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- Kaempferol Derivatives from Hedychium gardnerianum : Unveiling the Potential of an Invasive PlantPublication . Tavares, Wilson R.; Barreto, Maria do Carmo; Seca, Ana M. L.The therapeutic properties of plants and of their secondary metabolites are a current research topic of great interest. Considering that Hedychium species are used in folk medicine around the globe, Hedychium gardnerianum Sheppard ex Ker Gawl., an extremely aggressive invasive plant in Hawaii and in Azores, was selected and phytochemically studied in order to search for natural compounds with interesting biological activities. […].
- Uncharted Source of Medicinal Products : The Case of the Hedychium GenusPublication . Tavares, Wilson R.; Barreto, Maria do Carmo; Seca, Ana M. L.A current research topic of great interest is the study of the therapeutic properties of plants and of their bioactive secondary metabolites. Plants have been used to treat all types of health problems from allergies to cancer, in addition to their use in the perfumery industry and as food. Hedychium species are among those plants used in folk medicine in several countries and several works have been reported to verify if and how effectively these plants exert the effects reported in folk medicine, studying their essential oils, extracts and pure secondary metabolites. Hedychium coronarium and Hedychium spicatum are the most studied species. Interesting compounds have been identified like coronarin D, which possesses antibacterial, antifungal and antitumor activities, as well as isocoronarin D, linalool and villosin that exhibit better cytotoxicity towards tumor cell lines than the reference compounds used, with villosin not affecting the non-tumor cell line. Linalool and α-pinene are the most active compounds found in Hedychium essential oils, while β-pinene is identified as the most widespread compound, being reported in 12 different Hedychium species. Since only some Hedychium species have been investigated, this review hopes to shed some light on the uncharted territory that is the Hedychium genus.
- Macaronesian Plants as Promising Biopesticides against the Crop Pest Ceratitis capitataPublication . R. Tavares, Wilson; Jiménez, Ignacio A.; Oliveira, Luísa; Kuhtinskaja, Maria; Vaher, Merike; Rosa, José S.; Seca, A. M. L.; Bazzocchi, Isabel L.; Barreto, Maria do CarmoABSTRACT: Ceratitis capitata is responsible for significant economic losses in the fruit production industry, and the market lacks biopesticides that are effective but also cheaper and less contaminating, with fewer negative impacts on the environment. In this regard, the present study suggests as potential options ethanolic extracts from several Macaronesian plants, which inhibit the oviposition and are toxic to C. capitata, and whose preparation involve a non-toxic solvent (i.e., ethanol), low energy expenditure and cheap apparatus (i.e., maceration at room temperature). Among the evaluated species, the extracts of Hedychium gardnerianum, Cistus symphytifolius and Salvia canariensis are the most active (50 mg/mL), revealing an increase in C. capitata adults’ mortality from 21.15% to 27.41% after 72 h, a value statistically identical to azadirachtin (25.93%) at the recommended concentration (0.88 mg/mL). Considering the quantity and biomass available to prepare a biopesticide in the future, and the level of activity, the ethanolic extract of H. gardnerianum was fractionated and each fraction tested. The water fraction at 50 mg/mL proved to be more effective than the original extract, both in terms of mortality (57.69%), with LT50 = 72.5 h, and oviposition deterrence (83.43%), values statistically higher than those obtained by azadirachtin at 0.88 mg/mL. Analysis of this fraction by HPLC-MS/MS showed that it is mainly composed of glycosylated derivatives of quercetin and myricetin in addition to some triterpenes. These findings highlight some Macaronesian species, and in particular, the more polar fraction of H. gardnerianum ethanolic extract, as promising and ecological alternatives to conventional insecticides, for use in the integrated management of the C. capitata pest.
- A Gigante Invasora e a sua Inesperada Dádiva AtioxidantePublication . Tavares, Wilson R.A procura por novos produtos de origem natural com benefícios para a sociedade é um tema cada vez mais interessante, não só para a comunidade científica, mas também para a população em geral e para algumas indústrias. Por exemplo, na agricultura o uso excessivo ao longo dos anos de pesticidas sintéticos tem levantado muitas preocupações devido aos seus efeitos nocivos e ao impacto negativo no meio ambiente, pelo que são altamente desejadas alternativas a estes pesticidas que sejam mais ecológicas, seguras, práticas e acessíveis. Em relação à medicina, a busca por compostos bioativos com potenciais aplicações em saúde não cessa, surgindo todos os anos vários novos medicamentos com os mais variados tipos de ação: antibacteriano, anti-inflamatório, antioxidante, anti tumoral, antiviral, etc.