The goal of the present study was to compare the structural and compositional differences of cuticle between tender leaf and fully-expanded leaf in Camellia sinensis, and provide metabolic base for the further characterization of wax biosynthesis in this economically important crop species. The tender second leaf and the fully-expanded fifth leaf from new twig were demonstrated to represent two different developmental stages, their cuticle thickness were measured by transmission electron microscopy. The thickness of the adaxial cuticle on the second and fifth leaf was 1.15 µm and 2.48 µm, respectively; the thickness of the abaxial cuticle on the second and fifth leaf was 0.47 µm and 1.05 µm, respectively. The thickness of the epicuticular wax layer from different leaf position or different sides of same leaf were similar. However, the intracuticular wax layer of the fifth leaf was much thicker than that of the second leaf. Total wax lipids were isolated from the second leaf and the fifth leaf, respectively. Gas chromatography-mass spectrometry analysis identified 51 wax constituents belonging to 13 chemical classes, including esters, glycols, terpenoids, fatty acids and their derivatives. Wax coverage on the second and fifth leaf was 4.76 µg/cm2 and 15.38 µg/cm2, respectively. Primary alcohols dominated in the tender second leaf. However, triterpenoids were the major components from the fully-expanded fifth leaf. The predominant carbon chains varied depending on chemical class. These data showed that the wax profiles of Camellia sinensis leaves are development stage dependent, suggesting distinct developmental dependent metabolic pathways and regulatory mechanisms.

Six new megastigmane glycosides, sedumosides E 1 , E 2 , E 3 , F 1 , F 2 , and G, were isolated from the whole plant of Sedum sarmentosum (Crassulaceae). The structures of new constituents including the absolute configuration were elucidated on the basis of chemical and physicochemical evidence.

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We compare typical qualitative protein identification data from two-dimensional (2D) polyacrylamide gel electrophoresis and reconstructed protein arrays, in the context of measuring protein expression by the Gram-negative periodontal pathogen Porphyromonas gingivalis. The arrays were assembled computationally from genome annotations and tandem mass spectrometry data from an off-line HPLC fractionation combined with 2D capillary HPLC analysis of whole proteome enzymatic digests. The 2D separation was carried out with a standard binary gradient HPLC system, modified only slightly with readily available components. Compared to 2D gels, the number of annotated open reading frames identified using the 3D HPLC approach was typically larger by at least a factor of 30. However, the newer technology is currently limited in its ability to reflect the many protein variants derived from posttranscriptional and posttranslational processing.

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