[Professor of Chemistry, & Associated Faculty (Professor),
School of Biosciences & Bioengineering]
Currently, Director (Independent), Rashtriya Chemicals & Fertilizers Ltd, Mumbai. (A Govt. of India Undertaking, Ministry of Chemicals & Fertilizers).
Adjunct Professor and Visiting Fellow at the Institute of Chemical Technology, Mumbai (Category-I Deemed to be University & Elite Status-Centre of Excellence, Govt of Maharashtra).
Honorary Visiting Professor at BK Birla College (Autonomous) Kalyan.
Department of Chemistry,
Indian Institute of Technology
Bombay
Powai, Mumbai - 400 076
(India)
Phone: (+91-22) 2576
xxxx
Fax: (+91-22) 2576 7152
Email: Retinal[at]chem.iitb.ac.in
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Academic
Background
Ph.D. (1978): Indian Institute of
Technology, Kanpur
Post-Doctoral Research:
1978 :Florida State
University, Tallahassee
1979 :University of
Hawaii, Honolulu
1981 :Columbia
University, New York
Biographical Sketch
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Professional Experience
2019 - Director (Independent), Rashtriya Chemicals and Fertilizers Ltd, Mumbai.
2019 - Adjunct Professor at the Institute of Chemical Technology, Mumbai.
2011 - 2014 Vice Chancellor, University of Allahabad
2009 - Convenor, IIT Gandhinagar Cell
2007 - Vice Chancellor, Bundelkhand University
2004 - Dean, Academic Programs, I.I.T, Bombay
2002 - Director,
Regional Research Laboratory (CSIR) (Present day North-East Institute of Science and Technology), Jorhat
1993 - Head,
Chemistry Department, I.I.T, Bombay
1990 - Professor, I.I.T,
Bombay
1989 - Visiting
Scientist, University of Montreal, Canada & Syracuse University, New York, USA.
1988 - Associate
Professor, I.I.T, Bombay
1984 - Assistant
Professor, I.I.T, Bombay
1983 - Lecturer in Chemistry, I.I.T,
Bombay
1982 -
Lecturer in Chemistry, University of Roorkee, (now I.I.T Roorkee)
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RESEARCH INTERESTS
·
Photocontrol of
structure and function of biomolecules -
Retinal-bound photoreceptor proteins - synthesis and characterization of bacteriorhodopsin analogs. Development of photoswitchable systems, photoswitchable enzymes as reagents.
·
Biomolecular caging
-
Synthesis of novel phototriggers and their applications in caging of drugs and bioactive natural products.
·
Excited state
studies of linear polyenes -
Synthesis, photochemical and photophysical studies of linear polyenes including retinoids, diphenylpolyenes, indolic polyenes.
·
Fluorescence
probes -
Synthesis of neutral hydrophobic probes for various applications including characterization of microenvironment of organized assemblies and proteins, and as diagnostics.
·
Radioprotective/antioxidant
agents - Vitamin A and E related radioprotective / antioxidant compounds - synthesis and assay of their antiradical abilities.
·
Organic
nanoparticles -
Synthesis, characterization and biomedical applications.
·
Chemistry of vision - bioorganic
studies of rhodopsins and its analogs
One of the major thrust of our research is to provide molecular level chemical
insights into biological processes mediated by light, for example biological
sensory (vision) and energy (ion pumps) transductions. We have used bioorganic
chemistry approaches and studied various aspects of structure and mechanism of
functions of visual pigment rhodopsin and halobacterial pigment
bacteriorhodopsin (bR). Our studies involving synthesis of retinal analogs,
preparation of bR analogs from the synthetic retinal, followed by various
spectroscopic and other related studies have highlighted the role of water,
hydrogen bond interactions, tryptophan residues and polar excited states in the
structure and mechanism of functions of such photoreceptors. We use the
chromophore substitution method as well as chemical modifications of the protein
residues to obtain analogs and variants of bR having interesting opto-electronic
properties for possible application as photoactive element in molecular
electronic devices.
·
Biomolecular caging
Controlling biological activity with light has become an important
strategy in processes as diverse as light-induced enzymatic catalysis, the
activity of neurotransmitters, targeted drug delivery and development of
photoreceptors for molecular electronic devices. The success of this strategy of
optical control of the structure and function of biomacromolecular systems,
however, depends on the availability of suitable chromophores and their
applicability in biological surroundings. In this context, we are trying to
develop synthetic phototriggers capable of photoactivating enzymes and proteins,
drugs, and other bioactive compounds in a controlled and selective fashion. Some
of the phototriggers like NNM, anthracene-9-methanol and naphthyl based
chromophores developed in our lab bear interesting properties for biomolecular
caging.
·
CRICT capable diphenylpolyenes and
other organics, Fluorescence probes
Linear polyenes play crucial roles in sensory (vision) and energy transductions
(ion pumps) in many biological systems. Consequently, excited state structure
and dynamics of linear polyenes have attracted a great deal of attention. We
have synthesized several donor-accetor diarylpolyenes as models of
photobiologically active linear polyenes and studied their photochemical and
photophysical properties to further characterize the excited state structure and
dynamics of photobiologically important linear polyenes. We have demonstrated
that highly polar, conformationally relaxed intramolecular charge transfer
(CRICT) excited states can be involved in the photoprocesses of linear polyenes.
Some of these compounds exhibit interesting dual fluorescence and we have used
such excited state properties to design and develop diarylpolyene-based neutral
hydrophobic fluorescence probes as reporters of microenvironment of organized
assemblies and proteins.
·
Radioprotective molecules
With
the aim of counteracting the adverse effects of radiation, we are interested in
developing molecules, which could scavenge the damaging reactive oxygen species
produced in the living cells once they are exposed to radiation. Vitamin E and
A, and other bioactive synthetic/natural molecules can act as efficient
radio-protective agents, and in this context synthesis of such organics as
radio-protecting agents with desirable therapeutic characteristics are being
carried out.
We synthesize and characterize organic
Nanoparticles (NP) with emphasis on development of NP for opto-electronic and
biomedical applications including
diagnostics and drug delivery. Our
interest also lies in the fluorescent organic NP and applications of NP in
organic reactions and synthesis.
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PUBLICATIONS
I. Some Recent Publications
- A.K. Singh (2018) Guest Editorail on "Light-Induced Chemistry of Organic & Biomolecules". Indian J. Chem. Section B (including Organic & Medicinal), 57B, 207-209.
- P.K. Hota and A.K. Singh (2018) Donor-acceptor conjugated linear polyenes : A study of excited state intramolecular charge transfer, photoisomerization and fluorescence probe properties. J. Fluoresc., 28, 21-28.
- A. K. Singh and A. W. M. H. Ansari (2017) Fluorescent organic
nanoparticles of 3-styrylindoles - synthesis and characterization. J. Nanosci. Nanotechnol. 167, 1381-1386.
- P. K. Hota and A. K. Singh (2015)An overview on the excited state
properties of donor-acceptor conjugated linear diarylpolyenes studies of fluorescence, fluorescence probe, photoisomerization and photobiological implications. Int. J. Chem. 4, 311 - 324.
- P. K. Hota and A. K. Singh (2013) Synthetic photoresponsive systems, Lambert Academic, Germany, ISBN No. 978-3-659-44894-2.
- A. K. Singh and P.K. Khade (2011) 7-Methoxy-3-nitro-2-naphthalene methanol - a new phototrigger for caging applications, Tetrahedron Letters, 52, 4899-4902.
-
A. K. Singh; A. W. M. H.
Ansari (2010) Synthesis of uniform narrow-size nanoparticles of cholesterol
esters. Nanosci. Nanotechnol. Lett. 2,46-50.
-
A. K. Singh;
Solomon B. Libsu
(2010)
Antiradical
activity of
b-ionyl
compounds. Lett. Org. Chem. 7, 338-342.
-
A. K. Singh; K. Gopu
(2010) Synthesis and antioxidant properties of novel alpha-tocopherol
glycoconjugates. Tetrahedron Lett. 51, 1180-1184.
-
A. Asefa; A. K. Singh
(2009) Fluorescence emission enhancement in substituted 3-styrylindoles in
the solid state. J. Luminescence 130, 24-28.
-
A. K. Singh and A. Asefa
(2009) Novel fluorescence emissions from 3-styrylindoles. Indian J. Chem.
B. 48B, 1543-1547.
-
A. Asefa; A. K. Singh
(2009) A fluorescence study of novel styrylindoles in homogeneous and
microhterogeneous media. J. Fluorescence 19, 921-930.
-
A.K. Singh; A. Asefa
(2009) A fluorescence study of differently substituted 3-styrylindoles and
their interaction with bovine serum albumin. Luminscence : The Journal of
Biological and Chemical Luminscence 24, 123-230.
-
A. K. Singh, C. S. S. R.
Kumar and S. Achar (2007) A process for the preparation of polymers from
vinylic monomers using tetraethyl thiurium monosulfide (monosulfiram) as
photo-initiator: Indian Patent No. 204220 (2007).
-
A. K. Singh (2007)
Chemistry of some natural photoreceptors. Presidential Address. Proc. 94th
Indian Science Congress, Part II: Sect. IV, pp. 1-58.
-
P. K. Khade; A. K. Singh
(2007) A new caging phototrigger based on a 2-acetonaphthyl chromophore.
Tetrahedron Lett. 48, 6920-6923.
-
A. K. Singh; P. K. Hota.(2007)
Ethenyl indoles as neutral fluorescent hydrophobic probes. J. Phys. Org.
Chem. 20, 624-629.
-
A. K. Singh; P. K. Hota
(2007) Development of bacteriorhodopsin analogues and studies of charge
separated excited states in the photoprocesses of linear polyenes:
Photochem. Photobiol. 83, 50-62.
-
L. Solomon; A. K. Singh
(2007) Development of aqua-soluble compounds based on vitamin A series
molecules: Synthetic transformations of beta-ionone. Indian J. Chem.
B. 46B, 1297-1302.
-
P. K. Hota; A. K. Singh
(2007) Bacteriorhodopsin analogues from indolic chromophores. Letters
Org. Chem. 4, 300-305.
-
L. Solomon; A. K. Singh
(2007) Photochemical studies on
b-ionyl hydrazone.
Indian J. Chem. B. 46B, 1133-1136.
-
A. K. Singh; A. Asefa
(2007) N-Alkylation of indole compounds in modified Wittig-Horner reaction.
Synthetic Commun. 37, 1491-1494.
-
A. K. Singh; P. K. Hota
(2006) Substituent directed distal photoisomerization of C=C in indolic
dienyl chromophores. Indian J. Chem. B. 45B, 2469-2473.
-
A. K. Singh; P. K. Hota
(2006) Fluorescence and photoisomerization studies of p-nitrophenyl
substituted indolic ethenes. J. Phys. Org. Chem. 19, 43-52.
-
A. K. Singh; P. K. Hota
(2006) Chemistry of biological photoreceptors based on linear polyenes.
Natl. Acad. Sci. Lett. (India) 29, 231-252.
-
A. K. Singh; P. K. Hota
(2005) Absorption and fluorescence spectral properties of donor-acceptor
ethenes bearing indole and p-nitrophenyl substituents. Res. Chem.
Intermed. 35, 85-101.
-
A. K. Singh; P. K. Khade
(2005) Anthracene-9-methanol - A novel fluorescent phototrigger for
biomolecular caging. Tetrahedron Lett. 46, 5563-5566.
-
A. K. Singh; P. K. Khade
(2005) 3-Nitro-2-naphthalenemethanol: A photocleavable protecting group for
carboxylic acids. Tetrahedron 61, 10007-10012.
II. Recent Ph.D. Thesis
- Mr. W. M. H. Ansari, Thesis topic : Organic Nanoparticles.
- Dr. K. Gopu (2011) - Thesis title: Synthesis and antioxidant studies of some alpha-tocopherol compounds.
-
Dr. Abera Asefa Abebe (2009) - Thesis title: Studies of
excited states and fluorescence probe properties of 3-styrylindoles.
-
Dr. Solomon Libsu (2008) - Thesis title: Synthesis,
antioxidant and photochemical studies of some beta-ionyl compounds.
-
Dr. Prasanta K. Hota (2006) - Thesis title: Synthetic
photoresponsive systems - fluorescence and photoisomerisation studies on
indolic ethenyls and dienyls chromophore and development of
bacteriorhodopsin analogs.
-
Dr. Prashant K. Khade (2005) - Thesis title: Design and
development of novel phototriggers for biomolecular caging.
III. Recent Post-Doctoral Researcher
-
Dr. S. L. Bikila (Bahir Dar University, Ethiopia), Science and Technology/Innovation, FICCI, C. V. Raman Fellow (2011 - 2012), Research Topic: Studies of antioxidants
IV. Recent Master/Summer Trainees dissertations
- Souvik Ghosal (2015, Science Academies Joint Summer Research Fellow, Presidency University, Kolkata). Project title: Design and Synthesis of Molecular Fluorescent Viscosity Probes.
- Sudhanva Prasad S. S. (2015, Science Academies Joint Summer Research Fellow, Mangalore University, Mangalgangotri). Project title: Synthesis and fluorescence studies of tryptamine-based flurophores.
- Ashwin Chaturvedi (2015, Summer Project, BS-MS Intg Student/ INSPIRE Fellow, IISER Kolkata). Project title: Studies of organic nanoparticles - synthesis, characterization and applications.
- Chimala Prathusha (2015, Summer Project, BS-MS Intg Student/ INSPIRE Fellow, IISER Bhopal). Project title: Nanoparticles - mediated organic synthesis - preparation of copper nanoparticles and synthesis of glycotriazoles.
- Sushant Gajbhiye (2015, Summer Project, BS-MS Intg Student/ INSPIRE Fellow, IISER Trivendrum). Project title: Studies of retinoids as anti-cancer compound and synthesis of biologically active glycotriazoles.
- Shashwat Kulkarni, 2015, B.Tech. (Polymers) Summer Project, Student, Institute of Chemical Technology, Mumbai). Project title: Studies of fluorescent organic nanoparticles of medical and technological significance.
- Sanka Prabhakar Rao (2014, Inter Academy Summer Research Fellow, Osmania University, Hyderabad). Project title : Light-mediated synthesis of oxadiazoles.
- Shefali Banga (2013, Inter Academy Summer Research Fellow, SGRR PG College, Dehradun; HNB Garhwal University, Srinagar). Project title : Synthesis of triazoles and protonation of Schiff bases.
- Supriya Mishra (2013, Inter Academy Summer Research Fellow, National Institute of Technology, Rourkela). Project title : Studies of fluorescent carbon quantum dots.
- Dr. Niharika Verma (2013, Inter Academy Summer Research Fellow, Reader, Chemistry, Sri. JNPG College, University of Lucknow). Project title: Oxidation of organic compounds in aqueous medium using molecular oxygen as an oxidant.
- Mr. Ashish Kulkarni (2010, 5-Yr Intg. MSc (I) Chemistry, IIT Roorkee) Project title: Nano-catalysis in click chemistry and synthesis of glycoheterocycles.
- Loadh, Fatehbahadur P. (2010), External Project Student, M.Sc. Project, Chemistry, Jaihind College (University of Mumbai). Project title: Synthesis of vitamin E compounds as potential antioxidants
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Mr. S. Elamaran Guru (2009, Inter Academy Summer Research
Fellow, Madurai Kamaraj University). Project title: Design and synthesis of
novel
α-tocopherol glycoconjugates.
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Ms. V. Snehalatha (2009, Inter Academy Summer Research
Fellow, University of Hyderabad). Project title: Synthesis and
characterization of Fluorescent Organic Nanoparticles (FONs).
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Mr. Samik Jhulki (2009, Inter Academy Summer Research
Fellow, IIT, Kanpur). Project title: Synthesis and solid-state fluorescence
characterization of a 3-styrylindole.
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Ms. Nidhi Gupta (2009, M.Tech. Intg., Amity Institute of
Nanotechnology, Amity University, NOIDA). Project title: Photochromic
studies of organic nanoparticles.
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