• Bulletin of the Korean Chemical Society
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• 제17권7호
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• pp.631-637
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• 1996

The structures of fully dehydrated Ca2+- and Rb+-exchanged zeolite X, Ca31Rb30Si100Al92O384(Ca31Rb30-X; a=25.009(1) Å) and Ca28Rb36Si100Al92O384(Ca28Rb36-X; a=24.977(1) Å), have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd&bar{3} at 21(1) ℃. Their structures were refined to the final error indices R1=0.048 and R2=0.041 with 236 reflections for Ca31Rb30-X, and R1=0.052 and R2=0.043 with 313 reflections for Ca28Rb36-X; I>3σ(I). In both structures, Ca2+ and Rb+ ions are located at six different crystallographic sites. In dehydrated Ca31Rb30-X, sixteen Ca2+ ions fill site I, at the centers of the double 6-rings (Ca-O=2.43(1) Å and O-Ca-O=93.3(3)°). Another fifteen Ca2+ ions occupy site II (Ca-O=2.29(1) Å, O-Ca-O=119.5(5)°) and fifteen Rb+ ions occupy site II opposite single six-rings in the supercage; each is 1.60 Å from the plane of three oxygens (Rb-O=2.77(1) Å and O-Rb-O=91.1(4)°). About two Rb+ ions are found at site II', 1.99 Å into sodalite cavity from their three-oxygen plane (Rb-O=2.99(1) Å and O-Rb-O=82.8(4)°). The remaining thirteen Rb+ ions are statistically distributed over site III, a 48-fold equipoint in the supercages on twofold axes (Rb-O=3.05(1) Å and Rb-O=3.38(1) Å). In dehydrated Ca28Rb36-X, sixteen Ca2+ ions fill site I (Ca-O=2.41(1) Å and O-Ca-O=93.6(3)°) and twelve Ca2+ ions occupy site II (Ca-O=2.31(1) Å, O-Ca-O=119.7(4)°). Sixteen Rb+ ions occupy site II; each is 1.60 Å from the plane of three oxygens (Rb-O=2.81(1) Å and O-Rb-O=90.6(3)°) and four Rb+ ions occupy site II'; each is 1.88 Å into sodalite cavity from their three-oxygen plane (Rb-O=2.99(1) Å and O-Rb-O=83.8(2)°). The remaining sixteen Rb+ ions are found at III site in the supercage (Rb-O=2.97(1) Å and Rb-O=3.39(1) Å). It appears that Ca2+ ions prefer sites I and II in that order, and that Rb+ ions occupy the remaining sites. Rb+ ions are too large to be stable at site I, when they are competing with other smaller cations like Ca2+ ions.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.98-103
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• 1998

The crystal structure of dehydrated $Rb^+$-exchanged zeolite X, stoichiometry $Rb_{71}Na_{21}-X\; (Rb_{71}Na_{21}Si_{100}Al_{92}O_{384})$ per unit cell, has been determined from single-crystal X-ray diffraction date gathered by counter methods. The structure was solved and refined in the cubic space group Fd3, a=25.007(3) Å at 21(1) ℃. The crystal was prepared by ion exchange in a flowing stream using a 0.05 M aqueous RbOH solution (pH=12.7). The crystal was then dehydrated at 360 ℃ and $2{\times}10^{-6}$ torr for two days. The structure was refined to the final error indices, $R_1=0.047$ and $R_2=0.040$ with 239 reflections for which I> 3σ(I). In this structure, 71 $Rb^+$ ions per unit cell are found at six different crystallographic sites and 21 $Na^+$ ions per unit cell are found at two different crystallographic sites. Four and a half $Rb^+$ ions are located at site Ⅰ, the center of the hexagonal prism. Nine $Rb^+$ ions are found at site Ⅰ' in the sodalite cavity (Rb-O=2.910(15) Å and O-Rb-O=78.1(4)°). Eighteen $Rb^+$ ions are found at site Ⅱ in the supercage (Rb-O=2.789(9) Å and O-Rb-O=92.1(4)°). Two and a half $Rb^+$ ions, which lie at site Ⅱ', are recessed ca. 2.07 Å into the sodalite cavity from their three O(2) oxygen planes (Rb-O=3.105(37) Å and O-Rb-O=80.6(5)°). Thirty-two $Rb^+$ ions are found at site Ⅲ deep in the supercage (Rb-O=2.918(12) Å and O-Rb-O=71.9(4)°), and five $Rb^+$ ions are found at site Ⅲ'. Seven $Na^+$ ions also lie at site Ⅰ. Fourteen $Na^+$ ions are found at site Ⅱ in the supercage (Na-O=2.350(19) Å and O-Na-O=117.5(6)°).

• Bulletin of the Korean Chemical Society
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• 제15권3호
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• pp.236-241
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• 1994

The crystal structures of $Cd_6-A$ evacuated at $2{\times}10^{-6}$ Torr and 750$^{\circ}$C (a=12.216(l) ${\AA}$), and of the product of its reaction with Rb vapor (a= 12.187(l) ${\AA}$), have been determined by single-crystal x-ray diffraction techniques in the cubic space group Pm$\bar{3}$m at 21(l)$^{\circ}$C. Their structures were refined to the final error indices, $R_1$=0.055 and $R_2$=0.067 with 191 reflections, and $R_1$=0.066 and $R_2$=0.049 with 90 reflections, respectively, for which I>3${\sigma}$(I). In dehydrated $Cd_6-A$, six $Cd^{2+}$ ions are found at two different threefold-axis sites near six-oxygen ring centers. Four $Cd^{2+}$ ions are recessed 0.50 ${\AA}$ into the sodalite cavity from the (111) plane at O(3), and the other two extend 0.28 ${\AA}$ into the large cavity from this plane. Treatment at 250 $^{\circ}$C with 0.1 Torr of Rb vapor reduces all $Cd^{2+}$ ions to give $Rb_{13.5^-}$A. Rb species are found at three crystallographic sites: three $Rb^+$ ions lie at eight-oxygen-ring centers, filling that position, and ca. 10.5 $Rb^+$ ions lie on threefold axes, 8.0 in the large cavity and 2.5 in the sodalite cavity. In this structure, ca. 1.5 Rb species more than the 12 $Rb^+$ ions needed to balance the anionic charge of zeolite framework are found, indicating that sorption of $Rb^0$ has occurred. The occupancies observed can be most simply explained by two "unit cell" compositions, $Rb_{12^-}A{\cdot}Rb$ and $Rb_{12^-}A{\cdot}2Rb$, of approximately equal population. In sodalite cavities, $Rb_{12^-}A{\cdot}Rb$ would have a $(Rb_2)^+$ cluster and $Rb_{12^-}A{\cdot}2Rb$ would have a triangular $(Rb_3)^+$ cluster. Each of the atoms of these clusters must bind further through a six-oxygen ring to a large cavity $Rb^+$ to give $(Rb_4)^{3+}$ (linear) and $(Rb_6)^{4+}$ (trigonal). Other unit-cell compositions and other cationic cluster compositions such as $(Rb_8)^{n+}$ may exist.

• Journal of Ginseng Research
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• 제44권3호
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• pp.435-441
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• 2020

Background: As a process of aging, skeletal muscle mass and function gradually decrease. It is reported that ginsenoside Rb1 and Rb2 play a role as AMP-activated protein kinase activator, resulting in regulating glucose homeostasis, and Rb1 reduces oxidative stress in aged skeletal muscles through activating the phosphatidylinositol 3-kinase/Akt/Nrf2 pathway. We examined the effects of Rb1 and Rb2 on differentiation of the muscle stem cells and myotube formation. Methods: C2C12 myoblasts treated with Rb1 and/or Rb2 were differentiated and induced to myotube formation, followed by immunoblotting for myogenic marker proteins, such as myosin heavy chain, MyoD, and myogenin, or immunostaining for myosin heavy chain or immunoprecipitation analysis for heterodimerization of MyoD/E-proteins. Results: Rb1 and Rb2 enhanced myoblast differentiation through accelerating MyoD/E-protein heterodimerization and increased myotube hypertrophy, accompanied by activation of Akt/mammalian target of rapamycin signaling. In addition, Rb1 and Rb2 induced the MyoD-mediated transdifferentiation of the rhabdomyosarcoma cells into myoblasts. Furthermore, co-treatment with Rb1 and Rb2 had synergistically enhanced myoblast differentiation through Akt activation. Conclusion: Rb1 and Rb2 upregulate myotube growth and myogenic differentiation through activating Akt/mammalian target of rapamycin signaling and inducing myogenic conversion of fibroblasts. Thus, our first finding indicates that Rb1 and Rb2 have strong potential as a helpful remedy to prevent and treat muscle atrophy, such as age-related muscular dystrophy.

• 대한화학회지
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• 제51권3호
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• pp.265-269
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• 2007

국부적인 결정구조와 에너지 띠 간격 간 상관관계를 고찰하기 위하여 Nb를 포함하는 일련의 불소 산화물에 대하여 결정구조와 자외선-가시광선 확산 반사율 스펙트럼을 비교, 연구하였다. 이 실험에서 다룬 RbSrNb2O6F와 RbCaNb2O6F, RbNb2O5F는 공통적으로, 꼭지점 공유를 하고 있는 NbO5F 팔면체로 구성되어 있 다. 구조적 뒤틀림 정도의 척도로 볼 수 있는 Nb-O(F)-Nb 평균 결합각은 RbSrNb2O6F에서 158.6°, RbCaNb2O6F 에서 149.6° 그리고 RbNb2O5F에서 139.5o이다. 확산 반사율 스펙트럼으로부터 구한 에너지 띠 간격은 Nb-O(F)-Nb 결합각이 감소할수록 증가하는 경향을 보였다. 즉 RbSrNb2O6F, RbCaNb2O6F, RbNb2O5F 각각의 화합물에 대해 서 3.48 eV, 3.75 eV, 4.03 eV 의 값을 나타내었다. 이러한 실험적 결과는 Nb를 포함하는 불소 산화물에서 국 부구조의 변화를 통해 띠 간격을 약 0.6 eV의 범위에서 조절할 수 있음을 의미한다.

• Journal of Ginseng Research
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• 제45권2호
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• pp.287-294
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• 2021

Background: Ginsenoside Rb1 (G-Rb1), one of the major active compounds in Panax ginseng, has already been shown to reduce inflammation in various diseases. Osteoarthritis (OA) has traditionally been considered a degenerative disease with degradation of joint articular cartilage. However, recent studies have shown the association of inflammation with OA. In the present study, we investigated whether Rb1 had an antiinflammatory effect on monoiodoacetate (MIA)-induced OA in ovariectomized rats as a model of postmenopausal arthritis. Methods: G-Rb1 at a dosage of 3 and 10 ㎍/kg body weight was administered every 3 days intraarticularly for a period of 4 weeks to observe antiarthritic effects. Diclofenac (10 mg/kg) served as a positive control. Results: The administration of Rb1 significantly ameliorated OA inflammatory symptoms and reduced serum levels of inflammatory cytokines. Furthermore, G-Rb1 administration considerably enhanced the expression of bone morphogenetic protein-2 and collagen 2A and reduced the levels of matrix metalloproteinase-13 genes, indicating a chondroprotective effect of G-Rb1. G-Rb1 also significantly reduced the expression of several inflammatory cytokines/chemokines (interferon gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1)/CCL-2, interleukin [IL]-1β, and IL-6). Histological analysis demonstrated that G-Rb1 significantly attenuated the pathological changes in MIA-induced OA in ovariectomized rats. Safranin O and toluidine blue staining further demonstrated that G-Rb1 effectively prevented the degradation of cartilage and glycosaminoglycans, respectively. Conclusion: Overall, our results suggest that G-Rb1 exerts cartilage protective effect on MIA-induced ovariectomized OA rats, by inhibiting inflammatory mediators such as IL-6, IL-1β, MCP-1/CCL-2, cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE2). These results shed a light on possible therapeutic application of G-Rb1 in OA.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.63-69
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• 1988

Streptozotocin으로 유발시킨 당뇨병성 쥐(혈당수준$430{\pm}30ml/dl$)에게 ginsenoside-$Rb_{2}$를 연속적으로 복강투여 하였다. Ginsenoside $Rb_{2}$ 투여군은 현저한 혈당감소를 보였으며 이군들의 혈당수준은 6-9일 투여로 약 160mg/dl로 떨어졌다. 한편 대조군보다 먹이섭취량이 적지만 체중은 ginsenoside-$Rb_{2}$를 투여한 당뇨쥐에서 상당히 증가하였다. Ginsenoside-$Rb_{2}$투여군은 과식, 다뇨, 당뇨 등과 같은 당뇨병 증상이 개선 되었다. 혈당을 떨어뜨리는 작용기전을 연구하기위한 일환으로 간 및 지방조직 그리고 혈청 등에 있는 탄수화물 대사물질과 지질성분 등에 미치는 ginsenoside-$Rb_{2}$의 효과를 조사하였다. 당뇨쥐에서는 ginsenoside-$Rb_{2}$가 먼저 정상쥐에서와 같이 간에서 혈당의 이용을 촉진 시키고 그결과 지방조직에 triglyceride 들이 증가되는 것으로 추측된다.

• Journal of Ginseng Research
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• 제28권2호
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• pp.87-93
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• 2004

인삼성분 중 ginsenoside-Rb$_2$에 의한 LDL receptor발현 증가의 기전을 HepG$_2$세포에서 관찰하였고 이를 lovastatin과 비교하였다. 콜레스테롤 투여에 의하여 억제된 LDL receptor mRNA발현이 ginsenoside-Rb$_2$에 의하여 다시 증가하였고 이는 lovastatin에 의한 증가 효과보다 뛰어났다. SREBP mRNA의 발현 또한 콜레스테롤 투여에 의하여 억제되나 ginseonside-Rb$_2$에 의하여 발현이 증가하였고 이는 lovastatin에 의한 효과와 비슷하였다. 세포에 투여한 ginsenoside-Rb$_2$의 농도에 비례하여 SREBP-1 mRNA의 발현이 증가하였으며 ginsenoside-Rb$_2$의 대사체인 compound K를 투여한 경우에도 SREBP-1 mRNA가 비슷한 양상으로 혹은 더 많이 발현되었다. 따라서 ginsenoside-Rb$_2$에 의한 LDL receptor의 발현 증가는 SREBP의 발현 증가 때문이라고 설명할 수 있다. 즉 ginsenoside-Rb$_2$에 의한 SREBP 발현 증가는 콜레스테롤 투여에 의하여 억제된 LDL receptor발현을 증가시켜 결과적으로 혈중의 콜레스테롤을 효과적으로 제거하는 것으로 판단된다.

• 한국광물학회지
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• 제4권1호
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• pp.22-31
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• 1991

세 개의 탈수한 $Ag^+$이온과 $Ca^{2+}$ 이온으로 치환한 제올라이트 $A(Ag_4Ca_4-A,\;Ag_^Ca_3-A,\;Ag_8Ca_2-A)$를 0.1 Torr의 Rb 증기로 처리한 결정구조를 공간군 Pm3m을 써서 단결정 X-선 회절법으로 결정하였다. (단위세포상수 a는 각각 $12.271(1){\AA},\;12.255(1){\AA}$ 및 $12.339(1){\AA}$이다). 이들 구조의 최종 오차인수 R(무게)는 $I>3{\rho}(I)$가 되는 130 회절반사로 0.072, 110 회절반사로 0.050 및 86 회절반사로 0.082이었다. 각각의 구조에서 Rb 종은 세개의 다른 결정학적 위치에 위치하고 있다. 즉 단위세포당 3개의 $Rb^+$이온은 8-링 중심에 위치하고 약 2.5개 내지 3.0개의 $Rb^+$이온은 소다라이트 동공내 3회 회전축상에 위치한다. 또 Ag 종이 두 개의 다른 결정학적 위치에 위치하고 약 0.7∼2.1개의 $Ag^+$이온은 4-링과 마주보는 위치에, 약 2.2∼4.8개의 Ag 원자는 큰 동공 중심 가까이에 위치한다. 이들 구조에서 단위 세포당 Ag 원자이 수는 각각 2.2, 2.4 및 4.8개이었고 이들은 큰 동공 중심에 헥사실버 클라스터를 만든다. $Rb^+$이온은 8-링을 막고 있어서 Ag가 골조 밖으로 이동하는 것을 막고 있고 각각의 헥사실버 클라스터는 13개의 $Rb^+$ 이온과 배위하여 안정화된다. 단위 세포당 약 0.8개의 Rb원자가 과잉으로 존재하여 삼각 대칭형의 $(Rb_3)^{2+}$클라스터가 소다라이트 동공내의 존재한다. 적어도 하나의 큰 동공의 6-링 $Rb^+$ 이온은 소다라이트 동공의 $(Rb_3)^{2+}$클라스터에 접근하므로 이들 클라스터는 $(Rb)_4^{3+}$, $(Rb)_5^{4+}$ 혹은 $(Rb)_6^{5+}$가 형성될 수도 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2255-2258
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• 2013

The activity of Rb proteins is controlled by post-translational modifications, especially through phosphorylation. Acetylation of Rb2/p130 was reported recently in NIH3T3 cells but its physiological relevance in cell cycle control and tumorigenesis is still unknown. Efforts are underway to investigate possible interplay between Rb2/p130 phosphorylation and acetylation. Here we hypothesized that Rb2/p130 acetylation, like p53 acetylation, may play a role in development of the tumor phenotype. The proposed hypothesis regarding acetylation of Rb2/p130 in tumor VS normal cells was found to be true in our case study of 36 tumor samples. Statistical analysis of results suggest strong correlation among Rb2/p130 acetylation and cancer phenotype.