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Showing papers by "Indrapal Singh Aidhen published in 2013"


Journal ArticleDOI
TL;DR: Fluorescence intensity and lifetime decay analysis of the molecular probe 1-naphthol indicate that the interaction of FTY720 with the DMPC lipid bilayer membrane prevents partitioning of small molecules such as 1-methine to the membrane in both solid gel (SG) and liquid crystalline (LC) phases.
Abstract: This work focuses on the study of aqueous phase aggregation of the recently FDA approved oral drug molecule FTY720 (fingolimod hydrochloride) and its effect on dimyristoylphosphatidylcholine (DMPC) liposomes using different fluorescent molecular probes and fluorescence parameters The variation of the steady state fluorescence intensity of 8-anilino-1-naphthalene sulfonic acid (ANS) with FTY720 in water shows an efficient micellar aggregation with the critical micellar concentration (CMC) at ~75 μM The aggregation number calculation from steady state fluorescence quenching of pyrene shows the formation of small micellar aggregates in aqueous solution having an aggregation number of 42 ± 3 with the free energy of micellization ~-23 kJ mol(-1) Fluorescence intensity and lifetime decay analysis of the molecular probe 1-naphthol indicate that the interaction of FTY720 with the DMPC lipid bilayer membrane prevents partitioning of small molecules such as 1-naphthol to the membrane in both solid gel (SG) and liquid crystalline (LC) phases Temperature dependent fluorescence intensity studies of 1-naphthol and fluorescence anisotropy measurements of 1,6-diphenyl-1,3,5-hexatriene (DPH) have shown that above the CMC of FTY720, the SG to LC main phase transition temperature (T(M)) of the lipid bilayer membrane decreases from 23 °C to 21 °C in the aqueous medium

18 citations


Journal ArticleDOI
TL;DR: A new route based on the use of acyl anion chemistry was developed for the synthesis of (+)-centrolobine and its analogues as mentioned in this paper, which was the key step in the stereoselective formation of the cis

15 citations


Journal ArticleDOI
TL;DR: Several substrates containing both cyano and Weinreb amide functionalities have been synthesized to study the chemoselectivity of their reactions with organomagnesium bromides, affording cyano ketones in good-to-excellent yields.

12 citations


Journal ArticleDOI
29 Mar 2013
TL;DR: In this paper, a new octupolar molecule (E, E, E )-2,4,6-Tris [2-(4- N, N -diphenylaminophenyl) vinyl] pyridine (DPATSP) has been synthesized and studied by steady state and time-resolved fluorescence in condensed phase.
Abstract: A new octupolar molecule ( E , E , E )-2,4,6-Tris [2-(4- N , N -diphenylaminophenyl) vinyl] pyridine (DPATSP) has been synthesized and studied by steady state and time-resolved fluorescence in condensed phase. The large π-conjugation along the chain has been found to be responsible for large solvent-induced shift of fluorescence. Pumping with fs pulses at 790 nm have been found to induce the two-photon fluorescence. The two-photon absorption (2PA) cross section has been measured by the two photon induced fluorescence (2PIF) method. The N -methyl derivative of DPATSP shows a red shift in the absorption spectrum. The overlap of the fluorescence spectrum of DPATSP with the absorption spectrum of the DPATSP-Me makes a Forster resonance energy transfer (FRET) system. The FRET efficiency has been studied by embedding this dye pair in a polymer matrix.

10 citations


Journal ArticleDOI
TL;DR: In this paper, two bifunctional building blocks that enable a C-C bond formation through a Julia-Kocienski reaction were synthesized and the orthogonal nature of the two functional groups in these building blocks allowed the sequential olefination of commercially available aromatic aldehydes and the intermediate stilbene aldehyde to deliver an efficient and new route for bis(styrylbenzenes) with Weinreb amide (WA) functionality for the first time.

8 citations


Journal ArticleDOI
19 Jul 2013-Synlett
TL;DR: In this paper, a new strategy for the synthesis of vinyl ketones has been achieved, using β-phenylseleno-N-methoxy-Nmethylpropanamide, obtained through two simple reactions.
Abstract: A new strategy for the synthesis of vinyl ketones has been achieved. Hitherto unknown and easily accessible, β-phenylseleno-N-methoxy-N-methylpropanamide, obtained through two simple reactions, served as a building block for convenient access to vinyl ketones. The N-methoxy-N-methyl amide moiety ensured no overaddition of the Grignard reagent and, hence, the excellent formation of β-phenylseleno ketones; oxidative work-up with ­hydrogen peroxide provided ready access to the vinyl ketones with concomitant loss of phenylselanol.

7 citations


Journal ArticleDOI
TL;DR: The bis(5-arylfuran-2-yl)methane framework has been obtained through defunctionalization of aryl ketones, derived from abundantly available L-(+)-tartaric acid, under the influence of acid.

3 citations


Journal ArticleDOI
TL;DR: In this paper, two bifunctional building blocks that enable a C-C bond formation through a Julia-Kocienski reaction were synthesized and the orthogonal nature of the two functional groups in these building blocks allowed the sequential olefination of commercially available aromatic aldehydes and the intermediate stilbene aldehyde to deliver an efficient and new route for bis(styrylbenzenes) with Weinreb amide (WA) functionality for the first time.
Abstract: In an effort to arrive at bis(styrylbenzene) derivatives, which are known for their importance in connection to Alzheimer's disease, two bifunctional building blocks that enable a C–C bond formation through a Julia–Kocienski reaction were synthesized. The orthogonal nature of the two functional groups in these building blocks allow the sequential olefination of commercially available aromatic aldehydes and the intermediate stilbene aldehydes to deliver an efficient and new route for bis(styrylbenzenes) with Weinreb amide (WA) functionality for the first time. The successful incorporation of the WA functionality has facilitated convenient access to unknown bis(styrylbenzenes) with acyl and formyl groups as substituents This strategy has also paved the way for highly functionalized bis(styrylbenzenes) with a tetrafluorophenyl core, which have potential as new contrast agents for MRI applications.