Mosquitocidal activities of Chenopodium botrys whole plant n-hexane extract against Culex quinquefasciatus

This research aimed to investigate various mosquitocidal activities of Chenopodium botrys whole- plant n-hexane extract against Culex quinquefasciatus. The extract showed remarkable larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus. During the larvicidal and pupicidal activities, the 24-hour lethal concentration (LC50) of extract against 2nd instar larvae, 4th instar larvae and pupae were 324.6, 495.6 and 950.8 ppm, respectively. During the CDC (Centers for Disease Control and Prevention) bottle bioassay for adulticidal activity, the median knockdown times (KDT50) at 1.25% concentration was 123.4 minutes. During the filter paper impregnation bioassay for adulticidal activity, the KDT50 value at 0.138 mg/cm2 concentration was 48.6 minutes. The extract was fractionated into 14 fractions through silica gel column chromatography which were then combined into six fractions on the basis of similar retention factor (Rf) value. These fractions were screened for adulticidal activity by applying CDC bottle bioassay. The fraction obtained through 60:40 to 50:50% n-hexanes-chloroform mobile phase with 0.5 Rf value showed 100% adulticidal activity at 0.2% concentration. During oviposition deterrent activity, the highest concentration (1000 ppm) showed 71.3 ± 4.4% effective repellence and 0.6 ± 0.1 oviposition activity index. During adult emergence inhibition activity, the median emergence inhibition (EI50) value was 312.3 ppm. From the outcome of the present investigation, it is concluded that the n-hexane extract of C. botrys whole- plant possesses strong larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus.

Recent Advances in Sorbicillinoids from Fungi and Their Bioactivities (Covering 2016–2021)

Sorbicillinoids are a family of hexaketide metabolites with a characteristic sorbyl side chain residue. Sixty-nine sorbicillinoids from fungi, newly identified from 2016 to 2021, are summarized in this review, including their structures and bioactivities. They are classified into monomeric, dimeric, trimeric, and hybrid sorbicillinoids according to their basic structural features, with the main groups comprising both monomeric and dimeric sorbicillinoids. Some of the identified sorbicillinoids have special structures such as ustilobisorbicillinol A, and sorbicillasins A and B. The majority of sorbicillinoids have been reported from fungi genera such as Acremonium, Penicillium, Trichoderma, and Ustilaginoidea, with some sorbicillinoids exhibiting cytotoxic, antimicrobial, anti-inflammatory, phytotoxic, and α-glucosidase inhibitory activities. In recent years, marine-derived, extremophilic, plant endophytic, and phytopathogenic fungi have emerged as important resources for diverse sorbicillinoids with unique skeletons. The recently revealed biological activities of sorbicillinoids discovered before 2016 are also described in this review.

Phytochemical compounds of Guibourtia ehie and their antioxidant, urease and α-glucosidase inhibitory activities

Thirteen compounds (<b>1</b>‒<b>13</b>) were isolated and identified during phytochemical analysis of the leaves and stem bark of <i>Guibourtia ehie</i> (A. Chev) J. Leonard. Spectroscopic and spectrometric methods and the comparison of their results with those given in the literature were used to ascertain their structures. Furthermore, the acetylation of 3,3′-di-<i>O</i>-methylellagic acid 4′-<i>O</i>-β-D-xylopyranoside (<b>2</b>) afforded a new derivative 3,3′-di-<i>O</i>-methylellagic acid 4′-<i>O</i>-β-D-(4,2′′,4′′-triacetyl)-xylopyranoside (<b>2a</b>). Extracts, fractions, and isolated compounds were assessed for their antioxidant, urease, and α-glucosidase inhibitory activities. Compound <b>1</b> demonstrated potent antioxidant activity in the DPPH with an IC₅₀ value of 36.4 ± 0.2 µM, while rhaponticin (<b>3</b>), 2,6-dimethoxybenzoquinone (<b>4</b>), and taraxerol (<b>6</b>) exhibited a strong α-glucosidase inhibitory activity with the IC₅₀ values of 35.5 ± 0.1, 25.5 ± 0.2 and 43.4 ± 0.3 µM, respectively. The present study enriches the chemistry of <i>Guiboutia ehie</i> and provides further evidence on its bioactive constituents, which might help in the development of hypoglycaemic drugs.

Malonic Acid-Type Fullerene Derivatives Strongly Inhibit The SARS-Cov-2 Main Protease

COVID-19 is a disease that is causing a global pandemic. There is an urgent need to develop new drugs to treat it. In this study, we evaluated the inhibitory activities of a series of fullerene derivatives against the main protease of SARS-CoV-2, the virus that causes COVID-19. As a result, it was found that the malonic acid-type fullerene derivatives showed strong inhibitory activities.

Bradyrhizobium japonicum FN1 produces an inhibitory substance that affects competition for nodule occupancy

Bacteriocins are narrow spectrum antibiotics of bacterial origin that can affect competition in resource-limited environments such as the rhizosphere. Therefore, bacteriocins may be good candidates for manipulation in order to generate more competitive inocula for soybean. In this study,<i> B. japonicum</i> FN1 along with other Bradyrhizobia in our culture collection were screened for bacteriocin-like activity. A total of five distinct inhibitory activities could be observed. FN1 genes putatively involved in bacteriocin production were computationally identified. These genes were mutagenized and the subsequent strains were screened for loss of inhibitory activity. Mutant strain BRJ-48, with an insert in<i> bjfn1_01204</i>, displayed a loss of the ability to inhibit an indicator strain. This loss could be complemented by the introduction of a plasmid expressing <i>bjfn1_01204 </i>in trans. The strain carrying the mutation did not affect competition in broth cultures, but was shown to be less competitive for nodule occupancy. Annotation suggests that <i>bjfn1_01204</i> encodes a carboxymuconolactone decarboxylase, however the direct contribution of how this enzyme contributes to inhibiting the tester strain remains unknown.