Activity of plant extracts/essential oils against three plant pathogenic fungi and mosquito larvae: GC/MS analysis of bioactive compounds

Abstract

Certain natural products extracted from different parts of medicinal and aromatic plants were examined for their antifungal activity against three plant pathogenic fungi, Fusarium oxysporum, Rhizoctonia solani, and Alternaria solani, and insecticidal activity against mosquito larvae (Culex pipiens). Acetone extract of Tectona grandis showed the highest antifungal activity against R. solani and A. solani with EC50 values of 118 and 294 μg/mL, respectively. The highest larvicidal activity was displayed by the essential oils of Ocimum basilicum and Eucalyptus gomphocephala with LC50 value of 22, and 30 mg/L, respectively. By gas chromatography–mass spectrometry (GC/MS) analysis 3-allylguaiacol (65.8%) and eugenol acetate (46.6%) were the main compounds in Syzygium aromaticum methanolic extract and essential oil, respectively. The main compound in T. grandis acetone extract was cyclohexylpentyl oxalate (8.7%); its water extract contained (E)-4,4-dimethyl-2-pentene (51.1%); E. gomphocephala branch oil contained p-cymene (28.8%); Euphorbia paralias leaf extract contained 1βH-romneine (26.3%); the seed extract contained α-linolenic acid, TMS (15.2%); Punica granatum extract contained furfural (32.1%); and O. basilicum essential oil contained estragole (65.9%). Thus, extracts from the tested plants can be used as natural biofungicides to manage diseases caused by F. oxysporum, R. solani, and A. solani. Additionally, these extracts show potential larvicide activities against mosquito larvae.

Dwarf Pomegranate (Punica granatum L. var. nana): Source of 5-HMF and Bioactive Compounds with Applications in the Protection of Woody Crops

“…Concerning the high concentration of 5-HMF in the extract (37% peak area), it was initially ascribed to a failure in the extraction operating conditions (unexpected rise of the temperature), but the bibliographic reports of a 21% (peak area) content in an ethanolic extract by Kumar and Vijayalakshmi [33], a 32.1% (peak area) content by Hamad et al [11], and a 39.7% content by Mohamad and Khalil [35] encouraged us to repeat the extraction and determination, verifying that the result was consistent. This result is also in agreement with a study by Fischer et al [36], who explored the thermal impact on the anthocyanin and phenolic co-pigments of pomegranate juices and on the formation of 5-HMF and other degradation products and concluded that upon forced heating at 90 • C for five hours, the 5-HMF contents increased only slightly.…”

Detection of Fungi and Oomycetes by Volatiles Using E-Nose and SPME-GC/MS Platforms

“…We also used this technique in our experiments because of its high sensitivity and strong discriminatory ability. GC/MS is today the most used analytical tool for fungal VOC identification [102][103][104] and is easily coupled to solid-phase microextraction (SPME) techniques for the VOC extraction and concentration, which allows easy progression to environmental sampling and subsequent laboratory analysis [100]. However, it should be noted that results observed depend on both the nature of the fiber used and the extraction method [105].…”

Productivity and Post-Harvest Fungal Resistance of Hot Pepper as Affected by Potassium Silicate, Clove Extract Foliar Spray and Nitrogen Application

“…Furthermore, clove essential oil with its main compound, eugenol, was responsible for its antifungal properties [21]. Clove oil was reported to be effective at suppressing R. solani and F. oxysporum [22].…”