Use of Lignins from Sugarcane Bagasse for Assembling Microparticles Loaded withAzadirachta indicaExtracts for Use as Neem-Based Organic Insecticides

Abstract

Microcapsules of sugarcane bagasse lignin loaded with organic extracts of neem (Azadirachta indica) were prepared and evaluated as potential bioinsecticides. Lignins were extracted and modified by oxidation and acetylation reactions providing different biopolymers. Afterwards, they were characterized through several analytical techniques. The formulations were initially prepared as colloidal suspension of lignin nanoparticles, which were then spraydried. The products were submitted to quality control protocols using high performance liquid chromatography (HPLC), thermal and photochemical degradation studies, followed by biological assays against Spodoptera frugiperda and Diatraea saccharalis. The formulations showed increases in both thermal and photo stability of approximately 40% compared with control samples. All the formulated microparticles were efficient against the insects evaluated and required a shorter time to achieve 100% mortality than the controls. The use of sugarcane bagasse lignins to prepare microparticles improved the resistance of neem extracts against abiotic factors, retaining the biological activity of this biopesticide.

Neem extract formulations to control Diabrotica speciosa (Coleoptera: Chrysomelidae) larvae in maize

“…The current research has shown the efficiency of different formulations of neem-based bioinsecticides in the laboratory, and the most efficient doses are promising to be further assessed under greenhouse and field conditions. It is noteworthy that lignin-microencapsulated neem extract formulation is protected by a lignin layer, which prevents the rapid photo and thermal degradation of the active compound azadirachtin (Costa et al 2017); this is considered to be a limitation for the use of botanical insecticides in crop protection. Therefore, the lignin-microencapsulated Table 2.…”

“…Lignin-microencapsulated neem extract. Lignin used in this assay was obtained from sugarcane bagasse by sodapulping process as previously described by Costa et al (2017). To prepare the formulation lignin-microencapsulated neem extract the following components first were added in separate beakers: 0.6 g fractions of ethyl acetate from neem crude ethanolic extract, 0.67 g Tween ® 80, 3.5 g commercial neem oil (Baraúna, Catanduva, SP, Brazil), and 50 mL distilled water.…”

“…Thereafter, 3 % (m/v) micronized lignin was added and the emulsion was homogenized again. The colloidal suspension was dried using Spray-drying (Büchi B-290), obtaining powder microparticles (Costa et al 2017).…”

Green and Sustainable Separation of Natural Products from Agro-Industrial Waste: Challenges, Potentialities, and Perspectives on Emerging Approaches

“…The obtained data reflect the growing interest and potential of green and sustainable methods to separate natural products from waste. One tendency observed in particular was the innovative ways to remove (integrating extraction, purification and/or modification in the same integrated system) and use such compounds in more contemporary sectors, promoting human and environmental health instead of general and old-fashioned remediation [ 19 , 38 ]. As a result, new applications for food, nutraceutical, and agricultural sectors have been further explored, based on their advantageous properties as natural colorants, flavors, aromas, antioxidants, antifungals, bioformulations (bio-pesticides) or simply their use as precursors to generate other compounds for similar uses.…”

Extraction and Characterization of Lignin from Corn Straw (Zea mays L.)

“…9 O objetivo principal da hidrólise alcalina à alta temperatura e pressão é solubilizar a hemicelulose, permitindo o acesso à lignina nos demais procedimentos do tratamento. 15 Além disso, após a extração, a lignina pode ser aplicada em diversas áreas, gerando produtos de valor agregado. Um exemplo disto é o conceito de biorrefinaria que visa a transformação de biomassa em compostos úteis, através da combinação de diferentes processos e tecnologias, como combustíveis, pesticidas, polímeros e outros produtos químicos.…”