Anti-diabetic activities of phenolic compounds of sp., an endophyte isolated from the leaves of desert plants growing in Egypt.

Six phenolic compounds (talaroflavone (1), alternarienoic acid (2), altenuene (3), altenusin (4), alternariol (5), and alternariol-5--methyl ether (6)) were isolated from the solid rice culture media of sp., an endophyte isolated from the fresh leaves of three desert plants, Dammer (Solanaceae), L. (Amaryllidaceae) and L.

: new secondary metabolites and their cytotoxic activities.

Two new compounds, 11-methoxy-11,12-dihydro phytuberin (2) and 9-methoxy-benzocyclononan-7-one (6), together with twenty-six known ones were isolated from (Solanaceae). Their planar structure was established by extensive spectroscopic analyses. The absolute configuration of compound 6 was determined by time dependent density functional theory calculations (TDDFT).

A new glucoside with a potent α-glucosidase inhibitory activity from .

A new glucoside, 3-methoxy-4---D-glucopyranosyl-methyl benzoate, has been isolated from along with five known compounds through bioactivity guided fractionation of the total plant methanolic extract towards -glucosidase inhibitory activity. All the isolated compounds were tested for their inhibitory effect on -glucosidase enzyme. As a result, four of them showed a potent inhibitory activity and thus constitute a therapeutic approach to decrease postprandial hyperglycemia in diabetic patients.

Rational design and semisynthesis of betulinic acid analogues as potent topoisomerase inhibitors.

Chemical transformation studies were conducted on betulinic acid (1), a common plant-derived lupane-type triterpene. Eleven new rationally designed derivatives of 1 (2-5 and 7-13) were synthesized based on docking studies and tested for their topoisomerase I and IIalpha inhibitory activity. Semisynthetic reactions targeted C-3, C-20, and C-28 in 1.

Antiproliferative triterpenes from Melaleuca ericifolia.

Three new 28-norlupane triterpenes, 28-norlup-20(29)-en-3beta-hydroxy-17beta-hydroperoxide (1), 28-norlup-20(29)-en-3beta-hydroxy-17alpha-hydroperoxide (2), and 20 S-17beta,29-epoxy-28-norlupan-3beta-ol (3), were isolated from the leaves of Melaleuca ericifolia along with eight known pentacyclic triterpenes. The structures of the new compounds were elucidated by spectroscopic methods including 1D and 2D NMR spectroscopy and mass spectrometry. The isolated triterpenes were evaluated for antiproliferative activity against the malignant +SA mammary epithelial cell line.