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Alstonia scholaris is an important indole alkaloid rich medicinal plant with diverse pharmacological activity. To understand the effect of extraction techniques, the stem bark sample of A. scholaris was subjected to continuous hot percolation, ultrasonic extraction, and cold maceration techniques. Continuous hot percolation technique extractive exhibited a potential pancreatic lipase (PL) inhibitory activity and further bio-assay guided fractionation resulted in the isolation of echitamine with a PL inhibitory activity (IC50 = 10.92 µM). A new validated HPTLC-HRMS method was developed for the quantification of echitamine by using a mobile phase of chloroform: methanol (80:20, v/v) with 0.04% formic acid. Echitamine content in the individual extractives were in direct correlation with the PL inhibitory activity (Pearson's r = −0.9409). The molecular docking studies further confirmed the PL inhibitory potential of echitamine. These results clearly highlight the role of echitamine as a natural product-based lead for potent PL inhibitory activity. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the in vitro antimicrobial activity of crude extracts of three plants from Ayurveda tradition (Tinospora cordifolia, Alstonia scholaris, Crataeva nurvala) against reference microbial strains and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase-producing Klebsiella pneumoniae. IC50 values were obtained by micro-dilution methods meeting the requirements of the NCCLS standard. The cytotoxicity of the extracts was also investigated on a mammalian cell line. Extracts displayed a variable degree of antimicrobial activity and did not interfere with mammalian cell proliferation. T. cordifolia and A. scholaris exhibited a higher inhibitory activity against clinical isolates of MRSA and carbapenemase-producing K. pneumoniae compared with reference strains, while C. nurvala exhibited a different behaviour. An antifungal activity towards Candida albicans was observed for A. scholaris extract. Results indicate that constituents from T. cordifolia and A. scholaris may be a potential source of new therapeutic strategies for infectious diseases. [ABSTRACT FROM AUTHOR]

In the context of our previous communication on phytochemical studies of the ethanolic extract of flowers ofAlstonia scholarisof Pakistan origin, these have resulted in the isolation of two new triterpenoids. One is of the oleanane type, alstoprenyol, 3-β-hydroxy-28-β-acetoxy-5-olea triterpene (1), the other is of ursane type, alstoprenylene 3β-acetate-24-nor-urs-4,12,2′-triene ester triterpene (2) and together with four known triterpenes,α-amyrin acetate (3),α-amyrin (4), lupeol acetate (5) and 3β-hydroxy-24-nor-urs-4,12,28-triene triterpene (6)were isolated. The structures of1–6were elucidated with the aid of extensive NMR spectroscopic studies. [ABSTRACT FROM PUBLISHER]

Ethanolic and aqueous extracts of the leaves and flowers of Alstonia scholaris were evaluated for their antioxidant activity by investigating their effect on blood glutathione levels in alloxan-induced diabetic rats. The ethanolic extract of the leaves was the most active; therefore, its cytotoxicity against HepG2 cells was also tested. Promising GI50 values of 1.96, 4.34 and 4.65 µg mL–1 were observed for the extract, its chloroform and ethyl acetate fractions, respectively. The chloroform active subfraction I (GI50 = 2.97 µg mL–1) yielded betulin (1), betulinic acid (2) and ursolic acid (3) upon purification. Compounds 1–3 were identified using spectroscopic techniques and by comparison with reported data. GLC of unsaponifiable and saponifiable fractions of the hexane extract revealed β-sitosterol (7.37%) and n-tetracosane (54.4%) to be the major sterol and hydrocarbon components, respectively. Linoleic acid (48.89%) was the predominant fatty acid. [ABSTRACT FROM PUBLISHER]

A new indole alkaloid, N-formylscholarine, together with picrinine, strictamine and nareline has been isolated from the fruit pods of Alstonia scholaris, and their structures were established by various spectral data. This is the first report of these alkaloids in A. scholaris fruit pods. [ABSTRACT FROM AUTHOR]