In this study, some new nitroimidazole derivatives were obtained from 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethylamine dihydrochloride (4) and 1-(2-bromoethyl)-2-methyl-5-nitroimidazole (5), which were prepared using metronidazole. Compound 4 was reacted with arylisothiocyanates (6) to obtain 1-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-3-arylthioureas (7) and the latter with $\alpha$-bromoacetophenones (8) to give -3-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-2-arylimino-4-aryl-4-thiazolines (9). Also 1-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-2-phenyl-4-arylideneimidazolin-5-ones (11) were prepared by reaction of 4 with 2-phenyl-4-arylidene-5-oxazolones (10). The reaction of the other starting material 5 with 5-arylidenethiazolidin-2,4-dione (12) gave 3-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-5-arylidenethiazolidin-2,4-dione (13) derivatives. Structural elucidation of the compounds was performed by IR, $^1H-NMR$ and MASS spectroscopic data and elemental analysis results. Antimicrobial activities of the compounds were examined and moderate activity was obtained.

N'-(1-alkyl-2,3-dihydro-2-oxo-1H-3-indolyliden)-4-pyridinecarboxylic acid hydrazide derivatives, 3(a-g), were synthesized in a trial to overcome the resistance developed with the therapeutic uses of isoniazid (INH). The lipophilicity of the synthesized derivatives supersedes that of the INH as expressed by Clog p values. The synthesized compounds and INH were tested against bovin, human sensitive and human resist strains of Mycobacterium tuberculosis. Compounds 3a, 3d, 3f and 3g with 1-unsubstituted, 1-propyl, 1-propynyl and 1-benzyl groups respectively exhibited equipotent growth inhibitory activity (MIC 10 $\mu$mol) against the tested strains as compared with INH however the later has no activity against human resist strain. Pharmacokinetic study revealed that the rate and extent of absorption of the tested derivatives (3d and 3f) significantly higher than that of INH (p＜0.05). The relative bioavailabilities ($F_R%$) were 183.15 and 443.25 for 3f and 3d respectively as compared to INH. These results preliminary indicate the possible use of the prepared derivatives for treatment of tuberculosis infections in order to overcome the resistance developed with INH.

For the development of new anticonvulsive agents, GABAmimetics such as nipecotic acid, isonipecotic acid, ${\gamma}-aminobutyric$ acid (GABA), ${\gamma}-vinyl$ GABA (vigabatrin) and valproic acid were covalently coupled through an ester bond by a two-carbon linker chain as potential prodrugs and evaluated for their anticonvulsive activities.

Two known farnesylacetone derivatives (1 and 2) were isolated from the Korean brown alga Sargassum sagamianum off Jeju Island, Korea. Compounds 1 and 2 were identified as (5E,10Z)-6, 10, 14-trimethylpentadeca-5, 10-dien-2, 12-dione and (5E,9E,13E)-6, 10,4-trimethylpentadeca-5,9,13-trien-2,12-dione, respectively, by comparison with the literature data. Compounds 1 and 2 showed moderate acetylcholinesterase and butyrylcholinesterase inhibitory activities with $IC_{50}$ values of 65.0∼48.0 and 34.0∼23.0 $\muM$, respectively.

The effects of KR-31378, a neuroprotective agent for ischemia-reperfusion damage, on liver microsomal cytochrome P450s (CYPs) were investigated in male Sprague Dawley rats. When rats were treated orally with KR-31378 for 7 consecutive days, CYP3A-selective erythromycin N-demethylase (ERDM) activity was significantly induced in a dose-dependent manner. In Western immunoblotting, CYP 3A proteins were clearly induced by treatment with KR-31378. Within 24 h after treatment with 80 mg/kg of KR-31378, ERDM activity was induced in liver microsomes in accompanied by induction of the level of CYP 3A proteins. The present results suggest that KR-31378 might modulate the expression of CYP 3A enzymes in humans.

Preliminary microbial metabolism studies of bisphenol A (BPA) (1) on twenty six microorganisms have shown that Aspergillus fumigatus is capable of metabolizing BPA. Scale-up fermentation of 1 with A. fumigatus gave a metabolite (2) and its structure was established as bisphenol $A-O-{\beta}-D-glucopyranoside$ (BPAG) based on spectroscopic analyses.

Since reactive oxygen species (ROS) and hydroxyl radicals ($^-OH$) play an important role in the pathogenesis of many human degenerative diseases, much attention has focused on the development of safe and effective antioxidants. Preliminary experiments have revealed that the methanol (MeOH) extract of the stem of Prunus davidiana exerts inhibitory/scavenging activities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals, total ROS and peroxynitrites ($ONOO^-$). In the present study, the antioxidant activities of this MeOH extract and the organic solvent-soluble fractions, dichloromethane (CH$_2$Cl$_2$), ethyl acetate (EtOAc), and n-butanol (n-BuOH), and the water layer of P. davidiana stem were evaluated for the potential to inhibit $^-OH$ and total ROS generation in kidney homogenates using 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA), and for the potential to scavenge authentic $ONOO^-$. We also evaluated the inhibitory activity of seven flavonoids isolated from P. davidiana stem, kaempferol, kaempferol 7-Ο-$\beta$-D-glucoside, (+)-catechin, dihydrokaempferol, hesperetin 5-Ο-$\beta$-D-glucoside, naringenin and its 7-Ο-$\beta$-D-glucoside, on the total ROS, $^-OH$ and $ONOO^-$ systems. For the further elucidation of the structure-inhibitory activity relationship of flavonoids on total ROS and 'OH generation, we measured the antioxidant activity of sixteen flavonoids available, including three active flavonoids isolated from P. davidiana, on the total ROS and 'OH systems. We found that the inhibitory activity on total ROS generation increases in strength with more numerous hydroxyl groups on their structures. Also, the presence of an ortho-hydroxyl group, whether on the Aring or S-ring, and a 3-hydroxyl group on the C-ring increased the inhibitory activity on both total ROS and $^-OH$ generation.

The chloroform extract of the aerial part of Limnophila geoffrayi showed antimycobacterial and antioxidant activities. Bioassay-guided fractionation has led to the isolation of the flavones nevadensin (5,7-dihydroxy-6,8,4'-trimethoxyflavone, 1) and isothymusin (6,7-dimethoxy-5,8,4'-trihydroxyflavone, 2). Both compounds 1 and 2 exhibited inhibition activity against Mycobacterium tuberculosis, with equal MIC value of $200{\;}\mu\textrm{g}/mL$. Only compound 2 exhibited antioxidant activity against the radical scavenging ability of DPPH, with the $IC_{50}$ value of $7.7{\;}\mu\textrm{g}/mL$. The crude hexane, chloroform and methanol extracts as well as the pure compounds 1 and 2 did not exhibit mutagenic activity in the Bacillus subtilis recassay.

The effects of purple sweet potato anthocyanin (SPA) and Cordyceps mushroom extract (CME) on lipid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and cognitive deficits were examined. Both SPA and CME exhibited DPPH radical scavenging activities with similar potency. In contrast, only SPA was shown to effectively inhibit lipid peroxidation initiated by $Fe^{2+}$ and ascorbic acid in rat brain homogenates. Furthermore, SPA markedly enhanced cognitive performance, assessed by passive avoidance test in ethanol-treated mice. Combined treatments with SPA and CME did not significantly influence the effects of SPA alone. These results demonstrate that anthocyanin prepared from purple sweet potato exhibits memory enhancing effects, which may be associated with its antioxidant properties.

ADP-ribose pyrophosphatase (ADPRase) hydrolyzes ADP-ribose (ADPR) into AMP and ribose-5'-phosphate. It is classified into two groups, $Mg^{2+}$-dependent and $Mg^{2+}$-independent ADPRase, depending on its $Mg^{2+}$requirement. Here, we purified $Mg^{2+}$-dependent ADPRase from rabbit liver and examined what factors affect $Mg^{2+}$ requirement. The purified enzyme showed a single band with the molecular weight of 34 kDa on SDS-PAGE both in the presence and absence of 2-mercaptoethanol. The molecular weight of the native enzyme calculated by gel filtration was 68 kDa, indicating that ADPRase is a dimer made up of two identical subunits. $Mg^{2+}$-dependent ADPRase with the highest ADPR affinity had a $K_m$ of 160$\pm$10 $\mu$M and a pH optimum of around pH 9.5. Treatment of the purified ADPRase with heated cytosol fractions at 37$^{\circ}C$ for 3 h caused some changes in the chemical properties of the enzyme, including an increase in molecular weight, a decrease in solubility, and a loss of $Mg^{2+}$-dependency. The molecular weight of the cytosol-treated ADPRase measured by gel filtration was over 420 kDa, suggesting, for the first time, that ADPRase could be polymerized by undefined cytoplasmic factors, and that polymerization is accompanied by changes in the solubility and metal ion dependency of the enzyme.

Activated macrophages express inducible isoforms of nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and produce excessive amounts of nitric oxide (NO) and prostaglandin E$_2$ (PGE$_2$), which play key roles in the processes of inflammation and carcinogenesis. The root of Paeonia lactiflora Pall., and the root cortex of Paeonia suffruticosa Andr., are important Chinese crude drugs used in many traditional prescriptions. 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose (PGG) is a major bioactive constituent of both crude drugs. PGG has been shown to possess potent anti-oxidant, anti-mutagenic, anti-proliferative and anti-invasive effects. In this study, we examined the inhibitory effects of 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose (PGG) isolated from the root of Paeonia lactiflora Pall. on the COX-2 and iNOS activity in LPS-activated Raw 264.7 cells, COX-1 in HEL cells. To investigate the structure-activity relationships of gallate and gallic acid for the inhibition of iNOS and COX-2 activity, we also examined (-)-epigallocatechin gallate (EGCG), gallic acid, and gallacetophenone. The results of the present study indicated that PGG, EGCG, and gallacetophenone treatment except gallic acid significantly inhibited LPS-induced NO production in LPS-activated macrophages. All of the four compounds significantly inhibited COX-2 activity in LPS-activated macrophages. Among the four compounds examined, PGG revealed the most potent in both iNOS ($IC_{50}$ = 18 $\mu\textrm{g}/mL$) and COX-2 inhibitory activity (PGE$_2$: $IC_{50}$ = 8 $\mu\textrm{g}/mL$ and PGD$_2$: $IC_{50}$ = 12 $\mu\textrm{g}/mL$), respectively. Although further studies are needed to elucidate the molecular mechanisms and structure-activity relationship by which PGG exerts its inhibitory actions, our results suggest that PGG might be a candidate for developing anti-inflammatory and cancer chemopreventive agents.

Temperature change is one of the major environmental factors that influence the human skin. However, the relationship between temperature and melanogenesis has received little attention. In the present study, we investigated the effects of temperature change on melanogenesis in a mouse melanocyte cell line (Mel-Ab), and primary cultured human melanocytes. We found that Mel-Ab cells cultured at low temperatures (31 and 34$^{\circ}C$) produce less melanin than cells at 37$^{\circ}C$. These results were confirmed by experiments upon human melanocytes, demonstrating that the hypopigmenting effect of low temperatures is not cell type dependent. The observed melanin production was found to be accompanied by tyrosinase activity at each temperature, indicating that tyrosinase activity is regulated by temperature. We further examined whether the incubation period at low temperatures plays an important role in the regulation of melanogenesis. Short exposures to 27$^{\circ}C$ for 1 h or 3 h did not affect tyrosinase activity or melanin synthesis, whereas long exposures to 31$^{\circ}C$ for 2 days or 6 days significantly reduced tyrosinase activity and melanin synthesis in a duration-dependent manner. Our results suggest that exposure to low temperature and the duration of this exposure are important regulators of melanogenesis.

The oligomerization of G-proteincoupled receptors (GPCRs) has been shown to occur by various mechanisms, such as via disulfide covalent linkages, non covalent (ionic, hydrophobic) interactions of the N-terminal, and/or transmembrane and/or intracellular domains. Interactions between GPCRs could involve an association between identical proteins (homomers) or non-identical proteins (heteromers), or between two monomers (to form dimers) or multiple monomers (to form oligomers). It is believed that muscarinic receptors may also be arranged into dimeric or oigomeric complexes, but no systematic experimental evidence exists concerning the direct physical interaction between receptor proteins as its mechanism. We undertook this study to determine whether muscarinic receptors form homomers or a heteromers by direct protein-protein interaction within the same or within different subtypes using a yeast two-hybrid system. Intracellular loops (i1, i2 and i3) and the C-terminal cytoplasmic tails (C) of human muscarinic (Hm) receptor subtypes, Hm1, Hm2 and Hm3, were cloned into the vectors (pB42AD and pLexA) of a two-hybrid system and examined for heteromeric or homodimeric interactions between the cytoplasmic domains. No physical interaction was observed between the intracellular domains of any of the Hm/Hm receptor sets tested. The results of our study suggest that the Hm1, Hm2 and Hm3 receptors do not form dimers or oligomers by interacting directly through either the hydrophilic intracellular domains or the C-terminal tail domains. To further investigate extracellular domain interactions, the N-terminus (N) and extracellular loops (o1 and o2) were also cloned into the two-hybrid vectors. Interactions of Hm2N with Hm2N, Hm2o1, Hm2o2, Hm3N, Hm3o1 or Hm3o2 were examined. The N-terminal domain of Hm2 was found to have no direct interaction with any extracellular domain. From our results, we excluded the possibility of a direct interaction between the muscarinic receptor subtypes (Hm1, Hm2 and Hm3) as a mechanism for homo- or hetero-meric dimerization/oligomerization. On the other hand, it remains a possibility that interaction may occur indirectly or require proper conformation or subunit formation or hydrophobic region involvement.

The effect of silver sulfadiazine (SSD) on the proliferation of human dermal fibroblast (HDF) was studied to determine the impact of the drug on the wound healing process and dermal mechanical strength. Human dermal fibroblasts were cultured to 80% confluency using DMEM with 10% FBS and viability of the cell was estimated using neutral red assay. In addition, the $2^{nd}$ degree burn wound was prepared on the anterior part of rabbit ear skin and dressings containing SSD were applied for 96 h. Presence of inflammatory cells and degree of re-epithelialization were investigated in the wound. After 15 day of the induction of burn wounds, the treated area was excised and dermal mechanical strength was quantitatively measured with a constant speed tensiometer. SSD was found to be highly cyto-toxic in cultured HDF cells. The topical application of SSD (2%) could control the infection as evidenced by the lack of accumulation of inflammatory cells in histological evaluation. Therefore, these observations suggested that the impairment of dermal regeneration and decreased mechanical strength of dermal tissue was resulted from the cyto-toxic effect of SSD on dermal cells. Since the decreased mechanical strength may lead to reduction in resilience, toughness and maximum extension of the tissue, the identification of optimum dose for SSD that limits infection while minimizes the cyto-toxic effect may be clinically relevant.

Inhibitory effect of the lectins (KML-C) isolated from Korean mistletoe (KM; Viscum album coloratum) on tumor metastases produced by murine tumor cells (B16-BL6 melanoma, colon 26M3.1 carcinoma and L5178Y-ML25 lymphoma cells) was investigated in syngeneic mice. An intravenous (i.v.) administration of KML-C (20-50 ng/mouse) 2 days before tumor inoculation significantly inhibited lung metastases of both B16-BL6 and colon 26-M3.1 cells. The prophylactic effect of 50 ng/mouse of KML-C on lung metastasis was almost the same with that of 100 $\mu$ g/mouse of KM. Treatment with KML-C 1 day after tumor inoculation induced a significant inhibition of not only the experimental lung metastasis induced by B16-BL6 and colon 26M3.1 cells but also the liver and spleen metastasis of L5178Y-ML25 cells. Furthermore, multiple administration of KML-C given at 3 day-intervals after tumor inoculation led to a significant reduction of lung metastasis and suppression of the growth of B16-BL6 melanoma cells in a spontaneous metastasis model. In an assay for natural killer (NK) cell activity. i.v. administration of KML-C (50 ng/mouse) significantly augmented NK cytotoxicity against Yac-1 tumor cells 2 days after KML-C treatment. In addition, treatment with KML-C (50 ng/mouse) induced tumoricidal activity of peritoneal macrophages against B16-BL6 and 3LL cells. These results suggest that KML-C has an immunomodulating activity to enhance the host defense system against tumors, and that its prophylactic and therapeutic effect on tumor metastasis is associated with the activation of NK cells and macrophages.

Ginsenosides, major active ingredients of Panax ginseng, that exhibit various pharmacological and physiological actions are transformed into compound K (CK) or M4 by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. Recent reports shows that ginsenosides might playa role as pro-drugs for these metabolites. In present study, we investigated the effect of bovine serum albumin (BSA), which is one of major binding proteins on various neurotransmitters, hormones, and other pharmacological agents, on ginsenoside $Rg_{2-}$, CK-, or M4-induced regulation of $\alpha3\beta4$ nicotinic acetylcholine (ACh) receptor channel activity expressed in Xenopus oocytes. In the absence of BSA, treatment of ACh elicited inward peak current ($I_{Ach}$) in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor. Co-treatment of ginsenoside $Rg_2$, CK, or M4 with ACh inhibited IAch in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. In the presence of 1% BSA, treatment of ACh still elicited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and co-treatment of ginsenoside $Rg_2$ or M4 but not CK with ACh inhibited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. These results show that BSA interferes the action of CK rather than M4 on the inhibitory effect of $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and further suggest that BSA exhibits a differential interaction on ginsenoside metabolites.

The present study was carried out to examine the stability of microencapsulated ascorbic acid in simulated-gastric and intestinal situation in vitro and the effect of microencapsulated ascorbic acid on iron bioavailability. Coating materials used were polyglycerol monostearate (PGMS) and medium-chain triacylglycerol (MCT), and core materials were L-ascorbic acid and ferric ammonium sulfate. When ascorbic acid was microencapsulated by MCT, the release of ascorbic acid was 6.3％ at pH 5 and 1.32％ at pH 2 in simulated-gastric fluids during 60 min. When ascorbic acid was microencapsulated by PGMS, the more ascorbic acid was released in the range of 9.5 to 16.0％. Comparatively, ascorbic acid release increased significantly as 94.7％ and 83.8％ coated by MCT and PGMS, respectively, for 60 min incubation in simulated-intestinal fluid. In the subsequent study, we tested whether ascorbic acid enhanced the iron bioavailability or not. In results, serum iron content and transferring saturation increased dramatically when subjects consumed milks containing both encapsulated iron and encapsulated ascorbic acid, compared with those when consumed uncapsulated iron or encapsulated iron without ascorbic acid. Therefore, the present data indicated that microencapsulated ascorbic acid with both PGMS and MCT were effective means for fortifying ascorbic acid into milk and for enhancing the iron bioavailability.

Research in this paper focuses on the kinetic evaluation of swelling of the liquid crystalline phases of glyceryl monooleate (GMO). Swelling of the lamellar and cubic liquid crystalline phases of GMO was studied using two in vitro methods, a total immersion method and a Franz cell method. The swelling of the lamellar phase and GMO having 0 %w/w initial water content was temperature dependent. The swelling ratio was greater at $20^{\circ}^C than 37^{\circ}^C$ . The water uptake increased dramatically with decreasing initial water content of the liquid crystalline phases. The swelling rates obtained using the Franz cell method with a moist nylon membrane to mimic buccal drug delivery situation were slower than the total immersion method. The swelling was studied by employing first-order and second-order swelling kinetics. The swelling of the liquid crystalline phases of GMO could be described by second-order swelling kinetics. The initial stage of the swelling (t < 4 h) followed the square root of time relationship, indicating that this model is also suitable for describing the water uptake by the liquid crystalline matrices. These results obtained from the current study demonstrate that the swelling strongly depends on temperature, the initial water content of the liquid crystalline phases and the methodology employed for measuring the swelling of GMO.