Natural Products with Maleic Anhydride Structure:  Nonadrides, Tautomycin, Chaetomellic Anhydride, and Other Compounds

Hygrobafilomycin, a cytotoxic and antifungal macrolide bearing a unique monoalkylmaleic anhydride moiety, from Streptomyces varsoviensis

“…17,18 In stark contrast, the occurrence of alkylmaleic anhydride units in natural products is scarce. 19 Although several natural products containing a dialkylmaleic anhydride unit are known, only meliacinanhydride and C 21 norsesterterpene acid represent natural products with a monoalkylmaleic anhydride. 20,21 Biosynthetic considerations The structure of 6 is intriguing from a biosynthetic point of view, as the polyketide core shares structural features of both the bafilomycins and the hygrolidins, and carries an unprecedented side chain.…”

“…13 A particular importance of the maleic anhydride moiety, as found in other cases, could not be connoted. 19 As the compounds show only low cell line selectivities, a basic physiological function as cellular target seems plausible. However, comparison of the antitumor analysis with 94 reference compounds by the COMPARE algorithm did not show any significant correlation (rhoo0.5 for all compounds), and thus the mechanism of action remains unclear.…”

The First General and Selective Palladium(II)‐Catalyzed Alkoxycarbonylation of Arylboronates: Interplay among Benzoquinone‐Ligated Palladium(0) Complex, Organoboron, and Alcohol Solvent

“…Such diboron substrates are commercially available or readily prepared via Pt-catalyzed diboration of alkynes, [15] and the produced maleates are found in biologically active compounds from natural sources. [16] The diborylalkenes 3w and 3x were treated with 16 mol% (8 mol%/boron) PdA C H T U N G T R E N N U N G (OAc) 2 , 32 mol% (2 equiv./palladium) PPh 3 , and 2 equiv. (1 equiv./boron) of pbq at room temperature in MeOH under a CO atmosphere.…”

Antifungal activity of simple compounds with maleic anhydride or dimethylmaleimide structure against <i>Botrytis cinerea</i>

“…2,3) Natural products with a maleic anhydride structure are valuable antifungal agents, enzyme inhibitors, and herbicides. 4) Among them, tautomycin 1, 5,6) tautomycetin 2, 7) viburspiran 3, 8) phomoidride A 4, 9,10) phomoidride B 5, 9,10) zop ellin 6, 11,12) heveadride 7, 13,14) and scytalidin 8 [15][16][17] (Fig. 1) have good antifungal activities.…”