3D-QSAR Studies of 2-Arylbenzoxazoles as Novel Cholesteryl Ester Transfer Protein Inhibitors

Jahan B. Ghasemi,Mahnaz Ayati,Somayeh Pirhadi 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

The 3D-QSAR study of 2-arylbenzoxazoles as novel cholesteryl ester transfer protein inhibitors was performed by comparative molecular field analysis (CoMFA), CoMFA region focusing (CoMFA-RF) for optimizing the region for the final PLS analysis, and comparative molecular similarity indices analysis (CoMSIA) methods to determine the factors required for the activity of these compounds. The best orientation was searched by all-orientation search strategy using AOS, to minimize the effect of the initial orientation of the structures. The predictive ability of CoMFARF and CoMSIA were determined using a test set of twelve compounds giving predictive correlation coefficients of 0.886, and 0.754 respectively indicating good predictive power. Further, the robustness and sensitivity to chance correlation of the models were verified by bootstrapping and progressive scrambling analyses respectively. Based upon the information derived from CoMFA(RF) and CoMSIA, identified some key features that may be used to design new inhibitors for cholesteryl ester transfer protein.

Molecular Variation of Endosymbiotic Bacteria Wolbachia in Bemisia tabaci and Related Whiteflies

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll 경북대학교 농업생명과학대학 2012 Current Research on Agriculture and Life Sciences Vol.30 No.2

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.

Upregulation of probing‐ and feeding‐related behavioural frequencies in <i>Bemisia tabaci</i> upon acquisition of <i>Tomato yellow leaf curl virus</i>

Jahan, SM Hemayet,Lee, Gwan‐,Seok,Lee, Sukchan,Lee, Kyeong‐,Yeoll John Wiley Sons, Ltd 2014 Pest Management Science Vol.70 No.10

<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>The behaviour of insect vectors can be altered by the acquisition of plant viruses. <I>Bemisia tabaci</I>, which is the vector of <I>Tomato yellow leaf curl virus</I> (TYLCV), causes damage to susceptible tomato cultivars. Here, the frequencies of several behavioural characteristics related to probing and feeding that are exhibited by non‐viruliferous (NV) and TYLCV‐viruliferous (V) adult <I>B. tabaci</I> were compared using a sandwich‐type parafilm cage.</P><P><B>RESULTS</B></P><P>The frequencies of behaviours such as wing flapping, leg movement, body shaking and body position change while settling and feeding on plant leaves were higher in V than in NV whiteflies. Evaluation of probing frequencies by measuring the number and size of holes punctured in parafilm by whiteflies revealed that most holes had a diameter of 7.5–26.7 µm, which is within the range of proboscis diameters of whiteflies. There were more small‐sized holes than medium‐ and large‐sized holes. Male whiteflies produced more small‐sized holes, but females more mid‐sized holes. V whiteflies showed increased hole numbers but decreased feeding duration relative to NV whiteflies.</P><P><B>CONCLUSION</B></P><P>Adult <I>B. tabaci</I> showed higher frequencies of probing and feeding behaviours when infected with TYLCV. These manipulations of feeding behaviours of insect vectors may result in increased transmission of plant virus. © 2014 Society of Chemical Industry</P>

Censored Experiment for Average Run Length of General Control Chart

Jahan Lim,Sungim Lee 한국자료분석학회 2023 한국자료분석학회 학술대회자료집 Vol.2023 No.1

Acquisition of Tomato yellow leaf curl virus enhances attraction of Bemisia tabaci to green light emitting diodes

Jahan, S.M.H.,Lee, G.S.,Lee, S.,Lee, K.Y. 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol. No.

The light sensitivity of insects varies in response to different wavelengths of light. The change of light responses of vector insects plays an important role in the method of transmission and propagation of plant viruses. Here, we investigated whether the light attraction behaviors of whiteflies are altered by virus acquisition. Firstly, the light attraction rates of whiteflies were determined using LED light bulbs exhibiting different wavelengths in the visible and UV spectra. Whiteflies, Bemisia tabaci and Trialeurodes vaporariorum, were mostly attracted to green LEDs (526nm). The attraction rate to green LED light was higher in B. tabaci than in T. vaporariorum, whereas it did not significantly differ between the B- and Q-biotypes of B. tabaci. Secondly, we investigated whether or not the green light attraction behavior of B. tabaci is influenced by the acquisition of Tomato yellow leaf curl virus (TYLCV). The attraction rate to green LED light was 2.5-3 times higher in TYLCV-infected whiteflies than in TYLCV-free whiteflies. However, this difference disappeared when the distance from the light source was greater than 0.5m. Our results show that B. tabaci favors green light and its attraction is highly enhanced by the acquisition of the plant virus, TYLCV.

Molecular Variation of Endosymbiotic Bacteria Wolbachia in Bemisia tabaci and Related Whiteflies

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2012 慶北大農學誌 Vol.30 No.2

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.

Antimicrobial activity and toxicity of Quisqualis indica

Jahan, Fatima N.,Rahman, Mohammad S.,Hossain, Mahboob,Rashid, Mohammad A. Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.1

The plant Quisqualis indica (Compositae) has ehnopharmcological reputation of being used as a healing agent in Bangladesh. In this study, preliminary screenings were conducted to look at the antimicrobial susceptibility and cytotoxicity of the plant extract. The extractives of the plant were subjected to screening for inhibition of microbial growth by the disc diffusion method. The zones of inhibition demonstrated by the n-hexane, carbon tetrachloride, chloroform and aqueous soluble partitionates of the methanolic extract ranged from 8 - 15 mm, 8 - 18 mm, 12 - 20 mm and 10 - 16 mm, respectively at a concentration of 400 ${\mu}g$/disc. All the extractives were also subjected to brine shrimp lethality bioassay for primary cytotoxicity evaluation. Here, the carbon tetrachloride soluble materials demonstrated the highest cytotoxicity with $LC_{50}$ of 0.826 ${\mu}g$/ml, while n-hexane, chloroform and aqueous soluble partitionates of the methanolic extract revealed the $LC_{50}$ of 1.254, 3.866 and 5.366 ${\mu}g$/ml, respectively. This is the first report of the antimicrobial activity and cytotoxicity Q. indica.

Upregulation of Endosymbiont Densities in Bemisia tabaci by Acquisition of Tomato Yellow Leaf Curl Virus

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2012 慶北大農學誌 Vol.30 No.2

Sweetpotato whitefly, Bemisia tabaci, is a vector of more than 100 plant-diseased viruses, as well as a serious pest of various horticultural plants. This species harbors a primary endosymbiont Portiera along with several secondary endosymbionts such as Cardinium and Hamiltonella. We investigated whether or not TYLCV acquisition alters the densities of endosymbionts in the body of B. tabaci using quantitative real-time PCR. Our results showed that the densities of both Cardinium and Hamiltonella, but not Portiera, increased upon acquisition of TYLCV. In addition, expression of GroEL, a molecular chaperone produced by Hamiltonella, was significantly upregulated in TYLCV-infected whiteflies. Our results suggest that endosymbionts may play an important role in TYLCV transmission mechanism within the body of B. tabaci.

INTERANNUAL FLOW VARIABILITY IN THE SURMA RIVER, BANGLADESH: TELECONNECTION WITH SST AND PROSPECT FOR FLOOD FORECAST

JAHAN NASREEN,BHUIYAN M. ALI,ZOBEYER A.T.M. HASAN 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Analysis of Phosphatidylinositol 3,4,5-Trisphosphates of PTEN Expression on Mammalian Cells

Jahan, Nusrat,Park, Taeseong,Kim, Young Hwan,Lee, Dongsun,Kim, Hackyoung,Noh, Kwangmo,Kim, Young Jun Korean Society for Mass Spectrometry 2013 Mass spectrometry letters Vol.4 No.3

The goal of this study is to find an experimental condition which enables us to perform enzymatic studies on the cellular behavior of PTEN (phosphatase and tensine homolog) through identification of molecular species of phosphatidylinositol 3,4,5-trisphosphates and their quantitative analysis in a mammalian cell line using mass spectrometry. We initially exployed a two-step extraction process using HCl for extraction of phosphatidylinositol 3,4,5-trisphosphates from two mammalian cell lines and further analyzed the extracted phosphatidylinositol 3,4,5-trisphosphates using tandem mass spectrometry for the identification of them. We finally quantified the concentration of phosphatidylinositol 3,4,5-trisphosphates using internal standard calibration. From these observation, we found that HEK 293-T cells is a good model to examine the enzymatic behavior of PTEN in a cell, and the minimum amount of phosphatidylinositol 3,4,5-trisphosphates is more than 50 pmol for quantification in a mass spectrometer. These results suggest that the well-optimized experimental conditions are required for the investigation of the cellular PTEN in terms of the catalytic mechanism and further for the detailed identification of cellular substrates.