Jothiramsekar Saranya’s scientific contributions

The study was carried out to investigate the essential oil composition and antibacterial effects of Eugenia cotinifolia ssp. codyensis leaves. The fresh leaf essential oil was extracted hydrodistillation process using Clevanger apparatus. The compounds of the essential oil were analyzed using Gas Chromatography Mass Spectrometry (GC-MS) technique identified a total of 84 numbers of chemical constituents and resulted 99.99%. The essential oil was characterized by high content of sesquiterpene compounds (79.23%) and the major constituent being Germacrene D (17.95%). The leaf oil exhibited higher antibacterial effects against gram negative bacteria compare to gram positive bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the oil against the organism ranged between 0.25 – 0.75 mg/ml and 0.5 – 2.5 mg/ml respectively. The essential oil exhibited maximum inhibition at 0.25 mg/ml against Proteus vulgaris and the same inhibited Bacillus subtilis and Staphylococcus aureus at 0.75 mg/ml. The result of essential oil chemical constituents and antibacterial activity showed useful for preparation of commercial products.

Ten pigmented landraces of rice were analyzed for chemical composition and antioxidant properties. The results of proximate composition and calcium, iron, zinc content showed intra variability among landraces. The amylose, total anthocyanin (TAC) and phytate contents were found to be in the range of 22.01 - 44.38%, 28.73 - 193.36 mg cyanidin-3-glucoside/100 g and 1.16 - 24.49 mg Fe/100 g respectively. Total phenol and polyphenol contents were in the range of 233.92 - 251.38 mg ferulic acid equivalent/100 g and 252.43 - 284.36 mg gallic acid equivalent/100 g, respectively. Antioxidant assays of landraces showed free radical scavenging activity.

Antioxidant activities of wood and leaf extracts of Hopea erosa were investigated using five in vitro assays. Dichloromethane (DCM) and methanolic extracts were found to exhibit higher antioxidant activity compared to chloroform extract. The activity of DCM extract of leaf was higher in H2O2 and hydroxyl scavenging assays with 95.04 % and 93 % respectively. DPPH, FRAP and ABTS assays were highly sensitive to methanolic extract of leaf with 87.24 %, 91.08 % and 89.81 % respectively. Likewise, the DCM extract of wood possess higher activity in FRAP (95.72 %) and ABTS (94.53 %) and the methanolic extract exhibited higher activity in H2O2 (90.75 %) and DPPH (83.36 %) assays. The hydroxyl scavenging assay is sensitive to chloroform extract of wood. These results show promising perspectives for the exploitation of critically endangered tree species of Hopea erosa having considerable levels of antioxidant capacity.

Background: Hopea ponga has been categorised as an endangered tree species under International Union for Conservation of Nature red list of threatened species. Objective: To study the antibacterial, antioxidant activities, total phenolic and flavonoid contents of Hopea ponga leaf, extracted from different solvents viz., petroleum ether, chloroform and methanol. Materials and Methods: Antibacterial activity of leaf extract of Hopea ponga was determined by disc diffusion method against Escherichia coli, Proteus vulgaris, Bacillus cereus, Streptococcus faecalis and Pseudomonas aeruginosa. The antioxidant activities of the extracts were assayed through in-vitro models such as 2,2-diphenyl-1- picrylhydrazyl, 2,2′- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid), ferric reducing antioxidant power, hydrogen peroxide and hydroxyl scavenging activities. Total flavonoid content was determined using aluminium chloride colorimetric method and total phenolic content determined using Folin ciocaulteu reagent method. Results : Methanol extract showed higher scavenging activity against 2,2-diphenyl-1-picrylhydrazyl and reducing power activity against ferric ion (97.24 ± 0.11 and 88.01 ± 0.03) compared to other extracts. Methanol extract showed significant antibacterial activity against P. vulgaris and B. cereus. Among the tested extracts, methanol extract exhibited higher content of phenols (1318.749 mg of ferulic acid equivalent/100 gram dry weight of extract) and flavonoids (457.832 mg of quercetin equivalent/100 gram dry weight of extract). Conclusions : The present study suggests that the methanol extract may contain active compounds, which have effective antioxidant and antimicrobial activity. Hence, this endangered species have to be explored and conserved to serve the mankind.

Background: Syzygium caryophyllatum (L.) Alston is an endangered tree species belonging to the Myrtaceae family. Objective: To evaluate the antimicrobial, antioxidant and anticancer activities of the leaf extract. Materials and Methods: Disc diffusion method was used for antimicrobial screening of four bacterial and three fungal strains. Scavenging ability of the extract was determined using 2,2-diphenyl-1-picrylhydrazyl assay. Hep2 cell line was used to evaluate the cytotoxicity by 3-(4, 5-dimethyl thiazol-2yl)-2, 5-diphenyl tetrazolium bromide assay. Results: The zone of inhibition was high for the extract against all the selected strains used. Antioxidant potential was more at higher concentration (400 μg/ml). The extract showed maximum Hep2cell inhibition at higher concentration (9.80% cell viability in 1000 μg/ml). Conclusions: Antioxidant, antimicrobial and anticancer studies using leaves of Syzygium caryophyllatum showed that it has potential utilization in pharmaceutical industry.

Syzygium makul, is a tree species belonging to family Myrtaceae, categorised as vulnerable under the IUCN red list of threatened plant. Fresh leaf samples of Syzygium makul extracted by hydrodistillation process were analyzed for their chemical composition. A total of 72 compounds were identified among which beta-caryophyllene (20.31 %), cis-beta-Ocimene (11.23 %), delta-Cadinene (11.02 %), gamma-Maaliene (7.68 %) and 4,9-Cadinadiene (6.68 %) are the major constituents.