• 분석과학
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• 제17권3호
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• pp.282-288
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• 2004

Inclusion selectivities of the cyanocadmate host complexes with ammonium oniums, $[Cd_x(CN)_{2x}][onium{\cdot}zG]$ (onium = $NMe_3Et^+$, $NMeEt{_3}^+$ and $NEt{_4}^+$, G = guest), have been investigated for $C_6H_6$ (B), PhMe (T), PhEt (E), ortho (O), meta (M), and para (P) isomers of $C_6H_4Me_2$ as the aromatic guest molecules. From the binary, ternary, quaternary and quinary mixed guests of B, T, E, O, M and P, the order of preference in the $NMe_3Et+$-host is $B{\gg}$T>P${\fallingdotseq}O{\fallingdotseq}M$ and E>O${\gg}P{\fallingdotseq}M$; in the $NMeEt{_3}^+$-host is T>B>P${\gg}O{\fallingdotseq}M$ and E>P${\gg}$M>O; in the $NEt{_4}^+$-host is $B{\gg}T{\fallingdotseq}O{\fallingdotseq}M{\fallingdotseq}P$. However, the $NEt{_4}^+$-host complexes of E, O, M and P mixed-guests were not obtained. These inclusion selectivities were compared to our previous results of the $NMe{_4}^+$-host; T>B>P${\gg}$M>O and E>P${\gg}$M>O.

• 한국잠사곤충학회지
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• 제44권1호
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• pp.4-8
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• 2002

우리나라의 논둑, 밭둑 및 야산에서 자라고 있는 뽕나무 자원의 육종소재화 및 생리활성물질 이용 효율을 높이고자 횡성군 일대의 뽕나무와 오디를 지역별.그루별로 채취하여 뽕나무의 형태적 특성을 조사하였으며, 냉동건조시킨 야생오디의 추출물 및 분획물을 조제하여 고지혈증을 유발시킨 흰쥐에 투여함으로써 지질대사 및 간장기능에 미치는 영향을 살펴보았다. 1. 강원도 횡성군 일대에서 채취한 야생종(12점) 뽕나무의 엽선, 엽형, 엽각, 거치의 형태적 관찰 결과, 산상형(Morus bombycis) 백상형(Morus alba) 계통이 혼재함을 알 수 있었으나. 공시개체 중 노상형 계통은 존재하지 않았다. 2. 야생종 뽕나무의 오디 당도는 5.1~22.7 Brix %로서 지역별.그루별 차가 심하였다. 수집된 개체 중 6개체는 16Brix % 이상이었다. 3. 냉동건조시킨 야생오디 3kg으로부터 얻은 85% MeOH 추출물의 수율은 60.2%(1,805g)이었으며, MeOH 추출물로부터 얻은 Hexane, BuOH 및 Water 분획물의 수율은 각각 2.8%(50 g), 4.6%(82 g) 및 92.3%(1,666g)이었다. 4. 야생오디의 추출물 및 분획물 투언가 흰쥐의 지질대사 및 간장 효소에 미치는 영향을 분석한 결과, 콜레스테롤을 투여하여 고지혈증을 유발시킨 대조군의 체중 증가량은 정상군보다 12% 높았으나 MeOH 추출물과 물 분획물 투여군의 체중은 각각 6%, 3%만이 증가하였다. 총콜레스테롤, HDL-콜레스테롤/총콜레스테롤비 및 중성지질함량을 측정한 결과, MeOH 추출물과 물 분획물 투여군은 총콜레스테롤과 중성지질 함량을 감소시켰는데, 총콜레스테롤 함량은 각각 정상군의 71%, 70% 수준으로, 중성지질 함량은 각각 정상 군의 92%, 90% 수준까지 회복되었다. 또한 물 분획물 투여군은 GPT, GOT 및 LDH 활성에 있어서 각각 정상군 수준으로 회복되었다.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3795-3799
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• 2013

The second-order rate constants ($k_N$) have been measured spectrophotometrically for nucleophilic substitution reactions of Y-substituted-phenyl 2-methylbenzoates (6a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Comparison of the $k_N$ values for the reactions of 4-nitrophenyl 2-methylbenzoate (6d) with those reported previously for the corresponding reactions of 4-nitrophenyl 2-methoxybenzoate (5) reveals that 6d is significantly less reactive than 5, indicating that modification of 2-MeO in the benzoyl moiety of 5 by 2-Me (i.e., $5{\rightarrow}6d$) causes a significant decrease in reactivity. This supports our previous report that aminolysis of 5 proceeds through a six-membered cyclic intermediate, which is highly stabilized through intramolecular H-bonding interactions. The Br${\o}$nsted-type plot for the reactions of 6d with a series of cyclic secondary amines is linear with ${\beta}_{nuc}=0.71$, which appears to be a lower limit of ${\beta}_{nuc}$ for a stepwise mechanism with breakdown of an intermediate ($T^{\pm}$) being rate-determining step (RDS). The Br${\o}$nsted-type plot for the reactions of 6a-e with piperidine is curved, i.e., the slope of Br${\o}$nsted-type plot (${\beta}_{lg}$) decreases from -1.05 to -0.41 as the leaving-group basicity decreases. The nonlinear Br${\o}$nsted-type plot has been taken as evidence for a stepwise mechanism with a change in RDS (e.g., from the $k_2$ step to the $k_1$ process as the leaving-group basicity decreases). Dissection of $k_N$ into the microscopic rate constants associated with the reactions of 6a-e with piperidine (e.g., $k_1$ and $k_2/k_{-1}$ ratio) also supports the proposed mechanism.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.31-39
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• 2003

The enzymatic isolation of residual lignins obtained from spruce and beech pulps (obtained by sulfite, kraft, ASAM and soda/AQ/MeOH pulping processes) and their characterization was described in previous publications. Here, the residual lignins have been submitted to potassium permanganate oxidation (KMnO₄ degradation), and 9 aromatic carboxylic acids (3 of them are dimeric) were identified after methylation with diazomethane by GC/MS. The analytical challenge during qantification by the internal standard methods was the partly high protein content of the samples, which resulted in elevated anisic acid yields in the degradation mixture of sulfite residual lignins. The results are compared with the KMnO₄ degradation of the corresponding MWLs and discussed in terms of S/G ratios and degrees of condensation. The latter was calculated as a quotient between the aromatic carboxylic acids derived from condensed and non-condensed lignin structures. Typical degradation patterns for the various processes have been observed. Among other parameter, the relative compositions between iso-hemipinic acid (which is for condensation in pos. 5 of the aromatic ring) and meta-hemipinic acid and 3,4,5-trimethoxyphthalic acid (both are for condensation in pos. 6 of the aromatic ring) was found to be process specific. Kraft and soda/AQ/MeOH residual lignins yielded higher amounts of iso-hemipinic acid. In contrast, the relative yields of meta-hemipinic acid and 3,4,5-trimethoxyphthalic acid (the latter in beech lignins) are higher in sulfite and particularly in ASAM residual lignin. In case of beech residual lignins the amount of acids originated from non-condensed syringyl type lignin units was surprisingly high. The condensation degree of residual lignins was shown to be generally higher than that of MWLs. This was especially true for the G units. ASAM residual lignin exhibited very high S/G ratios and degrees of polymerization. Causality between condensation degree and total yield of degradation products was demonstrated.

• The Korean Journal of Ecology
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• 제24권1호
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• pp.1-7
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• 2001

침엽수림과 활엽수림의 산불지역에서 토양환경의 회복과정을 살펴보기 위해, 산불발생 후 시간이 경과함에 따른 토양화학적 성질과 토양미생물 변화를 조사하였다. 활엽수림인 삼신봉 지역 산화지에서의 산불직후 토양의 화학적 성질은 pH 5.8, 유기물량 7.42%, 전질소량 0.37%, 유효인산량 28.5 mg/kg, 치환성양이온인 $K^{＋}$이 1.3 me/100g, $Ca^{＋＋}$이 13.3 me/100g, $Mg^{＋＋}$이 2.2 me/100g로 나타났으나 시간이 경과할수록 감소하는 경향이었으며, 비산화지에서는 시간 경과에 따른 변화폭이 적었다. 침엽수림인 촛대산 산불지역에서 산불직후 토양의 화학적 성질은 pH 5.3, 유기물량 6.42%, 전질소량 0.25%, 유효인산량 24.4 mg/kg, 치환성양이온인 $K^{＋}$이 0.7 me/100g, $Ca^{＋＋}$이 3.7 me/100g, $Mg^{＋＋}$이 2.1 me/100g로 각각 나타났으며, 시간이 경과할수록 역시 감소하는 경향 이었다. 활엽수림 인 삼신봉 산불지역의 토양미생물은 호기성균 291$\times$$10^4$ CFU균, 방선균 523$\times$$10^4$ CFU균, 진균 691$\times$$10^4$ CFU균으로 진균의 개체수가 비교적 높게 나타났으며, 비산불지역에서는 호기성균 160$\times$$10^4$ CFU균, 방선균 745$\times$$10^4$ CFU균, 진균 594$\times$$10^4$ CFU균으로 방선균의 개체수가 높게 나타났다. 침엽수림인 촛대산 산불지역에서는 호기성균 350$\times$$10^4$ CFU균, 방선균 434$\times$$10^4$ CFU균, 진균 676$\times$$10^4$ CFU균으로 진균의 개체수가 비교적 높게 나타났으며, 비산불지역에서는 호기성균 328$\times$$10^4$ CFU균, 방선균 319$\times$$10^4$ CFU균, 진균 461$\times$$10^4$ CFU균으로 진균의 개체수가 높게 나타났다. 토양미생물은 호기성균, 방선균, 진균 모두 비산불지역 보다 산불지역에서 많이 나타났다. 본 조사지역에서 호기성균은 활엽수림보다 침엽수림에서 많게 나타났으며, 방선균과 진균은 침엽수림보다 활엽수림에서 많이 나타났다.

• 농업과학연구
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• 제24권1호
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• pp.11-15
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• 1997

태안해안(泰安海岸) 국립공원(國立公園) 지역의 곰솔나무림의 생태적인 특징을 밝히기 위하여 1996년 7월부터 9월 사이에 $relev{\acute{e}}$ method에 의하여 33개소를 선정하고 $10m{\times}10m$의 방형구를 설치하여 분석한 결과는 다음과 같다. 1 본 지역에서 중요치(重要値)가 높은 종(種)은 곰솔, 떡갈나무, 아까시나무, 굴피나무, 소사나무, 자귀나무, 중공솔, 졸참나무 등(等)의 순(順)이다. 2. 곰솔의 재적 성장률은 0.6%~10.5%로 평균 3.8%이었다. 3 토양의 화학적 특성은 pH는 4.8~6.3, 유기물함량은 1.51~11.79%, 유효인산은 2.5~14.5ppm, 치환성 Ca, Mg, K는 각각 1.3~6.6, 0.4~2.6, 0.23~1.89(me/100g)이다.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.903-908
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• 2005

The sharp-line absorption and emission spectra of $(H_{13}O_6)${$trans-[Cr(Me_2tn)_2Br_2]$}$_2Br_2(ClO_4)\;(Me_2$tn = 2,2-dimethyl-1,3-diaminopropane) have been measured between 13000 $cm^{-1}$ and 16000 $cm^{-1}$ at 5 K. The 298 K infrared and visible absorption spectra have also been measured. The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using observed transitions, a ligand field analysis has been performed to probe the ligand field properties of coordinated atoms in the title chromium(III) complex ion. The zero-phonon line in the sharp-line absorption spectrum splits into two components by 286 $cm^{-1}$, and the large $^2E_g$ splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the Me2tn ligand have a strong $\sigma$-donor character, but the bromide has weak $\sigma$- and $\pi$-donor properties toward chromium(III) ion.

• 한국자원식물학회지
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• 제24권4호
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• pp.351-357
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• 2011

본 연구는 양치식물로부터 phytoecdysteroids의 추출 효율을 향상시키기 위하여 시행하였다. 청나래고사리와 고비의 잎(엽상체)을 동결건조 한 후 곱게 분쇄하여 MeOH, 80% EtOH, $H_2O$(nano pure grade)를 용매로 하여 50배 추출하였으며, 각 용매별로 6시간 동안 침지, 교반(200 RPM), 60$^{\circ}C$ 환류냉각추출하거나 42 kHz의 초음파수조에서 15, 30, 45분 동안 추출하였다. 추출물은 $C_{18}$ cartridge로 정제하여 분석하였으며, HPLC를 이용하여 각 추출물의 20-hydroxyecdysone(20E)과 ponasterone A(PonA)의 함량을 조사하였다. 3종류의 용매를 6가지 방법으로 추출한 결과, 청나래고사리와 고비의 추출물 모두 MeOH를 용매로 30분 동안 초음파 추출했을 때 20E와 PonA의 용출량이 증가하였으며, 엽상체 건물중 1 g당 청나래고사리와 고비의 20E 함량은 66.76과 104.48 ${\mu}g$, PonA의 함량은 53.43와 43.82 ${\mu}g$이었다.

• 폴리머
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• 제32권3호
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• pp.239-245
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• 2008

Block copolymers of the general formula $[(-CO-R'-CO-HN-Ar-NH-CO-R'-CO)_xNH(CH_2)_3-(Me_2SiO)_y(CH_2)_3NH_2]_n$, [n=18.00 to 1175.0] where $R'=CH_2CH(CH_2GeCl_3)$;$CH_2CHGeCl_3CH_2$; and $Ar=-C_6H_4$;$-(o.CH_3C_6H_4)_2$;$-o.CH_3OC_6H_4)_2$;$-(o.CH_3C_6H_4)$ were prepared by a polycondensation reaction of polyamide containing a pendant trichlorogermyl group and terminal acid chloride $Cl(-CO-R'-CO-NH-Ar-NH-CO-R'-CO-)_xCl$ with aminopropyl-terminated polydimethylsiloxane $H_2N(CH_2)_3(Me_2SiO)_y-(CH_2)_3NH_2]$, (PDMS). These polymers were characterized by elemental analysis, $T_g$, FT-IR, $^1H$-NMR, solid state $^{13}C$-NMR, and molecular weight determination. The thermal stability of these copolymers was examined using thermal analysis techniques, such as TGA and DSC. Their molecular weights as determined by laser light scattering technique ranged $5.13{\times}10^5$ to $331{\times}10^5\;g/mol$. These polymers display their $T_g$ in the range of 337 to $393^{\circ}C$ with an average decomposition temperature at $582^{\circ}C$.

• Natural Product Sciences
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• 제25권4호
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• pp.326-333
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• 2019

The purpose of our study was to evaluate anti-AD potential of Cirsium maackii flowers. MeOH extract, CH₂Cl₂, EtOAc, and n-BuOH fraction of this flower notably inhibited BACE1 (IC₅₀ = 76.47 ± 1.66, 22.98 ± 1.45, 8.65 ± 0.63, and 72.47 ± 3.04 ㎍/mL, respectively). β-amyrenone (49.70 mg) (1), lupeol acetate (1.43 g) (2), lupeol (1.22 g) (3), lupenone (23.70 mg) (4), β-sitosterol (1.01 g) (6), and β-sitosterol glucoside (13.00 mg) (7) from CH₂Cl₂, apigenin (100.20 mg) (8), luteolin (19.00 mg) (9), apigenin 7-O-glucuronide methyl ester (21.30 mg) (14), and tracheloside (53.70 mg) (5) from EtOAc, apigenin 5-O-glucoside (11.00 mg) (10), luteolin 5-O-glucoside (11.00 mg) (11) and apigenin 7-O-glucuronide (91.00 mg) (12) from n-BuOH, and luteolin 7-O-glucuronide (22.00 mg) (13) from H₂O fraction were isolated. HPLC showed high levels of 8, 9 and 12 in MeOH extract (33.07 ± 0.07, 31. 44 ± 0.17 and 16.89 ± 0.33 mg/g, respectively), EtOAc (161.01 ± 1.78, 96.93 ± 0.34 and 73.38 ± 0.06 mg/g, respectively), and n-BuOH fraction (32.18 ± 0.33, 44.31 ± 0.32 and 105.94 ± 0.36 mg/g, respectively). Since, 3 and 9 are well-known BACE1 inhibitors, the anti-AD activity of C. maackii flower might be attributable to their presence.