Limonoids
The limonoids are a chemical group that includes highly oxidized triterpenoids . It is one of the furanolactones . Most compounds can be derived from a 4,4,8-trimethyl-17-furanyl steroid backbone. They are closely related to the quassinoid group . The most important representative of this group of substances is limonine . It was discovered as early as the 19th century, but it was not until 1938 that it was isolated, its properties were assigned more precisely and a structural formula was formulated. Other common representatives of the limonoids are azadirachtin , nomilin and nomilic acid.
|
|
|
|---|---|---|
| Limonine | Nomilin | Nomilic acid |
Occurrence
Limonoids occur naturally in two main forms. On the one hand, they appear in the form of glycosides in intact plants. Important representatives here are limonine glycoside and nomilic acid glycoside. They occur in oranges and lemons, among other things. On the other hand, they occur in the form of aglycones. These occur in the seeds and kernels of the plants, in which the glycosides of the limonoids also occur.
Furthermore, the representatives also appear in the leaves of the corresponding plants, which is why these are used in folk medicine as a remedy in the form of tea.
Biological modes of action
There are studies of numerous potential uses of limonoids. At the beginning of the research into limonoids, the representatives were awarded a high antioxidant effect. However, this has been refuted by studies. In fact, the total antioxidant capacity (TAC) is far behind that of common antioxidants such as ascorbic acid or butylated hydroxytoluene (BHT).
It is more important to assess the physiological importance that limonoids have. An antipyretic, antibacterial and antiviral effect has already been proven. They have also been used successfully in anti- malarial therapy. As anti-carcinogenic agents, they have been studied against breast, colon, pancreatic and liver cancer. It was also examined whether it can be used against leukemia . In addition, a reduced cholesterol release was determined when using certain limonoids. This means that they also have an antiatherogenic effect.
unwanted effects
Limonoid problems can arise in fruit juice production. Here the removal of the bitter substance limonin comes to the fore in order to improve the taste of the juices.
See also
Individual evidence
- ↑ a b c d e Jürgen Falbe, Manfred Regitz (Ed.): Römpp Chemie Lexikon, 9th edition, Georg Thieme Verlag, Stuttgart 1990, ISBN 3-13-734809-9 , p. 2514.
- ↑ a b Amit Roy, Shailendra Saraf: Limonoids: Overview of Significant Bioactive Triterpenes Distributed in Plants Kingdom , Biological and Pharmaceutical Bulletin , No. 29, 2006, pp. 191-201, doi: 10.1248 / bpb.29.191 .
- ↑ a b G. Koller, H. Czerny: About the limonin, the bittering agent orange seeds , Monatshefte fur Chemie and related parts of other sciences , No. 67, 1936, pp 248-268. Doi: 10.1007 / BF0271602 .
- ↑ a b Andrew P. Breksa, Gary D. Manners: Evaluation of the Antioxidant Capacity of limonin, nomilin, and limonin glucosides , Journal of Agricultural and Food Chemistry , No. 54, 2006, pp 3827 to 3831. Doi: 10.1021 / jf060901c .
- ↑ Jinhee Kim, Guddadarangavvanahally K. Jayaprakaska, Bhimanagouda S. Patil: Limonoids and their anti-proliferative and anti-aromatase properties in human breast cancer cells , Food & Funktion , No. 4, 2013, pp. 258-265, doi: 10.1039 / C2FO30209H .
- ↑ Stéphane C. Fayoux, Ruben J. Hernandez, Robert V. Holland: The Debittering of Naval Orange Juice Using Polymeric Films. In: Journal of Food Science . , No. 72, 2007, pp. E143-E154, doi: 10.1111 / j.1750-3841.2007.00283.x .
