**8.2 Mass spectrometry (MS)**

Mass spectrometry plays a vital role and works as a powerful analytical technique. It is the only technique used for identification of unknown compounds for its molecular weight. Thus, the quantification of known compounds and elucidation of the structure and chemical properties of molecules are possible due to MS. The most powerful MS spectrum gives an idea about the molecular weight of sample, which can be determined. The value of the technique is that it requires only microgram amounts of material and that it can provide an accurate molecular weight and that it may yield a complex fragmentation pattern, which is often characteristic of that particular compound. This technique works successfully for the structural elucidation of herbal extracts and organic compounds, for peptide or oligonucleotide sequencing. MS helps in monitoring the characterization of compounds in

 complex mixtures with a high specificity by defining both the molecular weight and a diagnostic fragment of the molecule simultaneously. Gas chromatography equipment can be directly coupled with rapid scan mass spectrometer (GCMS) of various types. High resolution analysis can be performed due to coupling of equipment.

Liquid chromatography–mass spectroscopy (LC–MS) offers accurate determination of molecular weight of proteins and peptides. Isotopes pattern can also be detected by this technique. Recent advances include electrospray, thermospray, and ionspray ionization techniques, which offer unique advantages of high detection sensitivity and specificity.

#### **8.3 Nuclear magnetic resonance spectroscopy (NMR)**

Nuclear magnetic resonance spectroscopy gives physical, chemical, and biological properties of matter. C13 NMR is used to identify the types of carbon present in the compound. H1-NMR is used to find out the types of hydrogen present in the compound and to find out how the hydrogen atoms are connected. Proton NMR spectroscopy basically works on principle by measuring the magnetic moments of its hydrogen atoms and it provides a method for determining the structure of an organic compound. In almost all compounds, hydrogen atoms are present, which are attached to different groups such as -CH2-, -CH-, -CHO, -NH2, -CHOH-, etc. The graphical representation of proton NMR spectrum provides a record of the number of hydrogen atoms in these different situations. It gives information only about the number of hydrogen atoms in the compound but not the number of carbon atoms. However, direct information on the nature of the carbon skeleton of the molecule can only be obtained by carbon 13 NMR spectroscopy. 13C-NMR spectroscopy works hand in hand with proton NMR and thus the combination of the results of two methods provides very useful information for identification of unknown compound. It is a powerful means of structural elucidation for new terpenoids, alkaloids, or flavonoids. It is also useful in the identification or analysis of glycosides, in indicating the linkage between sugar moieties and their configurations. Many proteins or other macromolecules can be identified by both proton and 13C-NMR. For NMR analysis, very small amount of sample is needed for analysis and that sample can be reused for further analysis. For examples, NMR instrument cost much so there are many sophisticated analytical instrumentation technical analysis are available to perform your research work. Scientist handling NMR has good hands on working of NMR. In order to get high resolution, the new technique is liquid chromatography–nuclear magnetic resonance (LC-NMR). It is a combination of chromatographic separation technique for isolation of active fraction and its number of hydrogen or carbon atom identification with NMR spectroscopy. It is one of the most powerful and time-saving method for the separation and structural elucidation of unknown compounds and mixtures, especially for the structure elucidation of herbal plant extracts and their isolates in herbal natural drug discovery.

#### **8.4 Development of new technologies in natural drug discovery research**

Nature is a God's gift for finding new herbal drugs for carrying out research scientifically. A new driving force for screening of novel drugs, biologically active metabolites from these products derived from nature which leads to the success of drugs. The chemistry is a branch where the new technologies are emerging in which pharmaceutical chemistry is very important because it deals with the health of common people. Combinatorial chemistry, high-throughput screening, bioinformatics, proteomics, and genomics are newer techniques that have emerged widely in the field of pharmaceutical discovery research. All drug discovery research and

#### *Natural Products in Drug Discovery DOI: http://dx.doi.org/10.5772/intechopen.82860*

 technologies have enormous potential to make use of the chemical and natural diversity of products. Newly developed techniques are growing rapidly with good outputs in natural drug discovery [20]. These include molecular diversity, compound-library design, protein 3D structures, NMR-based screening, 3D-QSAR in modern drug design, physicochemical concepts, and computer-aided drug design using different software, its prediction of drug toxicity, and metabolism [21]. New approaches to improve and accelerate the joint drug discovery and development processes are expected to take place mainly from the innovation in drug target elucidation and lead structure discovery. Powerful new technologies are revolutionizing drug discovery. Some software will be useful in performing studies, which are freely available such as Zinc.docking.org. It is used for calculating SWISSADME, drug properties, SMILES formula, drug likeness properties, and many more [8].

Technologies for drug discovery advanced and diversified greatly [22]. NPDD (natural product drug discovery) activities work hand in hand and make use strongly with HTS, combinatorial chemistry, and genomics. New approaches have proved to show improvement and accelerate the joint drug discovery and development processes. New techniques are emerging and take place mainly from the innovation in drug target elucidation. It finally leads to lead structure discovery. Powerful new technologies are revolutionizing natural herbal drug discovery.

#### **8.5 High-throughput screening**

High-throughput screening (HTS) is a specially deigned technique in herbal drug discovery that is a standard method for hit discovery based on identification through stored libraries. HTS is relevant to the fields of biology and chemistry and helps for scientific experimentation especially used in drug discovery.

 HTS is using data processing and control software and sensitive detectors that help researchers to carry out the research scientifically for designing and developing new structure from herbal drug discovery. It is robotics and allows a researcher to quickly conduct various biochemical, genetic, or phytopharmacological tests. Through HTS, one can rapidly identify bioactive compounds that can be useful in a particular biomolecular pathway in inhibiting the diseased condition. Thus, biomolecular pathway provides information about the mechanism of drug as well as internal way of diseased condition person. The knowledge and the results of these experiments provide starting points for designing a drug and for understanding the interaction or role of a particular biochemical process in biology.

HTS is a relatively recent innovation and it requires high-speed computer technology. It works on the principle of high-throughput screening of large amount of natural compounds using computer-based technology, which is more easy and more time saving. Knowledge can be further utilized for new herbal drug discovery. Interest of research can be generated in natural drug discovery through all these newer techniques. Many well-developed countries have highly specialized and expensive screening labs to run an HTS operation. However, the countries having interest of working in research that cases a small-to-moderately sized research institution will use the existing HTS facility as per their convenience rather than full set up.
