Phytochemistry

Phytochemistry is in the strict sense of the word the study of phytochemicals. These are chemicals derived from plants. In a narrower sense the terms are often used to describe the large number of secondary metabolic compounds found in plants. Many of these are known to provide protection against insect attacks and plant diseases. They also exhibit a number of protective functions for human consumers.

Techniques commonly used in the field of phytochemistry are extraction, isolation and structural elucidation (MS,1D and 2D NMR) of natural products, as well as various chromatography techniques (MPLC, HPLC, LC-MS).

Constituent elements

The list of simple elements of which plants are primarily constructed—carbon, oxygen, hydrogen, calcium, phosphorus, etc.—is not different from similar lists for animals, fungi, or even bacteria. The fundamental atomic components of plants are the same as for all life; only the details of the way in which they are assembled differs.

The following tables list element nutrients essential to plants. Uses within plants are generalized.

Macronutrients. (Necessary in large quantities)

Element	Form of uptake	Notes
Nitrogen	NO3– NH4+	Nucleic acids, proteins, hormones, etc.
Oxygen	O2 H2O	Various organic compounds
Carbon	CO2	Various organic compounds
Hydrogen	H2O	Various organic compounds
Potassium	K+	Cofactor in protein synthesis, water balance, etc.
Calcium	Ca2+	Membrane synthesis and stabilization
Magnesium	Mg2+	Element essential for chlorophyll
Phosphorus	H²PO4–	Nucleic acids, phospholipids, ATP
Sulfur	SO42–	Constituent of proteins and coenzymes

Micronutrients. (Necessary in small quantities)

Element	Form of uptake	Notes
Chlorine	Cl-	--
Boron	H BO3	--
Manganese	Mn2+	Activity of some enzymes
Zinc	Zn2+	Involved in the synthesis of enzymes and chlorophyll
Copper	Cu+	Enzymes for lignin synthesis
Molybdenum	MoO42-	Nitrogen fixation, reduction of nitrates
Nickel	Ni2+	Enzymatic cofactor in the metabolism of nitrogen compunds

Photosynthesis

Eastern medicine

Phytochemistry is widely used in the field of Chinese medicine especially in the field of herbal medicine.

Phytochemical technique mainly applies to the quality control of Chinese medicine or herbal medicine of various chemical components, such as saponins, alkaloids, volatile oils, flavonoids and anthraquinones. In the development of rapid and reproducible analytical techniques, the combination of HPLC with different detectors, such as diode array detector (DAD), refractive index detector (RID), evaporative light scattering detector (ELSD) and mass spectrometric detector (MSD), has been widely developed.

In most cases, biologically active compounds in Chinese medicine or herbal medicine have not been determined. Therefore, it is important to use the phytochemical methods to screen and analyze bioactive components, not only for the quality control of crude drugs, but also for the elucidation of their therapeutic mechanisms. Modern pharmacological studies indicate that binding to receptors or ion channels on cell membranes is the first step of some drug actions. A new method in phytochemistry called biochromatography has been developed. This method combines human red cell membrane extraction and high performance liquid chromatography to screen potential active components in Chinese medicine.

See also

• Photosynthesis
• Pharmacognosy
• Phytopharmacology
• Plant nutrition

References