Structure-Activity Relationship of Insecticidal Steroids. X. Androstane and Pregnane Derivatives

The androstane and pregnane steroids 1-10 were verified to have insecticidal activity for larvae of the Colorado beetle Leptinotarsa decemlineata. Insect growth and development regulators were found among these compounds.     

有机物对蝴蝶幼虫麻醉活性与结构参数的关系

应用量子化学HF/3-21G从头算法得到了20种有机分子的优势构象,利用HF/3-21G和分子图形学技术获得其电子结构参数和几何结构参数,并将这些参数与有机物对蝴蝶幼虫的麻醉活性相关联.结果表明,有机物麻醉活性与分子的范德华体积、分子最低空轨道能和分子偶极矩之间存在良好的多元线性相关性,成功地建立有机物对蝴蝶幼虫麻醉活性的构效关系式.     

温度和pH对不同日龄蓝点马鲛鱼仔鱼消化酶活性的影响

用生化方法研究温度和p H对蓝点马鲛鱼仔鱼蛋白酶和淀粉酶活力的影响.结果表明:随着p H值的升高,蓝点马鲛鱼仔鱼的蛋白酶先升高后下降,淀粉酶先升高后下降.其中,1日龄仔鱼蛋白酶最适p H值为8,7日龄和15日龄的蛋白酶最适p H值为2;1日龄的淀粉酶最适p H值为7,7日龄的淀粉酶最适p H值为7~7.5,15日龄的淀粉酶最适p H值为7.5.随着温度升高,蓝点马鲛鱼仔鱼的蛋白酶先升高后下降,淀粉酶随温度先升高后下降.其中,1日龄和7日龄仔鱼的蛋白酶最适温度为37℃,15日龄的蛋白酶最适温度为42℃;1日龄的淀粉酶最适温度为42℃,7日龄的淀粉酶最适温度为37~42℃,15日龄的淀粉酶最适温度为42℃.     

Antifeedant effects of mixed methylphenyl hexaorganoditin compounds of the type PhnMe6–nSnSn on larvae of Spodoptera littoralis and Epilachna varivestis

Compounds of the series Ph_nMe_6–nSn₂ were prepared and tested for their antifeedant effects against Spodoptera littoralis (Boisduval) and Epilachna varivestis (Mulsant) larvae. In addition, phytotoxicity towards bean seedlings was measured. The most active compound against both Spodoptera and Epilachna was Ph₃Me₃Sn₂. The compound at 50 mg dm^?3 was comparatively innocuous in phytotoxicity tests against bean seedlings.     

Luminaolide, a novel metamorphosis-enhancing macrodiolide for scleractinian coral larvae from crustose coralline algae

A new metamorphosis-enhancing macrodiolide, luminaolide (1), was isolated from the crustose coralline algae (CCA) Hydrolithonreinboldii. Its structure was determined by spectroscopic analysis. A fraction (1.30 μg/mL) eluted with 80% aqueous MeOH by ODS gel column chromatography of the same CCA extract induced larval metamorphosis (25.9 ± 7.4%) against Leptastrea purpurea, and its metamorphosis-inducing activity was further enhanced to 92.6 ± 2.9% with the addition of 1 (25.6 ng/mL).     

鱼类的非特异性免疫调节

介绍了鱼类的非特异性免疫器官及其免疫机制,通过免疫刺激剂可提高鱼类的非特异性免疫力,在仔鱼的特异性免疫器官尚未发育之前,仔鱼对外界病原微生物的抵抗力主要依靠来自母体的抗体和自身的非特异性免疫力,例举免疫刺激剂对提高仔鱼存活率的实验,并探讨了该方法在苗种生产中的应用前景。     

The Extracts of Polygonum cuspidatum Root and Rhizome Block the Entry of SARS-CoV-2 Wild-Type and Omicron Pseudotyped Viruses via Inhibition of the S-Protein and 3CL Protease

COVID-19, resulting from infection by the SARS-CoV-2 virus, caused a contagious pandemic. Even with the current vaccines, there is still an urgent need to develop effective pharmacological treatments against this deadly disease. Here, we show that the water and ethanol extracts of the root and rhizome of Polygonum cuspidatum (Polygoni Cuspidati Rhizoma et Radix), a common Chinese herbal medicine, blocked the entry of wild-type and the omicron variant of the SARS-CoV-2 pseudotyped virus into fibroblasts or zebrafish larvae, with IC₅₀ values ranging from 0.015 to 0.04 mg/mL. The extracts were shown to inhibit various aspects of the pseudovirus entry, including the interaction between the spike protein (S-protein) and the angiotensin-converting enzyme II (ACE2) receptor, and the 3CL protease activity. Out of the chemical compounds tested in this report, gallic acid, a phytochemical in P. cuspidatum, was shown to have a significant anti-viral effect. Therefore, this might be responsible, at least in part, for the anti-viral efficacy of the herbal extract. Together, our data suggest that the extracts of P. cuspidatum inhibit the entry of wild-type and the omicron variant of SARS-CoV-2, and so they could be considered as potent treatments against COVID-19.     

An analysis of bivalve larval shell pigments using micro‐Raman spectroscopy

Micro‐Raman spectroscopy has been used on adult bivalve shells to investigate organic and inorganic shell components but has not yet been applied to bivalve larvae. It is known that the organic matrix of larval shells contains pigments, but less is known about the presence or source of these molecules in larvae. We investigated Raman spectra of seven species of bivalve larvae to assess the types of pigments present in shells of each species and how the ratio of inorganic : organic material changes in a dorso‐ventral direction. In laboratory experiments, we reared larvae of three clam species in waters containing different organic signatures to determine if larvae incorporated compounds from source waters into their shells. We found differences in spectra and pigments between most species but found less intraspecific differences. A neural network classifier for Raman spectra classified five out of seven species with greater than 85% accuracy. There were slight differences between the amount and type of pigment present along the shell, with the prodissoconch I and shell margin areas being the most variable. Raman spectra of 1‐day‐old larvae were found to be differentiable when larvae were reared in waters with different organic signatures. With micro‐Raman spectroscopy, it may be possible to identify some unknown species in the wild and trace their natal origins, which could enhance identification accuracy of bivalve larvae and ultimately aid management and restoration efforts. Copyright © 2014 John Wiley & Sons, Ltd.     

Optimizing and assessing the performance of an algorithm that cross-correlates acquired acoustic emissions from internally feeding larvae to count infested wheat kernels in grain samples

An algorithm was developed with optimizable parameters to match sounds from individual insects in grain by cross-correlating signals from an acoustic sensor array. The algorithm was optimized in a series of trials conducted in the sample chamber of an Acoustic Location ‘Fingerprinting’ Insect Detector (ALFID). The sample chamber was filled with uninfested wheat, except for a single kernel, which was infested with an immature rice weevil. This kernel was placed at a known location in the sample chamber. With analysis parameters optimized, the algorithm successfully detected the single insect in 100% of the trials. The algorithm's capability to count multiple insects was assessed by combining signals in data files collected from single insects into a set that represented sounds from a pair of insects. In these analyses, the algorithm correctly detected the two insects in 100% of combinations three sensor spacings apart, 100% of combinations two sensor spacings apart, and 70% of combinations one sensor spacing apart. Based on these results and the dimensions of the ALFID sampling chamber, the algorithm has a 90% probability of identifying two randomly located insects producing sounds in a wheat sample.