Phenalenone-type phytoalexins from Musa acuminata synthesis of 4-phenyl-phenalenones

Phenalenone-type phytoalexins mediate resistance of banana plants ( Musa spp.) to the burrowing nematode Radopholus similis

“…Initial phytochemical analyses of R. similis-infected roots of the Musa cultivar Pisang sipulu identified the phenylphenalenone anigorufone (1) as a phytoalexin produced in response to nematode damage and confirmed earlier suggestions of the significant role of phytoalexins in the plant defense system (16). Phenylphenalenones are a group of special phenylpropanoidderived natural products (17), which are known as Musaceae phytoalexins (18). The activity of phenylalanine ammonia lyase (EC 4.3.15), the entry-point enzyme of the phenylpropanoid pathway, is correlated to the biosynthesis of specific phenylpropanoids involved in defense and was substantially induced in nematode infected roots of Ykm5 (19).…”

“…The activity of phenylalanine ammonia lyase (EC 4.3.15), the entry-point enzyme of the phenylpropanoid pathway, is correlated to the biosynthesis of specific phenylpropanoids involved in defense and was substantially induced in nematode infected roots of Ykm5 (19). Phenylphenalenone-related compounds show biological activity against bacteria, fungi, algae, and diatoms (18,(20)(21)(22). The formation of these compounds has been elicited in banana leaves by Mycosphaerella fijiensis (Black Sigatoka leaf streak disease), in the fruit peels by Colletotrichum musae (anthracnose disease), and in roots and rhizomes by F. oxysporum f. sp.…”

Chemical constituents from the aerial parts of Musella lasiocarpa

“…The known compounds were identified by comparison of their spectroscopic data with published values, as rel-(3S,4aR,10bR)-3-(4′-hydroxyphenyl)-8-hydroxy-9-methoxy-4a, 5,6,10b-tetrahydro-3H-naphtho[2,1-b]pyran (1, musellarin A), 7 2-hydroxy-9-(4′-hydroxyphenyl)-1H-phenalen-1-one (6, hydroxyanigorufone), 15 2-methoxy-9-(4′-hydroxyphenyl)-1H-phenalen-1-one (7), 8 2-hydroxy-9-(3′,4′-dihydroxyphenyl)-1H-phenalen-1-one (8, dihydroxyanigorufone), 15 2-hydroxy-4-(3′,4′-dihydroxyphenyl)-1H-phenalen-1-one (11), 16 2-hydroxy-4-(4′-methoxyphenyl)-1H-phenalen-1-one (12), 17 (4E,6E)-1,7-bis(4-hydroxyphenyl)-hepta-4,6-dien-3-one (14), 18 (4E,6E)-1-(3′,4′-dihydroxyphenyl)-7-(4′′-hydroxyphenyl)-hepta-4,6-dien- 20 Previously, a number of phenylphenalenones with moderate cytotoxic effects against P388 murine leukemia cell line were reported from Haemodorum simplex. 21 In this study, except for 13, 16, and 17, the other compounds were evaluated for cytotoxicity against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480) using the MTT method.…”

The Intramolecular Diels-Alder Reaction of Diarylheptanoids — Quantum Chemical Calculation of Structural Features Favoring the Formation of Phenylphenalenones

“…Phenylphenalenones are a group of polycyclic plant natural products mainly occurring in the Haemodoraceae [1][2][3][4] and the Musaceae [5][6][7][8]. There is ample evidence that the biosynthesis of phenylphenalenones, first discussed by Thomas in 1961 [9], involves a diarylheptanoid, which undergoes cyclization to form the substituted tricyclic phenylphenalenone.…”

“…The conversion could proceed either by chemical reaction in vitro [10], starting from compound 1a, or in vivo after administration to plant material [11]. [2][3][4][5][6][7][8][9][10][11][12][13] C]1-(3,4-Dihydroxyphenyl)-7-phenylhepta-4,6-dien-3-one (1a), when administered to cultured roots of Anigozanthos preissii, was smoothly converted to [8][9][10][11][12][13] C]anigorufone [11]. …”