Ecological Roles of Tryptanthrin, Indirubin and N‐Formylanthranilic Acid in Isatis indigotica: Phytoalexins or Phytoanticipins?

Abstract

Leaves of the plant species Isatis indigotica Fortune ex Lindl. (Chinese woad) produce the metabolites tryptanthrin, indirubin and N‐formylanthranilic acid upon spraying with an aqueous solution of copper chloride but not after spraying with water. The antifungal activities of these metabolites against the phytopathogens Alternaria brassicicola, Leptosphaeria maculans and Sclerotinia sclerotiorum established that tryptanthrin is a much stronger growth inhibitor of L. maculans than the phytoalexin camalexin. The biosynthetic precursors of tryptanthrin and N‐formylanthranilic acid are proposed based on the deuterium incorporations of isotopically labeled compounds. The overall results suggest that tryptanthrin is a phytoalexin and indirubin and N‐formylanthranilic acid are phytoanticipins in the plant species I. indigotica and that chemical diversity and biodiversity are intimately connected.

Phytoalexins and Signalling Metabolites Produced in the Wild Crucifer Neslia Paniculata: Camalexins and Arabidopsides

“…Curiously, due to the research impact of the model plant A. thaliana, camalexin ( 9) benefits from the highest popularity among the ca. 60 cruciferous phytoalexins reported to date (Pedras and Abdoli, 2017;Pedras et al, 2019;Pedras and Alavi, 2020). This popularity is reflected in the number of publications, with more than 440 articles retrieved through the SciFinder database (accessed March 2021 using the keyword "camalexin").…”

Tryptanthrin and Its Derivatives in Drug Discovery: Synthetic Insights

“…The synthetic approaches to attain this valuable tetracyclic alkaloid can be broadly divided into two main groups: the condensation reactions and the oxidation reactions. While most conventional condensation approaches comprise the reaction between isatin and anthranilic acid derivatives, including isatoic anhydride (5), the oxidative processes usually involve the oxidation of indigo to isatin, which is further oxidized to isatoic anhydride, followed by the condensation of these two compounds, in the presence of strong oxidizing agents. Other indole derivatives can also be applied in this sort of chemical transformation.…”

“…4 Recent studies indicate a potential ecological role of tryptanthrin as a phytoalexin in Isatis tinctoria, being produced as a mechanism of defense against phytoparasites. 5 This alkaloid has also been isolated from several microorganisms besides Candida lipolytica, including Pseudomonas aeruginosa, Oceanibulbus indolifex, Cytophaga sp. strain AM13.1, Schizophyllum commune, and Leucopaxillus cerealis.…”

“…4 Recent studies indicate a potential ecological role of tryptanthrin as a phytoalexin in Isatis tinctoria , being produced as a mechanism of defense against phytoparasites. 5…”

Recent advances of tryptanthrin and its derivatives as potential anticancer agents

“…11 Subsequently, the study on tryptanthrin alkaloid was discussed in another review article in 2013, where various synthetic methods were applied for the preparation of tryptanthrin. 12a Owing to its pharmacologically aromatic indoloquinazoline moiety with a wide range of biological and pharmacological activities, tryptanthrin has been extensively applied as a parental backbone via the modification of different functional groups for the development of new tryptanthrin derivatives with significant medicinal benefits as antitrypanosomal, 13 antifungal, 14,15 anti-phytopathogenic bacterial, 16 antibacterial, [17][18][19][20][21] anti-MRSA, 22 antiviral, [23][24][25][26] antiangiogenic, 27 anti-inflammatory, [28][29][30][31][32][33][34][35][36][37][38][39] anti-leishmanial, 40,41 antimalarial, 42 antiplasmodial, 43 antiparasitic, 44 antitubercular, [45][46][47] and anti-cancer [48][49][50][51][52][53][54]…”