Simplified Analysis of Lipoprotein Lipase Activity: Evaluation of Lipasemic Activity of Low Molecular Weight Heparin in Rats

지준필,Chong-Kook Kim,Seung-Hyun Nam,박유미,이효종,박요한,맹한주 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.6

A simple procedure for measuring lipoprotein lipase activity was developed by using newly formulated substrate with turbidimetry method. The activity of lipoprotein lipase was expressed as Yvalue (%) that was calculated by measuring UV absorbance (600 nm) at two time points (30 sec and 15 min). Lipid emulsions as the substrate and other factors affecting the lipolytic activity of lipase were studied. The optimal conditions for an in vitro experiment were found to be with LIPOMCT® as lipid substrate at 37oC in tris-HCl buffer (pH 7.4) in the presence of BSA. To evaluate an in vivo applicability, low molecular weight heparin (LMWH)-containing drug, Sulodexide®, was administered to the rats. The serum from LMWH-administered rats was incubated in an optimized analytical condition without BSA. As expected, increasing the amount of LMWH administered led to higher lipase activity. The newly developed method was successfully applied to an in vivo model suggesting the potential to be applicable for the pharmacodynamic studies of commercially available products of LPL analogues in human subjects, and for the diagnosis of acute pancreatitis in the clinical laboratory.

Isolation and Identification of Steroidogenic Peptides from Calf Spleen

지준필,김종국,진수언,반은미,이효종,박유미,박요한,맹한주,김형태 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.4

Since women with climacteric syndrome have significantly lower serum levels of estradiol and other related hormones, hormone replacement therapies (HRT) such as estrogen are needed to lessen symptoms. However, HRT can often cause severe adverse effects that include many cancers and stroke. Therefore, new and novel approaches to relieve climacteric syndrome still need to be developed. The aim of this study was to identify biologically active peptides from calf spleen that are responsible for stimulating biosynthesis of steroid hormone and to explore the potential of isolated peptides as therapeutic agents for menopausal syndrome. The reverse phase HPLC system was used to isolate active compounds from calf spleen extract, a cell culture system was used to screen the activity of stimulating hormone secretion, and Matrix-Assisted Laser Desorption/Ionization (MALDI) mass spectrometry was used for molecular weight determination. In the present study, two calf steroidogenic peptides, CSP-1 (MW; 4.655 kDa) and CSP-2 (MW; 8.331 kDa), were isolated and identified from calf spleen and may be putative climacteric syndrome therapeutic agents.

Development of Hydrogel Lenses with Surface-immobilized PEG Layers to Reduce Protein Adsorption

지준필,김호중 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.11

This paper describes the synthesis and characterization of a series of poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogel lenses coated with poly(ethylene glycol) (PEG) chains. A novel tri-branched PEG-substituted hydrazide is synthesized, which imparts densely packed, covalently bound PEG layers on hydrogels, to determine whether branching provides improved coverage of the lens surface, thereby reducing protein adsorption. Surface modification of hydrogels with PEG was performed via amide-coupling reactions between PEG-substituted hydrazide and the pHEMA matrix. Protein adsorption, water content, optical transparency, and surface properties of the hydrogels were investigated. The hydrogels exhibited transmittance of >90% and improved surface hydrophilicity. Notably, the amount of lysozyme adsorbed on tri-branched PEG-coated hydrogels decreased significantly compared to the amount adsorbed onto the surface of control and linear PEG-coated hydrogels. These results provide insight into the mechanism by which PEGs reduce lysozyme adsorption and suggest that PEG coating may offer an intriguing potential for ophthalmic biomaterials as well as protein-resistant devices.

Design and Synthesis of Novel 2'(β)-Fluoro-3'(α)-hydroxy-threose Nucleosides: Iso-FMAU Analogues as Potent Antiviral Agents

김세연,지준필,홍준희 조선대학교 기초과학연구원 2015 조선자연과학논문집 Vol.8 No.2

Novel 2'(β)-fluoro-3'(α)-hydroxy-threose nucleosides (iso-FMAU) as antiviral agents were designed and racemically synthesized from Solketal. Condensation successfully proceeded from a glycosyl donor 9 under Vorbrüggen conditions yielded the nucleoside analogues. Ammonolysis and hydrolysis of isopropylidene protection group gave the desired nucleoside analogues 12, 15, 18, and 19. The antiviral activities of the synthesized compounds were evaluated against the HIV-1, HSV-1, HSV-2 and HCMV. Compound 12 displayed some anti-HCMV activity (EC50=24.7 μg/ml) without exhibiting any cytotoxicity up to 100 μM.

Synthesis and Anti-Retroviral Activity of Novel 5′-Deoxy-5′,5′-difluoro-threosyl Nucleoside Phosphonic Acid Analogs

김세연,지준필,홍준희 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.8

Novel 5′-deoxy-5′,5′-difluoro-threose purine phosphonic acid analogs were designed and synthesized from 2-propanone-1,3-diacetate. Direct displacement of the triflate intermediate 12 with diethyl (lithiodifluoromethyl)phosphonate provided the corresponding (α,α-difluoroalkyl) phosphonate 13. Condensation successfully proceeded from a glycosyl donor 14 under Vorbrüggen conditions to provide the nucleoside phosphonate analogs 15α, 15β, 18α, and 18β, respectively. Ammonolysis and hydrolysis of the phosphonates 15β and 18β yielded the nucleoside phosphonic acid analogs 16, 17, 19b, and 20. Also, synthesis of prodrugs of adenine derivative was performed to increase cellular uptake. The synthesized nucleoside analogs were subjected to antiviral screening against human immunodeficiency virus (HIV)-1. Bis(SATE) prodrug 22 of the adenine analog exhibited significant in vitro activity against HIV-1.

컬럼 스위칭 고속액체크로마토그라프법을 이용한 혈장 중 플루코나졸의 분석

김양배,이미경,김종국,지준필,진숙 한국약제학회 2000 Journal of Pharmaceutical Investigation Vol.30 No.1

A column-switching high performance liquid chromatographic method has been developed for the determination of a fluconazole in human plasma. Each plasma sample was centrifuged for 10 min at 5000 g. After an aliqout of the supernatant was taken to nylon microcentrifuge filter, these samples were centrifuged for 10 min at 5000 g. An aliqout of the supernatant was injected directly onto the HPLC column. Deionized water was run for 2 min at a flow rate of 1.0 ㎖/min to retain fluconazole in an extration column, while proteins and endogenous interferences were eluted to the waste. The analyte was then back-flushed onto an analytical column, C_(18) reversed-phase column. The mobile phase for analytical column, 0.01 M sodium acetate (pH 5.0)-methanol (65:35, v/v), was run at a flow rate of 1.0 ㎖/min. The column effluent was monitored by ultraviolet detection at 261㎚. The retention time for fluconazole was 11.76 min in human plasma. The detection limit for fluconazole in human plasma was 0.2 ㎍/㎖. No interference from endogenous substances was observed.

Development of Cationic Liposomes for Enhanced Algicidal Efficacy of the Novel Algicidal Agent DP92

조유진,조관형,조훈,지준필 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.7

We have developed liposomes modified with various surface-charged lipids in order to solubilize the new algicidal agent, N-[(3,4-dichlorophenyl)methyl]cyclohexanamine (DP92), and enhance its algicidal activity against harmful algal blooms (HABs). The effect of liposome surface charge on algicidal activity was evaluated by using positively charged and neutral liposomes. The algicidal activity of the developed liposomes was evaluated by monitoring the inhibition of the growth rates of HABs (Heterosigma circularisquama (HC) and Heterosigma akashiwo (HA)). The algicidal activity of the liposomes was 2–6 times stronger compared to that of control. The solubilization of DP92 by entrapment in liposomes increased the solubility of DP92 and improved its algicidal activity up to sixfold. The electrostatic interaction between the negatively charged cell walls of HABs and the cationic liposomes additionally enhanced the algicidal activity of DP92.

Protein Adsorption and Bacterial Adhesion Resistance of Cross-linked Copolymer Hydrogels Based on Poly(2-methacryloyloxyethyl phosphorylcholine) and Poly(2-hydroxyethyl methacrylate)

Temmy Pegarro Vales,지준필,이원영,Ilgi Min,조성,김호중 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.4

Herein, the preparation of the cross-linked copolymer hydrogels composed of various weight ratios of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) monomers employing free-radical polymerization was reported. The integration of the MPC monomer into HEMA-based hydrogels showed good transmittance (>90%) and enhanced the water content retention (79?202%) relative to those of pure HEMA-based hydrogel. Notably, the MPC-containing hydrogels (MPC-H) exhibited the improved anti-biofouling properties due to the formation of a compact hydration layer produced by the biomimetic MPC units at the hydrogel surface. MPC-H exhibited a decrease in the bovine serum albumin (BSA) and lysozyme adsorption of approximately 40?70% and 44?65%, respectively, relative to those of control hydrogel without MPC monomer. The results presented herein demonstrate the potential of expending biocompatible monomers such as HEMA and MPC to efficiently generate a biomaterial that possesses both bio-membrane mimicking character and protein and bacterial resistant properties for various industrial and biomedical applications.

Anti-inflammatory function of 4-tert-butylphenyl salicylate through down-regulation of the NF-kappa B pathway

Yun Hee Choi,유진철,Baek Hee Na,Yoon Seok Choi,Md. Saifur Rahman,Mi Ri Kim,지준필,Jihoon Shin,서주원 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.3

The salicylic acid derivative 4-tert-butylphenyl salicylate (4-TBPS) possesses anti-inflammatory activity. We demonstrated this and elucidated the mechanisms involved by using the lipopolysaccharide-stimulated Raw 264.7 mouse macrophage model. The 3-(4, 5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blot, enzyme-linked immunosorbent assay, and reverse transcriptase-polymerase chain reaction were performed to explore 4-TBPS anti-inflammatory activity. We found that 4-TBPS decreased nitric oxide production without cytotoxic effects on macrophages and reduced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 in a dose-dependent manner. Additionally, mRNA expressions of iNOS and COX-2 significantly reduced, with concentrations between 1 and 15 lg/ml. Furthermore, 4-TBPS significantly inhibited the production of pro-inflammatory cytokines including tumor necrosis factor-a (TNF-a), interleukin- (IL)-1b, and IL-6. Moreover, mRNA gene expression of TNF-a, IL-1b, and IL-6 was attenuated in a dose-dependent manner. 4-TBPS potently inhibited translocation of nuclear factor-jB (NFjB) into the nucleus by degrading IjB kinase (IjBa) following its phosphorylation, thereby causing NF-jB to remain inactive. Collectively, our data indicate that 4-TBPS significantly (p\0.01) targets the inflammatory response of macrophages via inhibition of iNOS, COX-2, TNF-a, IL-1b, and IL-6 through downregulation of the NFjB pathway. This indicates that 4-TBPS may have therapeutic potential in inflammatory disorders.