Two new steroidal lactones of the withanolide‐type, 5β, 6α, 14α, 17β, 20β‐pentahydroxy‐1‐oxo‐20 S, 22R‐witha‐2, 24‐dienolide (1)and 6α, 7α‐epoxy‐5α, 14α, 17α, 23β‐tetrahydroxy‐1‐oxo‐22R‐witha‐2, 24‐dienolide (2), were isolated from the fruit of Withania somnifera (L.) Dunal (Solanaceae) growing in Southern Egypt, together with two known coumarins, scopoletin (3)and aesculetin (4), a known triterpene, viz. β‐amyrin (5), and two known phytosterols, viz. stigmasterol (6) and sitosterol (7). The structures of the isolated compounds have been elucidated by spectroscopic methods including UV, IR, 1H‐, 13C‐NMR, DEPT experiments, HRFAB‐, FAB‐, and EI‐mass spectrometry. The in vitro antimicrobial activity of the new withanolide (1) and the alcoholic fruit extract are discussed.

No abstract

Three complex 7-oxygenated-8-prenylflavones, (-)-semiglabrin and (-)-pseudosemiglabrin, which are diastereoisomers, and lanceolatin A have been isolated from the root of Tephrosia apollinea (Del.) Link (Leguminosae) growing in Southern Egypt, together with two phytosterols, stigmasterol and sitosterol. The structures of the isolated compounds have been elucidated by means of physical and several spectroscopic methods including UV, IR, 1 H, 13 C NMR, DEPT, 2D 1 H-1 H COSY, HSQC, HMBC experiments, and high resolution mass spectrometry (HR-MS), as well as some chemical transformations. The stereochemistry of the structures of (-)-semiglabrin and lanceolatin A have been confirmed by X-ray crystal structure analysis. The anticarcinogenic properties of the isolated compounds showed no inhibitory mechanisms concerning the initiation, promotion, and progression stage of carcinogenesis. Moreover, the in vitro antimicrobial activities of the root ethanolic extract are discussed.

No abstract

Results and DiscussionThe crude CH 2 Cl 2 /MeOH extract of the air-dried epigeal parts of D. graveolens showed significant bioactivities (vide infra). This extract was then subjected to flash column chromatography over a Silica gel, eluted with hexane, In bioassay-guided searches for novel bioactive natural products from higher plants of the Egyptian flora, two new eudesmane sesquiterpene derivatives, 3a a-hydroxyilicic acid methyl ester (1) and 2a a-hydroxy-4-epi-ilicic acid (2), together with 11 known sesquiterpenes were isolated from bioactive fractions of the active epigeal parts extracts of Dittrichia graveolens (L.) GREUTER (Asteraceae) growing in the coastal regions of northwestern Egypt.