Podophyllotoxin, a well-known naturally occurring aryltetralin lignan occurs in few plant species that is used as a precursor for the chemical synthesis of the anticancer drugs like etoposide, teniposide and etopophose phosphate. The availiability of this lignan is becoming increasingly limited because of the scarce occurance of its natural sources and also because synthetic approaches for its production are still commercially unacceptable. This paper reports first time the production of podophyllotoxin by an endophytic fungus Fusarium oxysporum isolated from the medicinal plant Juniperus recurva. Further confirmation and quantification of podophyllotoxin was performed by HPLC, LC-MS, and LC-MS/MS.

BackgroundBoswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus Boswellia. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays.ResultsAKBA was found to be the most active compound showing an MIC range of 2-8 μg/ml against the entire gram positive bacterial pathogens tested. It exhibited concentration dependent killing of Staphylococcus aureus ATCC 29213 up to 8 × MIC and also demonstrated postantibiotic effect (PAE) of 4.8 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S. aureus and Staphylococcus epidermidis and also reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide and leakage of 260 and 280 nm absorbing material by AKBA treated cells of S aureus indicating that the antibacterial mode of action of AKBA probably occurred via disruption of microbial membrane structure.ConclusionsThis study supported the potential use of AKBA in treating S. aureus infections. AKBA can be further exploited to evolve potential lead compounds in the discovery of new anti-Gram-positive and anti-biofilm agents.

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