(+)-Jaborol, an unusual phenolic withanolide from jaborosa magellanica

A novel withanolide with an unprecedented carbon skeleton from Physalis angulata

Aromaphysalin A (1), possessing an exceptional C(11)–C(15) bond and a rearranged 4,9-cyclized aromatic ring, is isolated from of Physalis angulata.

Antiproliferative activity of withanolide derivatives from Jaborosa cabrerae and Jaborosa reflexa. Chemotaxonomic considerations

Three withanolides were isolated from the aerial parts of Jaborosa reflexa Phil. Jaborosa cabrerae Barboza yielded five sativolide withanolides (including jaborosalactones R, S, 38, and 39) and two trechonolide withanolides epimeric at C-23 (trechonolide A and jaborosalactone 32). In addition, five derivatives were obtained by chemical derivatization of jaborosalactone 38, and all compounds were fully characterized by 1D and 2D NMR spectroscopic studies. The in vitro antiproliferative activities of the major natural withanolides and the semisynthetic derivatives were examined against HBL-100, HeLa, SW1573, T-47D, and WiDr human solid tumor cancer cell lines. Some chemotaxonomic considerations are discussed.

Withanolides from Jaborosa kurtzii

Two new withanolides were isolated and characterized from the aerial parts of Jaborosa kurtzii, namely, jaborosalactone 43 (1), with a spiranoid delta-lactone at C-22, and jaborosalactone 44 (2), a 12-oxowithanolide, which may function as a biosynthetic precursor to 1. These new compounds were fully characterized by a combination of spectroscopic methods. Compound 1 showed selective phytotoxicity toward a dicotyledon species, Lactuca sativa (lettuce).

Withanolides with phytotoxic activity from Jaborosa caulescens var. caulescens and J. caulescens var. bipinnatifida 1

Seven new withanolides (1-7) were isolated from the aerial parts of Jaborosa caulescens var. caulescens and Jaborosa caulescens var. bipinnatifida. Three of the new compounds are related to jaborosalactones R, S, and T with a delta-lactone side chain and a hemiketal (or ketal) ring formed between a 21-hydroxyl and a 12-ketone (1-3). Compounds 4-7 are trechonolide-type withanolides with a gamma-lactone side chain and a hemiketal (or ketal) ring formed between a 22-hydroxyl and a 12-ketone. Compounds 4 and 5 also contain a hydroxyl group at C-21. Compounds 1, 2, and 7 showed selective phytotoxicity toward monocotyledonous and dicotyledonous species.

Phytotoxic withanolides from Jaborosa rotacea

Twelve new withanolides were isolated from the aerial part of Jaborosa rotacea: five had a spiranoid delta-lactone (1-5); one contained a 26,12-delta-lactone and a C-12-C-23 bond (6); five corresponded to trechonolide-type withanolides with configuration at C-23 opposite of those previously isolated (7, 8, 10-12); two of these have an additional oxido-bridge between C-21 and C-24; finally a withanolide with a hemiketal ring formed between a 21-hydroxyl and a 12-ketone (13) and the closely related jaborosalactone R were also isolated. New compounds were fully characterized by a combination of spectroscopic methods (1D and 2D NMR and MS). The structures of the spiranoid withanolide and of the epimer of trechonolide A were confirmed by X-ray diffraction studies. Compounds 4, 5, 6, and 8 showed selective phytotoxicity toward monocotyledoneous and dicotyledoneous species.

Cytotoxicity screening of some South American Solanaceae

Alcoholic extracts of seven plants belonging to the Solanaceae family were phytochemically screened and evaluated for their cytotoxic activity by Brine Shrimp Test (BST) with Artemia salina larvae, Inhibition of Cell Division Test (ICDT) on sea urchin Loxechinus albus fertilized eggs and inhibition of crown gall tumors on Potato Disk Bioassay (PDB). From Salpichroa diffusa, bioassay-guided chromatographic separation afforded some active fractions from which epi-katonic acid was identified.