462-20-4Relevant articles and documents
Design and development of the first peptide-chelating bisphosphane bioconjugate from a novel functionalized phosphorus(III) hydride synthon
Gali, Hariprasad,Karra, Srinivasa R.,Reddy, V. Sreenivasa,Katti, Kattesh V.
, p. 2020 - 2023 (1999)
Remarkable oxidative stability is shown by the carboxylate- functionalized primary bisphosphane 1. Compound 1 can be used in conjugation reactions with biomolecules for functionalization through the COOH group without prior protection of PH2 groups. A novel water-soluble bisphosphane was obtained by reaction of the PH2 groups of 1 with formaldehyde under mild conditions.
Enhancing the stability and biological functionalities of quantum dots via compact multifunctional ligands
Susumu, Kimihiro,Uyeda, H. Tetsuo,Medintz, Igor L.,Pons, Thomas,Delehanty, James B.,Mattoussi, Hedi
, p. 13987 - 13996 (2007)
We have designed and synthesized a series of modular ligands based on poly(ethylene glycol) (PEG) coupled with functional terminal groups to promote water-solubility and biocompatibility of quantum dots (QDs). Each ligand is comprised of three modules: a PEG single chain to promote hydrophilicity, a dihydrolipoic acid (DHLA) unit connected to one end of the PEG chain for strong anchoring onto the QD surface, and a potential biological functional group (biotin, carboxyl, and amine) at the other end of the PEG. Water-soluble QDs capped with these functional ligands were prepared via cap exchange with the native hydrophobic caps. Homogeneous QD solutions that are stable over extended periods of time and over a broad pH range were prepared. Surface binding assays and cellular internalization and imaging showed that QDs capped with DHLA-PEG-biotin strongly interacted with either NeutrAvidin immobilized on surfaces or streptavidin coupled to proteins which were subsequently taken up by live cells. EDC coupling in aqueous buffer solutions was also demonstrated using resonance energy transfer between DHLA-PEG-COOH-functionalized QDs and an amine-terminated dye. The new functional surface ligands described here provide not only stable and highly water-soluble QDs but also simple and easy access to various biological entities.
Metal ion induced fluorescence resonance energy transfer between crown ether functionalized quantum dots and rhodamine B: Selectivity of K+ ion
Lee, Hsin-Lung,Dhenadhayalan, Namasivayam,Lin, King-Chuen
, p. 4926 - 4933 (2015)
We report a ratiometric fluorescent metal ion sensor based on the mechanism of fluorescence resonance energy transfer (FRET) between synthesized 15-crown-5-ether capped CdSe/ZnS quantum dots (QDCE) and 15-crown-5-ether attached rhodamine B (RBCE) in pH 8.3 buffer solution. Fluorescence titration with different metal ions in pH 8.3 buffer solution of the QDCE-RBCE conjugate showed a decrease and an increase in the fluorescence intensity for QDCE and RBCE moieties respectively due to FRET from QDCE to RBCE. This sensor system shows excellent selectivity towards K+ ions resulting in increasing efficiency of FRET. Energy transfer efficiency depends on the affinity between metal ions and crown ether functionalized with QDCE/RBCE. The detailed analysis of FRET was explored. This water soluble ratiometric sensor system can act as a good FRET probe for sensing applications especially in biological systems.
PH-Responsive quantum dots via an albumin polymer surface coating
Wu, Yuzhou,Chakrabortty, Sabyasachi,Gropeanu, Radu A.,Wilhelmi, Joerg,Xu, Yang,Er, Kai Shih,Kuan, Seah Ling,Koynov, Kaloian,Chan, Yinthai,Weil, Tanja
, p. 5012 - 5014 (2010)
Multifunctional peptide?polymer hybrid materials have been applied as efficient and biocompatible quantum-dot coating materials. Significant pH responsiveness (e.g., an influence of the pH on the quantum yields of the peptide?polymer/QDs) was found and is attributed to conformational rearrangements of the peptide backbone.
Design and characterization of α-lipoic acyl shikonin ester twin drugs as tubulin and PDK1 dual inhibitors
Lin, Hong-Yan,Han, Hong-Wei,Sun, Wen-Xue,Yang, Yu-Shun,Tang, Cheng-Yi,Lu, Gui-Hua,Qi, Jin-Liang,Wang, Xiao-Ming,Yang, Yong-Hua
, p. 137 - 150 (2018)
Shikonin exhibits powerful anticancer activities for various cancer cells, but its poor solubility and strong toxicity hinder its development as clinical anticancer agent. We previously confirmed that shikonin and its derivatives can disturb mitosis through targeting tubulin. In this study, α-lipoic acid, the naturally-occurring co-factor of pyruvate dehydrogenase (PDH), was introduced into shikonin to design the twin drugs against both mitosis (tubulin) and glycolysis (PDK). 18 kinds of α-lipoic acid shikonin ester derivatives were achieved through three rounds of screening process performed by computer assistant drug design method, being designated as the outstanding compounds. Among them, 1c displayed the most potent cytotoxicity towards cervical cancer cells (HeLa) with an IC50 value of 3.14 ± 0.58 μM and inhibited xenotransplanted tumor growth in a dose-dependent manner. Further pharmacologic study demonstrated that 1c can cause cell cycle arrest in G2/M phase as tubulin polymerization inhibitor. Moreover, it also showed good PDK1 inhibitory activity, promoting PDH activity and forced HeLa cells to process more aerobic metabolism to undergo cell apoptosis. We reported here the first dual inhibitors of tubulin and PDK1 based on shikonin. It may form a basis for shikonin optimization through twin drug design framework for the discovery of new and potent shikonin derivatives in the study of targeted cancer therapy.
Driving oxygen coordinated ligand exchange at nanocrystal surfaces using trialkylsilylated chalcogenides
Caldwell, Marissa A.,Albers, Aaron E.,Levy, Seth C.,Pick, Teresa E.,Cohen, Bruce E.,Helms, Brett A.,Milliron, Delia J.
, p. 556 - 558 (2011)
A general, efficient method is demonstrated for exchanging native oxyanionic ligands on inorganic nanocrystals with functional trimethylsilylated (TMS) chalcogenido ligands. In addition, newly synthesized TMS mixed chalcogenides leverage preferential reactivity of TMS-S bonds over TMS-O bonds, enabling efficient transfer of luminescent nanocrystals into aqueous media with retention of their optical properties.
Facile synthesis of water-soluble fluorescent silver nanoclusters and HgII sensing
Adhikari, Bimalendu,Banerjee, Arindam
, p. 4364 - 4371 (2010)
A single step facile synthesis of highly emissive, water-soluble, fluorescent Ag nanoclusters has been reported using a small molecule, dihydrolipoic acid. These clusters were characterized using ultraviolet/visible (UV/vis) spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), dynamic light scattering (DLS), and X-ray diffraction (XRD) studies. Mass spectrometric analysis shows the presence of a few atoms in nanoclusters containing only Ag4 and Ag5. The reported fluorescent Ag nanoclusters show excellent optical properties, including narrow emission profile, larger Stokes shift (more than 200 nm), and good photostability. Interestingly, these nanoclusters also exhibit semiconducting property. Moreover, as-prepared fluorescent Ag nanoclusters have been utilized as an indicator for selective and ultrasensitive detection of highly toxic Hg II ions in water, even at subnanomolar concentrations.
Synthesis of compact multidentate ligands to prepare stable hydrophilic quantum dot fluorophores
Uyeda, H. Tetsuo,Medintz, Igor L.,Jaiswal, Jyoti K.,Simon, Sanford M.,Mattoussi, Hedi
, p. 3870 - 3878 (2005)
We describe a simple and versatile scheme to prepare an array of heterofunctional multidentate ligands that permit strong and stable interactions with colloidal semiconductor nanocrystals (quantum dots, QDs) and render them soluble in aqueous environments. These ligands were synthesized by reacting various chain length poly(ethylene glycols) with thioctic acid, followed by ring opening of the dithiolane moiety, creating a bidentate thiol motif with enhanced affinity for CdSe-ZnS core-shell QDs. Functionalization with these ligands permits processability of the nanocrystals not only in aqueous but also in many other polar solvents. These ligands provide a straightforward means of preparing QDs that exhibit greater resistance to environmental changes, making them more amenable for use in live cell imaging and other biotechnological applications.
Highly chemiluminescent gold nanopopcorns functionalized by N-(aminobutyl)-N-(ethylisoluminol) with lipoic acid as a co-stabilizing reagent
Zhang, Hongli,Liu, Mengxiao,Huang, Guangming,Yu, Yuqi,Shen, Wen,Cui, Hua
, p. 970 - 977 (2013)
Herein we report a novel facile synthesis of Au nanopopcorns (AuNPCs) with high chemiluminescent yield by reducing (±)-α-lipoic acid (LA) and HAuCl4 with N-(aminobutyl)-N-(ethylisoluminol) (ABEI) in ethyl alcohol solution at room temperature through a seed growth method. The morphologies of AuNPCs could be changed by adjusting the mole ratios of ABEI, LA and HAuCl4. The characterization results demonstrated that ABEI and the reduction product of LA as stabilizers were coated on the surface of AuNPCs during the synthesis. The AuNPCs, functionalized with ABEI, could react with various oxidants (H2O2, KMnO4, NaClO, Fe(CN)63- and AgNO3) to produce chemiluminescence (CL). The special morphology of AuNPCs maintains the large specific surface area, inherited from its shape and demonstrated excellent catalytic property when involved in CL reaction with H2O2. Thus the CL efficiency of AuNPCs was more than two orders of magnitude higher than that of ABEI functionalized gold nanoparticles in our previous work. The AuNPCs are capable of direct conjugation with protein and DNA while maintaining their luminescent properties, thus they could be potentially useful as a bio-probe for immunoassays and DNA assays. The Royal Society of Chemistry 2013.
One-pot development of water soluble copper nanoclusters with red emission and aggregation induced fluorescence enhancement
Li, Dan,Chen, Zhenhua,Wan, Zhanghui,Yang, Tiezhu,Wang, Hao,Mei, Xifan
, p. 34090 - 34095 (2016)
One-pot synthesis of water-soluble Cu NCs using DHLA protection ligands by different reducing reagents including NaBH4, N2H4 and THPC was developed. Furthermore, it was found that the as prepared Cu NCs using THPC as a reducing reagent describe fluorescence enhancement in the presence of Zn2+ and Al3+. It is proposed that the binding of Zn2+ and Al3+ to OH on the copper core of Cu NCs promotes the formation of CuNC-OH-Zn-OH-Cu NCs and CuNC-OH-Al-OH-Cu NCs aggregates respectively, which enables aggregation induced fluorescence enhancement. Additionally, it was found that the fluorescence enhancement were partly reversible by the introduction of an alkaline buffer solution and Zn2+.
