The evolution of pharmacognosy takes up subjects of applied pharmaceutical botany, reflections on drugs and not on the medicinal plant. Influences of an endogenous and exogenous nature identify internal factors, which belong to the genetic heritage of the plant, factors that are part of the ontogenetic cycle of that particular species, as well as natural factors that influence the quality of the plant, but which in the end must reflect on the intended drug as its healthy expression. All these elements, endogenous and exogenous, as well as the factors properly called artificial, greatly influence the quality of a drug and its active principles, both in qualitative and quantitative terms; for this reason quality control is very important both chemically and biologically.
Numerous factors influence the quality of a drug in terms of chemical expression, as quantity and quality of active principles, and in biological terms, relative to its appearance, its size, and therefore its morphological characterization. Some examples:
Altea officinalis : Malvacee family, using the root that constitutes the drug. The active principles are the mucilages, which from the chemical point of view fall into the category of heteropolysaccharides; that is, they are high molecular weight carbohydrate molecules, with a polymeric characterization where the individual monomers are different. These mucilages can vary in concentration from 5 to 9%, compared to the dry weight of the drug.
Witch hazel : Hamamelis virginiana, Amamelidacee family; shrub of American origin, whose leaves are mainly used; active ingredients are tannins, high molecular weight polyphenolic molecules with a firming action, which can range from 1 to 8%.
Belladonna : Atropa belladonna, Solanaceae family; it is a medicinal plant whose leaves are rich in alkaloids; these are molecules that generally have basic properties in solution; they can vary in Belladonna from 0.3 to 1% compared to the dry weight of the drug.
Artichoke : Cynara scolymus, is a plant of the Composite family whose leaves are used; the active principles of the artichoke belong to different categories, the flavonoids, however, can vary in concentration from 0.5 to 1%.
All this to say that the endogenous, exogenous and artificial factors are elements that can dramatically influence the concentration of active principles, thus determining in an extremely significant way its belonging to a health sector rather than to a "simply" diet sector.
China : it is a typical plant of the Andes, the bark is used and the active principles are titrated in quinine. Quinine is the active ingredient that characterizes the quality of the phytocomplex and that can vary from 9 to 12% of the dry weight of the bark; the factors that influence the quality of china are genetic factors or exogenous factors, such as altitude. Also important are the hybrid ones: different species, but similar, are crossed to give hybrid china plants with quantities of active principles close to the maximum concentration. Also the altitude is important: if the china is cultivated in the plain it grows well, but not with medicinal qualities.
Opium : a drug characterized by coagulated latex that flows from the immature capsules of the Papaver somniferum, an annual cultivated plant, whose cultivation is allowed only for medicinal purposes and only in some countries. Opium produces very important alkaloids in the health field, such as morphine, but also many others. The concentration can vary from 7 to 20%.
Senna : Cassia senna, shrub of African origin, cultivated also in India; the leaves and the fruits are used. The active principles, called sennosides, are anthraquinones, molecules with stimulating laxative properties; the senna can vary its content of active principles by 50% compared to factors that are not only endogenous, but also climatic: it is a plant that lives in hot and dry climates.
