Actinoplanones C, D, E, F and G, new cytotoxic polycyclic xanthones from Actinoplanes sp.

Kibdelones: Novel Anticancer Polyketides from a Rare Australian Actinomycete

“…Complete relative stereostructures were assigned to kibdelones A-C (1-3), kibdelone B rhamnoside (5), 13-oxokibdelone A (7), and 25-methoxy-24-oxokibdelone C (8) on the basis of detailed spectroscopic analysis and chemical interconversion, as well as mechanistic and biosynthetic considerations. Under mild conditions, kibdelones B (2) and C (3) undergo a facile equilibration to kibdelones A-C (1-3), while kibdelone B rhamnoside (5) equilibrates to a mixture of kibdelone A-C rhamnosides (4)(5)(6). A plausible mechanism for this equilibration is proposed and involves air oxidation, quinone/hydroquinone redox transformations, and a choreographed sequence of keto/enol tautomerizations that aromatize ring C via a quinone methide intermediate.…”

“…The upfield 13 C NMR chemical shift for the C-1 lactam carbonyl (d C = 156.36 ppm) was consistent with it being peri to a carbonyl/quinone (compare xantholipin) [2] as opposed to the sp 2 -hybridized carbon atom of a hydroquinone (compare actinoplanones and simaomicin). [3,4,5] The 13 C NMR shift for one of the remaining unassigned carbon atoms was indicative of a quinone (d C = 183.4 ppm), and was attributed to C-3-thereby defining ring B as a p-quinone. The four structure fragments described in Figure 1 account for all but three quaternary sp 2 carbon atoms.…”

Xanthone Derivatives: New Insights in Biological Activities

“…Diuretics, Uricosurics [456][457][458] oxyacetoxy, dihydrofurocarboxy [456][457][458] Antilipemic [289*,459] adrenaline-and theophylline-induced lipolysis [459], fat metabolizing enzymes, lipolysis [ Antiosteoporotics [471,472] bone resorption [471,472] propoxy/ipriflavone analogs [471], glycosyl [472] In Fibrotic Diseases [187*] HSP47 gene expression, inhibit collagen production on human dermal fibroblast [187*] polycyclic [187*] In Erectile Dysfunction [473] corpus cavernosum [473] tri-oxygenated [473] In Achondrogenesis [ see Table 5 see Section 2.1. for natural products; see Table 4 for synthetic derivatives [149,168,176,187,188], fibrosarcoma [154], epithelial tumor cells [114,188], nasopharynx epidermoid carcinoma [176,178,[189][190][191], and Friend tumor cells [139]. Moreover, several in vivo studies in xenographic tumor models have been carried out in colon adenocarcinoma [81,[100][101][102][192][193][194]…”

“…To this end, the structure-activity relationship (SAR) studies are currently available for the following activities: tuberculostatic [16,[85][86][87], antimycotic [88], antimalarial [89,90], antiplatelet [91][92][93][94], antithrombotic [95], antiinflammatory [54,96,97], antiallergic [13,22,24], antitumor [7,17,81,[98][99][100][101][102][103][104][105][106][107], antimutagenic [108][109][110], and antioxidant [38,43,55]. Furthermore, SAR studies have been also developed in the field of adrenergic blocking agents [7,11] [112], leukotriene (LT) B4 receptors blocking agents [113][114][115], as well as for effects on several enzymes, such as acetylcholinesterase [116,117], aldose reductase [118], aromatase …”

Naturally occurring pentaoxygenated, hexaoxygenated and dimeric xanthones: a literature survey

“…In general, xanthones and their derivatives were shown to be effective as an allergy inhibitor and bronchodialator in treatment of asthma 18. A series of isoprenylated xanthones isolated from moraceous plants showed interesting biological activities such as hypotensive effect, anti-rhinoviral activity, inhibition of the formation of some prostanoids and anti-tumor promoting activity 71 . The actinoplanones, polycyclic xanthones isolated from culture broth of Actinoplanes sp showed strong antimicrobial activities against bacteria and the rice fungus as well as exhibited strong cytoloxicity against the cells and inhibitory action on DNA synthesis 90 . Fermentations of Penicillium glabrum produce a complex mixture of dimeric xanthones with potent CD4-binding activity in an ELISA based on the binding of the monoclonal antibody anti-Leu 3a to soluble recombinant CD4 161 .…”