Antitubercular constituents from Premna odorata Blanco.
BACKGROUND
Premna odorata Blanco (Lamiaceae) is a medicinal plant traditionally used in Albay Province, in southeastern Luzon, Philippines to treat tuberculosis. This study aimed to determine the antitubercular property of the crude extract and sub-extracts of the leaves, and to isolate the bioactive principles from the active fractions.


METHODS
Through extraction, solvent polarity-based fractionation and silica gel chromatography purification of the DCM sub-extract, compound mixtures from the bioactive fractions were isolated and screened for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv using the colorimetric Microplate Alamar Blue assay (MABA).


RESULTS
The crude methanolic extract and sub-extracts showed poor inhibitory activity against Mycobacterium tuberculosis H37Rv (MIC≥128µg/mL). However, increased inhibitory potency was observed for fractions eluted from the DCM sub-extract (MIC=54 to 120µg/mL). Further purification of the most active fraction (MIC=54µg/mL) led to the isolation of a 1-heneicosyl formate (1), 4:1 mixture of β-sitosterol (2), stigmasterol (3) and diosmetin (4), which were identified through GC-MS analysis (with dereplication) and NMR experiments. The MIC of compound 1 was 8µg/mL.


CONCLUSIONS
The results of this study provide scientific basis for the traditional use of Premna odorata as treatment for tuberculosis.
Graduate School, University of Santo Tomas, España, Manila 1015, Philippines.
Stephen B
SB
Lirio
Graduate School, University of Santo Tomas, España, Manila 1015, Philippines; Phytochemistry Laboratory, Research Center for the Natural and Applied Sciences, Thomas Aquinas Research Complex, University of Santo Tomas, España, Manila 1015, Philippines.
Allan Patrick G
AP
Macabeo
Phytochemistry Laboratory, Research Center for the Natural and Applied Sciences, Thomas Aquinas Research Complex, University of Santo Tomas, España, Manila 1015, Philippines.
Erickson M
EM
Paragas
Institut fur Organische Chemie, Universitat Regensburg, Universitatsstrasse 31, 93053 Regensburg, Germany.
Matthias
M
Knorn
Institut fur Organische Chemie, Universitat Regensburg, Universitatsstrasse 31, 93053 Regensburg, Germany.
Paul
P
Kohls
Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612-7231, USA.
Scott G
SG
Franzblau
Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612-7231, USA.
Yuehong
Y
Wang
Graduate School, University of Santo Tomas, España, Manila 1015, Philippines; Phytochemistry Laboratory, Research Center for the Natural and Applied Sciences, Thomas Aquinas Research Complex, University of Santo Tomas, España, Manila 1015, Philippines. Electronic address: alicia.aguinaldo@gmail.com.
Ma Alicia M
MA
Aguinaldo
D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D020834:Ethnopharmacology; D019686:Lamiaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000254:growth & development; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry
D000995:Antitubercular Agents; D010936:Plant Extracts
1-heneicosyl formate; Antitubercular; Diosmetin; Premna odorata; Tuberculosis