1.Environmental contamination status of norovirus outbreaks in schools and nurseries in Linhai City
ZHENG Jianjun, WANG Xi,HONG Danyang, LI Yaling, XU Qiumeng, ZHANG Huili, HAN Qian, LU Da, ZHENG Qiao
Chinese Journal of School Health 2025;46(4):601-603
Objective:
To investigate the environmental contamination of norovirus in nurseries and primary/secondary schools, so as to provide a scientific basis for effective prevention and control measures.
Methods:
A total of 483 external environmental samples were collected from 34 cluster outbreaks of norovirus gastroenteritis in kindergartens and primary/secondary schools in Linhai City from 2021 to 2024. Pathogen detection was conducted using a rapid nucleic acid extraction kit and realtime fluorescence RT-PCR, and the results were analyzed using the χ2 test or Fishers exact test.
Results:
Among the collected external environmental samples, the total positive rate of surface contamination was 13.66%. The positive rates in kindergartens and primary/secondary schools were 12.20% and 15.82%, respectively. In kindergartens, the five surfaces with the highest detection rates were desks/chairs (23.33%), toilet stool troughs (20.69%), urinal troughs (12.00%), washbasins/sinks (11.11%), and toilet mops (9.38%). In primary/secondary schools, the top five were toilet stool troughs (38.30%), urinal troughs (23.53%), toilet door handles (13.04%), toilet mops (12.50%), and drinking cups (11.11%). The difference in positive detection rates among different external environments in primary/secondary schools was statistically significant (Fishers exact probability test, P<0.01). The positive detection rate in sanitary toilets was higher than that in classroom environments (χ2=17.38), while the positive detection rate in classroom environments of kindergartens was higher than that in primary/secondary schools (χ2=5.42)(P<0.05).
Conclusions
Norovirus exhibits a high contamination rate in nurseries and schools, particularly in restroom areas. Strengthening sanitation and disinfection in highrisk environments, and improving hygiene awareness among children and staff, are essential for the effective prevent and control of norovirus.
2.Endovascular Treatment for Acute Posterior Circulation Tandem Lesions: Insights From the BASILAR and PERSIST Registries
Wei LI ; Mohamed F. DOHEIM ; Zhongming QIU ; Tan WANG ; Zhibin CHEN ; Wenjie ZI ; Qingwu YANG ; Haitao GUAN ; Hongyu QIAO ; Wenhua LIU ; Wei HU ; Xinfeng LIU ; Jinbo HUANG ; Zhongkui HAN ; Zhonglun CHEN ; Zhenqiang ZHAO ; Wen SUN ; Raul G. NOGUEIRA
Journal of Stroke 2025;27(1):75-84
Background:
and Purpose Limited evidence exists on the effectiveness of endovascular treatment (EVT) for acute posterior circulation tandem lesion (PCTL). This study aimed to explore the role of extracranial vertebral artery (VA) stenting in patients with PCTL stroke undergoing EVT.
Methods:
Individual patient data were pooled from the BASILAR (EVT for Acute Basilar Artery Occlusion Study) and PERSIST (Posterior Circulation Ischemic Stroke) registries. Patients with PCTLs who underwent EVT were included in the present cohort and divided into the stenting and nonstenting groups based on the placement of extracranial VA stents. The primary efficacy outcome was the modified Rankin Scale (mRS) scores at 90 days and 1 year. Safety outcomes included 24-hour symptomatic intracranial hemorrhage (sICH) and all-cause mortality at 90 days and 1 year post-surgery.
Results:
A combined dataset of 1,320 patients with posterior circulation artery occlusion, including 263 (19.9%) with tandem lesions, of whom 217 (median age, 65 years; 82.9% male) met the inclusion criteria for the analysis. The stenting group had 84 (38.7%) patients, while the non-stenting group had 133 (61.3%). After adjustment for the potential confounders, extracranial VA stenting was associated with favorable shifts in mRS scores at both 90 days (adjusted common odds ratio [OR], 2.30; 95% confidence interval [CI], 1.23–4.28; P<0.01) and 1 year (adjusted OR [aOR], 2.04; 95% CI [1.05–3.97]; P=0.04), along with lower rate of mortality at both 90 days (aOR, 0.45; 95% CI [0.21–0.93]; P=0.01) and 1 year (aOR, 0.36; 95% CI [0.16–0.79]; P=0.01), with no significant difference in sICH incidence (aOR, 0.35; 95% CI [0.06–1.98]; P=0.24).
Conclusion
Extracranial VA stenting during EVT may improve functional outcomes and reduce mortality in patients with PCTL strokes.
3.Endovascular Treatment for Acute Posterior Circulation Tandem Lesions: Insights From the BASILAR and PERSIST Registries
Wei LI ; Mohamed F. DOHEIM ; Zhongming QIU ; Tan WANG ; Zhibin CHEN ; Wenjie ZI ; Qingwu YANG ; Haitao GUAN ; Hongyu QIAO ; Wenhua LIU ; Wei HU ; Xinfeng LIU ; Jinbo HUANG ; Zhongkui HAN ; Zhonglun CHEN ; Zhenqiang ZHAO ; Wen SUN ; Raul G. NOGUEIRA
Journal of Stroke 2025;27(1):75-84
Background:
and Purpose Limited evidence exists on the effectiveness of endovascular treatment (EVT) for acute posterior circulation tandem lesion (PCTL). This study aimed to explore the role of extracranial vertebral artery (VA) stenting in patients with PCTL stroke undergoing EVT.
Methods:
Individual patient data were pooled from the BASILAR (EVT for Acute Basilar Artery Occlusion Study) and PERSIST (Posterior Circulation Ischemic Stroke) registries. Patients with PCTLs who underwent EVT were included in the present cohort and divided into the stenting and nonstenting groups based on the placement of extracranial VA stents. The primary efficacy outcome was the modified Rankin Scale (mRS) scores at 90 days and 1 year. Safety outcomes included 24-hour symptomatic intracranial hemorrhage (sICH) and all-cause mortality at 90 days and 1 year post-surgery.
Results:
A combined dataset of 1,320 patients with posterior circulation artery occlusion, including 263 (19.9%) with tandem lesions, of whom 217 (median age, 65 years; 82.9% male) met the inclusion criteria for the analysis. The stenting group had 84 (38.7%) patients, while the non-stenting group had 133 (61.3%). After adjustment for the potential confounders, extracranial VA stenting was associated with favorable shifts in mRS scores at both 90 days (adjusted common odds ratio [OR], 2.30; 95% confidence interval [CI], 1.23–4.28; P<0.01) and 1 year (adjusted OR [aOR], 2.04; 95% CI [1.05–3.97]; P=0.04), along with lower rate of mortality at both 90 days (aOR, 0.45; 95% CI [0.21–0.93]; P=0.01) and 1 year (aOR, 0.36; 95% CI [0.16–0.79]; P=0.01), with no significant difference in sICH incidence (aOR, 0.35; 95% CI [0.06–1.98]; P=0.24).
Conclusion
Extracranial VA stenting during EVT may improve functional outcomes and reduce mortality in patients with PCTL strokes.
4.Endovascular Treatment for Acute Posterior Circulation Tandem Lesions: Insights From the BASILAR and PERSIST Registries
Wei LI ; Mohamed F. DOHEIM ; Zhongming QIU ; Tan WANG ; Zhibin CHEN ; Wenjie ZI ; Qingwu YANG ; Haitao GUAN ; Hongyu QIAO ; Wenhua LIU ; Wei HU ; Xinfeng LIU ; Jinbo HUANG ; Zhongkui HAN ; Zhonglun CHEN ; Zhenqiang ZHAO ; Wen SUN ; Raul G. NOGUEIRA
Journal of Stroke 2025;27(1):75-84
Background:
and Purpose Limited evidence exists on the effectiveness of endovascular treatment (EVT) for acute posterior circulation tandem lesion (PCTL). This study aimed to explore the role of extracranial vertebral artery (VA) stenting in patients with PCTL stroke undergoing EVT.
Methods:
Individual patient data were pooled from the BASILAR (EVT for Acute Basilar Artery Occlusion Study) and PERSIST (Posterior Circulation Ischemic Stroke) registries. Patients with PCTLs who underwent EVT were included in the present cohort and divided into the stenting and nonstenting groups based on the placement of extracranial VA stents. The primary efficacy outcome was the modified Rankin Scale (mRS) scores at 90 days and 1 year. Safety outcomes included 24-hour symptomatic intracranial hemorrhage (sICH) and all-cause mortality at 90 days and 1 year post-surgery.
Results:
A combined dataset of 1,320 patients with posterior circulation artery occlusion, including 263 (19.9%) with tandem lesions, of whom 217 (median age, 65 years; 82.9% male) met the inclusion criteria for the analysis. The stenting group had 84 (38.7%) patients, while the non-stenting group had 133 (61.3%). After adjustment for the potential confounders, extracranial VA stenting was associated with favorable shifts in mRS scores at both 90 days (adjusted common odds ratio [OR], 2.30; 95% confidence interval [CI], 1.23–4.28; P<0.01) and 1 year (adjusted OR [aOR], 2.04; 95% CI [1.05–3.97]; P=0.04), along with lower rate of mortality at both 90 days (aOR, 0.45; 95% CI [0.21–0.93]; P=0.01) and 1 year (aOR, 0.36; 95% CI [0.16–0.79]; P=0.01), with no significant difference in sICH incidence (aOR, 0.35; 95% CI [0.06–1.98]; P=0.24).
Conclusion
Extracranial VA stenting during EVT may improve functional outcomes and reduce mortality in patients with PCTL strokes.
5.Effects of Xiaozhong Zhitong Mixture (消肿止痛合剂) on Angiogenesis and the Dll4/Notch1 Signaling Pathway in Wound Tissue of Diabetic Foot Ulcer Model Rats
Xiao HAN ; Tao LIU ; Yuan SONG ; Jie CHEN ; Jiaxuan SHEN ; Jing QIAO ; Hengjie WANG ; Lewen WU ; Yazhou ZHAO
Journal of Traditional Chinese Medicine 2025;66(16):1695-1703
ObjectiveTo investigate the potential machanism of Xiaozhong Zhitong Mixture (消肿止痛合剂, XZM) in the treatment of diabetes foot ulcer (DFU). MethodsFifty SD rats were randomly divided into blank group, model group, XZM group, inhibitor group, XZM plus inhibitor group (combination group), with 10 rats in each group. Except for the blank group, rats were fed with high-sugar, high-fat, high-cholesterol diet, intraperitoneally injected with streptozotocin, and subjected to skin defect to establish DFU model. After successful modeling, the XZM group and the combination group were given 1 ml/(100 g·d)of XZM by gavage, while the blank group, model group, and inhibitor group were all given an equal volume of 0.9% sodium chloride injection by gavage. Thirty minutes later, the inhibitor group and the combination group were intraperitoneally injected with 5 mg/(kg·d) of Notch1 inhibitor DAPT. All groups were treated once a day. After 14 days of administration, the skin tissue from the dorsal foot of the blank group rats and wound tissue from the other groups were collected. The pathological changes of granulation tissue in the wound were detected using hematoxylin eosin (HE) staining. The microvascular density (MVD) in wounds was detected through immunohistochemical staining. Real time fluorescence quantitative polymerase chain reaction (RT-PCR) and western blotting were used to detect the mRNA and protein levels of Notch1 homolog (Notch1), Delta-like ligand 4 (Dll4), Delta-like ligand 4 (VEGF), and angiopoietin 2 (Ang-2), respectively. ResultsHistological results showed that the epidermal structure in the dorsal foot skin tissue of the rats in the blank group was intact. In the wound tissue of the model group, the epidermis exhibited excessive keratinization, vacuolar cytoplasm, and a large number of inflammatory cells infiltrating the tissue, while in the XZM group, a large amount of scab formation was observed in the epidermis, with no significant inflammatory cell infiltration and a noticeable increase in fibroblasts. In the combination group and the inhibitor group, partial epidermal scab formation was observed in the wound tissue with a small amount of inflammatory cell infiltration. Compared to those in the blank group, the MVD in the wound tissue increased in the model group, as well as the mRNA expression and protein levels of Notch1 and Dll4, while VEGFA and Ang-2 mRNA expression and protein levels significantly decreased (P<0.05 or P<0.01). Compared to those in the model group, the MVD in the wound tissue of all medication groups significantly increased, and the mRNA and protein levels of Notch1 and Dll4 decreased, while VEGFA and Ang-2 mRNA expression and protein levels increased (P<0.05 or P<0.01). Compared to the XZM group, the inhibitor group and the combination group showed decreased MVD in wound tissue, increased Notch1 and Dll4 mRNA and protein levels, and decreased expression of VEGFA and Ang-2 mRNA and proteins (P<0.05 or P<0.01). ConclusionXZM can effectively promote wound healing in DFU rats, and its mechanism of action may be related to the inhibition of Dll4/Notch1 signaling pathway in the wound tissue, therey promoting angiogenesis.
6.Preparation and in vitro evaluation of polyethylene glycol derivatives modified IL-12
Yi LIU ; Zhenyang ZOU ; Zongyan LI ; Feng HAN ; Tiankui QIAO ; Jiangang WANG
Chinese Journal of Immunology 2024;40(7):1495-1500,1506
Objective:To prepare IL-12 modified with polyethylene glycol derivatives and determine its modification sites,and to evaluate it in vitro in terms of stability,hemogram recovery,anti-tumor effects and other aspects.Methods:IL-12 was modified with polyethylene glycol propionaldehyde and maleimide imide derivatives,and modified sites of two different derivatives were deter-mined by ultra performance liquid chromatography(UPLC).Recombinant human IL-12 and PEG-IL-12 were used to stimulate NK92 cells,activity and cytotoxicity of IFN-γ were evaluated by kits.CD34+was stimulated to evaluate its blood picture recovery potential.NK cell killing was stimulated to evaluate its effectiveness in improving immunity and anti-tumor effects.Results:Compared with recombinant human IL-12,PEG-IL-12 had higher stability,blood picture recovery potential and anti-tumor effects.Conclusion:PEG-IL-12 can effectively overcome many drawbacks of recombinant human IL-12,greatly improving possibility of its widespread applica-tion in clinical trials.
7.Clinical and genetic analysis of one patient with familial glucocorticoid deficiency type 4 caused by NNT gene variation
Junlin WANG ; Mingying HAN ; Changjuan ZHAO ; Shuli WANG ; Xiuying QIAO ; Yang GUO ; Meihong SUN
Chinese Journal of Endocrinology and Metabolism 2024;40(7):580-585
Familial glucocorticoid deficiency type 4(FGD4) is a rare autosomal recessive disorder caused by mutations in the nicotinamide nucleotide transhydrogenase(NNT) gene. The article presented clinical data, laboratory results, and genetic mutation findings of a child with FGD4. Additionally, a retrospective analysis of the clinical data of FGD4 patients reported domestically and internationally was conducted, summarizing the types of gene mutations and clinical characteristics. This case identifies novel mutation sites in the NNT gene, providing a basis for the early diagnosis and treatment of FGD4 patients.
8.Cornus officinalis with high pressure wine steaming enhanced anti-hepatic fibrosis:Possible through SIRT3-AMPK axis
Han XIN ; Ning YAN ; Dou XINYUE ; Wang YIWEN ; Shan QIYUAN ; Shi KAO ; Wang ZEPING ; Ding CHUAN ; Hao MIN ; Wang KUILONG ; Peng MENGYUN ; Kuang HAODAN ; Yang QIAO ; Sang XIANAN ; Cao GANG
Journal of Pharmaceutical Analysis 2024;14(5):758-771
Cornus officinalis,a medicinal and edible plant known for its liver-nourishing properties,has shown promise in inhibiting the activation of hepatic stellate cells(HSCs),crucial indicators of hepatic fibrosis,especially when processed by high pressure wine steaming(HPWS).Herein,this study aims to investigate the regulatory effects of cornus officinalis,both in its raw and HPWS forms,on inflammation and apoptosis in liver fibrosis and their underlying mechanisms.In vivo liver fibrosis models were established by subcutaneous injection of CCl4,while in vitro HSCs were exposed to transforming growth factor-β(TGF-β).These findings demonstrated that cornus officinalis with HPWS conspicuously ameliorated his-topathological injury,reduced the release of proinflammatory factors,and decreased collagen deposition in CCl4-induced rats compared to its raw form.Utilizing ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometer(UHPLC-QTOF-MS)combined with network analysis,we identified that the pharmacological effects of the changed components of cornus officinalis before and after HPWS,primarily centered on the adenosine phosphate(AMP)-activated protein kinase(AMPK)pathway.Of note,cornus officinalis activated AMPK and sirtuin 3(SIRT3),promoting the apoptosis of activated HSCs through the caspase cascade by regulating caspase3,caspase6 and caspase9.small interfering RNA(siRNA)experiments showed that cornus officinalis could regulate AMPK activity and its mediated-apoptosis through SIRT3.In conclusion,cornus officinalis exhibited the ability to reduce inflammation and apoptosis,with the SIRT3-AMPK signaling pathway identified as a potential mecha-nism underlying the synergistic effect of cornus officinalis with HPWS on anti-liver fibrosis.
9.Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients (version 2024)
Yao LU ; Yang LI ; Leiying ZHANG ; Hao TANG ; Huidan JING ; Yaoli WANG ; Xiangzhi JIA ; Li BA ; Maohong BIAN ; Dan CAI ; Hui CAI ; Xiaohong CAI ; Zhanshan ZHA ; Bingyu CHEN ; Daqing CHEN ; Feng CHEN ; Guoan CHEN ; Haiming CHEN ; Jing CHEN ; Min CHEN ; Qing CHEN ; Shu CHEN ; Xi CHEN ; Jinfeng CHENG ; Xiaoling CHU ; Hongwang CUI ; Xin CUI ; Zhen DA ; Ying DAI ; Surong DENG ; Weiqun DONG ; Weimin FAN ; Ke FENG ; Danhui FU ; Yongshui FU ; Qi FU ; Xuemei FU ; Jia GAN ; Xinyu GAN ; Wei GAO ; Huaizheng GONG ; Rong GUI ; Geng GUO ; Ning HAN ; Yiwen HAO ; Wubing HE ; Qiang HONG ; Ruiqin HOU ; Wei HOU ; Jie HU ; Peiyang HU ; Xi HU ; Xiaoyu HU ; Guangbin HUANG ; Jie HUANG ; Xiangyan HUANG ; Yuanshuai HUANG ; Shouyong HUN ; Xuebing JIANG ; Ping JIN ; Dong LAI ; Aiping LE ; Hongmei LI ; Bijuan LI ; Cuiying LI ; Daihong LI ; Haihong LI ; He LI ; Hui LI ; Jianping LI ; Ning LI ; Xiying LI ; Xiangmin LI ; Xiaofei LI ; Xiaojuan LI ; Zhiqiang LI ; Zhongjun LI ; Zunyan LI ; Huaqin LIANG ; Xiaohua LIANG ; Dongfa LIAO ; Qun LIAO ; Yan LIAO ; Jiajin LIN ; Chunxia LIU ; Fenghua LIU ; Peixian LIU ; Tiemei LIU ; Xiaoxin LIU ; Zhiwei LIU ; Zhongdi LIU ; Hua LU ; Jianfeng LUAN ; Jianjun LUO ; Qun LUO ; Dingfeng LYU ; Qi LYU ; Xianping LYU ; Aijun MA ; Liqiang MA ; Shuxuan MA ; Xainjun MA ; Xiaogang MA ; Xiaoli MA ; Guoqing MAO ; Shijie MU ; Shaolin NIE ; Shujuan OUYANG ; Xilin OUYANG ; Chunqiu PAN ; Jian PAN ; Xiaohua PAN ; Lei PENG ; Tao PENG ; Baohua QIAN ; Shu QIAO ; Li QIN ; Ying REN ; Zhaoqi REN ; Ruiming RONG ; Changshan SU ; Mingwei SUN ; Wenwu SUN ; Zhenwei SUN ; Haiping TANG ; Xiaofeng TANG ; Changjiu TANG ; Cuihua TAO ; Zhibin TIAN ; Juan WANG ; Baoyan WANG ; Chunyan WANG ; Gefei WANG ; Haiyan WANG ; Hongjie WANG ; Peng WANG ; Pengli WANG ; Qiushi WANG ; Xiaoning WANG ; Xinhua WANG ; Xuefeng WANG ; Yong WANG ; Yongjun WANG ; Yuanjie WANG ; Zhihua WANG ; Shaojun WEI ; Yaming WEI ; Jianbo WEN ; Jun WEN ; Jiang WU ; Jufeng WU ; Aijun XIA ; Fei XIA ; Rong XIA ; Jue XIE ; Yanchao XING ; Yan XIONG ; Feng XU ; Yongzhu XU ; Yongan XU ; Yonghe YAN ; Beizhan YAN ; Jiang YANG ; Jiangcun YANG ; Jun YANG ; Xinwen YANG ; Yongyi YANG ; Chunyan YAO ; Mingliang YE ; Changlin YIN ; Ming YIN ; Wen YIN ; Lianling YU ; Shuhong YU ; Zebo YU ; Yigang YU ; Anyong YU ; Hong YUAN ; Yi YUAN ; Chan ZHANG ; Jinjun ZHANG ; Jun ZHANG ; Kai ZHANG ; Leibing ZHANG ; Quan ZHANG ; Rongjiang ZHANG ; Sanming ZHANG ; Shengji ZHANG ; Shuo ZHANG ; Wei ZHANG ; Weidong ZHANG ; Xi ZHANG ; Xingwen ZHANG ; Guixi ZHANG ; Xiaojun ZHANG ; Guoqing ZHAO ; Jianpeng ZHAO ; Shuming ZHAO ; Beibei ZHENG ; Shangen ZHENG ; Huayou ZHOU ; Jicheng ZHOU ; Lihong ZHOU ; Mou ZHOU ; Xiaoyu ZHOU ; Xuelian ZHOU ; Yuan ZHOU ; Zheng ZHOU ; Zuhuang ZHOU ; Haiyan ZHU ; Peiyuan ZHU ; Changju ZHU ; Lili ZHU ; Zhengguo WANG ; Jianxin JIANG ; Deqing WANG ; Jiongcai LAN ; Quanli WANG ; Yang YU ; Lianyang ZHANG ; Aiqing WEN
Chinese Journal of Trauma 2024;40(10):865-881
Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.
10.Two types of coumarins-specific enzymes complete the last missing steps in pyran- and furanocoumarins biosynthesis.
Yucheng ZHAO ; Yuedong HE ; Liangliang HAN ; Libo ZHANG ; Yuanzheng XIA ; Fucheng YIN ; Xiaobing WANG ; Deqing ZHAO ; Sheng XU ; Fei QIAO ; Yibei XIAO ; Lingyi KONG
Acta Pharmaceutica Sinica B 2024;14(2):869-880
Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.


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