• YAKHAK HOEJI
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• v.39 no.2
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• pp.200-204
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• 1995

Chemical examination of the leaves of Rubus coreanum has led to the isolation and characterization of six phenolic compounds. The structures of these compounds were elucidated as kaempferol(l), quercetin(2), sodium salt of quercetin 3-O-$\beta$-D-glucuronide(3), sodium carboxylate of quercetin 3-O-$\beta$-D-glucuronide(4), ellagic acid(5) and sanguiin H-5(6) on the basis of physicochemical and spectroscopic evidences.

• YAKHAK HOEJI
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• v.43 no.5
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• pp.547-552
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• 1999

Phytochemical examination of the leaves of Alnus hirsuta, one of the indigenous species grows in Korea, has led to the isolation of one flavan 3-ol and two flavonol glycosides. Structures of these compounds are identified as (-)-epicatechin (1), quercetin $3-O-{\beta}-D-galactopyranoside$ (2), quercetin $3-O-{\beta}-D-galactopyranoside$ (3) by means of physico-chemical and spectral evidences.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.280-285
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• 2012

Six polyphenolic compounds, such as chlorogenic acid (CA), rutin (RT), isoquercitrin (IQT), quercetin-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (QMG), astragalin (AG), kaempferol-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (KMG), were isolated from mulberry leaves by a series of isolation procedures, such as Diaion HP-20, silica-gel, Sephadex LH-20, and ODS-A column chromatographies. The chemical structures of the phenolic compounds were identified by UV and NMR spectral analyses. Levels of polyphenols in mulberry leaves from six different mulberry cultivars ranged from 1,042.16 to 1,871.97 mg% per dry weight; Guksang cultivar showed the highest levels of polyphenols, whereas Gaeryangdaehwa contained the least polyphenol contents. Generally, levels of polyphenols in mulberry leaves decreased with increasing harvest time, except for Yoolmok, but increased with heat processing time, except QMG and KMG. These results suggest that the heat processed mulberry leaves of Guksang cultivar harvested in early May can be potentially useful sources for production of high quality mulberry leaf teas.

• Culinary science and hospitality research
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• v.23 no.8
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• pp.90-97
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• 2017

This study investigated optimal extraction conditions for application of Hippophae rhamnoides leaves as a natural antioxidant. Hippophae rhamnoides leaves were extracted using ethanol at various concentrations (0, 30, 50, and 70%) and extraction times (4, 8, and 12 hrs) at $70^{\circ}C$ and then evaluated for extraction yield (22.51%), total phenolic contents (84.21~149.25 mg/g), total flavonoid contents (63.10~124.14 mg/g), as well as antioxidant activities DPPH, ABTS radical scavenging activity, reducing power, and FRAP. Antioxidant activities (DPPH, ABTS radical scavenging activity, reducing power) were correlated with total phenolic and flavonoid contents. 70% EtOH extracts for 12 h at $70^{\circ}C$ showed the highest total phenolic and flavonoid contents with strong antioxidant activities, and that the leaves of Hippophae rhamnoides could be considerd as a candidate of new functional antioxidant agents. This extract could be a good source for natural antioxidants and good health food. This work offers would be useful for chemical and biological studies of natural plants and its products.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.417-424
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• 2019

Melanose, caused by Diaporthe citri, is one of severe diseases in citrus, a major economic resource in Jeju island. To reduce the usage amount of organic synthetic fungicide, bio-sulfur was tested as an alternative chemical to control citrus melanose in the present study. Direct antifungal activity of bio-sulfur against D. citri was determined through in vitro experiment using artificial nutrient media. Disease severity of melanose on bio-sulfur pretreated citrus leaves was lower than that on untreated ones. To illustrate the mechanism of disease suppression by bio-sulfur, infection structures were observed with a fluorescent microscope and a scanning electron microscope. In fluorescent microscopic observation, most conidia rarely germinated. In addition, hyphal growth on leaves pretreated with bio-sulfur was inhibited compared to that on untreated ones. In scanning electron microscope images of bio-sulfur pretreated leaves, surfaces of most conidia were shrunk while hyphae were morphologically changed and frequently branched. Such microscopic observations were also found for leaves pretreated with a commercial fungicide Dithianon. These results suggest that bio-sulfur may be used to control citrus melanose as an environment friendly alternative to organic synthetic fungicides

• Biomedical Science Letters
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• v.28 no.4
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• pp.322-326
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• 2022

The purpose of this study was to develop hydrolysate from silkworm (Cudrania Silkworm Fibroin Peptide; CSFP), a food containing components for improving blood vessel health. In general, Cudrania tricuspidata leaves contain about 5 times more rutin and 25 times more dihydroquercetin than mulberry leaves. 1-Deoxynojirimycine (1-DNJ), dihydroquercetin and rutin inhibit the activity of carbohydrate-digesting enzymes, inhibit blood lipid peroxidation, and regulate insulin secretion, which helps blood vessels to be healthy. When the diet-controlled silkworm was enzymatically hydrolyzed, it was confirmed that rutin content was about 8 times higher than that of the in general silkworm as a control. In the silkworm hydrolysate, CSFP, developed as a final food material, the active ingredients were 65 mg/kg for rutin, 3,328 mg/kg for DNJ, 0.43 mg/kg for dihydroquercetin, and 82,624 mg/kg for total polyphenol, which was confirmed through LC-MS/MS analysis. In conclusion, it was found that silkworms fed with C. tricuspidata leaves as a diet had more active components that can help control blood sugar and improve blood vessel health than silkworms fed with mulberry leaves.

• KSBB Journal
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• v.17 no.4
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• pp.357-364
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• 2002

For the effecient extraction methods of essential oil, pretreatment of leaves, ratios of water and leaves, extraction time, and collection season from the Chamaecyparis obtusa and Chamaecyparis pisifera leaves were studied. The chemical composition of essential oil was analyzed by GC-MS. The yield of essential oil from ground leaves was higher than that of chopped leaves. The yield of essential oil was not affected much by mixing ratios of water and leaves. The yield of essential oil reached maximum after 5 hours. The content of essential oil of C. obtusa leaves collected during winter was 4.5%, whereas the content of essential oil of C. pisifera collected during fall was 5.3%. The composition of essential oils extracted form C. obrusa and C. pisifera was different. The major constituents in the essential oil of C. obtusa were monoterpene as limonene, terpinene-4-ol, ${\gamma}$-selinene, and a-cedrene, and those of C. pisifera was monoterpens as ${\alpha}$-pinene, myrcene, limonene, bornyl acetate, ${\beta}$- caryophyllene, longifolene, and ${\beta}$-cedrene.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.40-45
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• 2003

Volatile components in the leaves and fruits of Z. schinjfolium and Z. piperitum were analyzed by Headspace SPME(Solid phase Microextraction). Fifty two and 48 components in the leaves and fruits, repectively, were identified in Z. schinifolium. (E)-2-hexenal, ${\alpha}-pinene$, (Z)-ocimene+limonene, estragole, germacrene-d were detected at common components in the leaves and estragole in the fruits of Z. schinjfolium. Regardless of collection sites hexanal, (Z)-3-hexenol, (E)-2-hexenal, n-hexanol were appeared in the leaves while undecanone in the fruits. Thirty and 27 components in the leaves and fruits, respectively, were identified in Z. piperitum. ${\alpha}-pinene,\;{\beta}-phellandrene$, 1,8-cineole, citronellal and myrcene, (Z)-ocimene+limonene, ${\beta}-phellandrene$ were appeared as common components in the leaves and fruits collected from Baeck-yang-sa and Nae-jang-sa. (Z)-3-hexenol, (E)-2-hexenal, ${\alpha}-pinene\;myrcene\;and\;{\beta}-phellandrene$, citronellal, geranyl acetate were major components in the leaves and fruits from Tong-do-sa.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.141-146
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• 1994

As a foundational study for processing persimmon leaves tea, the physico-chemical characters were investigated in persimmon leaves from Chungdo Bansi, Sagoksi, Kyungsan Bansi and Hiratanenasi during growth. Flesh weights increased rapidly until the middle of May and then decreased slightly. Moisture contents decreased continuously from $79{\sim}81%$ at the beginning of May during growth. Water soluble tannin contents reached $1.55{\sim}2.25%$, maximum values at the middle of May and at the beginning of June, and increased again at the middle of July and then decreased. Contents of catechins, precursor of condensed tannin, indicated $12{\sim}27\;mg%$ at the middle of May and reached $17{\sim}34\;mg%$, maximum values at the middle of June. Contents of catechin were low in order of (+)-catechin, (-)-epicatechin, (-)-epicallocatechingallate, (-)-epigallocatechin and (-)-epicatechingallate. Sugars present in persimmon leaves were composed of sucrose, glucose, fructose, raffinose and mannitol. Sucrose increased continuously, glucose and fructose decreased during growth. Raffinose content was less than 0.1%. Glucose and fructose took more than 90% until the beginning of May, and then sucrose took up $60{\sim}80%$ of total sugar contents. Total vitamin C contents indicated maximum values at the middle of May and at the beginning of June in Chungdo Bansi, Sagoksi and Kyungsan Bansi, maximum vaule at the middle of July in Hiratanenasi. From the basis of these data It was suggested that proper period for picking persimmon leaves prior to processing persimmon leaves tea was from the middle of May to the beginning of June. Since maximum values for most of chemical components occurred at the middle of May and at the beginning of June and persimmon leaves thicken after the middle of June.

• Journal of the Korean Society of Tobacco Science
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• v.29 no.2
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• pp.85-89
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• 2007

This study was conducted to evaluate the prediction of sensory characteristics of smoke from the leaf chemical compounds and characterize leaf chemical components for the best tobacco taste's leaves in oriental tobacco. For analytical and sensory evaluations, seventy two grades were used. Sensory evaluation of tobacco smoke for six attributes were scored on fifteen-point scale by $10{\sim}14$ expert panels trained to estimate smoking quality quantitatively. The major leaf chemical compounds to predict the sensory characteristics of smoke were ether extract for tobacco-like, nicotine for impact and total nitrogen/nicotine ratio for irritation, and total sugar for off taste & odor. Within ${\pm}20%$ range of difference, the predictable probabilities of sensory characteristics of smoke from the leaf chemical compounds were 87.5 % for off taste & odor and $94.4{\sim}98.6\;%$ for tobacco-like, impact and irritation. As a result of K-means cluster analysis on the basis of tobacco taste, the desirable leaf chemical compound contents were $5.9{\sim}8.3\;%$ in ether extract, $1.35{\sim}2.27\;%$ in nicotine and $1.17{\sim}2.24$ in total nitrogen/nicotine ratio. This study suggest that the some regression equations may be useful to predict the sensory characteristics of tobacco smoke with a few selected leaf chemical compounds in oriental tobacco and to select the oriental tobacco leaves by means of enhancing the tobacco taste of cigarette.