ABSTRACT
Classification of the Group of Compounds ............................................... 482 19.3 Natural Sources of Diterpene Compounds ................................................ 485
19.3.1 Higher Plants................................................................................ 485 19.3.2 Marine Products ........................................................................... 486 19.3.3 Fungi ............................................................................................ 486 19.3.4 Insects........................................................................................... 486
19.4 Biological Activities of Diterpenes and Their Pharmacological Use........ 486 19.5 Chemotaxonomic Importance of Diterpenes ............................................. 488 19.6 Thin Layer Chromatography-Methods of Analysis and the Isolation
of Diterpene Compounds in Natural Materials.......................................... 488 19.6.1 Sample Preparation-Extraction and Purification Methods ........ 488 19.6.2 Qualitative Analysis-Identification of Diterpenes
in Materials and Preparations....................................................... 490 19.6.2.1 Chromatographic Systems........................................... 490 19.6.2.2 Detection Methods (Including Densitometry),
and Derivatization ....................................................... 490 19.6.2.3 Qualitative TLC Analysis of Diterpenes
as a Preliminary Technique of the Optimization of Separation in PTLC and CC Methods.................... 490
19.6.2.4 Analytical TLC of Diterpenes as CC Fraction Composition Control ................................................... 492
19.6.3 Quantitative TLC Analysis of Diterpenes.................................... 500 19.6.3.1 Chromatographic Systems........................................... 500
19.6.4 Preparative TLC as a Method of Isolation (or Purification) of Diterpenes on Semipreparative Scale ...................................... 504 19.6.4.1 Chromatographic Systems........................................... 504
19.6.5 Special Techniques in TLC of Diterpenes................................... 504 References ............................................................................................................. 511
Diterpenes-C20 terpenes-are a big group of compounds consisting of four 5-carbon (C5) units called the active isoprene. These compounds play an important role in plant physiology. They are also known for their pharmacological and toxicological activities. The group of diterpenes consists of about 800 various substances with a known structure, and occurs mainly in higher plants (sometimes in oleoresines and latices), microorganisms, and marine products. In phytochemistry, diterpenes are known as bitter substances, toxic diterpene alkaloids, as well as plant growth hormones (gibberellins) and other secondary metabolites. There is also vitamin A (retinol), which reveals the features of the diterpene structure, and occurs in human and animal organisms. It has also been discovered that pro-vitamin A-the group of tetraterpenoid compounds (carotenoids)—is present in plants.
