Toxicity of Substances Isolated from Helietta puberula RE Fr. (Rutaceae) to the Leaf-cutting Ant Atta sexdens L. (Hymenoptera: Formicidae) and the Symbiotic Fungus Leucoagaricus gongylophorus (Singer) Möller

Abstract

Möller RESUMO -As formigas cortadeiras são pragas que podem causar sérios prejuízos para a agricultura e silvicultura, uma vez que elas possuem o hábito de cortar material vegetal fresco para cultivar o fungo simbionte, sua principal fonte alimentar. Atualmente, métodos químicos têm sido largamente empregados para o controle de formigas cortadeiras e isso tem acarretado sérios problemas à saúde humana, assim como para o meio ambiente e outros organismos não-alvo. Nesse sentido, espécies vegetais são promissoras fontes de novas moléculas inseticidas que podem ser tóxicas tanto para as formigas cortadeiras quanto para o fungo simbionte, além de serem mais degradáveis e menos tóxicas para mamíferos. Em vista disso, o presente estudo objetivou a determinação da toxicidade de extratos, frações e substâncias puras de Helietta puberula RE Fr. (Rutaceae) para operárias médias de Atta sexdens L. (Hymenoptera: Formicidae) e para o seu fungo simbionte, Leucoagaricus gongylophorus (Singer) Möller. A toxicidade para as saúvas foi determinada através de bioensaios por ingestão, enquanto que com o fungo simbionte, foi avaliado o seu desenvolvimento em meio de cultura contendo os extratos vegetais. Os resultados mostraram que dentre as seis substâncias isoladas de H. puberulla, três delas foram concomitantemente tóxicas para as saúvas e para o fungo, mostrando ser essa espécie vegetal uma fonte promissora de novas substâncias para o controle de formigas cortadeiras. PALAVRAS-CHAVE -extratos vegetais, atividade inseticida, atividade fungicida, Rutaceae, controleABSTRACT -Leaf-cutting ants may be a serious pest for the agriculture and silviculture once they cut plant material to cultivate a symbiotic fungus, which is their main food source. Currently, chemical methods are largely used for controlling of these insects, but sometimes with serious damages to human health, environment and other non-target organisms as well. Considering this, some plants are promising as a source of toxic substances, which can be toxic both to leaf-cutting ants and the symbiotic fungus. The main objective of this research was to determine the toxicity of extracts, fractions and isolated substances from Helietta puberula RE Fr. (Rutaceae) to Atta sexdens L. (Hymenoptera: Formicidae) workers and their symbiotic fungus, Leucoagaricus gongylophorus (Singer) Möller. Toxicity of vegetal extracts to leaf-cutting ants were determined by ingestion bioassays, while the activity against the symbiotic fungus was evaluated by its development in a culture medium containing vegetal extracts in it. The results showed that three out of six compounds isolated from H. puberula have effectively targeted both partners simultaneously, indicating that this plant is a promising source of novel insecticidal substances for the control of leaf-cutting ants.

Maculine: a furoquinoline alkaloid from the family Rutaceae: sources, syntheses and biological activities

“…46 The antiparasitic characteristic of maculine was studied against trypomastigote forms of Trypanosoma cruzi and malaria and it was moderate for both parasites. 19,47 Additionally, this furoquinoline alkaloid revealed a photo-mutagenic effect against a mutant strain of Chlamydomonas reinhardtii using a dose of 40 µg/ml with exposure of the cells to irradiation with UV-A. 10,48 Its photosensitizer activity could be attributed to the planar structure, and so its capability of intercalating into DNA.…”

Antiparasitic Derivatives of the Furoquinoline Alkaloids Kokusaginine And Flindersiamine

“…Kokusaginine ( 1 ) and flindersiamine ( 2 ) were first described by Rapoport in 1960 [11,12] . There are many biological activities reported in the literature for both alkaloids such as antimicrobial activity, [13,14] cytotoxic activity, [15–18] anti‐cholinesterase activity, [19,20] fungicide activity, [21,22] and antifouling activity [23] . Unlike flindersiamine, kokusaginine was reported to inhibit the spinach chloroplasts photosynthetic system [24] .…”