• YAKHAK HOEJI
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• v.43 no.6
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• pp.696-702
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• 1999

The first and versatile total synthesis of isopimarol diterpene has been achieved via stereoselective construction of C-13 quaternary carbon unit as a key step. Isopimarol diterpene was synthesized from the known decalone in 17% overall yield of 16 steps.

• Journal of Life Science
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• v.10 no.1
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• pp.107-113
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• 2000

This study carried out to investigate activities of the superoxide dismutase(SOD), peroxidase(POD) and diterpene cyclase of rice plant treated by environmental stress conditions. The rice leaves of Ilpum was shown to have the most highest specific activity of POD. POD activity in the susceptible cv. Ilpum and Hwasung during the disease progress show a increase, while for a decreasing activity in the resistant cv. Dasan. SOD activity of rice plants treated by chitosan were increased as the treatment concentration increased. At the chitosan application, the SOD activity in the susceptible cv. Hwansung at the rice leaves 14days after treatment was higher in treatment than chitosan-untreated control. The activity of POD in the susceptible cv. Ilpum decreased as long as UV-B irradiation, while that in the resistant cv. Dasan increased. Futhermore, activity of that in Dasan were similar to as time on UV irradiation, Hwasung showed two times higher than untreated control at 40 minutes after UV-B exposure. The activity of diterpene cyclase in rice plants inoculated with Pyricularia oryzae has much higher tendency than UV-B irradiation. The activity of diterpene cyclase in the rice leaves gradually increased until 5 days after inoculation with Pyricularia oryzae.

• YAKHAK HOEJI
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• v.16 no.2
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• pp.65-72
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• 1972

A new diterpene glycoside, $C_{26}H_{44}O_{8}{\cdot}H_{2}O, $ m.p. <$225-6^{\circ}, [{\alpha}]_D^{20}=-48^{\circ}$ (0.1% in EtOH) was isolated from methylalcohol extract of Siegesbeckia pubescens $M_{AKINO}$ which has been used as a folk remedy for hypertensive in Korea and its chemical structure was established as (III).

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.660-664
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• 2006

The aerial part of Siegesbeckia pubescens (Compositae) has been used to treat rheumatoid arthritis and hypertension in the Oriental medicine. This crude drug has been used without process (SP-0) or with three times-process of steaming and drying (SP-3) or the nine times of that process (SP-9). To search for the antinociceptive anti-inflammatory components from this crude drug, activity-directed fractionation was performed on this crude drug. Since the $CHCl_3$ extract was shown to have a more potent effect than other extracts, it was subjected to silica gel & ODS column chromatography to yield two diterpene compounds (1). Compound 1 was structurally identified as ent-16 (H, 17-hydroxykauran-19-oic acid, which were tentatively named siegeskaurolic acid A. A main diterpene, siegeskaurolic acid A was tested for the antiiflammatory antinociceptive effects using both hot plate- and writhing anti-nociceptive assays and carrageenan-induced anti-inflammatory assays in mice and rats. Pretreatment with siegeskaurolic acid A (20 and 30mg/kg) significantly reduced the stretching episodes, action time of mice and carrageenan-induced edema. These results support that siegeskaurolic acid is a main diterpene responsible for antinociceptive and antiiflammatory action of S. pubescens. In addition, the assays on SP-0, SP-3 and SP-9 produced the experimental results that SP-9 had more significant effects than other two crude drugs. These results suggest that the processing on the original plant may lead to the higher pharmacological effect.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.189-191
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• 1986

The effects of diterpene acids (i. e. pimaradienoic acid, kaurenoic acid, hydroxy cembratrienoic acid and dihydroxycembratetraenoic acid) on malondialdehyde generation by rat platelets in response to thrombin were studied. All the compounds inhibited the generation of MDA.

• Korean Journal of Pharmacognosy
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• v.18 no.2
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• pp.103-106
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• 1987

Two diterpene alkaloids were isolated from Aconitum napiforme which is a native plant in Korea, and identified as hypaconitine and mesaconitine by UV, IR, MS and NMR data.

• Natural Product Sciences
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• v.10 no.2
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• pp.59-62
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• 2004

A novel chlorinated diterpene quinone methide; chlorosmaridione (7-chloro-11-hydroxy-abeita-7,9(11),13-triene-6,12-diode) was isolated from petroleum ether extract of the stems of Rosemarinus officinalis L. growing in Egypt. In addition, ${\beta}-sitosterol$, stigmasterol, lupeol acetate, ${\alpha}-amyrin,\;{\beta}-amyrin$, lupeol, acetyloleanolic acid, acetylursolic acid taxodione, horminone, and cryptotanshinone were also identified. Chemical structures of the isolated compounds have been elucidated on the bases of physical, chemical, and spectral data including IR, UV, MS, 1D-and 2D-NMR spectra.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3840-3842
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• 2013

• Korean Journal of Pharmacognosy
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• v.4 no.2
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• pp.63-65
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• 1973

A component, $C_{20}H_{32}O_3$, m.p. $207.5^{\circ}$, was isolated from Siegesbeckia pubescens $M_{AKINO}$. This compound was identified as $17-hydroxy-16{\beta}-(-)-kauran-19-oic\;acid$, using spectroscopies and synthesizing various derivatives of the compound.

• Korean Journal of Pharmacognosy
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• v.19 no.3
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• pp.181-187
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• 1988

$Two\;C_{19}-diterpene\;alkaloids$ were isolated from the root of Aconitum psedolaeve var. erectum Nakai, and identified as lycoctonine and septentriodine by UV, IR, MS and NMR data.