中国南蛇藤属 (卫矛科) 一新记录种及其意义

在开展南蛇藤属分类修订的过程中,于 2011 年在中国云南省西双版纳傣族自治州勐腊县发现南蛇藤属中国分布新记录——拟独子藤 ( Celastrus monospermoides) 。该种形态与独子藤 ( C. monospermus) 较为相似,主要区别为前者叶片窄椭圆形,先端渐尖,果实成熟后不具雌蕊柄,种子长12 mm 以内; 后者叶片椭圆形、阔椭圆形至倒卵椭圆形,果实具有明显的雌蕊柄,种子长15 mm 以上。分子系统学研究表明,拟独子藤与独子藤处于不同分支中,与青江藤 ( C. hindsii) 系统关系最近。由于原记录仅分布于印度尼西亚、马来西亚和菲律宾等热带地区,因此在原产地和我国云南省之间的地区应有更多居群分布,这为探讨南蛇藤属的起源和扩散提供了线索。     

Anatomy and ultrastructure of the floral nectary of Tontelea micrantha (Celastraceae: Salacioideae)

Among several native species of the Brazilian cerrado, a shrub, Tontelea micrantha, is exploited by traditional communities for the valuable oil extracted from its seeds, which has anti‐inflammatory properties. There have been no studies on the anatomy of its flower, and so the aim of this study is to describe the anatomy and ultrastructure of its floral nectary. Flower buds and flowers in anthesis were collected, fixed and processed for light and electron microscopy. The discoid floral nectary is composed of epidermis and a secretory parenchyma. Secretory cells are rich in plastids with starch grains and mitochondria. The nectar, sucrose dominant, is just sufficient to form a thin film on the nectary. The secretory cells show starch and oil droplets; however, during nectar production there is no evidence of hydrolysis of starch and some lipid reserves remain unchanged. Our results suggest a reduction in the amount of oil in the secretory cells during the secretory phase but this does not appear to imply a release of oil as a nectar component. In addition to maintaining part of the reserves, the lower frequency of organelles involved in nectar synthesis reinforces the hypothesis that phloem sap is the origin of nectar sugars. The tiny nectar film, released through modified stomata, is attractive to small insects such as flies. Considering the importance and intensity of use of T. micrantha in the Brazilian cerrado, we think that these data about its floral nectary can help to better explain its reproductive biology with positive impacts on its management and conservation.     

Polyhydroxyagarofuran derivatives from Austroplenckia populnea

The larvicidal extract of Austroplenckia populnea leaves gave two new polyesters of 8-oxo-1,2,3,4,9,14-hexahydroxydihydroagarofuran, a compound which is typical of Celastraceae species.     

A lupenediol from Euonymus revolutus

A new lupane derivative isolated from Euonymus revolutus (Celastraceae) has been established to be 2α,3α-dihydroxy-lup-20(29)-en-28-oic acid on the basis of chemical interconversions and spectroscopic data.     

Elaeodendrol and elaeodendradiol,new nor-triterpenes from Elaeodendron glaucum

The isolation of six known and two new D:A-friedooleananes is reported from the bark of Elaeodendron glaucum. The structures of the new nor-triterpenes, elaeodendrol and elaeodendradiol, were established respectively as 17β- hydroxy-28-norfriedelan-3-one and l7β,25-dihydroxy-28-norfriedelan-3-one by a study of the methyl chemical shifts in their ¹H NMR spectra.     

Triterpenes from Gymnosporia emarginata

Triterpene quinone-methides, lupenone, β-amyrin, dulcitol, and sitosterol have been isolated from the timber, root and leaf extracts of Gymnosporia emarginata. Their chemotaxonomic significance is discussed.     

Insecticidal sesquiterpene polyol ester from Celastrus angulatus

An insecticidal sesquiterpene polyol ester, angulatin A, was isolated from the root bark of Celastrus angulatus. Its structure was established as 1,2-diacetoxy-8β,15-diisobutyryloxy-9-benzoyloxy-4β, 6β-dihydroxydihydro-β-agarofuran by spectroscopic methods.     

Triterpenes from Euonymus revolutus

Fourteen pentacyclic triterpenes, which included ten D:A-friedooleananes, three lup-20(29)-enes and 2α,3α-dihydroxy-olean-12-en-28-oic acid, were isolated from the stem bark extract of Euonymus revolutus.     

10种卫矛科植物次生韧皮部的比较解剖

研究了卫矛科（Ｃｅｌａｓｔｒａｃｅａｅ）５ 属１０ 种植物次生韧皮部的结构。根据筛管分子、韧皮射线及厚壁组织的结构特征,将这１０ 种植物次生韧皮部分为３ 种类型。类型Ⅰ：筛管分子端壁倾斜,筛域数多,都为复筛板,韧皮射线大多为单列。卫矛属（Ｅｕｏｎｙｍ ｕｓ）的５ 种植物属于这一类型;类型Ⅱ：包括南蛇藤属（Ｃｅｌａｓｔｒｕｓ）和雷公藤属（Ｔｒｉｐｔｅｒｙｇｉｕｍ ）,其特征是筛管分子短,端壁倾斜度小,筛域数少,纤维不木质化,射线多列;类型Ⅲ：筛管分子多为单筛板,端壁接近水平,在不具功能韧皮部出现成簇的石细胞和纤维,射线单列或两列。属于此类型的有十齿花属（Ｄｉｐｅｎｔｏｄｏｎ）和核子木属（Ｐｅｒｒｏｔｔｅｔｉａ）