Coumarins

Introduction

  • Intro
  • Natural occurring coumarins
  • Biosynthesis of coumarins

The treatment and prevention of diseases have been boosted by the discovery of coumarins. These are some of the vital forms of phytochemicals that have contributed a lot to the field of medicine. Plants are usually viewed as the crucial sources of coumarins and form a notable part of the human diet since they have considered to have important medicinal uses. Research has shown that plant extracts with coumarins have many pharmacological benefits. This could be proven regarding how they eased pain and reduced inflammation in a variety of illnesses. Thus, it is with no doubt that the versatility of coumarins can be harnessed.

Naturally occurring coumarins

The plant kingdom is highly known for the production of phytochemicals. These can be defined as chemical compounds which are formed naturally and give their respective sources their organoleptic aspects. Besides coumarins, other phytochemicals are chromones, carotenoids, and flavonoids. Despite being referred to as naturally occurring phytochemicals, not all of them can be beneficial to human life or health. Thus, it is essential to make crucial choices on which ones can be useful. The most critical statistics indicate that there exist more than 4,000 various types of phytochemicals which can fight off a variety of illnesses some of which are terminal while others are degenerative.

In the current world, people are turning away from the use of generic drugs to phytochemical which can be easily incorporated in their food supplements. Thus, different types of plant supplements are in use which produces coumarins. Applying chemistry to this, it is evident that coumarins form the principal group of the 1-benzopyran derivatives originating from plants. Since the members of the family of benzopyrones are naturally significantly distributed, they can be associated with the integuments of flowers, seeds, roots, leaves, and stems. Regardless of this broad representation, it is important to note that the highest concentrations are majorly reserved to flowers and fruits. This is the reason behind the use of these two elements when it comes to the creation of food supplements used in medication.

 

 

Fig 1: Coumarin’s chemical structure

The Origin and Nature of Coumarin

Coumarin is a name derived from a French word which refers to Tonka bean (coumarou). These are the seeds belonging to Dipteryx odorata (Coumarouna odorata) (Fabaceae/Leguminosae). Historically, this was the first cradle of the coumarin extract when it was separated as a natural product in 1820. During this time, the pioneers found out that the product had sweet scent or odor and this prompted them to apply it as a perfume as from 1882. It was one of the best aromas , and the extracts and flavors are still used to date in some countries such as France.

Apart from the use of coumarins as perfumes, they were also applied as industrial additives and cosmetics. Tobacco companies have also incorporated coumarins in enhancing the aroma of their cigarettes and even some of the hard drinks. However, these require a specific industrial process, which can be costly. In medicine, coumarins are preferred for pharmacological activity since they have fewer side effects and do not portray drug resistance compared to generic drugs.

Extraction and Application of Coumarins

To ensure the efficacy of coumarins as medicine, it is essential to apply the most effective procedures to separate and purify the biological components. This is done in a variety of animals, plants, and microorganisms. There are also some artificially made compounds which have a crucial impact on the field of medicine apart from the naturally occurring ones.

While looking at the role played by coumarins, it is crucial to note that they are vital phytochemicals which are mainly derived from natural sources. Thus, one should know the types of plants that have medicinal phytochemicals.

Classification of Coumarin Derivatives

Coumarin derivatives come in many forms. The chemical classification can be done in accordance with the universally acceptable components. These are complex coumarins, simple coumarins, and other types. The coumarins which are more complex are usually fused with other heterocycles (4). As a result, they can be grouped into four classes which include dihydrofurocoumarins, simple coumarins, pyranocoumarins (linear and angular), furocoumarins, biscoumarins, phenylcoumarins. However, there are some coumarins which are extracted from plants and they are furocoumarins, simple hydroxycoumarins, biscoumarins and isofurocoumarins among others (1).

 

Classes of coumarin

 

Example with Reference

 

Pharmacological activity

 

1 Simple coumarins

 

Coumarin

 

 

 

Ammoresinol

 

 

Esculetin

 

 

 

 

Osthole

 

 

 

 

 

Ostruthin

 

Anticancer

Anti-inflammatory

 

 

Antibacterial

 

Antioxidant

Antiadipogenic

Neuroprotective

 

 

 

Anticonvulsant

Antifungal

Antibacterial

Anticancer

 

 

Antibacterial

Antifungal

            2 Furano coumarins

 

Imperatorin

 

 

 

 

Psoralen

 

Anticonvulsant

Antibacterial Antifungal

Anti-inflammatory Antiviral Anticancer

 

Antifungal Anti-TB

3 Dihydrofurano coumarins

 

Marmesin, rutaretin

Felamidin

 

Anti-TB

Antibacterial

 

4a Linear type

 

 

Grandivittin

Agasyllin

 

Antibacterial

 

            4b Angular type

 

Inophyllum A, B, C, E, P, G1, and G2  

Antiviral

 

5 Bicoumarins

 

 

 

Dicoumarol

 

Anticoagulant

 

6 Phenyl coumarins Isodispar B, dispardiol B

 

 

 

Figure 2: Types of Coumarins and their benefits

The figure above shows numerous classes of coumarins and their corresponding pharmacological properties (1).

Regarding the latest statistics, there are more than 40 plant families which are sources of coumarins. Thus, most of the scientists concentrate on these families when looking for extracts that would be useful in various fields such as medicinal chemistry, phytochemistry, pharmacology, food science and dietetics, and medicinal chemistry (2).

Research has also shown that coumarins are involved in many biological activities and some of them include anti-hypertensive, anticancer, antiviral, antibacterial, and antifungal and anticonvulsant among others. While analyzing the effectiveness of coumarins, it is essential to consider the biochemical properties and patterns of substitution since these play a crucial role (5-6). Most importantly, the plants from the Apiaceae family are known to be health-promoting. These include favorite spices and vegetables which contain vital phytochemicals which comprise coumarins and flavonoids (rutin, quercetin). The primary ways through which such coumarins achieve their tasks is through the inhibition of fungi, bacteria and a raft of viruses. This can be seen in the case of anti-inflammation, anti-allergens and immunosuppression activities. Some of the plants that fall under the Apiaceae family include cumin, fennel, coriander, parsley and carrots among others. Apart from vegetables and fruits, there are also coffee, olive oil, black and green tea among other sources of coumarins (7).

Nutrition is known for its impacts on epigenetics. When pregnant mothers visit a prenatal care clinic, they need to be advised regarding the food that they should take into consideration to prevent non-communicable diseases. Coumarins are known to influence epimutations since these aspects have transgenerational impacts (8).

Extraction Methods

Coumarins can be extracted through many methods. Some of them include supercritical fluid, sonication, microwave, and many others. Other techniques include electrophoresis which is utilized during the isolation of natural products. When extracting and analyzing coumarins, one can use spectrophotometric, titrimetric, and paper and thin layer chromatography among others (1).

 

References

 

  1. https://www.hindawi.com/journals/bmri/2013/963248/abs/
  2. https://www.intechopen.com/books/phytochemicals-isolation-characterisation-and-role-in-human-health/coumarins-an-important-class-of-phytochemicals
  3. https://www.ingentaconnect.com/content/ben/cpd/2013/00000019/00000021/art00013
  4. https://books.google.com.mt/books?hl=en&lr=&id=N_luK703FKEC&oi=fnd&pg=PA23&dq=Borges+F,+Roleira+F,+Milhazes+N,+Uriarte+E,+Santana+L.+Simple+coumarins:+Privileged+scaffolds+in+medicinal+chemistry.+Front+Med+Chem+Biol+Inter.+2009%3B4:23-85.+DOI:10.2174/978160805207310904010023.&ots=bav9JR9NNs&sig=eWPIZ18cr0xyC8346Y4-_W1VWRA&redir_esc=y#v=onepage&q&f=false
  5. https://link.springer.com/article/10.1007/s10616-013-9538-6
  6. http://en.cnki.com.cn/Article_en/CJFDTotal-SZGY201303093.htm
  7. https://www.sciencedirect.com/science/article/pii/S0308814607006851
  8. https://academic.oup.com/icb/article/54/1/21/2797829