$ Fraxinus rhynchophylla Hance: $4.666\times10^9\;dyne/cm^2$ 2. The ratio of dynamic transverse Young's modulus to dynamic modulus of rigidity, $E_T/G_{LT}$, was 24.922 for Fraxinus rhynchophylla Hance, which was the highest, 7.317 for Paulownia tomentosa (Thunb.) Steudel, which was the lowest among Korean commercial species measured. 3. The value of longitudinal dynamic Young's modulus was about 3.7% and 19.8%, respectively, higher than those of transverse dynamic and static Young's modulus. The value of transverse dynamic Young's modulus was about 15.5% higher than that of static Young's modulus. 4. Predicted value of MOR in terms of correlation coefficient by transverse dynamic Young's modulus was slightly higher than that of static Young's modulus, but no significance was found out. 5. Transverse dynamic Youne's modulus was $(2.002\pm0.288)\times10^{11}\;dyne/cm^2$ for Fraxinus mandshurlca Rupr., which was the highest, $(0.601\pm0.100)\times10^{11}\;dyne/cm^2$ for Paulownia tomentosa (Thunb.) Steudel, which was the lowest among Korean commercial species measured. The sound velocity of sitka spruce was 5,685 m/sec, which was the highest. 6. Internal friction of Paulownia tomentosa (Thunb.) Steudel was shown the lowest value among Korean commercial species, $(8.795\pm1.795)\times10^{-3}$, but was higher than that of sitka spruce, $(7.331\pm0.991)\times10^{-3}$. Internal friction was shown negative correlation with density and dynamic Young's modulus, respectively. 7. K value was affected largely by internal friction and was the highest, $2.225\times10^8$ for Paulownia tomentosa (Thunb.) Steudel and was the lowest, $0.550\times10^8$ for Fraxinus rhynchophylla Hance. K value of Paulownia tomentosa (Thunb.) Steudel was higher than that of sitka spruce and K values of melapi and cottonwood, which have been considered to be replaceable species with sitka spruce in the piano industry, were lower than those of Paulownia tomentosa (Thunb.) Steudel and mill amurensis Rupr.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.287-290
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• 2007

Phytochemical investigation of the MeOH extract of the dried stem barks of Fraxinus rhynchophylla Hance (Oleaceae), as guided by cytoprotective activity against tert-butyl hydroperoxide (t-BHP)-induced cell injury in mouse hippocampal HT22 cells, furnished two coumarins, esculetin (1) and fraxetin (2). Compounds 1 and 2 had the significant cytoprotective effects on t-BHP-induced cellular oxidative injury in HT22 cells. Furthermore, compounds 1 and 2 showed potent DPPH radical scavenging effect, exhibiting $IC_{50}$ values of 14.68 and 9.64 ${\mu}M$, respectively.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.280-289
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• 2023

Diverse native tree species are distributed in Korean forests; however, information on their regeneration strategies is limited. This study analyzed seed rain from 2011 to 2013, seedling emergence, seedling survival, lifespan distribution, and the relationship between seedling mortality and herbaceous vegetation for 3 years, from 2012 to 2014, to understand the natural regeneration and early survival characteristics of Fraxinus rhynchophylla Hance in natural broad-leaved forests. Seed rain and emerged seedling density significantly differed among the years (p < .05). An increase in seed rain was followed by an increase in seedling emergence in the following year. Seed rain in 2013 and seedling emergence in 2014 showed a significant correlation (p < .05), confirming the trait of F. rhynchophylla seeds that germinate in the following year after seed production. Seedlings emerged in late spring and early summer. Of the seedlings, 78% emerged in the early summer of 2014. Most seedlings died immediately after emergence. Of the seedlings that emerged in August 2012, 56% died within 2 months, and 38% of those that emerged in July 2014 died within 1 month. Shade and competition against ground vegetation chiefly affected the seedling survival of F. rhynchophylla. Fraxinus rhynchophylla showed mast seeding, with a large number of seed production in a particular year. A surge of seedling emergence followed in the early summer of the next year. However, most seedlings died in the same year of emergence. Fraxinus rhynchophylla has a high seedling mortality, but mast seeding and the resulting high seedling emergence produce a few survived seedlings, enabling the continuation of the F. rhynchophylla population. Efforts and research on the natural regeneration of native tree species are required to effectively manage natural forests in Korea.

• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.117-123
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• 2015

Necrotic enteritis (NE) caused by Clostridium (C.) perfringens commonly occurs in domestic broiler farms since antibiotic supplementation in poultry feed has been banned. We evaluated the antibacterial activities of medicinal plant extracts against C. perfringens isolates to select alternative compounds for preventing NE. We compared antibacterial activities using two methods and evaluated susceptibilities of the isolates based on minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Two (Fraxinus rhynchophylla Hance [FRH] and Geranium koreanum Kom. [GKK]) of the 30 plant extracts had potent antibacterial activities against C. perfringens ATCC 13124 in two assays. The MIC values for FRH and GKK against 20 C. perfringens isolates were $128{\sim}256{\mu}g/mL$ and $32{\sim}128{\mu}g/mL$, respectively. The geometric MIC mean values for the two extracts were $147.2{\mu}g/mL$ and $68.8{\mu}g/mL$, respectively. The MBCs for the two extracts against the same strains were $1,024{\sim}2,048{\mu}g/mL$ and $256{\sim}1,024{\mu}g/mL$, respectively. The geometric mean MIC and MBC for GKK were about two-fold lower than those of FRH. The modified spot-on-lawn assay may be useful for measuring primary antibacterial potential. FRH and GKK are expected to be used as feed additives to prevent or treat NE in veterinary practice.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.469-476
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• 1999

This study was carried out to investigate the growth and physiological response of shade intolerant and intermediate tree seedlings to enhanced UV-$B_{BE}$(biologically effective UV-B) radiation. The seedlings of Betula platyphylla var. japonica Hara(shade intolerant species) and Fraxinus rhynchophylla Hance(shade intermediate species) were treated with one of the three levels of UV-$B_{BE}$ dosages - ambient UV-$B_{BE}$, ambient+3.2, and ambient+$5.2\;KJ\;m^{-2}day^{-1}$) for 14 weeks in the field condition. Height and root collar diameter growth, leaf area, and biomass production of the seedlings of two species were reduced by enhanced UV-B radiation. Leaf stomatal resistance to water vapor of the F. rhynchophylla seedling was increased by the UV-B increment. The reductions in total chlorophyll and carotenoid were more apparent in the F. rhynchophylla than B. platyphylla seedling. There was no statistically significant changes in the concentration of UV-B absorbing compound($A_{300}$) in the leaves of the two species among the UV-B treatment. However the $A_{300}$ tented to be increased in F. rhynchophylla by enhanced UV-B radiation. These results indicate that the growth and the physiological and biochemical responses between B. platyphylla and F. rhynchophylla were different to enhanced UV-B environment.

• Journal of Korean Society of Forest Science
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• v.78 no.3
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• pp.280-286
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• 1989

The present study was to examine the effects of light, temperature, and water stress on the photosynthesis and respiration rates and its seasonal changes in 3-Year-old Fraxinus rhynchophylla and Fraxinus mandshurica seedlings raised in pot in nursery. The results obtained are as follows: 1. The estimated light compensation points at which net photosynthesis approached zero were 35 and $28{\mu}Em^{-2}\;s^{-1}$ for F. rhyrachophylla and F. mandsdzurica leaves, respectively, The light saturation points occurred at $700{\mu}Em^{-2}\;s^{-1}$ in these species. 2. The maximum rates of net photosynthesis of leaves occurred at about $25^{\circ}C$ in F. rhynchophylla and at $20^{\circ}C$ in F. mandshurica. 3. The decrease in net photosynthetic rates of leaves began at -13 bars in F. rhynchophylla and -10 bars in F. mandshurica, and then its rates approached approximately zero at -23 bars in F. mandshurica and -29 bars in F. rhynchophylla. 4. The dark respiration rates of leaves were similar from $10^{\circ}C$ to $40^{\circ}C$ between these species, Also these increased from -10 bars to -28 bars, and then decreased remarkably in these species. 5. The net photosynthetic rates of leaves of F. mandshurica were higher than those of F. rhynchoplaylla until June, and after that lower than F. rhynchophylla. The dark respiration rates of leaves of F. rhynchophylla were higher than those of F. mandshurica from June to August, and After that similar between these species. 6. The respiration rates of stem and root were highest in April during the growing season. These values of F. rhynchophylla were slightly higher than those of F. mandshurica throughout the growing season.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.266-276
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• 2001

This study was conducted to clarify the taxonomic implications of F. chiisanensis Nakai based on morphology and flavonoids of four taxa of Fraxinus [F. chiisanensis Nakai, F. mandshurica Rupr., F. chinensis Roxb. var. rhynchophylla (Hance) Hemsl. and F. sieboldiana Blume] in Korea with one species of China and Japan (F. platypoda Oliv.). Morphologically F. chiisanensis was clearly distinguished from other taxa due to the presence of panicle from leafless lateral bud of previous year, apetalous flower, persistent calyx, and brownish naked bud. A survey of the foliar flavonoids of five species showed two distinctive chemical types. Unique flavones with flavonols, C-glycosylflavone and flavanone were detected in F. chiisanensis (chiisanensis type), while only flavonols, C-glycosylflavone, and flavanone were present in other four taxa (chinensis type). This study showed that F. chiisanensis was not a hybrid between F. mandshurica and F. chinensis var. rhynchophylla, but an endemic taxon distributed in southwestern Korea. Morphologically F. chiisanensis should be included into subgen. Fraxinus, sect. Melioides according to Chang and Qiu's classification. F. platypoda, a taxon of sect. Meliodies in China and Japan, was different from F. chiisanensis with respect of scaled bud, decurrent wing of samara and the lack of flavones (chinensis type). Since four American taxa of sect. Melioides contained flavones (chiisanensis type), they are more closely related with F. chiisanensis chemically.