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Update on Wednesday, February 28, 2007, at 9:26PM
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About this Author              Resume Dr.S.Aravamudhan
A Personal Page with Current updates and Link to Contact Info

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A project proposal to the Centre for Bioinformatics, NEHU

 CLICK HERE to display a page URL with documentation of an Elementary article on NMR written by Dr.Aravamudhan

                                                                                                                                             

North East Indian Medicinal Plant Chemistry & Conservation: The Use of NMR Technology as aid for the required processing

 

S.Aravamudhan

Department of Chemistry, North Eastern Hills University, Shillong 793022 Meghalaya INDIA 

Email:saravamudhan@nehu.ac.in                                                                                                                                                                           

1. Standardization of herbal medicines  

2. Bio-prospecting Natural Products for Medicinal properties 

3.  Bio-prospecting and Search for New Chemical Entity [NCE]

4. Computer aided storage and retrieval systems-generating data bases

5.  Prospecting Genomes for Bioactive Molecules   

6.   Computer aided storage and retrieval systems-generating data bases      

7. Prospecting Genomes for Bioactive Molecules                                                                                                                                                                                                                                                                        

All the above listed medicinal plant aspects concern with identifying and characterizing Chemical Entities, and    trying to know the extent possible the detailed characteristic chemical transformations which are responsible for specific medicinal effectiveness of the formulations. It is in general the holistic approach which practically enables categorizing and using the plant species for their medicinal effectiveness. It is not possible to discard with this traditional method altogether since it is this method which reveals the possibility of what ever potential modern technological tools have in improving the situation for the conservation and utilization of medicinal plants.

Nuclear Magnetic Resonance is a Spectroscopic tool for the study of molecules for their Structure and Reactivity. The NMR has been found to be such a potential tool for the macromolecules, the biologically significant macromolecules in particular, that efforts are made to develop sophisticated instrumentation requiring advanced technological inputs. This type of developing instruments is possible in the NMR regime which in turn unfolds several new techniques based on the Nuclear Magnetic Resonance phenomenon involving theory and experiment. The interpretative potential and inferences from the currently available NMR spectroscopic resources seems to be limited only by the extent to which the user wants to look for the details rather than the actual applicability of the NMR technique.

To emphasize and substantiate the importance of NMR as extold above it suffices to cite two instances of scientific gathering held in INDIA as below.

1.               A workshop on “NMR in the Post-genomic Era” was held in Lucknow in the year 2002 which was a Indo-Italian collaborative effort.

2.              A Symposium on “NMR, Drug Design and Bioinformatics” was held in the year 2004 at Saha Institute of Nuclear Physics at Kolkata

A glance through the program and lecture titles would reveal the extent to which NMR can be useful in such studies.

References 1 &2 cited at the end of this description, and the references therein, indicate that specific approaches are being initiated and tested using NMR technique which conforms to the trends of holistic approach prevalent in traditional practices, while the capability of NMR methods for the molecular level characterizations has been unequivocally established. Thus when it becomes necessary to acquire such detailed molecular level informations for standardizing medicinal plant materials, the NMR technique would not be found wanting while the traditional methods have a severe drawback for such detailed studies. Hence it seems that an effort, to adapt the NMR technique for what prevails in traditional practices in standardizing medicinal plant materials with the view to exploit the NMR potentials for revealing molecular details, would prove to be rewarding. It is intended to make a beginning by trying to look for the applicability of this potential NMR tool for whatever is known in the traditional practices in North East for the utilization of medicinal plant materials.

References:

1.                          A robust Clustering Approach for NMR Spectra of natural product extracts”:  Gregory K.Pierens et.al., Magnetic Resonance in Chemistry, Vol. 43: 359-365 (2005)

2.                         “Screening by NMR: A new Approach for the Study of Bioactive Natural Products? The Example of Pleurotus ostreatus Hot Water Extract” , Matteo Politi et.al., European Journal of Organic Chemistry, (2005) 1392-1396.


CLICK HERE  to display a webpage with particulars of BOOK ON
Solid State Characterization of Pharmaceuticals
which contains a Chapter on
Characterizing Structure and Dynamics in Pharmaceutical Solids by Solid-State NMR Spectroscopy.


To order your copies, special discount price for bulk purchase, please write to:

Ms. Sarulatha/Ms. Mythili
Research Publishing Services
H12F Double Tank Colony, K.K. Nagar
Chennai - 600 078, Tamil Nadu
Phone: +044-24350149; 044-24720542; HP: 9841029371
E-mail:  enquiries@researchpubonline.com

Dr.Aravamudhan participated in the National Seminar and Workshop on Bioinformatics and Computational Biology NSWBCB2006 held at Mahila Mahavidyalaya, Banaras Hindu University, Varanasi during March 22-24, 2006. Below is the fascimile of the Cover page of the Abstract book

Click on this picture to display particulars of the participation in NSWBCB2006


pacificyew_050506
CLICK HERE to display the source page from "SpectroscopyNow.com" for the material below
Solid-state NMR studies of the molecular structure of Taxol

[May 5, 2006]
Solid-state NMR studies of the molecular structure of Taxol
Magnetic Resonance in Chemistry 2006, 44, 581-585
Yu Ho, Der-Lii M. Tzou and Feng-I Chu

Abstract: Solid-state 13C{1H} cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been utilized to extract the molecular structure information of Taxol, which is an anti-tumor therapeutic medicine extracted from the yew bark. The 13C signals have chemical shift values quite consistent with those measured in solution phase, and the overall chemical shift range is over 200 ppm. Notably, most of the 13C resonances of the taxane ring have two clearly resolved spectral components except the resonance peaks of C-15, C-16 and C-17, which are located at the central part of the taxane ring. On the basis of our NMR data, we propose that these doublets originate from two slightly different molecular conformations of the taxane ring and still the central part of the ring remains structurally similar. Furthermore, it is demonstrated that the 13C chemical shift difference deduced from the doublet splittings can serve as a direct measure of the structural difference between the two conformations, which could possibly correlate with the anti-tumor activity of Taxol.

This paper is free to view to spectroscopyNOW registered users until July 2006. After this time it will be available via Wiley's Pay-Per-View service for US$25.


CLICK HERE to display the source webpage from "SpectroscopyNow.com" for the material below

SN7b_NMR_astragalus

SN7b_huangqi
The root of Chinese medicine
[April 15, 2006]

Huángqí is a plant root used in one of the most common tonics of Chinese herbal medicine with purported activity in cancer, diabetes, inflammation, and nephritis. As such, there is a lot of interest in the active ingredients of this species as it might lead to novel pharmaceuticals against a range of illnesses. Now, researchers in China have used proton NMR to identify active components, and report their results in the journal Magnetic Resonance in Chemistry.

Xingang Du, Yanjing Bai, Hong Liang, Zhiying Wang, Yuying Zhao, and Qingying Zhang of the School of Pharmaceutical Sciences, at Peking University Health Science Center, in Beijing and Luqi Huang of the Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, also in Beijing, have focused on the chemistry of extracts of Astragalus membranaceus var. mongholicus. The dry roots of this leguminous plant, more usually known as Radix Astragali, or huángqí (yellow leader) in traditional Chinese medicine (TCM) is one of the most important tonics used to reinforce "Qi" (the principle of vital energy in TCM). Practitioners claim that this strengthens superficial resistance to disease, promotes the discharge of pus and the growth of new tissue. In clinical tests it has demonstrated physiological activity in liver protection, as an antioxidant, an antiviral compound, and in lowering blood pressure and stimulating the immune system.

The researchers used one- and two-dimensional NMR, including 1H, 13C, COSY, HSQC, HMBC, and NOESY sequencesto establish structures of extracts of huángqí. They isolated four 3'-hydroxy-4'-methoxy-isoflavonoids from the dried roots. Namely, calycosin-7-O-beta-D-glucopyranoside, calycosin, pratensein-7-O-beta-D-glucopyranoside, and pratensein. This latter compound was previously unknown and represents a potential new lead for the development of novel pharmaceuticals from this traditional remedy.

Interestingly, the team found that during structural elucidation of the compounds, solvent obscured the proton signal patterns somewhat producing mis-assignments. The team therefore used a range of deuterated solvents to side-step this issue and were able to correctly assign the novel compound with confidence as well as correct the previously reported literature structures for the others.

Related links:
Magn. Reson. Chem., in press
Zhang's Institute Page
Astragalus

                                       

       

                                                                                                                                                                                                                                                                                                                                                          

                 

 

 

 

 

 

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