Toxicity of Methyl Benzoate and Analogs to Adult Aedes aegypti

ABSTRACT Methyl benzoate is a natural product (floral volatile organic compound) that is currently used as a food flavoring ingredient. This compound has shown to be insecticidal in laboratory studies against agricultural and urban pests, including spotted wing drosophila Drosophila suzukii, brown marmorated stink bug Hyalomorpha halys, the diamondback moth Plutella xylostella, and the common bed bug Cimex lectularius, to name several insect taxa. In this study we topically treated adult Aedes aegypti females with methyl benzoate and analogs and determined their toxicities. We found that among adult females, 4 analogs—butyl benzoate, n-pentyl benzoate, vinyl benzoate, and methyl 3-methoxybenzoate—were more toxic than the parent compound, methyl benzoate.

Coordinated and High-Level Expression of Biosynthetic Pathway Genes Is Responsible for the Production of a Major Floral Scent Compound Methyl Benzoate in Hedychium coronarium

Methyl benzoate is a constituent of floral scent profile of many flowering plants. However, its biosynthesis, particularly in monocots, is scarcely reported. The monocot Hedychium coronarium is a popular ornamental plant in tropical and subtropical regions partly for its intense and inviting fragrance, which is mainly determined by methyl benzoate and monoterpenes. Interestingly, several related Hedychium species lack floral scent. Here, we studied the molecular mechanism of methyl benzoate biosynthesis in H. coronarium. The emission of methyl benzoate in H. coronarium was found to be flower-specific and developmentally regulated. As such, seven candidate genes associated with methyl benzoate biosynthesis were identified from flower transcriptome of H. coronarium and isolated. Among them, HcBSMT1 and HcBSMT2 were demonstrated to catalyze the methylation of benzoic acid and salicylic acid to form methyl benzoate and methyl salicylate, respectively. Methyl salicylate is a minor constituent of H. coronarium floral scent. Kinetic analysis revealed that HcBSMT2 exhibits a 16.6-fold lower Km value for benzoic acid than HcBSMT1, indicating its dominant role for floral methyl benzoate formation. The seven genes associated with methyl benzoate biosynthesis exhibited flower-specific or flower-preferential expression that was developmentally regulated. The gene expression and correlation analysis suggests that HcCNL and HcBSMT2 play critical roles in the regulation of methyl benzoate biosynthesis. Comparison of emission and gene expression among four Hedychium species suggested that coordinated and high-level expression of biosynthetic pathway genes is responsible for the massive emission of floral methyl benzoate in H. coronarium. Our results provide new insights into the molecular mechanism for methyl benzoate biosynthesis in monocots and identify useful molecular targets for genetic modification of scent-related traits in Hedychium.

STUDY INTO INHIBITOR-BIOCIDAL PROPERTIES OF ACETATE AND CHLORIDE SALTS OF TRANS- (2 - ((1H-BENZO [D] [1,2,3] TRIAZOL-1-YL) METHYL)) -1,3-DIOXALAN-4-YL) METHYL BENZOATE

Benzotriazol əsasında sintez edilmiş trans-(2-((1H-benzo [1,2,3] triazol-1-il) metil) -1,3-dioksalan-4-il) metil benzoatın sirkə (DQ-I) və xlorid turşusu (DQ-II) ilə duzları hazırlanmış, onların fiziki-kimyəvi xassələri öyrənilmiş və müxtəlif qatılıqlarda həm biosid həm də, hidrogen sulfid korroziyasına qarşı təsirləri öyrənilmişdir. Müəyyən olunmuşdur ki, hər iki reagent 15mq/l qatılıqda sulfatreduksiyaedici bakteriyalar (SRB), karbohidrogen oksidləşdirici bakteriyalar (KOB) və dəmir bakteriyalarına (FeB) qarşı 100%, hidrogen sulfid korroziyasına qarşı isə 77% mühafizə effekti göstərmişdir.

Methyl Benzoate Is Superior to Other Natural Fumigants for Controlling the Indian Meal Moth (Plodia interpunctella)

The Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is an insect pest that commonly affects stored and postharvest agricultural products. For the control of insect pests and mites, methyl benzoate (MBe) is lethal as a fumigant and also causes contact toxicity; although it has already been established as a food-safe natural product, the fumigation toxicity of MBe has yet to be demonstrated in P. interpunctella. Herein, we evaluated MBe as a potential fumigant for controlling adults of P. interpunctella in two bioassays. Compared to the monoterpenes examined under laboratory conditions, MBe demonstrated high fumigant activity using a 1-L glass bottle at 1 μL/L air within 4 h of exposure. The median lethal concentration (LC50) of MBe was 0.1 μL/L air; the median lethal time (LT50) of MBe at 0.1, 0.3, 0.5, and 1 μL/L air was 3.8, 3.3, 2.8, and 2.0 h, respectively. Compared with commercially available monoterpene compounds used in pest control, MBe showed the highest fumigant toxicity (toxicity order as follows): MBe > citronellal > linalool > 1,8 cineole > limonene. Moreover, in a larger space assay, MBe caused 100% mortality of P. interpunctella at 0.01 μL/cm3 of air after 24 h of exposure. Therefore, MBe can be recommended for use in food security programs as an ecofriendly alternative fumigant. Specifically, it provides another management tool for curtailing the loss of stored food commodities due to P. interpunctella infestation.

A New Megastigmane Glucoside and Other Constituents from Desmodium gangeticum

A new megastigmane glycoside, gangeticoside (1), and three known compounds leonuriside A (2), methyl benzoate 2-O-β-D-glucopyranoside (3), and tortoside A (4) were isolated from the aerial part of Desmodium gangeticum. Their structures were determined by 1D and 2D NMR spectra. The isolated compounds were evaluated for their inhibitory effect on NO production in LPS-stimulated RAW264.7 cells. Among them, compounds 1, 2, and 3 exhibited strong effect with the IC50 values of 22.3, 15.6, 7.3 μM, respectively.