• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2009-2014
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• 2012

Objective: Taspine, isolated from Radix et Rhizoma Leonticis has demosntrated potential proctiective effects against cancer. Tas13D, a novel taspine derivative synthetized by structure-based drug design, have been shown to possess interesting biological and pharmacological activities. The current study was designed to evaluate its antiproliferative activity and underlying mechanisms. Methods: Antiproliferative activity of tas13D was evaluated by xenograft in athymic mice in vivo, and by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and cell migration assays with human liver cancer (SMMC-7721) cell lines in vitro. Docking between tas13D and VEGFR and EGFR was studied by with a Sybyl/Surflex module. VEGF and EGF and their receptor expression was determined by ELISA and real-time PCR methods, respectively. Results: Our present study showed that tas13D inhibited SMMC-7721 xenograft tumor growth, bound tightly with the active site of kinase domains of EGFR and VEGFR, and reduced SMMC-7721 cell proliferation (IC=34.7 ${\mu}mol/L$) and migration compared to negative controls. VEGF and EGF mRNAs were significantly reduced by tas13D treatment in a dose-dependent manner, along with VEGF and EGF production. Conclusion: The obtained results suggest that tas13D inhibits tumor growth and cell proliferation by inhibiting cell migration, downregulating mRNA expression of VEGF and EGF, and decreasing angiogenic factor production. Tas13D deserves further consideration as a chemotherapeutic agent.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.221-225
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• 2009

Lithospermum erythrorhizon has been known well as one of traditional medicine for fever reduction, detoxication, and blood circulation improvement. This study was carried out to isolate biological active compounds from roots of Lithospermum erythrorhizon and to investigate their low density lipoprotein (LDL) antioxidant and anticancer activities. The hexane extract of Lithospermi Radix has been separated on silica gel chromatography and a naphthoquinone pigment compound 1 has been isolated. The structure of the compound 1 has been identified by spectroscopic technique, including MS and NMR, as acetylshikonin (1). Acetylshikonin showed significantly inhibitory activity on $Cu^{2+}$-induced human LDL oxidation with $IC_{50}$ value of $8.8\;{\mu}M$ and obvious anticancer effect by inhibiting farnesyl:protein transferase (FPTase) activity with $IC_{50}$ value of $23\;{\mu}M$, which suggested that acetylshikonin might be useful for the treatment of atherosclerosis and cancer.

• Analytical Science and Technology
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• v.13 no.4
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• pp.504-510
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• 2000

The impurity profiles from the raw materials of glycyrrhizin were performed by the high performance liquid chromatography (HPLC)/electrospray ionization (ESI)- mass spectrometry (MS). For the HPLC experiment, a $C_{18}$($3.9{\times}300mm$, $10{\mu}m$) column was used and the mobile phase was acetic acid/$H_2O$ (1:10):acetonitrile=3:2 with a flow rate of 0.8 ml/min. The effluent was splitted into the ratio of 50:1 and went into the ESI-MS. Three to six impurities were found and informed of the identification of the structure of the impurities by ESI-MS. And the structures of impurities were suggested to a hydroxy-glycyrrhizin which is added with hydroxy group (-OH) in the glycyrrhetic acid moiety and a reduced-glycyrrhizin which the position of 12 of the glycyrrhetic acid moiety is reduced. The purities of the standard materials were about 90%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.9C
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• pp.861-870
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• 2002

In this paper, with targeting on the drawback of RSA of operation speed, a new 1024-bit RSA cryptosystem has been proposed and implemented in hardware to increase the operational speed and perform the variable-length encryption. The proposed cryptosystem mainly consists of the modular exponentiation part and the modular multiplication part. For the modular exponentiation, the RL-binary method, which performs squaring and modular multiplying in parallel, was improved, and then applied. And 4-stage CSA structure and radix-4 booth algorithm were applied to enhance the variable-length operation and reduce the number of partial product in modular multiplication arithmetic. The proposed RSA cryptosystem which can calculate at most 1024 bits at a tittle was mapped into the integrated circuit using the Hynix Phantom Cell Library for Hynix 0.35㎛ 2-Poly 4-Metal CMOS process. Also, the result of software implementation, which had been programmed prior to the hardware research, has been used to verify the operation of the hardware system. The size of the result from the hardware implementation was about 190k gate count and the operational clock frequency was 150㎒. By considering a variable-length of modulus number, the baud rate of the proposed scheme is one and half times faster than the previous works. Therefore, the proposed high speed variable-length RSA cryptosystem should be able to be used in various information security system which requires high speed operation.