• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.72-77
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• 2005

Streptococcus mutans is known as a strong cariogenic bacterium and produces dental caries. This study was carried out to develop anticariogenic agents from Callistemon citrinus. Crude extracts and thier various solvent fractions of the plant extracts were tested for the antibacterial activity against S. mutans. The anticariogenic activity was evaluated with by paper disc diffusion method and minimal inhibition concentration (MIC). The extract from the fruit and its hexane fraction showed a strong inhibitory effect on the growth of S. mutans and the MICs were 31.2 and $3.9{\mu}g/m{\ell}$, respectively.

• Korean Journal of Plant Resources
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• v.21 no.6
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• pp.431-434
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• 2008

Dental caries is the destruction of the enamel of teeth by Streptoccus mutans. S. mutans has been isolated from human dental plaque and is associated with the initial development of enamel lesions. We have studied the antibacterial action of the fruit of Callistemon citrin us against a cariogenic bacterium, S. mutans. From the fruit of C. citrinus, piceatannol (3,3',4',5-tetrahydroxystilbene) was isolated by repeated column chromatography with $SiO_2$ and Sephadex LH-20. Its structure was elucidated by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. This compound was isolated from the fruit of C. citrin us for the first time. The anticarcinogenic activity of this compound was determined by using agar well-diffusion method and minimal inhibition concentration (MIC).

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.107-113
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• 2002

This study was performed to obtain the information on fruit set, propagation and flowering habits of the exotic ornamental bottle brush tree (Callistemon citrinus). Trees have fruit capsules for four years since the fruit set and they have enlarged for three years. While 2 and 3-year-old capsules have similar seeds in number and size, 1-year-old ones have fewer and smaller seeds. Most dried capsules open when they have 75％ relative water contents. Two year old seeds which they were dried at 30％ germinated better than others. Removal of capsule bearing twigs resulted in greatly increased subsequent flower numbers (an average of 14 flowers per tree) compared with twigs where seed capsule were allowed to remain. In cutting for propagation, semi-hard wood branches dipped in 100mgι$^{-1}$ IBA for 24 hours rooted at 86.4 ％ and had an average of 12.6 primary roots.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.212-215
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• 2005

Ethanol crude extracts of wood, bark, leaf, and fruit of Callistenwn citrinus were compared for their antioxidant activities based on DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and reducing power. Bark extract showed the most potent radical-scavenging activity and reducing power, showing 94.1 and 0.64% at 25 and $100\;{\mu}g/mL$, respectively. Total phenolic content of the bark extracts (275.0 mg GAE/g) was higher than those of others. Further fractionation of the bark extract using hexane, $CH_2Cl_2$, and EtOAc showed EtOAc fraction had the highest antioxidant activity ($IC_{50}\;6.7\;{\mu}g/mL$) and reducing power (0.82 at $100\;{\mu}g/mL$), with total phenolic content of 611.1 mg GAE/g. Total phenolic contents correlated with antioxidant activity ($R^2\;=\;0.7061$) and reducing power ($R^2\;=\;0.7399$).