Antimicrobial activity of Calophyllum inophyllum crude extracts ...

More documents

Recommendations

Info

Antimicrobial activity of Calophyllum inophyllum crude extracts obtained by pressurized liquid extraction / AsianJournal of Traditional Medicines, 2009, 4 (4)Table 2. Extraction of Calophyllum inophyllum fruit peel with methanol or n-hexane by PLE and Soxhlet extractionNo.SolventCrude extract yield(% w/w)Crude extract mass(mg)1 st 2 nd Average Vial 1 Vial 2Extraction timeSolvent : feedratioExtract descriptionPressurized liquid extraction1 Methanol 10.19 9.78 9.98 510 490Dark brown sticky oil25-30 min 80:10:002 n-Hexane 1.12 0.79 0.96 57 40 Oily yellowSoxhlet extraction1 Methanol 3.91 4.18 4.05 80 86 8 h2 n-Hexane 0.9 0.99 0.95 18 20 6 h100:01:00Oily dark yellowYellow amorphoussolidTable 3. TLC-monitoring of methanolic and n-hexane crude extract of Calophyllum inophyllum fruit peel.No.CrudeextractMobile phaseA B CDetectionUV 254 UV 366 FeCl 35 % UV 254 UV 366 FeCl 35 % UV 254 UV 366 FeCl 35 %R fvalue1 Methanol 0.560.530.470.410.340.270.220.18-0.53-0.400.32-0.24--0.53-0.400.32-0.24-0.620.580.520.40--0.220.14-0.58-0.400.330.26-----0.400.330.26--0.850.700.640.470.410.350.300.200.850.700.640.470.410.350.300.20-0.700.640.470.410.350.300.200.110.060.130.050.130.05--0.180.050.180.05Number of spots 10 6 6 6 6 5 8 8 72 n-Hexane 0.790.530.470.390.320.260.200.130.790.650.470.39-0.24-0.130.790.650.470.39-0.24-0.130.82-0.590.48-0.280.220.150.820.640.590.440.350.26---0.640.590.440.350.26--0.850.780.700.640.510.470.350.300.850.780.700.640.510.470.350.30-0.780.700.640.510.470.350.300.070.03----Number of spots 10 6 6 6 6 5 8 8 7144
Antimicrobial activity of Calophyllum inophyllum crude extracts obtained by pressurized liquid extraction / AsianJournal of Traditional Medicines, 2009, 4 (4)Table 4. Antimicrobial activity of the Calophyllum inophyllum fruit peel methanolic and n-hexane extracts obtained by PLE (100 µgof the extract per loaded disc).Mean zone of inhibition (extract) / Mean zone of inhibition (stabdard) % (n = 2)Extraction solvent employedS. aureus Ps. aeruginosa M. smegmatisMethanol 58.1 Nil 46.9n-Hexane 53.8 Nil 37.5DiscussionThis results indicate that PLE can be employed toextract phenolic and antimicrobial compounds fromthe fruit peel of Calophyllum inophyllum. Whileextraction using n-hexane as the solvent resultedin similar extraction yield as Soxhlet extraction,methanolic PLE extracts resulted in a 2.5-foldgreater yield. n-hexane usually extracts lipophilicmaterial, such as plant waxes and essential oils,which normally account for a small fraction of thetotal dry weight of the plant. Methanolic extracts, onthe other hand, mainly extract moderately to highlypolar components, such as tannins, plant phenoliccompounds, as well as high molecular weightcompounds, such as sugars, starches, thus accountingfor their much higher yields [4] . Soxhlet extractionwas carried out at the boiling point of methanol whichwas 64.7 o C. The PLE extraction was carried out attemperatures above the boiling point as well as at anelevated pressure. In this instance, extraction yieldswould be increased for several reasons. (1) Thedielectric constant of methanol is reduced at elevatedtemperature and pressure resulting in lowering of thesolvent polarity. Hence, the spectrum of compoundsextracted by methanol in PLE would be markedlyenhanced compared with Soxhlet extraction. (2) Thehigh pressures employed in PLE allowed the solventto be driven into the matrix of the fruit peel. The-OH group of methanol would bind to polar matrixsites causing swelling of the plant matrix. Thisimproves accessibility to the solvent and improveddissolution of compounds in the extract. (3) The hightemperatures employed improve the mass transferrates as well as the desorption of compounds from thematrix [3] .The thin-layer chromatography results presentedin Table 3 indicate the presence of moderately tohighly polar phenolic compounds in the methanolicextract whereas less polar compounds were found inn-hexane extract.The crude extracts obtained by PLE demonstratedpromising antimicrobial activities against Staphylococcusaureus, and Mycobacterium smegmatis. The experimentswere performed with the corresponding positive controls,methicillin 5 µg and streptomycin 10 µg, respectively,and the ratio of the mean inhibition zones of thespecimen discs over the control discs was calculatedto compensate for the error due to the micro-organismdiffusion rate. The methanolic crude extract gave higherzones of inhibition in comparison with the n-hexaneextracts indicating that the antimicrobial agents ofCalophyllum inophyllum consisted of moderately tohighly polar compounds. Earlier studies confirmed thatseveral phenolic constituents from the root bark and thenut of Calophyllum inophyllum exhibited antimicrobialactivities against Staphylococcus aureus [7] . Both polarand non-polar extracts demonstrated good activityagainst M. smegmatis and this result is promising asM. smegmatis is closely related to Mycobacteriumtuberculosis, which is the pathogen involved intuberculosis. It is likely that the n-hexane fractionalso possessed activity as lipophilic compounds aremore likely to permeate through the mycobacteriummembrane. None of the extracts inhibited Ps.aeruginosa, as this Gram-negative bacteria possess145
Page 1 and 2: Antimicrobial activity of Calophyll
Page 3: Antimicrobial activity of Calophyll

Antimicrobial activity of Calophyllum inophyllum crude extracts ...

Create successful ePaper yourself

Delete template?

Save as template?