The crude methanolic extract of Dillenia indica Linn. (Dilleniaceae) leaves has been investigated for the evaluation of antimicrobial and cytotoxic activities. Organic solvent (n-hexane, carbon tetrachloride and chloroform) fractions of methanolic extract and methanolic fraction (aqueous) were screened for their antimicrobial activity by disc diffusion method. Besides, the fractions were screened for cytotoxic activity using brine shrimp (Artemia salina) lethality bioassay. Among the four fractions tested, n-hexane, carbon tetrachloride, and chloroform fractions showed moderate antibacterial and antifungal activity compared to standard antibiotic, kanamycin. The average zone of inhibition was ranged from 6 to 8 mm at a concentration of 400 µg/disc. But the aqueous fraction was found to be insensitive to microbial growth. Compared to vincristine sulfate (with LC50 of 0.52 µg/ ml), n-hexane and chloroform fractions demonstrated a significant cytotoxic activity (having LC50 of 1.94 µg/ml and 2.13 µg/ml, respectively). The LC50 values of the carbon tetrachloride and aqueous fraction were 4.46 µg/ml and 5.13 µg/ ml, respectively. The study confirms the moderate antimicrobial and potent cytotoxic activities of Dillenia indica leaves extract and therefore demands the isolation of active principles and thorough bioassay.

The current study was designed to isolate and characterize some bioactive secondary metabolites by using repeated chromatographic and spectroscopic techniques, targeting their anticancer, antimicrobial, and antioxidant properties through in vitro and in silico approaches. Six compounds were isolated and analyzed by thin layer chromatographic technique and the compounds were identified as 5- O -caffeoyl quinic acid ( 1 ), syringin ( 2 ), luteolin ( 3 ), apigenin ( 4 ), jhanol ( 5 ), and jhanidiol ( 6 ) based on spectroscopic methods. The cytotoxic effect of each compound was dose-dependent, and compound 1 showed a higher anti-proliferative effect (IC 50 = 181.3 μg/ml) than other compounds (compound 2 , 4 , 5 , and 6 ). Besides, compound 1 showed the most promising antibacterial activity with a zone of inhibition ranges from 12–15 mm against different strains compared to ciprofloxacin (14–22 mm). In contrast, compound 3 exerted the highest scavenging property against DPPH free radical. Finally, the in vitro bioactivities were also supported by molecular docking studies. The computational study demonstrated that the isolated compounds exerted stronger affinity compared to the standard drugs towards the binding sites of dihydrofolate reductase (DHFR), glutathione reductase, and urase oxidase.

Extracts from the leaves of the Bangladeshi medicinal plant Terminalia citrina were prepared, and 13 new furofuran lignan glucosides, terminalosides A-K (1-4, 6-12), 2-epiterminaloside D (5), and 6-epiterminaloside K (13), were characterized using various spectroscopic techniques. Twelve of the isolates were found to contain rare tetraoxygenated aryl groups in their structures. Analysis of the NMR chemical shifts for the oxymethine signals in the furofuran ring suggested a pragmatic approach to determining the relative configuration of these compounds. The ECD and NOESY spectroscopic data obtained allowed for the deduction of the absolute configurations and conformations of the compounds. The isolates were tested for their estrogenic/antiestrogenic activity using the MCF-7 and T47D estrogen-responsive human breast cancer cell lines. Terminalosides B (2) and G (8) exhibited inhibitory effects for both cell lines, and estradiol-enhanced cell proliferation was suppressed by 90% at concentrations lower than 10 μM. Terminaloside E (6) showed inhibitory activity against the T47D cell line, whereas terminalosides C (3), F (7), and I (10) and 6-epiterminaloside K (13) displayed antiestrogenic activity against MCF-7 cells.

This study was undertaken to evaluate antioxidant property, cytotoxicity and antimicrobial activity of Lasia spinosa leaves. Ethyl acetate soluble partitionate of the methanolic extract of the plant material showed significant antioxidant property using DPPH (1,1-diphenyl-2-pecrylhydrazyl) assay with IC50 value of 16.42 ?g/ml. In the brine shrimp lethality bioassay, LC50 values obtained from the best fit line slope were 0.544, 3.181, and 4.096 ?g/mL for standard (vincristine sulphate), dichloromethane and ethylacetate soluble partitionates of the methanolic extract respectively. The leaves extracts showed mild antimicrobial property. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 215-218 DOI: http://dx.doi.org/10.3126/njst.v13i2.7739