[Research progress on finite element analysis of internal fixation for clavicular fracture].

Clavicular fracture is a common upper limb fracture. Because of its special anatomical structure, it directly affects the function of the shoulder joint. The different injury mechanisms of clavicular fracture affect the mechanical effect of internal fixation, so the selection of internal fixation method has been puzzling orthopedists. As a modern computer based mechanical analysis, finite element analysis application in the internal fixation of clavicular fracture can not only clarify the pathogenesis of fractures, biomechanical properties of internal fixators and complications of fractures, but also provide guidance for preoperative planning. Therefore, it is beneficial to preoperative planning and individualized selection of surgical methods, and is expected to become an indispensable part in preoperative planning for clavicular fracture. In this paper, the pathogenesis, related influencing factors, selection of internal fixation and postoperative complications of clavicular fracture based on finite element analysis and problems during finite element analysis were reviewed.

Eremophilane-type Sesquiterpenes from the Leaves of Ligularia virgaurea.

A phytochemical study of the ethanolic extract of the leaves of Ligularia virgaurea led to the isolation of a new eremophilane-type sesquiterpene lactone, (4S,5R,6S,8S,lR)-6ß-angeloyloxy-eremophil-7(l l)-en-10ßH-8α,12-olide (1), along with a known eremophilane-type sesquiterpene, (4S,5R,6S,lOS)-6ß- angeloyloxy-10ßH-furanoeremophil-9-one (2). Their structures were elucidated by extensive spectroscopic methods, including ID and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry experiments, and the absolute configurations were confirmed by single-crystal X-ray diffraction analysis using the anomalous scattering of Cu Ka radiation.

Euphorikanin A, a Diterpenoid Lactone with a Fused 5/6/7/3 Ring System from Euphorbia kansui.

Euphorikanin A (1), an unprecedented diterpenoid lactone which possesses a novel 5/6/7/3-fused tetracyclic ring skeleton, was isolated from the roots of Euphorbia kansui. The chemical structure and absolute stereochemistry were elucidated on the basis of extensive spectroscopic methods and single-crystal X-ray diffraction analysis. Compound 1 exhibited moderate cytotoxicity against two human tumor cell lines HeLa and NCI-446. A proposed biosynthetic pathway of compound 1 is also described.

A new norsesquiterpenoid from Ligularia virgaurea.

A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves of Ligularia virgaurea. The structure of 1 was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound 2 was identified by comparison of its physical and spectral data with those reported in the literature. Compound 1 was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines.

A Novel Norclerodane Diterpenoid from the Roots of Croton crassifolius.

A chemical investigation of Croton crassifolius afforded a novel norclerodane diterpenoid (1) with an unprecedented six-membered oxygen ring between C-1 and C-12, together with three known compounds. The structure of the new compound was elucidated based on spectroscopic (IR, 1D, and 2D NMR) and HR-ESI-MS techniques. This report describes the first example of a natural norclerodane with a 4H-chromene ring system.

8ß-Eth-oxy-eremophil-3,7(11)-diene-8α,12;6α,15-diolide.

The title compound, C17H20O5, an eremophilane sesquiternoid, was isolated from the roots of Ligularia lapathifolia. The mol-ecule contains four fused rings of which the six-membered ring A adopts a half-chair conformation, the six-membered ring B adopts a chair conformation, the five-membered ring C is almost planar (r.m.s. deviation = 0.015 Å) and the five-membered ring D adopts an envelope conformation with the quaternary C atom as the flap. The methyl and the eth-oxy groups adopt a syn conformation and the A/B ring junction is cis-fused. No directional inter-molecular inter-actions could be identified in the crystal.