Two New Bibenzyl Glucosides from Dendrobium chrysotoxum

Fa-Wu Dong,Huai-Rong Luo,Qin-Li Wan,Feng-Qing Xu,Weiwei Fan,Kai-Jin Wang,Ning Li,Jiang-Miao Hu 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

Two new bibenzyl glucosides, 3,3',4',5-tetramethoxybibenzyl-4-O-β-D-glucopyranoside (1) and 3,4,4',5- tetramethoxybibenzyl-3'-O-β-D-glucopyranoside (2), together with five known ones, chrysotobibenzyl (3), erianin (4), chrysotoxine (5), gigantol (6) and tristin (7) were isolated from the stems of Dendrobium chrysotoxum. The structures of those compounds were elucidated by extensive spectroscopic analysis. Moreover, compounds 1-7 were assessed for inhibitory activity of two enzymes-AChE (acetylcholine esterase) and BChE (butyrylcholine esterase).

Two New Bibenzyl Glucosides from Dendrobium chrysotoxum

Dong, Fa-Wu,Luo, Huai-Rong,Wan, Qin-Li,Xu, Feng-Qing,Fan, Wei-Wei,Wang, Kai-Jin,Li, Ning,Hu, Jiang-Miao Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

Two new bibenzyl glucosides, 3,3',4',5-tetramethoxybibenzyl-4-O-${\beta}$-D-glucopyranoside (1) and 3,4,4',5-tetramethoxybibenzyl-3'-O-${\beta}$-D-glucopyranoside (2), together with five known ones, chrysotobibenzyl (3), erianin (4), chrysotoxine (5), gigantol (6) and tristin (7) were isolated from the stems of Dendrobium chrysotoxum. The structures of those compounds were elucidated by extensive spectroscopic analysis. Moreover, compounds 1-7 were assessed for inhibitory activity of two enzymes-AChE (acetylcholine esterase) and BChE (butyrylcholine esterase).

Diabetes Mellitus Increases the Risk of Bladder Cancer: An Updated Meta-analysis

Yang, Xiao-Qing,Xu, Chen,Sun, Yan,Han, Rui-Fa Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Purpose: Studies have indicated that diabetes mellitus (DM) is a risk factor for bladder cancer; however, not all evidence supports this conclusion. The aim of this meta-analysis was to collate and evaluate all primary observational studies investigating the risk of bladder cancer associated with DM. Methods: The PubMed and Google Scholar databases were searched to identify studies that estimated the association of DM and bladder cancer. Summary effect estimates were derived using a random-effects meta-analysis model. Results: A total of 23 studies (8 case-control studies, 15 cohort studies) including 643,683 DM and 4,819,656 non-DM cases were identified. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer compared with non-DM overall (OR=1.68, 95% CI 1.32-2.13). Analysis of subgroups demonstrated this to be the case in both case-control studies (OR=1.59, 95% CI 1.28-1.97, $I^2$=58%) and cohort studies (RR=1.70, 95% CI 1.23-2.33, $I^2$=96%). There was no gender difference in DM-associated bladder cancer risk. Bladder cancer risk was increased in Asia and the North America region, but not in Europe. Furthermore, DM-associated bladder cancer risk was obviously higher in Asia than North America and Europe or in those with Caucasian ethnicity. With extension of follow-up time, the bladder cancer risk was not increased for the patients with DM. Conclusions: This meta-analysis provided further evidence supporting theDM association with a significantly higher risk of bladder cancer obtained from observational studies.

ACOS5 is Required for Primexine Formation and Exine Pattern Formation During Microsporogenesis in Arabidopsis

Hui-hui Xie,Lin Chen,Fa-qing Xu,Wan-sheng Guo,Shui Wang,Zhong-Nan Yang,Sen Zhang 한국식물학회 2017 Journal of Plant Biology Vol.60 No.4

Pollen exine, mainly composed of sporopollenin,plays important roles during microspore development. It hasbeen reported that Acyl-CoA Synthetase5 (ACOS5) is requiredfor sporopollenin biosynthesis in Arabidopsis. Here we showthat ACOS5 is essential for primexine formation duringArabidopsis microspore development. Through genetic screen,we identified a point mutation of ACOS5 allele, acos5-2,showing abnormal microspore development. Its microsporeswere degenerated and aborted after released from the tetrads. Transmission electron microscopy showed that primexineformation was reduced in acos5-2 mutant as compared tothat of the wild-type. Consequently, sporopollenin wasaggregated and randomly deposited on the microspores. Insitu hybridization indicated that the key regulators of tapetumdevelopment, DYT1 and TDF1, are required for the expressionof ACOS5 in tapetum. Furthermore, the GUS reporter showedthat the 593-bp promoter sequence was sufficient for theexpression of ACOS5 in the anther. Our data provide evidencethat ACOS5 is required for primexine formation andsporopollenin deposition during microspore development.

Screening and Anti-virulent Study of N-Acyl Homoserine Lactones DNA Aptamers against Pseudomonas aeruginosa Quorum Sensing

Zu-Guo Zhao,Yun Mei Yu,Bi Yu Xu,Shuang-Shuang Yan,Jun-Fa Xu,Fang Liu,Guo-Ming Li,Yuan Lin Ding,Shu Qing Wu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

In Pseudomonas aeruginosa, a quorum sensing (QS) system regulates the expression of many virulence factors. N-acyl homoserine lactone (HSL) is the signal molecule of QS system. In order to find a novel HSL binder to interfere with QS signaling and to attenuate P. aeruginosa virulence, an amino lactam surrogate (ALS) of HSL was used as a target to screen HSL aptamers with the technique of systematic evolution of ligands by exponential enrichment (SELEX). Eight HSL aptamers with high affinities for 3O-C12-HSL (20 nM ≤ Kd < 35 nM) or C4-HSL (25 nM < Kd < 50 nM) were finally obtained. In vitro QS-inhibiting study of P. aeruginosa showed that HSL aptamers could inhibit virulence in a dose-dependent manner. ALSap-8 which bound C4-HSL primarily acted on the rhl system and inhibited the secretion of pyocyanin. ALSap-5 which bound 3O-C12-HSL not only showed strong inhibitory activity on biofilm formation as well as secretions of LasA protease and LasB elastase, but also reduced pyocyanin secretion. Since the las system is capable of activating the rhl system mildly, we speculated that ALSap-5 can simultaneously interfere with the las and rhl systems. High-affinity aptamers against HSL in this study are novel QS and virulence-inhibitors, and may have potential as drug candidates for the treatment of P. aeruginosa infection.

Epidemiological Investigation of Asymptomatic Dogs with Leishmania Infection in Southwestern China Where Visceral Leishmaniasis is Intractable

Gui-Hua Zhao,Kun Yin,Wei-Xia Zhong,Ting Xiao,Qing-Kuan Wei,Yong Cui,Gong-Zhen Liu,Chao Xu,Hong-Fa Wang 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.6

Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.

An Aqueous Extract of Yunnan Baiyao Inhibits the Quorum-Sensing-Related Virulence of Pseudomonas aeruginosa

Zu-Guo Zhao,Shuang-Shuang Yan,Yun-Mei Yu,Na Mi,La-Xi Zhang,Jun Liu,Xiao-Ling Li,Fang Liu,Jun-Fa Xu,Wei-Qing Yang,Guo-Ming Li 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

Yunnan Baiyao is a famous Chinese medicine that has long been directly applied to wounds to reduce bleeding, pain, and swelling without causing infection. However, little is known about its ability to prevent infection. The present study aimed to assess in vitro the anti-virulence activity of an aqueous extract of Yunnan Baiyao (YBX) using Pseudomonas aeruginosa as a pathogenic model. We found that a sub-MIC (2.5 mg/ml) of YBX can efficiently interfere with the quorum-sensing (QS) signaling circuit. Real-time polymerase chain reaction analysis showed that a sub-MIC of YBX downregulated the transcriptions of lasR, lasI, rhlR, and rhlI,which resulted in global attenuation of QS-regulated virulence activities, such as biofilm formation, and secretion of LasA protease, LasB elastase and pyocyanin. Further, YBX reduced the motility of P. aeruginosa related to QS, and impaired the formation of biofilms. These results suggest that YBX may possess global inhibitory activity against the virulence of P. aeruginosa and that YBX may also exhibit antimicrobial activity in vivo. The present study suggests that Yunnan Baiyao represents a potential source for isolating novel, safe, and efficacious antimicrobial agents.