Withanolides activity

As a group these steroids and the corresponding chlorohydrins display interesting biological activity. Several withanolides induce quinone reductase... 

Within the cucurbitacins and withanolides it has been found that certain structural analogues possess agonistic rather than antagonistic activity hexanorcucurbitacin D (EC50 = 2.5 x 10 5M) and withaperuvin D (EC50 = 2.5 x 10 5M) [170], In the case of hexanorcucurbitacin D, this concurs with the hypothesis that antagonistic activity of cucurbitacins is associated with the presence of an a,(3-unsaturated ketone in the side-chain [205], which hexanorcucurbitacin D lacks. 

Shohat, B., Kirson, I., Lavie, D. (1978). Immunosuppressive activity of two plant steroidal lactones withaferin A and withanolide E. Biomedicine, 28,... 

The stereocontrolled syntheses of steroid side chains for ecdysone, crustecdysone, brassinolide, withanolide, and vitamin D3 have been reviewed (185). Also, other manuscripts, including reviews on the partial synthesis of steroids (186), steroid drugs (187—189), biologically active steroids (190), heterocyclic steroids (191), vitamin D (192), novel oxidations of steroids (193), and template-directed functionalization of steroids (194), have been published. 

During an infestation by larvae of the Egyptian cotton leafworm Spodoptera littoralis (Boisd) in the summer of 1978, it was noticed that shrubs of Physalis peruviana L. (cape gooseberry) were not attacked, whereas other Physalis and Nicandra spp. suffered heavy damage. Asher and co-workers demonstrated that withanolide E (118) and 4(3-hydroxywithanolide E (119), isolated from P. peruviana, as well as several related steroids, had insect antifeedant properties. Further studies on other withanolides showed antifeedant effects and species-specific activity on three insects, S. littoralis (Boisd.) (Lepidoptera), the Mexican bean beetle, Epilachna varivestis Muls. (Coleoptera) and the red flour beetle, Tribolium castaneum (Herbst) [62]. 

The first studies on cancer chemopreventive activity were performed by Kennedy and co-workers on withanolides isolated from Physalis philadelphica. The most potent compounds were found to be ixocarpalactone A (34), philadelphicalactone A (36), 4p,7(3,20R-trihydroxy-l-oxowitha-2,5-dien-22,26-olide (42), and ixocarpalactone B (38), all of which contained a 4p-hydroxy-2-en-l-one structural unit [73]. 

Activity-monitored fractionation of a chloroform-soluble extract of Deprea subtriflora using a quinone reductase induction assay led to the C-18 norwithanolides mentioned previously. Six of the active compounds obtained from this plant (44, 46, 47, 49, 52 and 53), presentes an a,P-unsaturated ketone unit in ring A. Compound 55 -with a doubly unsaturated ring A ketone- was found to be inactive in the QR assay, while compound 54 was active [72]. It has been suggested that the presence of an a,p-unsaturated ketone unit in ring A of withanolides is important for inducing activity in the cell-based QR induction assay,... 

Recently withanolides isolated from Iochroma australe and the norbomane-type withanolide jaborosalactol 18 (3) isolated from Jaborosa bergii, showed phytotoxic activity on monocotyledoneous and dicotyledoneous species. Iochroma australe extract and the major constituent (17S,20R,22R)-4p,7(3,20-trihydroxy-l-oxowitha-2,5,24-... 

Withanolides, Biologically Active Natural Steroidal Lactones A Review... 

During the last two and a half decades many withanolides and their related compounds have been isolated from Withania and other Solanceous species and some of them possess remarkable physiological activity. Withanolides have been isolated so far from the following species... 

Hydroxy group along with 58,66-epoxy system is essential for the antitumor activity, eg. withanolide E (46), 48-OH withanolide E (53). Thus 17-isowithanolide (34) possessing 17 -OH... 

Physalins which resemble closely in their structure to withanolides occur mainly in the plants of Physalis species. The plants as such as well as the isolated physalins have been reported to exhibit varied pharmacological activity. 

Senthil, V., S. Ramadevi, V. Venkatakrishnan, et al. 2007. Withanolide induces apoptosis in HL-60 leukemia cells via mitochondria mediated cytochrome c release and caspase activation. Chem. Biol. Interact. 167 (l) 19-30. 

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

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