scholarly journals Dual Insecticidal Effects of Adenanthera pavonina Kunitz-Type Inhibitor on Plodia interpunctella is Mediated by Digestive Enzymes Inhibition and Chitin-Binding Properties

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4344 ◽  
Author(s):  
Caio Fernando Ramalho de Oliveira ◽  
Taylla Michelle de Oliveira Flores ◽  
Marlon Henrique Cardoso ◽  
Karen Garcia Nogueira Oshiro ◽  
Raphael Russi ◽  
...  

The Indianmeal moth, Plodia interpunctella, is one of the most damaging pests of stored products. We investigated the insecticidal properties of ApKTI, a Kunitz trypsin inhibitor from Adenanthera pavonina seeds, against P. interpunctella larvae through bioassays with artificial diet. ApKTI-fed larvae showed reduction of up to 88% on larval weight and 75% in survival. Trypsin enzymes extracted from P. interpunctella larvae were inhibited by ApKTI, which also demonstrated capacity to bind to chitin. Kinetic studies revealed a non-competitive inhibition mechanism of ApKTI for trypsin, which were further corroborated by molecular docking studies. Furthermore, we have demonstrated that ApKTI exhibits a hydrophobic pocket near the reactive site loop probably involved in chitin interactions. Taken together, these data suggested that the insecticidal activity of ApKTI for P. interpunctella larvae involves a dual and promiscuous mechanisms biding to two completely different targets. Both processes might impair the P. interpunctella larval digestive process, leading to larvae death before reaching the pupal stage. Further studies are encouraged using ApKTI as a biotechnological tool to control insect pests in field conditions.

2021 ◽  
Vol 17 ◽  
pp. 2260-2269
Author(s):  
Luiz Claudio Ferreira Pimentel ◽  
Lucas Villas Boas Hoelz ◽  
Henayle Fernandes Canzian ◽  
Frederico Silva Castelo Branco ◽  
Andressa Paula de Oliveira ◽  
...  

The enzyme tyrosine kinase BCR-Abl-1 is the main molecular target in the treatment of chronic myeloid leukemia and can be competitively inhibited by tyrosine kinase inhibitors such as imatinib. New potential competitive inhibitors were synthesized using the (phenylamino)pyrimidine-pyridine (PAPP) group as a pharmacophoric fragment, and these compounds were biologically evaluated. The synthesis of twelve new compounds was performed in three steps and assisted by microwave irradiation in a 1,3-dipolar cycloaddition to obtain 1,2,3-triazole derivatives substituted on carbon C-4 of the triazole nucleus. All compounds were evaluated for their inhibitory activities against a chronic myeloid leukemia cell line (K562) that expresses the enzyme tyrosine kinase BCR-Abl-1 and against healthy cells (WSS-1) to observe their selectivity. Three compounds showed promising results, with IC50 values between 1.0 and 7.3 μM, and were subjected to molecular docking studies. The results suggest that such compounds can interact at the same binding site as imatinib, probably sharing a competitive inhibition mechanism. One compound showed the greatest interaction affinity for BCR-Abl-1 in the docking studies.


2021 ◽  
Author(s):  
Luiz Claudio Ferreira Pimentel ◽  
Lucas Villas Boas Hoelz ◽  
Henayle Fernandes Canzian ◽  
Frederico Silva Castelo Branco ◽  
Andressa Paula de Oliveira ◽  
...  

The enzyme tyrosine kinase Bcr-Abl-1 is the main molecular target in the treatment of chronic myeloid leukemia and can be competitively inhibited by tyrosine kinase inhibitors such as imatinib. New potential competitive inhibitors were synthesized using the phenylamino pyrimidine pyridine (PAPP) group as a pharmacophoric fragment, and these compounds were biologically evaluated. The synthesis of the twelve new compounds was performed in three steps and assisted by microwave irradiation in a 1,3-dipolar cycloaddition to obtain 1,2,3-triazole derivatives substituted on carbon C-4 of the triazole nucleus. All of them had their inhibitory activities evaluated against a chronic myeloid leukemia cell line (K562) that expresses the enzyme tyrosine kinase Bcr-Abl-1 and against healthy cells (WSS-1) to observe their selectivity. Three compounds had promising results, showing an IC50 between 1.0 and 7.3 mM, and were subjected to molecular docking studies. This result suggests that such compounds can interact at the same binding site as imatinib, probably sharing a competitive inhibition mechanism. One of them showed the greatest interaction affinity for Bcr-Abl-1 in the docking studies.


2020 ◽  
Vol 16 (2) ◽  
pp. 155-161
Author(s):  
Ebrahim S. Moghadam ◽  
Mohammad A. Faramarzi ◽  
Somayeh Imanparast ◽  
Mohsen Amini

Background: Diabetes mellitus (DM) is an important global health problem especially in developed countries and insufficient lifestyle induces this phenomenon. Finding efficient treatment for DM is an interesting goal for researchers. Objective: Herein we tried to design and synthesize a series of quinazoline derivatives and investigate their bioactivity as possible α-Glucosidase inhibitor agents. Method: Compounds 1-14 were synthesized using a multicomponent reaction. 1HNMR, 13C NMR, MS, and IR spectroscopy were used for the characterization of synthesized compounds. α- Glucosidase inhibitory activity of compounds 1-14 was evaluated using p-nitrophenyl‐α‐Dglucopyranoside (pNPG) as a substrate of the α-glucosidase enzyme (EC3.2.1.20, Saccharomyces cerevisiae). The mechanism of inhibition of the α-glucosidase enzyme was investigated using kinetic studies. Molecular docking was also done using autodock software to find the possible mode of interaction of compound 8 and the enzyme active site. Results: Most of the tested compounds showed higher activity in inhibition of the enzyme in comparison to the standard, acarbose. Compound 8 exerted the best activity with the IC50 value of 291.5 μM. A kinetic study indicated a competitive inhibition of the α-glucosidase enzyme by compound 8. Finally, docking studies showed the interactions between compound 8 and enzyme active site residues. Conclusion: 2,4-Diarylquinazoline scaffold has good antidiabetic activity, so it is interesting to synthesize more 2,4-diarylquinazoline derivatives and evaluate their antidiabetic activities.


2021 ◽  
Vol 22 (12) ◽  
pp. 6192
Author(s):  
Patrícia Correia ◽  
Hélder Oliveira ◽  
Paula Araújo ◽  
Natércia F. Brás ◽  
Ana Rita Pereira ◽  
...  

Tyrosinase is the central enzyme involved in the highly complex process of melanin formation, catalyzing the rate-limiting steps of this biosynthetic pathway. Due to such a preponderant role, it has become a major target in the treatment of undesired skin pigmentation conditions and also in the prevention of enzymatic food browning. Numerous phenolic-based structures from natural sources have been pointed out as potential tyrosinase inhibitors, including anthocyanins. The aim of the present study was to individually assess the tyrosinase inhibitory activity of eight purified compounds with a variable degree of structural complexity: native anthocyanins, deoxyanthocyanins, and pyranoanthocyanins. The latter two, the groups of anthocyanin-related compounds with enhanced stability, were tested for the first time. Compounds 1 to 4 (luteolinidin, deoxymalvidin, cyanidin-, and malvidin-3-O-glucoside) revealed to be the most effective inhibitors, and further kinetic studies suggested their inhibition mechanism to be of a competitive nature. Structure–activity relationships were proposed based on molecular docking studies conducted with mushroom tyrosinase (mTYR) and human tyrosinase-related protein 1 (hTYRP1) crystal structures, providing information about the binding affinity and the different types of interactions established with the enzyme’s active center which corroborated the findings of the inhibition and kinetic studies. Overall, these results support the applicability of these compounds as pigmentation modulators.


2020 ◽  
Vol 16 (2) ◽  
pp. 135-144
Author(s):  
Ravneet K. Grewal ◽  
Baldeep Kaur ◽  
Gagandeep Kaur

Background: Amylases are the most widely used biocatalysts in starch saccharification and detergent industries. However, commercially available amylases have few limitations viz. limited activity at low or high pH and Ca2+ dependency. Objective: The quest for exploiting amylase for diverse applications to improve the industrial processes in terms of efficiency and feasibility led us to investigate the kinetics of amylase in the presence of metal ions as a function of pH. Methods: The crude extract from soil fungal isolate cultures is subjected to salt precipitation, dialysis and DEAE cellulose chromatography followed by amylase extraction and is incubated with divalent metal ions (i.e., Ca2+, Fe2+, Cu2+, and Hg2+); Michaelis-Menton constant (Km), and maximum reaction velocity (Vmax) are calculated by plotting the activity data obtained in the absence and presence of ions, as a function of substrate concentration in Lineweaver-Burk Plot. Results: Kinetic studies reveal that amylase is inhibited un-competitively at 5mM Cu2+ at pH 4.5 and 7.5, but non-competitively at pH 9.5. Non-competitive inhibition of amylase catalyzed starch hydrolysis is observed with 5mM Hg2+ at pH 9.5, which changes to mixed inhibition at pH 4.5 and 7.5. At pH 4.5, Ca2+ induces K- and V-type activation of amylase catalyzed starch hydrolysis; however, the enzyme has V-type activation at 7mM Ca2+ under alkaline conditions. Also, K- and V-type of activation of amylase is observed in the presence of 7mM Fe2+ at pH 4.5 and 9.5. Conclusion: These findings suggest that divalent ions modulation of amylase is pH dependent. Furthermore, a time-saving and cost-effective solution is proposed to overcome the challenges of the existing methodology of starch hydrolysis in starch and detergent industries.


Insects ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Md Munir Mostafiz ◽  
Errol Hassan ◽  
Rajendra Acharya ◽  
Jae-Kyoung Shim ◽  
Kyeong-Yeoll Lee

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.


Bee World ◽  
1983 ◽  
Vol 64 (4) ◽  
pp. 163-168 ◽  
Author(s):  
J. B. Free ◽  
A. W. Ferguson ◽  
Susan Winfield

A survey was conducted to investigate rice storage practices at the farmer’s level and the prevalence of insects’ status through a pretested questionnaire in Mymensingh and Jashore districts, Bangladesh. For seed purposes, large, medium, and small farmers store about 40, 10, and 5 kg, respectively in the Aman season for 7 months whereas in the Boro season large and medium farmers keep about 80 and 20 kg for 5 months. Average storage time was the highest (7 months) for Boro and Aman rice by large and small farmers, respectively for consumption. Eleven storage items namely, Dole, Motka, Tin, Plastic Drum, Gunny Bag, Bamboo Gola, Dhari, Bamboo Auri, Berh, Steel Drum, and Plastic Bag were found. About 57 and 74% of farmers stored rice, among them 47 and 58% used traditional Dole in Jashore and Mymensingh, respectively. Tin and Berh (1%) were the least used storage structures. About 11 and 17%; 3 and 4% of farmers used neem leaf and chemicals especially phostoxin in storage as an insect repellent in these areas, respectively. The use of Plastic Bags increased sharply due to lightweight, availability, and low price, whereas Bamboo Gola, Berh, Motka users decreased remarkably. Relative abundance of the insect species was: Rice Moth Sitotroga cerealla, Rice Weevil Sitophilus oryzae, Red Flour Beetle Tribolium castoreum, and Lesser Meal Worm Alphitobious diaperinus. Maximum insect infestation was found in stored paddy in Dole followed by Motka, and Plastic Bag; and the least amount was observed in Plastic Drum in both regions. Three fourth of the respondents took no measures to control insect pests in stored rice.


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