• The Korean Journal of Ecology
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• v.16 no.2
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• pp.181-190
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• 1993

To elucidate phytotoxic effects on the growth of receptor plant, germination and growth experiment of selected species have been performed with aqueous extracts and volatile substances of leaf and of donor plant, Thuja orientalis. The extracts of T. inversely proportional to the concentration. Gas chromatography method was employed for analysis and indentification of phytotoxic substances from T. orientalis. Forty-two kinds of KDICicals including ${\alpha}-thujone$ were identified from T. orientalis essential oil. Bioassay was performed with 6 KDICical such as ${\alpha}-pinene, \;{\alpha}-terpinene, \;{\gamma}-terpinene, \; {\beta}-myrcene$, and among them bornyl acetate was the strongest growth inhibitor.

• The Korean Journal of Ecology
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• v.27 no.5
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• pp.307-310
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• 2004

It was found that seed germination and seedling growth of selected species were inhibited by phytotoxic substance released from fir trees. The aqueous extracts of leaves caused significant inhibition in the seed germination of the receptor plants, Whereas seed germination of some species was not inhibited in extracts of leaves, but seedling elongation of the receptor plants was also decreased by the aqueous extract. Dry weight growth was slightly increased in lower concentration of the extract, while that was proportionally inhibited by higher concentration of the extracts. Chemical substances of fir trees were shown the biological toxicity. The GC method was employed for analysis of phytotoxic chemicals and sixteen chemical substances were identified such as benzoic, phenylacetic, etc. Also 33 volatile substances were identified from the fir tree. These chemical compounds are assumed the substances related to allelopathic potential of Abies holophylla plant species.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.133-137
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• 1999

This study was undertaken to test for anti-Hepatitis B virus (HBV) activity of the aqueous extracts prepared from Eugenia caryophyllate, Ephedra sinica, Cinnamomum cassia. Aqueous extracts were assayed for the inhibition of HBV replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HePG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 128 to 256 $\mu$g/ml and inhibited the production of HBsAg dose-dependently. Our findings suggest that these three hebal medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.458-463
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• 1999

This study was undertaken to test for antiviral activity of the aqueous extracts prepared from 4 medicinal plants of Korea (Terminalia chebula, Sanguisorba officinalia, Rubus coreanus, Rheum palmatum). Aqueous extracts were assayed for the inhibition of hepatitis B virus (HBV) replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to $128{\;}\mu\textrm{g}/ml$ and inhibited the production of HBsAg dose-dependently. Among the 4 tested plants, Terminalia chebula exhibits the most prominent anti-HBV activities. Our findings suggest that these 4 medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.331-335
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• 2002

Aqueous extracts of garlic (Allium sativum) preparation were prepared after the samples were exposed to various heat treatments. A quantitative assessment of antimicrobial activities was carried out by determining the minimum inhibitory and microbicidal concentrations (MICs and MMCs) of the various extracts against some selected bacteria and fungi. The antimicrobial activity of garlic decreased as the heating temperature increased. This fact implies that alliinase may be the most critical rate-determinant to produce the activity when garlic is heated.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.1-7
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• 2019

Japanese anise (Illicium anisatum L.) leaves were collected and ground after drying, then immersed with 50 % aqueous acetone for 3 days. After filtration, the extracts were fractionated with n-hexane, chloroform ($CHCl_3$), ethylacetate (EtOAc) and $H_2O$, and then freeze dried after concentration. A portion of EtOAc (3.12 g) and $H_2O$ (6.08 g) soluble fractions were chromatographed on a Sephadex LH-20 column with various aqueous MeOH solution to isolate the compounds. Compound 1 ((+)-catechin) was isolated from EtOAc soluble fraction. Compounds 2 (quercetin), 3 (quercitrin) and 4 (2''-O-rhamnosylvitexin) were isolated from $H_2O$ soluble fraction. For the first time, quercitrin (3) and 2''-O-rhamnosylvitexin (4) of the isolated compounds were obtained from the extracts of japanese anise leaves.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.108-111
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• 2001

This study examined effects of aqueous extracts of rice bran on the inhibition of germination and early growth of annual weeds, barnyardgrass and eclipta. Germination of barnyardgrass treated with 5%(w/v)-sterilized and nonsterilized extracts of rice bran were inhibited by 27% and 63% at 7 days after treatment(DAT), respectively, compared to control. However, plant height and fresh shoot weight of barnyardgrass treated with aqueous extract of rice bran was reduced significantly at higher than 1% for both sterilized and nonsterilized extracts. Plant height and fresh shoot weight of barnyardgrass treated with 5% extract of rice bran were inhibited by 66 to 68% and 75 to 78% at 7 DAT, irrespective of sterilization. The germination of eclipta treated with sterilized and nonsterilized extracts of rice bran were significantly inhibited at concentrations of more than 0.5% and completely at 4% and 5%. Plant height and fresh shoot weight of eclipta affected by the rice bran extracts showed trends similar to the germination rate. The sterilization of rice bran extract resulted in higher inhibition of germination and early growth of eclipta. Rice bran extract was more inhibitory to the germination and growth of eclipta than barnyardgrass. These results suggest that aqueous extracts of rice bran may have inhibitory potential to germination and early growth of weeds.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9517-9522
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• 2014

Purple rice (Oryza sativa L. var. indica) cv. Kum Doisaket is cultivated in northern Thailand. This study evaluated the mutagenic and antimutagenic properties of hydrophilic and lipophilic components of purple rice using the Ames test. The seed and hull of purple rice were extracted with hexane, methanol, ethanol, and water. The methanol extracts had the highest amounts of phenolic acids and flavonoids, while the hexane extracts contained large amount of tocols and ${\gamma}$-oryzanol. None of the extracts were mutagenic in Salmonella typhimurium strains TA98 and TA100. The hexane extract of rice hull and the methanol extract of rice seed were strongly effective against aflatoxin B1- and 2-amino-3, 4 dimethylimidazo (4, 5-f) quinoline-induced mutagenesis, while aqueous extracts showed weakly antimutagenic properties. All extracts with the exception of aqueous extracts enhanced the number of revertant colonies from benzo (a) pyrene induced-mutagenesis. None of the extracts inhibited mutagenesis induced by the direct mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and sodium azide. The hull extracts showed more potent antimutagenicity than the seed extracts. Based on a chemical analysis, ${\gamma}$-oryzanol and ${\gamma}$-tocotrienol in the hull and cyanidin-3-glucoside and peonidin-3-glucoside in the seed are candidate antimutagens in purple rice. The antimutagenic mechanisms of purple rice might be related to either modulation of mutagen metabolizing enzymes or direct attack on electrophiles. These findings supported the use of Thai purple rice as a cancer chemopreventive agent.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.160-167
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• 1992

The growth of weeds and some other plants has been considered to be inhibited by sicklepod(Cassia tora L.) sharing the habitat. The study was conducted, for the first time, to propose that this phenomenon is not only due to competition for physical and nutritional conditions but also due to allelopathy. In addition, autotoxicity of sicklepod was examined. The results are summarized as follows. 1. Rice sheath length reduced progressively from 18 % to 36 % with increasing the concentration of treating aqueous extracts of sickle pod seeds, but rice germination was not affected. In contrast, radish hypocotyl length was not reduced by the aqueous extract treatment but radish germination was significantly reduced by 66 % at 1 : 10 and 1 : 5 treatment. 2. Total chlorophyll contents in rice seedling decreased from 50 % to 65 % by treatment of seed aqueous extracts diluted from 1 : 50 to 1 : 5 ratio. 3. Aqueous extracts of sicklepod leaves significantly reduced hypocotyl length and fresh weight in radish and germination in rice, but mung bean was slightly affected by aqueous extracts only in fresh weight. 4. Volatiles from fresh, immature seeds with husk reduced the radish germination and seedling growth and radish root growth appeared to be more sensitive to the exposure to volatiles from fresh immature seeds than both germination and hypocotyl growth. 5. Volatiles from sickepod leaves inhibited germination and growth of radish, rice and mung bean, and seedling growth was more sensitive to volatiles from leaves than germination. 6. Volatiles from sicklepod leaves reduced germination and radicle length of sicklepod itself. 7. Collectively, it is concluded that there are water-soluble and volatile substances responsible for allelopathy in sicklepod.

• Advances in Traditional Medicine
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• v.4 no.1
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• pp.53-59
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• 2004

The effect of aqueous and alcoholic extract of the leaves of Ocimum. sanctum was studied on the spontaneous movements of the whole worm (w.w) preparation and nerve muscle (n.m.) complex of Setaria cervi (S. cervi) and on the survival of microfilariae (m.f.) in vitro. Both the extracts caused inhibition of the spontaneous motility of the w.w. and n.m. complex of S. cervi characterized by initial stimulation followed by reversible paralysis, aqueous extract at a higher concentration showed immediate effect and irreversible paralysis. The concentration required to inhibit the movements of n.m. complex was $1/4^{th}$ for aqueous and $1/3^{rd}$ for alcoholic extract compared to that for the w.w., suggesting a cuticular permeability barrier. On the m.f. the lethal concentration (LC 50 and LC 90) were 35 and 50 ng/ml for aqueous whereas, 60 and 85 ng/ml for alcoholic extracts respectively.