• Natural Product Sciences
• /
• v.7 no.2
• /
• pp.33-37
• /
• 2001

Methanol extracts of eighty Chinese medicinal plants were investigated for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Extracts of Cratoxylon ligustrinum, Kalimeris indica, Euonymus japonica, Ophiopogon japonicus, Gleditsia sinensis, Clausena lansium, Agave sisalana were found to exhibit significant inhibitory effects. Chloroform partition of the Methanol extract of Kalimeris indica was further fractionated by column chromatography to afford one strong active subfraction with 93.6% inhibition at a concentration of $100{\mu}g/ml$.

• Nuclear Engineering and Technology
• /
• v.47 no.4
• /
• pp.500-511
• /
• 2015

In this study, the natural frequencies of the perforated square plate with a square penetration pattern are obtained as a function of ligament efficiency using the commercial finite-element analysis code ANSYS. In addition, they are used to extract the effective modulus of elasticity under an assumption of a constant Poisson's ratio. The effective modulus of elasticity of the fully perforated square plate is applied to the modal analysis of a partially perforated square plate using a homogeneous finite-element analysis model. The natural frequencies and the corresponding mode shapes of the homogeneous model are compared with the results of the detailed finite-element analysis model of the partially perforated square plate to check the validity of the effective modulus of elasticity. In addition, the theoretical method to calculate the natural frequencies of a partially perforated square plate with fixed edges is suggested according to the Rayleigh-Ritz method.

• Natural Product Sciences
• /
• v.15 no.2
• /
• pp.90-95
• /
• 2009

Phytochemical investigation of the MeOH extract of the leaves of Nelumbo nucifera resulted in the isolation of five norsesquiterpenes, four flavonoids, two triterpenes and one alkaloid. Their chemical structures were characterized by spectroscopic methods to be (E)-3-hydroxymegastigm-7-en-9-one (1), (3S,5R,6S,7E)- megastigma-7-ene-3,5,6,9-tetrol (2), dendranthemoside B (3), icariside $B_2$ (4), sedumoside $F_1$ (5), luteolin (6), quercetin 3-0-${\beta}$-D-glucuronide (7), quercetin 3-0-${\beta}$-D-glucoside (8), isorhamnetin 3-0-rutinoside (9), alphitolic acid (10), maslinic acid (11), and N-methylasimilobine (12). Norsesquiterpenoids (1-5) and triterpenes (10-11) were isolated for the first time from this plant. Compounds 6 and 10-12 exhibited considerable cytotoxicity against four human cancer cell lines in vitro using a SRB bioassay.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.05a
• /
• pp.76-76
• /
• 2003

Oxidative stress is considered to be associated with many diseases, such as inflammatory and cardiovascular diseases, aging, and cancer. An important etiological mechanism of these diseases may be a causal relationship between the presence of oxidants and the generation of lipid hydroperoxides derived from enzymatic reactions or xenobiotic metabolism. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.8
• /
• pp.725-733
• /
• 2013

An improved formulation of the MNDIF method is introduced to extract highly accurate natural frequencies of concave plates with arbitrary shape. Originally, the MNDIF method cannot yield accurate natural frequencies for concave plates. It can be applicable to only convex plates. To overcome this weak point, a new approach of dividing a concave plate into two convex domains and applying the MNDIF method to each domain is proposed and the validity and accuracy are shown in verification examples.

• Korean Journal of Pharmacognosy
• /
• v.43 no.2
• /
• pp.127-136
• /
• 2012

Eight flavonoids were isolated from the BuOH fraction of the 70% EtOH extract of Zizyphus jujuba var. spinosa seeds along with three known compounds, daucosterol (1), butyl ${\beta}$-D-fructofuranoside (2), and magnoflorine (4). On the basis of spectroscopic methods and comparison with literature values their structures were elucidated as 6"'-feruloylspinosin (3), nicotiflorin (5), 6"'-p-coumaroylspinosin (6), isospinosin (7), 6"'-vanilloylspinosin (8), spinosin (9), hovetrichoside C (10), and camelliaside B (11). Compounds 1, 2, 10, and 11 were isolated from this plant for the first time.

• Korean Journal of Pharmacognosy
• /
• v.14 no.4
• /
• pp.145-148
• /
• 1983

Angiotensins and bradykinin play important roles in blood pressure regulation and in other physiological and pathological conditions. The present work is aimed to investigate potential antagonists against either angiotensin or bradykinin from plant sources. Each methanol extract of selected 25 plants was solvent fractionated to three fractions. The effects of total of 75 plant samples against the contractions induced by angiotensin I or bradykinin in rat ileum were measured. The results are summarized.

• Korean Journal of Pharmacognosy
• /
• v.39 no.2
• /
• pp.91-94
• /
• 2008

Column chromatographic separation of the MeOH extract from the aerial parts of Paris verticillata led to the isolation of three phenolics, two terpene glucosides and two pyrrolidine alkaloids. Their structures were characterized to be methyl caffeate (1), 5-hydroxy pyrrolidin-2-one (2), vanillic acid (3), benzyl alcohol glucopyranoside (4), (6S, 9R)-roseoside (5), staphylionoside H (6) and 5-methoxy pyrrolidin-2-one (7) by spectroscopic means. The isolated compounds (1-7) were for the first time reported from this source. The isolated compounds were tested for their cytotoxicity against four human tumor cell lines by SRB method in vitro.

• Korean Journal of Pharmacognosy
• /
• v.39 no.1
• /
• pp.37-42
• /
• 2008

From the 70% EtOH extract from the roots of Paeonia lactiflora (Paeoniaceae), nine triterpenoids were isolated and identified as ${\beta}-amyrin$ (1), 24-methylenecycloartanol (2), betulinic acid (3), oleanolic acid (4), hederagenin (5), 30-norhederagenin (6), 30-norarjunolic acid (7), arjunolic acid (8), and $3{\beta},4{\beta},23-trihydroxy-24,30-dinorolean-12,20(29)-dien-28-oic$ acid (9) by spectroscopic methods. Among these compounds, 1, 2, 7, 8 and 9 were isolated for the first time from this plant.

• Korean Journal of Pharmacognosy
• /
• v.39 no.1
• /
• pp.28-36
• /
• 2008

From the 70% EtOH extract of Paeonia lactiflora roots (Paeoniaceae), fourteen phenolic and related compounds were isolated. They were identified as ${\alpha}-tocopherol$ (1), dioctylphthalate (2), ${\alpha}-tocospiro$ B (3), paeonol (4), 3,3'-di-O-methylellagic acid(5), 3,4'-di-O-methylellagic acid (6), benzoic acid (7), aromadendrin (8), p-hydroxybenzoic acid (9), (+)-catechin (10), gallic acid (11), nicotinamide (12), methyl gallate (13) and $1,2,3,4,6-penta-O-galloyl-{\beta}-D-glucose$ (14) by spectroscopic methods. Among these compounds, 1-3, 5, 6, 8 and 12 were isolated for the first time from this plant.