Bioactivity‑Guided Isolation of Totarane‑Derived Diterpenes from Podocarpus neriifolius and Structure Revision of 3‑Deoxy‑2α‑hydroxynagilactone E

Bioactivity-guided phytochemical investigation of Podocarpus neriifolius D.Don.(Podocarpaceae)has led to the isolation of one new(2)and three known(1,3,and 4)B-type podolactones,along with three totarane-type diterpenes(5-7).Their structures were determined by interpretation of High Resolution ElectroSpray Ionization Mass Spectrometry(HRESIMS)and 1D and 2D NMR data,and comparison with the values reported in the literature.The structure of compound 1,previously identifed as 3-deoxy-2α-hydroxynagilactone E(8),was revised as its 2β-epimer,which has been reported recently as a new compound.All of the isolates were evaluated for their antiproliferative activity against a panel of four human cancer cell lines,namely,ovarian(OVCAR3),breast(MDA-MB-231),colon(HT-29),and melanoma(MDA-MB-435),and compounds 1 and 3 were found to be cytotoxic with IC_(50) values in the low micromolar range for most of the cell lines used.The major compound,inumakilactone A(3),was further tested in vivo using the HT-29,MDA-MB-435,and OVCAR3 cells in a murine hollow fber model,for the frst time.

Comparison of Positron Emission Tomography Using 2-[^18F]-fluoro-2-deoxy-D-glucose and 3-deoxy-3-[^18F]-fluorothymidine in Lung Cancer Imaging

Background： The detection of solitary pulmonary nodules （SPNs） that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography （CT） imaging results remains a significant challenge. The 2-[^18F]-fluoro-2-deoxy-D-glucose （^18F-FDG） positron emission tomography （PET）/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-[^18F]-fluorothymidine （^18F-FLT） in lung cancer PET/CT imaging. Methods： The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established （n = 12）, and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values （SUVs）, and Ki-67 proliferation marker expression were investigated. Results： The cell-tracer binding ratio for the A549 cells using the ^18F-FDG was greater than the ratio using 18F-FLT （P 〈 0.05）. The Ki-67 expression showed a significant positive correlation with the ^18F-FLT binding ratio （r = 0.824, P〈 0.01）. The tumor-to-nontumor uptake ratio of ^18F-FDG imaging in xenografts was higher than that of ^18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of ^18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of ^18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of ^18F-FDG and ^18F-FLT （r = 0.658, P〈 0.05 and r = 0.724, P〈 0.01, respectively）. Conclusions： The ^18F-FDG uptake ratio is higher than that of ^18F-FLT in A549 cells at the cellular level.^18F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.

RNase A-catalyzed synthesis of dinucleotides containing 2' -deoxy-2' -fluoro-pyrimidinenucleosides at 3'-termini

RNase A catalyzes the hydrolysis of ribonucleic acids to form oligonucleotide fragments containing pyrimidineribonucleoside 2’, 3’-cyclic phosphate at the 3’-termini, which are then further hydrolyzed to produce oligonucleotide fragments with 3’ -phosphate group as the final products. This enzyme can also catalyze the formation of internucleotide linkage from pyrimidineribonucleoside 2’, 3’-cyclic phosphate and a nucleoside component with

披针叶茴香果实的化学成分研究

目的研究八角科（Illiciaceae）植物披针叶茴香（Illicium lanceolatum）果实的化学成分。方法应用硅胶、Sephadex LH-20、MCI等各种色谱技术进行分离纯化，根据化合物的理化常数和波谱数据鉴定其结构。结果从披针叶茴香果实的体积分数95％乙醇提取物中分离得到12个化合物，通过渡谱数据和理化常数分别鉴定为2，4-dihydroxy—allylbenzene-2-O-β-D—glucopyranoside（1），（＋）-儿茶素（2），槲皮素-3-O-β-L-鼠李糖苷（3），芦丁（4），异鼠李素-3-D-β-D-芸香糖苷（5），6-deoxy-1-hy—droxy neoanisatin（6），莽草毒素（7），icarisideE3（8），（75，8R）-urolignoside（9），对羟基苯甲酸（10），莽草酸（11），β-谷甾醇（12）。结论化合物1，4～6，8～10为首次从该植物中分离得到。