Calycilactone A, a novel hexacyclic alkaloid from Daphniphyllum calycillum

A novel Daphniphyllum alkaloid with a rearranged fused-hexacyclic ring system, calycilactone A, was isolated from the leaves of Daphniphyllum calycillum (Daphniphyllaceae), and the structure and relative stereochemistry of the new compound were elucidated on the basis of spectroscopic data.     

Nukiangendines A and B,two novel 13,14-seco-abietanes from Abies nukiangensis

From Abies nukiangensis, two novel 13,14-seco-abietane diterpenes, nukiangendines A (1) and B (2) were isolated. Their relative structures were determined by extensive NMR and HRMS spectroscopic analysis. The absolute configuration of 1 was established by ECD calculations. Compound 1 showed significant anti-hepatitis C virus (HCV) effects.     

舞花姜的化学成分

舞花姜（Ｇｌｏｂｂａｒａｃｅｍｏｓａｓｍｉｔｈ）为姜科舞花姜属植物,产于我国南部、西南部等地。其根和果实在民间药用,有健胃、消炎的功能,用于治疗胃炎、消化不良、急慢性肾炎等［１］。尚未见有关舞花姜属植物化学成分和药理活性的研究报道,为此我们对其地下部分的化学成分进行了研究。乙醇提取物的石油醚可溶部分经硅胶柱和萄聚糖凝胶柱层析分离得到五个化合物,经光谱鉴定为木栓酮（ｆｒｉｅｄｅｌｉｎ１）,ｃｙｃｌｏｅｕｃａｌｅｎ－ｏｌ（２）、３－羟基－豆甾－５烯－７－酮（３－ｈｙｄｒｏｘｙ－ｓｔｉｇｍａｓｔ－５－…     

Isolation and Structural Study on Carbohydrates from Cynanchum otophyllum and Cynanchum paniculatum

Three new carbohydrates were isolated from the acidic hydrolysis part of the ethyl acetate extract of Cynanchum otophyllum Schneid (Asclepiadaceae) and one new carbohydrate from the ethyl acetate extract of Cynanchum paniculatum Kitagawa. Their structures were determined as methyl 2,6-dideoxy-3-O-methyl-α-D-arabino-hexopyranosyl-(1 → 4)-2,6-deoxy-3-O-methyl-β-D-arabino-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-α-D-arabino-hexopyranoside (1), ethyl 2,6-dideoxy-3-O-methyl-β-D-ribo-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-α-l-lyxo-hexopyranoside (2), met hyl 2,6-dideoxy-3-O-methyl-α-l-ribo-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-β-D-lyxo-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-α-D-arabino-hexopyranoside (3), and 2,6-dideoxy-3-O-methyl-β-D-ribo-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-α-d-arabino-hexopyranosyl-(1 → 4)-2,6-dideoxy-3-O-methyl-α -d-arabino-hexopyranose (4), respectively, by spectral methods.     

A novel synthesis route to furo[3,2-a]carbazole

In this paper,we report a novel approach to the heteroaryl-condensed nuclei of natural furo[3,2-a]carbazole alkaloids.Our synthetic studies use N-phthaloyl tryptophan methyl ester as starting material and zinc ion mediated transamination reaction as the key step.This work also implicated a novel strategy to assemble other [a]-fused carbazoles.     

Charge transfer dynamics of 3,4,9,10-perylene-tetracarboxylic-dianhydride molecules on Au(111) probed by resonant photoemission spectroscopy

Charge transfer dynamics across the lying-down 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) organic semiconductor molecules on Au(111) interface has been investigated using the core-hole clock implementation of resonant photoemission spectroscopy. It is found that the charge transfer time scale at the PTCDA∕Au(111) interface is much larger than the C 1s core-hole lifetime of 6 fs, indicating weak electronic coupling between PTCDA and the gold substrate due to the absence of chemical reaction and∕or bonding.     

声光可调近红外光谱技术快速检测再造烟叶的厚度

厚度是衡量再造烟叶品质及稳定性的一项重要指标,目前再造烟叶厚度测定方法存在读数不稳定、测量准确性受样品特性影响,不利于检测和控制.本文应用声光可调滤光器近红外光谱仪建立再造烟叶厚度检测方法模型,能准确预测再造烟叶厚度指标,具有准确性好,精密度高的特点,符合再造烟叶厚度检测的需要.     

New monoterpenoid coumarins from Clausena anisum-olens

Two new monoterpenoid coumarins: anisucumarin A (1) and B (2), a pair of epimers, were isolated from Clausena anisum-olens. Their structures were established based on extensive spectroscopic analyses.     

Lathyranone A: a diterpenoid possessing an unprecedented skeleton from Euphorbia lathyris

Lathyranone A (1), a novel diterpenoid with a rearrangement skeleton, along with a known diterpenoid, Euphorbia factor L(11) (2), was isolated from the seeds of Euphorbia lathyris. The structure and relative stereochemistry of 1 were elucidated by extensive spectroscopic analysis. A possible biosynthetic pathway for lathyranone A (1) was proposed.     

Structure elucidation and biomimetic synthesis of hostasinine A, a new benzylphenethylamine alkaloid from Hosta plantaginea

Hostasinine A (1), a benzylphenethylamine alkaloid with an unprecedented skeleton featuring a C-4-C-6 linkage and a nitrone moiety, was isolated from Hosta plantaginea. Its structure was established on the basis of spectroscopic data, and was further confirmed by single-crystal X-ray diffraction. The alkaloid was postulated biogenetically from haemanthidine via N-oxidation and aza-aldol-type condensation and was synthesized biomimetically. The inhibitory activities of 1 on acetylcholinesterase (AChE) and two tumor cell lines (K562 and A549) were also evaluated.