Antimicrobial activities of neo- and 1-epineo-isoshinanolones from Plumbago zeylanica roots.
BACKGROUND
The roots of Plumbago zeylanica Linn. (Plumbaginaceae) are reputed to have a wide spectrum of therapeutic properties in the Ayurvedic system of medicine. They are useful in curing many ailments such as skin diseases, diarrhea, plague and leprosy.


OBJECTIVE
The study was aimed at isolating, separating and evaluating the antimicrobial properties of compounds such as neoisoshinanolone and 1-epineo-isoshinanolone from the roots of P. zeylanica.


METHODS
The crude petroleum ether extract of roots of P. zeylanica was subjected to repeated chromatographic techniques to separate compounds 2 and 3 along with plumbagin. Structure elucidation was carried out using nuclear magnetic resonance (NMR), infra red (IR) and mass spectroscopy. The serial dilution method was used to test antimicrobial activities and their minimum inhibitory concentration (MIC) expressed in microg/mL.


RESULTS
1-Epineo-isoshinanolone is more active with a MIC of 12.5-25 microg/mL whereas neoisoshinanolone has recorded a MIC of 50-100 microg/mL. The activities are compared with plumbagin (0.78-3.13 microg/mL) and standards streptomycin for bacteria and nystatin for fungi.


CONCLUSIONS
Earlier researchers have established the presence of plumbagin in the roots of P. zeylanica and its antimicrobial activities. The structure elucidation of two more biologically active biogenetic precursors along with their activities in the root extracts has been established for the first time in the present study.


CONCLUSIONS
The root extract of P. zeylanica possesses good antimicrobial activity, which suggests its therapeutic use in the Ayurvedic system of medicine to cure skin diseases.
Jetty
Annapurna
A
Microbiology Laboratory, Bioengineering and Environmental Center, Indian Institute of Chemical Technology, Hyderabad, India. annapurna@iict.res.in
Subhakar
Chennupati
C
Rajagopal
Duddumpudi
D
Jetty
Manasa
M
Subramanyam
Mukkamala
M
Marthanda Murthy
Madugula
M
D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D055808:Drug Discovery; D005658:Fungi / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008515:Medicine, Ayurvedic; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry*; D029606:Plumbaginaceae / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013764:Tetrahydronaphthalenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D044366:Transition Temperature
D000890:Anti-Infective Agents; D009285:Naphthoquinones; D010936:Plant Extracts; D013764:Tetrahydronaphthalenes; C434363:isoshinanolone; C014758:plumbagin