eChapters

Phenolic compounds constitute a major class of plant secondary metabolites that are widely distributed in the Plant Kingdom. Plant phenolics are biosynthesized through the shikimate/phenylpropanoid pathway leading to different compound classes. They may occur in their natural sources in free forms, as glycosylated or acylated derivatives, and as oligomeric and polymerized structures, such as hydrolyzable and condensed tannins, phlorotannins or lignins. They may also be found linked to plant matrix components such as cell walls, carbohydrates or proteins. It should be indicated that although the terms “plant phenolics” and “polyphenols” are indistinguishably used by some authors, they are not synonymous.

Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. Alkaloids showed quite diverse medicinal properties (Rates, 2001). Many of them possess local anesthetic properties, but their practical use is limited for clinical purposes (Hesse, 2002). Morphine is one of the most known alkaloids isolated from Papaver somniferum (opium poppy), which had been used and still is for medical purposes. This alkaloid is a powerful narcotic which is used for the relief of pain, but its usefulness is limited because of its addictive properties.

The following plants have been worked out in the laboratory of Prof. N. Raaman: Cynodon dactylon, Artemisia pallens, Leptadenia reticulata, Clausena dentata, Tylophora indica, Aristolochia bracteolata, A. indica, Cissus quadrangularis, Hypericum mysorense. and Solanum trilobatum. Out of some of the data of these plants have been included in the previous chapters. In this chapter, compound isolation (CD1) from Clausena dentata (worked by Dr. R. Kamaraj) and characterization of the compound are given in detail.

Phytochemicals are the individual chemicals from which the plants are made. Phytochemical is simply a word that means plant chemicals. Plants have the ability to synthesize mixtures of structurally diverse bioactive compounds with multiple and mutually potential therapeutic effects. The plants have the capacity of manufacturing the secondary products. Phytochemicals with antioxidant properties tend to be brightly colored because they contain chromophores, ie, a series of alternating single-bonded and double-bonded carbons. Isoprene is often the building block of such units. The darkest green vegetables contain the most chlorophyll, and vegetables with the most chlorophyll require the most antioxidants.

After isolation and purification of the compound, it has to be identified. It is necessary to find out the class of the compound first and then to find out the specific compound within the class. The class of compound is usually determined from the colour tests, solubility, Rf properties and UV spectral characteristics of the compound. Further identification within the class depends on measuring physical properties and spectral measurements and then comparing these data with those in the literature.

For qualitative and quantitative analysis of phytochemicals, chromatography can be used. Gas chromatography is a powerful means of performing qualitative and quantitative measurements of complex mixtures of volatile substances, which are vaporizable without decomposition.Gas Chromatography-Mass Spectrometry (GCMS) system is a widely used instrument for qualitative and quantitative analysis of solid, liquid, and gaseous samples. Samples are converted into gaseous ions and then separated on the basis of their mass-tocharge ratio. 

All separation procedures depend mainly on some physical characteristics of the compounds. It is relatively easy to separate compounds that have significantly different physical characteristics by simple techniques such as solvent extraction. If the various compounds are similar to each other in their molecular size, any slight difference in any one of their physical properties is exploited to achieve separation. 

The different qualitative chemical tests can be performed for establishing profile of given extract for its chemical composition. The following tests may be performed on extracts to detect various phytoconstituents present in them.

Extraction is a process whereby the desired constituents of a plant are removed using a solvent. The primary ways for extraction of organic molecules of interest to biologists and medical investigators involve breaking open the cells. Cell rupturing is carried out in a variety of ways. The method used depends on the type of tissue used. For plant cells grown in cell suspension culture or for plant callus tissue, a French press or a sonicator can be used to break open the cell.

Phytochemicals from various parts of a plant or tree such as the leaves, the flowers, the seeds, the barks, the roots and the shrubs can be isolated. Once one comes in from collecting plants in the field, it is good idea to freeze them immediately in a freezer at – 20°C or a commercial freezer held at – 80°C (Kaufman et al., 1999). According to Harborne (1984, 1998), fresh plant tissues should be used for phytochemical analysis and the material should be plunged into boiling alcohol within minutes of its collection. Alternatively, plants may be dried before extraction.

Dietary supplements from plant sources are sometimes referred to as phytopharmaceuticals. They are produced from fresh, dried or otherwise preserved plants or parts of plants. The active ingredients are usually not completely isolated but rather are obtained along with other naturally occurring components of the plant. These other components are often believed to influence the efficacy of the active ingredient. Sometimes the active ingredients are concentrated, and undesirable substances such as chlorophyll, tannins, or resins, are removed.

Plants are used as medicine since time immemorial. One of the area of Ethnobotany, Ethnopharmacology is considered as the scientific evaluation of traditional medicinal plants (Cotton, 1996). Cox (1994) has suggested that the ethno-directed sampling is most likely to succeed in identifying drugs used in the treatment of gastrointestinal, inflammatory and dermatological complaints. The Plant kingdom is a virtual goldmine of potential drug targets and other active molecules awaiting to be discovered. It has been estimated that only 10 - 15 per cent of the 7,50,000 existing species of higher plants have been surveyed for biologically active compounds.

Sonograms of animals suffering from different diseases are presented along with other investigations as case studies to provide a comprehensive picture of the disease.

Utility of ultrasound has extended from diagnostic realm to alternate therapies. Therapeutic ultrasound is also known as ultrasound physiotherapy. It is a commonly used modality for the rehabilitation of the soft tissues of the musculoskeletal system.

Ultrasonography is being routinely practiced in canine and feline medicine for the diagnosis of diseases of the organs and also to confirm pregnancy. Its routine use in ruminant medicine is mainly restricted to pregnancy diagnosis. Recently the potential of ultrasonography is also being explored in zoo and wild animals as well as in exotic pets. Information available in companion and other domestic animals cannot be applied blindly to zoo and wild animals.

During last two decades significant advances have been made in diagnostic ultrasound .These advances have positively impacted on diagnostic imaging across all species of animals and have made ultrasound as an indispensable diagnostic modality in veterinary medicine. Since equines have been more a sport and pack animals, the ultrasound technique has long been utilized in the diagnosis of equine musculo-skeletal disorders. Recent years have witnessed its utility in the management of equine reproduction beside its use in the diagnosis of colic and other diseases.

For the sake of convenience ruminants are broadly divided into two categories as large ruminants and small ruminants. Large ruminants consist of cattle and buffaloes and small ruminants consist of goats and sheep. Sonography is becoming an important part of diagnostic modalities in ruminants also. Its major use in ruminants is in reproduction and lameness.

Architecture of the organ is affected in the primary or secondary diseases of the organs. Ultrasonography plays a significant role in detecting the changes in the organs in various diseases.

Focused assessment with sonography for trauma (abdominal and thoracic) refers to the limited ultrasound examination with the main focus on quick identification of the presence of free fluid within peritoneal, pleural and pericardial spaces in trauma cases in intensive care units. Despite limitations, findings of FAST are helpful in stabilizing the emergency patients.

Abdominal organs in different species of animals have distinctive features with respect to their shape, size, location and echogenicity and echo texture. This is true for dogs and cats also. Therefore, information with respect to sonographic features of dogs cannot be taken for granted for cats in totality