**4. Families of phytochemicals**

To establish an ordering, these compounds will be classified considering some characteristics like: their biosynthetic origin, the common structural characteristics and the solubility properties.

Other natural nitrogenated products with an important biological activity are alkaloids; some examples of alkaloids are in **Figure 4**. Alkaloids are a large family of more than 15,000 secondary metabolites that have these three characteristics in common: they are soluble in water, contain at least one nitrogen atom in the molecule and exhibit biological activity. The majority of them are heterocyclic although some are aliphatic (noncyclic) nitrogen compounds such as

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• Phenolic compounds, with at least one hydroxyl group attached to one or more aromatic rings in its chemical structure, most of which are water-soluble and biosynthetically

• Terpenoids, with the isoprene molecule as a structural unit, liposoluble, and biosynthetically associated to the mevalonic acid pathway or to the glyceraldehyde phosphate-pyruvic

mescaline or colchicine, for example [28].

derived from shikimic acid.

**Figure 4.** Alkaloid structures.

**Figure 3.** Structure of the amygdalin.

Some large groups of secondary metabolites are:

• Nitrogen and sulfur compounds, characterized by possessing nitrogen and/or sulfur in their structure, of solubility and diverse biosynthetic origin, but mostly derived from amino acids. Example of these compounds are the cyanogenic glycosides are nitrogen compounds, which are not toxic by themselves but degrade when the plant is crushed releasing toxic volatile substances such as hydrogen cyanide (HCN). An example is the amygdalin (**Figure 3**), found in the seeds of almond, apricot, cherry or peach.

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**Figure 3.** Structure of the amygdalin.

The polarity of the compounds is another element to be taken into account, when considering the solubility of a solute in a given solvent. Thus, strongly polar solvents dissolve ionic or highly polar solutes, while low-polar solvents do not efficiently dissolve ionic solutes but do

Nuclear magnetic resonance spectroscopy (NMR)

The extraction of the vegetal material is done consecutively using solvents, from a low polar-

The obtained extracts can be clarified by filtration through celite with a vacuum pump and then concentrated under reduced pressure. This is generally carried out in a rotary evaporator, in which the solutions are concentrated until a volume reduction is achieved, at tempera-

In the separation and identification of natural products, different techniques for isolation and

To establish an ordering, these compounds will be classified considering some characteristics like: their biosynthetic origin, the common structural characteristics and the solubility properties.

• Nitrogen and sulfur compounds, characterized by possessing nitrogen and/or sulfur in their structure, of solubility and diverse biosynthetic origin, but mostly derived from amino acids. Example of these compounds are the cyanogenic glycosides are nitrogen compounds, which are not toxic by themselves but degrade when the plant is crushed releasing toxic volatile substances such as hydrogen cyanide (HCN). An example is the amygdalin

(**Figure 3**), found in the seeds of almond, apricot, cherry or peach.

tures between 30 and 50°C. The concentrated extracts must be stored refrigerated.

identification have been developed, in **Table 1** is a summary of the main techniques.

dissolve low-polarity solutes.

**4. Families of phytochemicals**

Some large groups of secondary metabolites are:

ity until reaching the water, which is the most polar solvent.

Chromatography Thin-layer chromatography (TLC)

30 Phytochemicals - Source of Antioxidants and Role in Disease Prevention

Electrophoresis Thin-layer electrophoresis (TLE)

Spectroscopic techniques UV spectroscopy

**Table 1.** Separation and identification techniques.

Gas chromatography (GC)

Capillary electrophoresis (CE)

Infrared spectroscopy (IR)

Mass spectroscopy (MS)

Near infrared spectroscopy (NIR)

High-resolution liquid chromatography (HPLC)

Isotachophoresis (ITP) (electrophoresis at uniform speed)

Capillary liquid chromatography (u-LC)

**Figure 4.** Alkaloid structures.

Other natural nitrogenated products with an important biological activity are alkaloids; some examples of alkaloids are in **Figure 4**. Alkaloids are a large family of more than 15,000 secondary metabolites that have these three characteristics in common: they are soluble in water, contain at least one nitrogen atom in the molecule and exhibit biological activity. The majority of them are heterocyclic although some are aliphatic (noncyclic) nitrogen compounds such as mescaline or colchicine, for example [28].



treatment of breast, ovarian, lung and Kaposi's sarcoma related to HIV. Hence, the impor-

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Several studies have been conducted on the biosynthesis of taxoids, especially Taxol. In **Figure 6**, it is one of the biosynthetic routes for the production of Taxol. Biosynthesis is a process that requires knowing the mainly enzymatic reactions that involve the construction of the skeleton and the addition of various oxygen and acyl functional groups. The central skeleton of the Taxol molecule is a taxane ring of isoprenoid nature and is derived from geranylgeranyl diphosphate (GGPP). What is the common precursor of 20 carbon atoms isoprenoids (diterpenes), among which compounds such as carotenoids can be found. The phytol chain of chlorophylls or gibberellins participates in the growth and development of plants. However, all of them are formed in the same way precursors, isopentenyl diphosphate (IPP) and dimethylalyl diphosphate (DMAPP) are formed. However, and despite the studies carried out, no biosynthetic route of Taxol has been reached. In **Figure 2**, there is one of the

Several researches have been developed with the aim of finding new sources to obtain Taxol. But it has only been isolated from trees of the *Taxus* species. **Table 3** shows the percentage of yield obtained from the Taxol extractions of the different species of the *Taxus* spp., as well as

Based on the previous table of contents, another taxonomic species was investigated such as *Taxodium mucronatum*. The *Taxodium mucronatum* belongs to the Cupressacea which is a gymnosperm. They are large trees over 25 m in height and 1.5 m in diameter from the trunk at chest height. Its leaves are small, elongated and grouped in twigs, in autumn the leaves turn

The new shoots appear in spring. They can be distinguished at a distance by their dense foliage and their hanging branches, and they are always close to the water or in places with

They are distributed from Texas (USA) to Guatemala, but its presence is larger in Mexico. Best known as Ahuehuete tree, which comes from Nahuatl "atl" which means water and "huehuetl" which means old or grandfather, so the whole meaning is "old" of the water" [29–31]. The reason to choose this species, in addition to being abundant from North America to South America, this tree species has many similar characteristics to the species of *Taxus*,

The plant material from *Taxodium mucronatum* was collected by members of the Biotechnology laboratory of the Technological Institute of Celaya, from the community of Chamacuaro located on the outskirts of the municipality of Salvatierra in the state of Guanajuato, on the banks of the Lerma river. We proceeded to separate the plant material (branches, fruits and

tance of knowing everything related to the production of this powerful medicine.

**5.2. Biosynthesis of Taxol**

**5.3. Research carried out**

reddish and fall.

shallow water table (**Figure 7**).

which makes it a potential source of Taxol.

leaves), then dried under pressure and room temperature.

different proposed schemes for Taxol biosynthesis.

the analysis of the different parts of the species.

**Table 2.** Classification of terpenoids.

**Figure 5.** Examples of terpenoid structures.

acid pathway, depending on the class of terpenoids in question [29]. **Table 2** shows the classification of the terpenoids, with respect to the number of isoprene units they contain, as well as an example of each type of terpenoid and **Figure 5** shows some structures of terpenoids.
