• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5895-5900
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• 2013

Dictamnine (Dic) has the ability to exert cytotoxicity in human cervix, colon, and oral carcinoma cells and dihydroartemisinin (DHA) also has potent anticancer activity on various tumour cell lines. This report explores the molecular mechanisms by which Dic treatment and combination treatment with DHA and Dic cause apoptosis in human lung adenocarcinoma A549 cells. Dic treatment induced concentration- and time-dependent cell death. FCM analysis showed that Dic induced S phase cell cycle arrest at low concentration and cell apoptosis at high concentration in which loss of mitochondrial membrane potential (${\Delta}{\Psi}m$) was not involved. In addition, inhibition of caspase-3 using the specific inhibitor, z-DQMD-fmk, did not attenuate Dic-induced apoptosis, implying that Dic-induced caspase-3-independent apoptosis. Combination treatment with DHA and Dic dramatically increased the apoptotic cell death compared to Dic alone. Interestingly, pretreatment with z-DQMD-fmk significantly attenuated DHA and Dic co-induced apoptosis, implying that caspase-3 plays an important role in Dic and DHA co-induced cell apoptosis. Collectively, we found that Dic induced S phase cell cycle arrest at low concentration and cell apoptosis at high concentration in which mitochondria and caspase were not involved and DHA enhanced Dic induced A549 cell apoptosis via a caspase-dependent pathway.

• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.209-214
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• 1997

This study was carried out to find new antitumor agents from plant resource. Three cytotoxic agents were isolated from the root of Dictamnus albus by hexane extraction, silica gel column chromatography and HPLC. They were identified to be dictamnine $(C_{12}H_9NO_2)$, preskimmianine $(C_{17}H_{21}NO_4)$ and fraxinellone $(C_{14}H_{16}O_3)$ on the basis of spectroscopic evidences. In this study, it was newly found that these compounds possess a cytotoxic activity against lung lymphoma L1210 cell line. Among them. Preskimmianine was the most potent against the lymphoma L1210 with a $IC_{50}$ of $3.125\;{\mu}g/ml\;(10.3\;{\mu}M)$. Toxicity of preskimmianine against normal Iymphocyte was observed at the concentration of $50\;{\mu}g/ml\;(165\;{mu}M)$. These results support the pharmacological role of D. albus, a herb known as Paeksun in Korea and used as an anticancer agent in folk medicine.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.78-85
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• 1998

The antifungal activity of methanol extracts against dermatophytes was the highest at root-bark methanol extract, and the highest inhibitory effect was revealed in petroleum ether fraction of root-bark methanol extract. Compound I and compound II with significant antifungal activity were isolated from the fractions by silica gel column chromatography. As a result of the instrumental analyses, compound I and compound II were already known alkaloids. Compound I was identified as 4-methoxyfuro[2,3-6]quinoline (dictamnine ; $C_{12}H_9NO_2$) and compound II was identified as 4-methoxy-lmethyl-2(1H)-quinolinone ($C_{11}H_{11}NO_2$). The MIC of compound I against T. mentagrophytes and T. rubrum was $40{\mu}g/m\ell$ and the MIC of compound II against the same fungi was $800{\mu}g/m\ell$.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.1-15
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• 2005

Pathogens, insects and weeds have significantly reduced agricultural productivity. Thus, to increase the productivity, synthetic agricultural chemicals have been overused. However, these synthetic compounds that are different from natural products cannot be broken down easily in natural systems, causing the destruction of soil quality and agricultural environments and the gradually difficulty in continuous agriculture. Now agriculture is faced with the various problems of minimizing the damage in agricultural environments, securing the safety of human health, while simultaneously increasing agricultural productivity. Meanwhile, plants produce secondary metabolites to protect themselves from external invaders and to secure their region for survival. Plants infected with pathogens produce antibiotics phytoalexin; monocotyledonous plants produce flavonoids and diterpenoids phytoalexins, and dicotylodoneous plant, despite of infected pathogens, produce family-specific phytoalexin such as flavonoids in Leguminosae, indole derivatives in Cruciferae, sesquitepenoids in Solanaceae, coumarins in Umbelliferae, making the plant resistant to specific pathogen. Growth inhibitor or antifeedant substances to insects are terpenoids pyrethrin, azadirachtin, limonin, cedrelanoid, toosendanin and fraxinellone/dictamnine, and terpenoid-alkaloid mixed compounds sesquiterpene pyridine and norditerpenoids, and azepine-, amide-, loline-, stemofoline-, pyrrolizidine-alkaloids and so on. Also plants produces the substances to inhibit other plant growths to secure the regions for plant itself, which is including terpenoids essential oil and sesquiterpene lactone, and additionally, benzoxazinoids, glucosinolate, quassinoid, cyanogenic glycoside, saponin, sorgolennone, juglone and lots of other different of secondary metabolites. Hence, phytoalexin, an antibiotic compound produced by plants infected with pathogens, can be employed for pathogen control. Terpenoids and alkaloids inhibiting insect growth can be utilized for insect control. Allelochemicals, a compound released from a certain plant to hinder the growth of other plants for their survival, can be also used directly as a herbicides for weed control as well. Therefore, the use of the natural secondary metabolites for pest control might be one of the alternatives for environmentally friendly agriculture. However, the natural substances are destroyed easily causing low the pest-control efficacy, and also there is the limitation to producing the substances using plant cell. In the future, effects should be made to try to find the secondary metabolites with good pest-control effect and no harmful to human health. Also the biosynthetic pathways of secondary metabolites have to be elucidated continuously, and the metabolic engineering should be applied to improve transgenics having the resistance to specific pest.