• Natural Product Sciences
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• 제23권4호
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• pp.253-257
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• 2017

The phytochemical study for the extract of Nelumbo nucifera (Nymphaceae) seeds has led to the isolation of ten compounds including five simple phenolic compounds, two indole derivatives, a flavonoid glycoside, two abscisic acid derivatives. The interpretation of 1D and 2D NMR and ESI-Q-TOF-MS spectroscopic data revealed the chemical structures of isolates to be p-hydroxybenzoic acid (1), protocatechuic acid (2), (E)-p-coumaric acid (3), (E)-ferulic acid (4), (E)-sinapate-4-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (5), tryptophan (6), 3-indoleacetic acid (7), isoschaftoside (8), dihydrophaseic acid (9), dihydrophaseic acid 3'-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (10). To the best of our knowledge, 1 - 5 and 7 were identified for the first time from N. nucifera seeds, and the presence of dihydrophaseic acid (9) and its glucoside (10) were demonstrated secondly in this plant.

• 통합자연과학논문집
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• 제7권4호
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• pp.227-233
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• 2014

Caspases, a family of cysteinyl aspartate-specific proteases plays a central role in the regulation and the execution of apoptotic cell death. Activation of caspases-3 stimulates a signaling pathway that ultimately leads to the death of the cell. Hence, caspase-3 has been proven to be an effective target for reducing the amount of cellular and tissue damage. In this work, comparative molecular similarity indices analysis (CoMSIA) was performed on a series of 3,4-dihydropyrimidoindolones derivatives which are inhibitors of caspase-3. The best predictions were obtained for CoMSIA model ($q^2$ = 0.586, $r^2$ = 0.955). The predictive ability of test set ($r^2_{pred}$) was 0.723. Statistical parameters from the generated QSAR models indicated the data is well fitted and have high predictive ability. Our theoretical results could be useful to design novel and more potent caspase-3 derivatives.

• 통합자연과학논문집
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• 제5권1호
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• pp.6-12
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• 2012

c-Jun N-terminal kinase-3 (JNK-3) has been identified as a promising target for neuronal apoptosis and has the effective therapeutic for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and other CNS disorders. Herein, we report the essential structural and chemical parameters for JNK-3 inhibitors utilizing comparative molecular field similarity indices analysis (CoMSIA) using the derivatives of 3,5-disubstituted quinolines. The best predictions were obtained CoMSIA model (q2=0.834, r2=0.987) and the statistical parameters from the generated 3D-QSAR models were indicated that the data are well fitted and have high predictive ability. The resulting contour map from 3D-QSAR models might be helpful to design novel and more potent JNK3 derivatives.

• Mass Spectrometry Letters
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• 제14권1호
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• pp.1-8
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• 2023

Eutylone, dibutylone, and dimethylone are potential psychotropic designer drugs. The purpose of this study was to investigate the in vitro metabolic pathways of synthetic cathinones with methylenedioxy groups. The three methylenedioxy derivatives were incubated with human liver microsomes. The metabolites were characterized based on liquid chromatography and quadrupole-time-of-flight mass spectrometry. Eutylone, dibutylone, and dimethylone were metabolized to yield three, six, and four metabolites, respectively. Reduction and demethylenation were the major metabolic pathways for all three drugs tested. However, dibutylone and dimethylone showed an additional metabolite generated via N-oxidation. These results provide evidence for the in vivo metabolism of methylenedioxy synthetic cathinones, and could be applied to the analysis of synthetic cathinones and their relevant metabolites in biological samples.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1859-1864
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• 2018

Synthesis of flavonoid glycoside is difficult due to diverse hydroxy groups in flavonoids and sugars. As such, enzymatic synthesis or biotransformation is an approach to solve this problem. In this report, we used stepwise biotransformation to synthesize two quercetin bisglycosides (quercetin 3-O-glucuronic acid 7-O-rhamnoside [Q-GR] and quercetin 3-O-arabinose 7-O-rhamnoside [Q-AR]) because quercetin O-rhamnosides contain antiviral activity. Two sequential enzymatic reactions were required to synthesize these flavonoid glycosides. We first synthesized quercetin 3-O-glucuronic acid [Q-G], and quercetin 3-O-arabinose [Q-A] from quercetin using E. coli harboring specific uridine diphopsphate glycosyltransferase (UGT) and genes for UDP-glucuronic acid and UDP-arabinose, respectively. With each quercetin 3-O-glycoside, rhamnosylation using E. coli harboring UGT and the gene for UDP-rhamnose was conducted. This approach resulted in the production of 44.8 mg/l Q-GR and 45.1 mg/l Q-AR. This stepwise synthesis could be applicable to synthesize various natural product derivatives in case that the final yield of product was low due to the multistep reaction in one cell or when sequential synthesis is necessary in order to reduce the synthesis of byproducts.

• Journal of applied mathematics & informatics
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• 제14권1_2호
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• pp.251-266
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• 2004

We consider a controlled nonlinear mechanical system described by the Lagrange equations. We determine the control forces $Q_1$ and the restrictions for the perturbations $Q_2$ acting on the mechanical system which allow to guarantee the asymptotic stability of the program motion of the system. We solve the problem of stabilization by the direct Lyapunov's method and the method of limiting functions and systems. In this case we can use the Lyapunov's functions having nonpositive derivatives. The following examples are considered: stabilization of program motions of mathematical pendulum with moving point of suspension and stabilization of program motions of rigid body with fixed point.

• Biomolecules & Therapeutics
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• 제25권6호
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• pp.578-585
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• 2017

Recently, there has been a rise in the number of amphetamine derivatives that serve as substitutes for controlled substances (e.g. amphetamine and methamphetamine) on the global illegal drug market. These substances are capable of producing rewarding effects similar to their parent drug. In anticipation of the future rise of new and similar psychoactive substances, we designed and synthesized four novel amphetamine derivatives with N-benzyl, N-benzylamphetamine HCl (NBNA) substituent on the amine region, 1,4-dioxane ring, ethylenedioxy-amphetamine HCl (EDA), methyl, para-methylamphetamine HCl (PMEA), and naphthalene, 2-(aminopropyl) naphthalene HCl (2-APN) substituents on the phenyl site. Then, we evaluated their abuse potential in the conditioned place preference (CPP) test in mice and self-administration (SA) test in rats. We also investigated the psychostimulant properties of the novel drugs using the locomotor sensitization test in mice. Moreover, we performed qRT-PCR analyses to explore the effects of the novel drugs on the expression of D1 and D2 dopamine receptor genes in the striatum. NBNA, but not EDA, PMEA, and 2-APN, induced CPP and SA in rodents. None of the test drugs have produced locomotor sensitization. qRT-PCR analyses demonstrated that NBNA increased the expression of striatal D1 dopamine receptor genes. These data indicate that NBNA yields rewarding effects, suggesting potential for abuse. Continual observation for the rise of related substances is thus strongly encouraged.

• Korean Journal of Mathematics
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• 제17권1호
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• pp.53-66
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• 2009

We show the existence of a nontrivial periodic solution for the superquadratic parabolic equation with Dirichlet boundary condition and periodic condition with a superquadratic nonlinear term at infinity which have continuous derivatives. We use the critical point theory on the real Hilbert space $L_2({\Omega}{\times}(0 2{\pi}))$. We also use the variational linking theorem which is a generalization of the mountain pass theorem.

• Applied Biological Chemistry
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• 제47권3호
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• pp.351-356
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• 2004

HQSAR 방법으로 일련의 새로운 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene 유도체들중 A = 3,4,5,6-tetrahydrophthalimino, B = 3-chloro-4,5,6,7-tetrahydro-2H-indazolyl 및 C = 3,4-dimethylmaleimino 치환체들의 구조 변화에 따른 벼(Orysa sativa L.)와 논피(Echinochloa crus-galli) 뿌리와 줄기부위 사이의 살초활성 관계를 연구하였다. 두 가지 초종의 뿌리와 줄기의 살초활성에 대하여 유도된 4개의 HQSAR 모델들은 예측성, cross-validated $r^2\;_{cv.}$값$(q^2\;=\;0.760{\sim}0.924)$, non-cross-validated 상관계수$(r^2\;_{cv.}\;=\;0.868{\sim}0.970)$ 및 PRESS 값$(0.123{\sim}0.261)$에 근거하여 매우 양호한 통계값들을 나타내었다. 유도된 HQSAR 모델들은 벼 보다는 논피에 대하여 양호한 경향을 나타내었으며 CoMFA 모델에 비하여 예측성은 좋았으나$(q^2\;=\;HQSAR\;>\;CoMFA)$ 저해활성과의 상관성은 약간 낮은$(r^2\;=\;HQSAR\;<\;CoMFA)$ 경향이었다. 또한, HQSAR 기여도로부터 논피에 대한 선택적인 살초활성은 2-fluoro-4-chloro-5-alkoxy anilino 및 C-phenyl 고리상 $R_3-$치환기에 의존적임을 알았다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1604-1612
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• 2011

We developed three-dimensional quantitative structure activity relationship (3D-QASR) models for 17 adamantyl derivatives as P-glycoprotein (P-gp) inhibitors. Eighteen different partial charge calculation methods were tested to check the feasibility of the 3D-QSAR models. Best predictive comparative molecular field analysis (CoMFA) model was obtained with the Austin Model 1-Bond Charge Correction (AM1-BCC) atomic charge. The 3D-QSAR models were derived with CoMFA and comparative molecular similarity indices analysis (CoMSIA). The final CoMFA model ($q^2$ = 0.764, $r^2$ = 0.988) was calculated with an AM1-BCC charge and electrostatic parameter, whereas the CoMSIA model ($q^2$ = 0.655, $r^2$ = 0.964) was derived with an AM1-BCC charge and combined steric, electrostatic, hydrophobic and HB-acceptor parameters. Leave-five-out (LFO) cross-validation was also performed, which yielded good correlation coefficient for both CoMFA (0.801) and CoMSIA (0.656) models. Robustness of the developed models was checked further with 1000 run bootstrapping analyses, which gave an acceptable correlation coefficient for CoMFA (BS-$r^2$ = 0.997, BS-SD = 0.003) and CoMSIA (BS-$r^2$ = 0.996, BS-SD = 0.018).