N-hexane Extract Of Stem Bark Research Articles

A Nortriterpenoid and Steroid from the Stem Bark of Aglaia angustifolia Miq (Meliaceae)

A nortriterpenoid, 3-epi-cabraleahydroxylactone (1) and a steroid, stigma-4-en-3-on (2) were isolated from the n-hexane extract of stem bark of Aglaia angustifolia Miq. Compound (2) was isolated for the first time from this Genus. The structure of both compounds were identified by spectroscopic datas including one and two-dimensional NMR as well as infrared spectrum, high-resolution mass spectrometric analysis and by comparing with those spectral data previously.

PHYTOCHEMICAL EXTRACTIONS, QUALITATIVE ANALYSIS, AND EVALUATION OF ANTIMICROBIAL ACTIVITY IN THE LEAF AND STEM BARK OF SOLANUM PUBESCENS WILLD.

Objective: The objective of this study was to extract the phytochemicals from leaf and stem bark of Solanum pubescens, perform qualitative analysis, and evaluate antimicrobial activity of the phytochemicals against certain microbial pathogens.
 Methods: Leaf and stem bark of S. pubescens was subjected to phytochemical extractions using Soxhlet apparatus with five different solvents, identified the major constituents in different solvent extracts using standard protocols and investigated the potential antimicrobial activities of the extracts against certain selected bacterial and fungal pathogens by agar well diffusion method.
 Results: The maximum yield was in methanolic extracts of leaf and stem bark of the study plant such as 18.51 and 12.5%, respectively, followed by the hydroalcohol extracts (14.23 and 10.00%). Qualitative phytochemical analysis revealed maximum number of extracted bioactive compounds when compared to other similar studies. Among the five different solvent extracts of S. pubescens, n-hexane extract of stem bark was found to be active against all the bacterial pathogens and stem bark extracts made with methanol and hydroalcohol showed antifungal activity against all the four fungal pathogens tested. Leaf extracts made with solvents such as n-hexane and ethyl acetate showed inhibition against Klebsiella pneumoniae and Staphylococcus aureus, respectively, hydroalcohol extract was active against Pseudomonas aeruginosa and Salmonella typhimurium while none of the leaf extracts of the study plant showed inhibition zones against fungal pathogens tested.
 Conclusion: Multiple solvent extraction approach yielded the phytochemicals which are not yet reported and the antimicrobial activities of phytochemicals acknowledged their medicinal value.

Antiplasmodial activity of two fractions obtained from n-hexane extract of Garcinia parvifolia Miq stem bark

Antiplasmodial activity of fractions A and B obtained from n-hexane extract of stem bark of Garcinia parvifolia have been evaluated. The in vitro antiplasmodial activity was investigated on two strains of Plasmodium falciparum, FCR-3 a chloroquine resistant and D10, a chloroquine sensitive strains and their antiplasmodial activity was expressed by the concentration inhibiting 50.% of the parasite growth (IC50). The results showed that the fractions A and B were active against P. falciparum with the IC50 values of 2,79 ± 0,10 μg/mL and 12,30 ± 1,21.μg/mL on FCR-3 strain and 1,52 ± 0,24.μg/mL and 4,66 ± 1,24 μg/mL on D10 strain. Identification of active constituents in the both fractions showed the existence of triterpenoide, steroide and flavonoide compounds. Key words: Antiplasmodial activity , Garcinia parvifolia, active constituents.

Triterpenoids from Mangifera indica

From the neutral fraction of the n-hexane extract of stem bark of Mangifera indica, (var./cv Banganpalli) six new tetracyclic triterpenoids, cycloart-24-ene-3β,26-diol, the C-24 epimers of cycloart-25-ene-3β,24,27-triol, the C-24 epimers of cycloartane-3β,24,25-triol and 3-ketodammar-24 E-ene-20 S,26-diol together with the known compounds cycloartenol, α-amyrin, β-amyrin, sitosterol 3β-hydroxycycloart-25-en-26-al, dammarenediol II, the C-24 epimers of cycloart-25-ene-3β,24-diol, 24-methylenecycloartane-3β,26-diol, ψ-taraxastane-3β,20-diol and ocotillol II have been isolated. The acidic fraction of the same extract, on esterification with diazomethane followed by chromatography, yielded methyl mangiferonate, methyl isomangiferolate, methyl mangiferolate and the diazomethane adduct of methyl mangiferolate. The structures were elucidated by spectroscopic and chemical methods.