No abstract

No abstract

Tecoma stans (L.), popularly known as ipê-mirim, is used in traditional medicine for the treatment of diabetes and digestive problems. The components of the hexane (HE) and methanol (ME) extracts obtained from the pericarp of T. stans were identified by gas chromatography-mass spectrometry (GC-MS) in their methyl ester forms (FAME).The antioxidant and cytotoxic activities of extracts, fatty acids, and methyl esters were evaluated. Methyl linolenate, methyl linoleate, and methyl palmitate were the major compounds in the HE, while methyl hexacosanoate was the main component in the ME. The samples exhibited significant antioxidant potential by DPPH assay. In the A. salina larvae bioassay, FAME (HE) and FAME (ME) were considered toxic. This study showed, for the first time to our knowledge, the chemical composition of the hexane and methanol extracts from T. stans pericarp as well as the antioxidant and cytotoxic activities of the extracts, fatty acids, and methyl esters.

Culex quinquefasciatus (Diptera: Culicidae) is responsible for the transmission of lymphatic filariasis. The search for natural sources of new insecticides to control mosquitoes has intensified in recent years. Tecoma stans is an exotic species in Brazil, known as "ipê de jardim". T. stans pericarps were extracted with hexane in Soxhlet apparatus, and fatty acids (FA) and methyl esters (FAME) were obtained by transesterification reaction of hexane extract (HE). HE, FA, and FAME were evaluated against 3 rd. and 4 th. instar larvae of Culex quinquefasciatus. Analysis by gas chromatography-mass spectrometry (GC/MS) identified the hydrocarbon nonacosane (81.69%) as the major compound in HE, and linolenic (16.89%), linoleic (16.83%), and palmitic acids (21.00%) were predominant in FA.FA and HE, at a concentration of 250 g/mL, promoted mortality of 81.67% and 68.66% of larvae, respectively. HE and FA obtained from T. stans pericarps have larvicidal potential for the control of C. quinquefasciatus.

Tecoma stans (L.) Juss. Ex Kunth is a species belonging to the Bignoniaceae family, popularly known as yellowing, yellow bell, and garden little ipe. Studies with T. stans seeds are scarce and it have potential in the search for natural compounds with biological activities. This study aimed to evaluate the toxicity and antioxidant activity of the ether extract (EE) and fractions from T. stans seeds. The EE was obtained in Soxhlet apparatus with petroleum ether and fractions were obtained by hydrolysis and esterification reactions. Phytochemical screening evaluated the presence of steroids, triterpenoids, alkaloids, coumarins and anthraquinones in EE. The toxicity was evaluated by the A. salina lethality test and antioxidant activity by DPPH method. It was observed the presence of steroids, triterpenoids and alkaloids in EE, which had no toxicity to A. salina (LC50 > 1000 µg/mL). The fractions of seeds exhibited toxicity on A. salina. All samples showed antioxidant activity with EC50 between 0.9 and 1.1 µg/mL. These results indicated potential applications for T. stans seeds.