Coumarin antifungal activities

The major types of bioactive constituents reported from Broussonetia papyrifera are the prenylated flavonoids, which include compounds of the diphenylpropane, chalcone, flavan, flavanone, flavone, flavonol, and aurone classes (Table 2), Fig. (7). An early study on B. papyrifera resulted in the isolation of two diphenylpropanes, broussonins A (29) and B (30), and a coumarin, marmesin (52), with antifungal activity [39]. Also, a diprenylated diphenylpropane derivative, kazinol F (31) [40], was reported as an antioxidant and tyrosinase inhibitory constituent [34]. 

Abstract We report here the synthesis of newly coumarinic derivatives by using 4-hydroxy coumarine as starting material. These newly compounds were screened in vitro for their antimicrobial and antifungal activities. The structures of the synthesized compounds were proved by IR, H NMR, 13 C NMR and mass-spectral. 

Sardari, S., Mori, Y., Horita, K., Micetich, R.G., Nishibe, S. and Daneshtalab, M. (1999) Synthesis and antifungal activity of coumarins and angular furanocoumarins. Bioorg. Med. Chem., 7,1933-40. 

Fungal cultures of Microsporum cookie were incubated with the aqueous extract of German chamomile (Chamomila recutita) and one coumarin hemiarin, Fig. (41), isolated from this plant [242]. Both hemiarin. Fig. (41) and Chamomila recutita extract show a clear antifungal activity at 100 and 23 pg/ml, respectively. The main changes were due to inhibition of hyphal outgrowth, apical furcation and thickening of the cell wall. 

Among the non-fused coumarin derivatives those with the substitution on C-3 had shown superior in vitro antifungal activity to compare with the unsubstituted congeners. For example, 3-(l,2,4-triazol-5-yl)coumarins (48a-e) have been reported to exhibit more than 75% activity in concentrations lower than 250 ppm on A. niger, P. digitatum, and T. viride [254]. 

Hydroxylation of the aromatic ring in coumarins has substantial effect on their antifungal activities. For example, in vitro activity of 3-phenyl... 

Substitution of a carbonyl containing functional group generally decreases the antifungal activity in coumarins. For example carbamo-dithioic acid esters of 3-acetylcoumarins (54) do not show activity against Trichophyton sp. and Microsporum sp. [259]. 

The mechanism of action of coumarins are too complex and far fi-om being completely understood. However, they generally can be divided into two light-dependent and independent processes. Since there are already many reports on the light-dependent action of coumarins and furanocoumarins [10,241,269,270,271,272,273] that can explain their antifungal activity, here we try to focus on the light-independent mechanisms. 

Chakraborty DP, Das Gupta A, Bose PK (1957) On the Antifungal Activity of Some Natural Coumarins. Ann Biochem Expt Med 17 59... 

In this review we have discussed published results concerning the QSAR research on antimicrobial properties of synthetic and natural compounds. Antifungal and antimicrobial activity of some coumarin derivatives, various types of biological activities of benzamides, several studies on cinnamic acid derivatives with antibacterial and antifungal activity, reports on the biological activity of homoisoflavanones and phenolic compounds, as well as pharmaceutical applications of furan derivatives have been shown. 

Several coumarin derivatives have revealed pronounced medicinal value as antibacterial and antifungal agents [57,58]. Others have displayed antituber-cular activity [59] and some have insecticidal properties [60]. This prompted us to investigate the preparation of a new series of compounds containing coumarin moieties with different side chains or fused rings. 

Rehman, S.U., Chohan, Z.H., Gulnaz, F. and Supuran, C.T. (2005) In-vitro antibacterial, antifungal and cytotoxic activities of some coumarins and their metal complexes. /. Enzyme Inhib. Med. Chem., 20,333-40. 

Their application in the biomedical field is clearly demonstrated by the preponderance of patents as compared to publications in the field. Calixarenes functionalized at the wide rim with sulfonic acid and sulfonamide groups showed anticoagulant and antithrombotic properties, approaching the activity of heparin and coumarin, currently used as anticoagulants in antithrombotic therapy. Calixarene derivatives are also active as antiviral, antimicrobial. and antifungal agents. 

Isocoumarin (2) is the structural isomer of coumarin some isocumarin derivatives show antifungal, antimicrobial, and phytotoxic activities [44]. 

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