Solanaceae, withanolides

Withanolides. Withanolides are Cis-steroidal lactones that are isolated from the Solanaceae plant family. Withanolides are characterized by an ergostane-type skeleton, the Cl 7-side chain of which is transformed into a six-member lactone ring. The withanolides and the related crgostancs arc tile only known natural steroids obtained Ifum the same family dial have representatives with both a- and -orientations of the Cl7 side chain. 

CHEMISTRY AND BIOACTIVITY OF WITHANOLIDES FROM SOUTH AMERICAN SOLANACEAE... 

Table 1 Southamerican genera and species from Solanaceae, containing withanolides...

A group of withanolides structurally related to trechonolide A (64), have been subsequently isolated from different Solanaceae. From J. magellanica (Punta Arenas, Chile) were isolated (-)-jaborotetrol (65), (-)-jaborolone (66), (+)-jaborochlorotriol (67) and (-)-jaborochlorodiol (68)... 

Withania somniferum (Solanaceae), known as ashwaganda in Ayurvedic medicine, contains steroidal lactones called withanolides which exhibit antitumour and hepatoprotective activities. 

In addition to the plants of Solanaceae family, certain withanolides named minabeolides have been reported from the sea soft coral belonging to the genus Paraminabea, representing the first class of marine withanolides [7, 9]. Minabeolides were reported three decades ago and found to be structurally similar to the simple withanolides such as withaferin A (2). However, recently they have attracted attention because of numerious reports of their cytotoxic properties. 

The withanolides containing plants of the family Solanaceae possess a wide range of pharmacological properties and are well-known sources of medicinal agents, stimulants, and poisons [52]. 

Non-solanaceous Occurrence. Withanolides have been discovered also in certain Tacca spp. of the Taccaceae (taccalonolides Huang et al. 2002) and Ajuga spp., e.g., A. parviflora Benth., Lamiaceae (ajugins Khan et al. 1999) as well as in some marine organism. Nevertheless, their occurrence in the Solanaceae is predominating by far. 

Veleiro AS, Oberti JC, Burton G (2005) Chemistry and bioactivity of withanolides from South American Solanaceae. In Atta-ur-Rahmtm (ed) Studies in natural products chemistry, vol 32 (part L). Elsevier, Amsterdam, NL, pp 1019-1052 Veras ML, Bezerra MZB, Lemos TLG, Uchoa DEA, Braz-Frlho R, Chai HB, Cordell GA, Pessoa ODL, (2004a) Cytotoxic withaphysalins from the leaves of Acnistus arborescens. J Nat Prod 67 710-713... 

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