**1. Introduction**

 Most research work on plant source for medicines end up without the researcher reaching a conclusive indication of the implicated chemical name/structure for the cure claimed. A large majority stops at just authenticating the claimed folkloric use of the crude extract of the said plant. Another group of researchers search for the bioactivity even when there is not a history or folkloric evidence giving lead to their quest. In the hunger of researchers' quest and bid not to "perish" and the unavailability of fund, we are satisfied with the mere authentication of crude plant extract. This is seen in the richness of the literature that abounds on the Internet with multiple claims of almost every disease cure and plant use. The "publish or perish" syndrome which is not matched with the provision of research funds or available research grants and the stiff promotion requirements seem to be counterproductive in terms of paucity of robust quality research especially in the developing world.

 The researcher, in most times is like a child who wants to know the reason for everything around him. The child does not just stop at the first answer but persist to the exact utmost reason for his curiosity. The difficulties encountered in a conclusive end of a research quest are numerous though. That notwithstanding there should be some effort at our very best. In so doing, our goal would be met with genuine success and mind-blowing inventions. There could be some difficulty in the knowledge of how to go about the research work, and such the available becomes the only option. And being that the majority seen in the source (internet) is inconclusive, we satisfy our minds at the ease of a publishable authentication of the crude

extract. This chapter is met to follow up from the identification of a choice of plant part particularly seed, through to the process of isolation of the active ingredient and structural characterization.

 Our ancient fathers knew the natural source of medicines which was once the only option known to man. They used this source to cure every disease that came their way. Over the centuries several options of drug source and discovery were uncovered. The era of synthetic substances (synthesized drugs) relegated our once popular natural gift of nature. The history of drug discovery has cited several drugs from natural sources with plant source earning a reasonable portion [1]. The notion that is still held high about natural products is its likelihood of being accepted by the body than synthetic substances [2]. Herbs due to their high chemical diversity and broad biological functionality have consistently been considered the leading source of pharmaceuticals, employed in the treatment of various human diseases [3]. An important drug used in treatment of diabetes, metformin, is a derivative of plant-derived compound guanidine from *Galega officinalis* [4]. It is now commonplace to include herbal or botanical extracts as a part of medical treatment (as an adjunct to hypoglycemia agents) [5]. It is obvious there still lay in nature's bank a lot of uncovered chemicals useful for the treatment of the numerous diseases that inflict man. These await researchers dogged enough to uncover them. They may remain hidden (researches) if we satisfy ourselves with just the authentication of herbal use. There is need therefore to conduct pharmacognostic and pharmacological studies conclusively, to ascertain chemicals with therapeutic values.

In the bid to guide researchers through a thorough authentication experimental process from plant identification, literature, methodology to bioassay-guided pursuance of the active compound, a bias toward diabetes and a seed plant part research would be described with some effort at generalizing the process.

#### **2. Research study justification**

 In Africa, hundreds of plants are used traditionally for the management of diabetes mellitus; however, only a few of these African medicinal plants have received scientific scrutiny, even though the World Health Organization has recommended medical and scientific examinations of these plants that are undertaken [6]. Diabetes mellitus, a serious endocrine syndrome, is a group of multiple disorders with different etiologies and characterized by derangement of carbohydrate, protein, and fat metabolism caused by a complete or relative insufficiency in insulin secretion and/or insulin action [7]. Approximately 140 million people worldwide are estimated to suffer from diabetes mellitus [8]. The side effects of taking insulin and oral hypoglycemic agents have brought about a growing interest among patients for using natural products having antidiabetic activity [9]. Pharmacology and toxicological evaluations of medicinal plants are essential for drug discovery, and not to forget, there lay in nature's bank a lot of uncovered chemicals useful for the treatment of numerous diseases that inflict man.

In the guide of the above paragraph, and with a lead to its use, such as a traditional medicine practitioner use whose patient was patronizing an orthodox medical practitioner that was noticed a once poorly controlled diabetic patient having an almost normal control by laboratory test, the choice of the plant seed was drawn from the concoction implicated. Several lead modest stories abound literatures for numerous plants as with the choice of a seed plant part, *Corchorus olitorius* explored for antidiabetic property [10]. Worldwide, a number of plants with acclaimed antidiabetic properties are being studied, among these are *Treculia africana* and *Bryophyllum pinnatum* [11], *Gynostemma pentaphyllum* tea [12], *Ganoderma lucidum*  *Pharmacognostic Study of a Plant Seed Extract DOI: http://dx.doi.org/10.5772/intechopen.81860* 

[13] ginger and garlic [14], *Phyllanthus niruri* [15] *Ficus religiosa* [16], *Boerhaavia diffusa* and *Ocimum sanctum* [17], and *Fumaria parviflora* [18]. Other plants reported study the world over, of hypoglycemic effect are *Fructus Mume* formula [19], Diabetan tablet (a blend of *Salvia officinalis, Trigonella foenum*, and *ginseng)*  [20], flower heads of *Artemisia maritima* [21], *Eriobotrya japonica* seeds [22], and fenugreek (*Trigonella-foenum graecum*) seed [23] to mention few.

After this lead choice of the plant (seed), the plant identity is sort, with the help of a botanist, following purchase from traders of seeds of farm produce. The plant and part (seed) of the plant of interest are deposited in the researchers' institution with a herbarium voucher specimen number obtained. The ecology of the choice plant is a necessary literature to be included in the researcher's write-up. *Corchorus olitorius* plant grows in grassland and does well on abandoned fields, often close to marshes, rivers, and lakes, ranging from warm temperate through tropical desert to wet forest life zones, at up to 1250(−1750) m altitude [24]. It thrives best under hot and humid conditions [24]. The geographical origin of *Corchorus olitorius* is often disputed; it is rather pantropical in distribution [24]. In the savanna and Sahel zone, it grows best during the hot rainy season [24]. It is cultivated where annual rainfall averages 600–2000 mm [24]. The optimal temperature is 25–32°C, and growth stops below 15°C [24]. *Corchorus olitorius* is a short-day species. In Nigeria a day length of 12.5 hours caused a much stronger vegetative growth expressed in weight of roots, stems, and leaves than a day length of 11.5 hours, but the fruit and seed production was higher at a photoperiod of 11.5 hours [24]. The plant grows best in sandy loam soils rich in organic matter and grows poorly on heavy clay [24]. It is a leading leaf vegetable in Côte d'Ivoire, Benin, Nigeria, Cameroon, Sudan, Kenya, Uganda, and Zimbabwe [24]. It is also cultivated as a leaf vegetable in the Caribbean, Brazil, India, Bangladesh, China, Japan, Egypt, and the Middle East [24]. *Corchorus* is genus of about 40–100 species of flowering plants in the family *Malvaceae* [24]*.* The specie of interest is *Corchorus olitorius*, others are *Corchorus capsularis*, *Corchorus tridens*, *Corchorus walcottii*, etc. [24].

The following description of the process of seed preparation, extraction, fractionation, and bioassay is guided by works of Egua et al. [10, 25–27]*.* Care is taken here at the generalization of the procedure for all seeds and plant parts and advice for an educated modification in choice of solvents for intending users.

#### **3. Preparation of seed extract**

 The dried seeds are grinded to powder using a blending machine. Soxhlet extractor is used for extraction of the dried powdered seed using ethanol as the solvent. A 10 g of the powdered seed extract is placed inside the thimble made from thick filter paper, which is loaded into the main chamber of the Soxhlet extractor. The Soxhlet extractor allows for several cycles to repeat many times, over hours and days with the desired compound dissolved in the warm ethanol solvent. During each cycle, a portion of the nonvolatile compound (powdered extract) dissolved in the solvent. After many cycles the desired compound is concentrated in the distillation flask. The advantage of this system is that instead of many portions of warm solvent passing through the sample, just one batch of solvent is recycled. After extraction, the solvent is removed by means of a rotary evaporator, yielding the extracted compound (which is weighed). The non-soluble portion of the extract remains in the thimble and is weighed also before it is discarded. These values would help in the calculation of the yield of crude extract from the seed.

The crude extract is first tested for the acclaimed bioactivity before the fractionation procedure is carried out. At this stage, the entire model met for sufficient scientific authentication of the disease is used as it is documented later. And the crude extract is also tested for its phytochemical properties.
