Sheng-Zehn Yang

Artocarpol A. a Novel Constituent with Potent Anti-inflammatory Effect. Isolated from Artocarpus rigida

A novel phenolic compound, artocarpol A (1), was isolated from the root bark of Artocarpus rigida and its structure determined by spectroscopic methods and by comparison with its diacetate derivative. Compound 1 strongly inhibited superoxide formation in phorbol 12-myristate 13-acetate (PMA) stimulated rat neutrophils in a concentration-dependent manner with an IC50 value of 13.7±0.7 μM. Compound 1 also showed a significant inhibitory effect on tumor necrosis factor-α (TNF-α) formation in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.

The First National Vegetation Inventory in Taiwan

This article describes the successful implementation and preliminary results of the first national vegetation inventory in Taiwan. This project which aimed to establish national criteria for vegetation classification, map island-wide forest vegetation at a scale of 1: 5000 and establish a vegetation data management system was launched in 2003. More than 3000 permanent plots (20 m×20 m) were set up throughout Taiwan, and 792 articles on vegetation of Taiwan were located to acquire vegetation data. Vegetation types were identified according to the physiognomic appearances in aerial photographs. The national vegetation classification system was constructed by referring to field observations, vegetation data, and currently available vegetation classification schemes. This project was finalized in 2008. Up to 67% of native vascular plant species in Taiwan were recorded, and 59% of the total area of Taiwan was mapped in this project. Preliminary vegetation analyses identified 9 major vegetation types and their diagnostic species, constant species and dominant species. The Taiwan Vegetation Information was established and has performed the functions of data management for the current project since 2003. The latest version of the Taiwan Vegetation Classification System was released in 2007. The achievement and experiences of the current project have paved the way for the successful implementation of subsequent large-scale surveys in Taiwan.

Two Novel and Anti‐Inflammatory Constituents of Artocarpus rigida

With the scope of our search for biologically active compounds, two new phenolic compounds, artocarpols G (1) and H (2), and two known compounds, rubraflavone C (3) and trans-stilbene-2,4,3′,5′-tetrol, were isolated from the root bark of Artocarpus rigida. Their structures were determined by spectroscopic methods and comparison with data reported in the literature. Compound 4, previously isolated from this plant, strongly inhibited in a concentration-dependent manner the release of β-glucuronidase and histamine from mast cell degranulation caused by compound 48/80, with IC50 values of 10.9±1.4 and 13.2±0.6 μM, respectively. Compound 4 also showed a concentration-dependent inhibitory effect on the formyl-peptide-stimulated superoxide anion formation in neutrophils with an IC50 value of 26.0±5.6 μM.

Artocarpol F, a phenolic compound with a novel skeleton, isolated from Artocarpus rigida

Abstract A novel phenolic compound containing an oxepine ring, artocarpol F ( 1 ) was isolated from the root bark of Artocarpus rigida . The structure including relative configuration was elucidated by spectroscopic data and computer-generated 3D drawing.

A New Ferulic Acid Ester, a New Ellagic Acid Derivative, and Other Constituents from Pachycentria formosana: Effects on Neutrophil Pro- Inflammatory Responses

A new ferulic acid ester derivative, tetracosane‐1,24‐diyl di[(Z)‐ferulate] (1), and a new ellagic acid derivative, 3,4 : 3′,4′‐bis(O,O‐methylene)ellagic acid (2), have been isolated from leaves and twigs of Pachycentria formosana, together with eight known compounds. Their structures were determined by in‐depth spectroscopic and mass‐spectrometric analyses. Among the isolated compounds, oleanolic acid (6), ursolic acid acetate (7), and 3‐epibetulinic acid (9) exhibited potent inhibition (IC50 values ≤21.8 μM) of O2⋅− generation by human neutrophils in response to N‐formyl‐L‐methionyl‐L‐leucyl‐L‐phenylalanine/cytochalasin B (fMLP/CB). In addition, oleanolic acid (6), 3‐O‐[(E)‐feruloyl]ursolic acid (8), 3‐epibetulinic acid (9), and lawsonic acid (10) also inhibited fMLP/CB‐induced elastase release with IC50 values ≤18.6 μM.

Classification of the High-Mountain Coniferous Forests in Taiwan

Vegetation of boreal coniferous forests has been extensively studied in many areas of northern Eurasia and North America, but similar forests in the high mountains of subtropical and tropical eastern Asia have been poorly documented so far. This paper, focusing on such forests, is the first phytosociological study at a national scale in Taiwan. The relevés from the National Vegetation Diversity Inventory and Mapping Project database were used to define vegetation types of the high-mountain coniferous forests and to characterize their distribution in Taiwan. Environmental variables such as aspect, elevation, soil rockiness and slope were related to species composition. Cluster analysis was used to classify vegetation plots and establish groups that were interpreted as nine associations belonging to two alliances. The alliance Juniperion squamatae represents woodlands and forests scattered in the subalpine belt, in which Juniperus squamata dominates the canopy and subalpine meadow species occur in the understorey. The Abieti kawakamii-Tsugion formosanae alliance includes forests dominated by Abies kawakamii and Tsuga chinensis var. formosana with shade-tolerant herb species in the upper montane belt. In addition to regional vegetation description, an identification key for the studied forests was developed based on the classification tree technique.

Constituents with a Novel Skeleton Isolated from Amentotaxus formosana

A novel compound consisting of two diterpenoid substructures, amentotaxin BA (1), and two novel terpenoids with a new skeleton, amentotaxins WA (2) and WB (3), were isolated from the barks and heart woods of Amentotaxus formosana, respectively. Their structures, including the relative configuration, were elucidated from spectroscopic data and a computer-generated plot for the 3D structure.

New Constituents ofArtocarpus rigida

Four new phenolic compounds containing an oxepine ring, artocarpols B (1), C (2), D (3), and E (4), were isolated from the root bark of Artocarpus rigida. The structures, including relative configurations, were elucidated by means of spectroscopic data.

Cambial variations of Piper (Piperaceae) in Taiwan

BackgroundCambial variations in lianas of Piperaceae in Taiwan have not been studied previously. The stem anatomy of seven Piper species from Taiwan was examined to document cambial variations and better distinguish the species when leaves are absent.ResultsA key for the seven species is provided, based on the internal stem anatomy. The seven Piper species climb via adventitious roots, and in cross section, the stems were generally eccentric and oblate, although a transversely elliptic stem was found in P. kadsura (Choisy) Ohwi and P. sintenense Hatus. A cambial variant with secondary growth of external primary vascular bundles and xylem in plates was observed in all species except Piper betle L., which developed another cambium variant with xylem furrowed deeply by parenchyma proliferation. The sclerenchymatous ring surrounding the medullary vascular bundles was always continuous except in P. betle, where it was discontinuous. Mucilage canals varied from absent to present in the center of the pith, or present in the pith and inner cortex. Different sizes of vessels dispersed throughout the stem were ring or diffuse porous. The numbers of medullary and peripheral vascular bundles were distinctive and the widths of rays were noticeably different in each species. Differences in the growth rate of the medullary vascular bundles produced two development types of vascular bundles, although in both types, the peripheral vascular bundles gradually lengthen and become separated from each other by wide rays.ConclusionsWe documented the internal stem anatomy of six previously unstudied species of Piper, including three endemic species, P. kwashoense Hayata, P. sintenense, and P. taiwanense Lin and Lu, and found that P. betle had deeply furrowed xylem, which had not been reported for the species before. The descriptions and photographs of seven Piper species will also provide a basis for further morphological studies.

Endocarps of menispermaceous plants in Taiwan

BackgroundThe fruits of the family Menispermaceae are drupes, and because the drupe endocarps are morphologically diverse, they are generally used to classify members of this family. There is a lack of detailed knowledge of Menispermaceae endocarps in Taiwan. Therefore, in this study, the endocarps of seven genera and 14 species were dissected, and their morphological characters were photographed and described. Furthermore, a key for the 14 species based on the endocarps features, as well as a key of the studied genera, is proposed.ResultsThe endocarp types comprise a straight shape in Tinospora dentata Diels and a horseshoe shape in the other 13 species. In general, the genus Cyclea bears two dorsal crests with 16 small spines, although there are about 25 spines in Cyclea insularis (Makino) Hatusima. The genus Cocculus has a dorsal convex endocarp with a subannular. In Taiwan, the endocarp of Sinomenium acutum (Thunb.) Rehder & E. H. Wilson has up to 26 transverse ridges, without spines on the crest and might be categorized under the genus Menispermum. Transverse endocarp ridges are found in Stephania cephalantha Hayata and Stephania tetrandra S. Moore, whereas transverse endocarp strips are found in Stephania japonica (Thunb.) Miers, Stephania longa Lour. and Stephania merrillii Diels. ConclusionWe believe that the descriptions and photographs of the endocarp traits of T. dentata, which is endemic to Taiwan, will provide more evidence for further studies on extant and fossil species.