Apigeninidin as a leucoderivative in Ephedra frustillata

Aerial parts of Ephedra frustillata are shown to contain leucoderivatives based on apigeninidin and pelargonidin. This is the first report of leuco     

Flavonol glycosides from the stems of Trigonella foenum-graecum

Two kaempferol glycosides [kaempferol 3-O-beta-D-glucosyl(1-->2)-beta-D-galactoside 7-O-beta-D-glucoside and kaempferol 3-O-beta-D-glucosyl(1-->2)-(6"-O-acetyl)-beta-D-galactoside 7-O-beta-D-glucoside] as well as the quercetin glycoside [quercetin 3-O-beta-D-glucosyl(1-->2)-beta-D-galactoside 7-O-beta-D-glucoside] were isolated from the stems of Trigonella foenum-graecum L. (Leguminosae) along with a known kaempferol glycoside, lilyn [kaempferol 3-O-beta-D-glucosyl(1-->2)-beta-D-galactoside]. Their structures were established by analysis of chemical and spectral evidence.     

Iridoid glycosides from the stems of Pithecoctenium crucigerum (Bignoniaceae)

Sixteen crude extracts from six Panamanian plants of the family Bignoniaceae were submitted to rapid TLC tests against DPPH and acetylcholinesterase. Pithecoctenium crucigerum (L.) A.H. Gentry, which showed interesting activity against DPPH, has been studied. The chemical investigation of the methanol extract from the stems afforded the iridoid glycoside theviridoside and three derivatives (6'-O-cyclopropanoyltheviridoside, 10-O-hydroxybenzoyltheviridoside and 10-O-vanilloyltheviridoside), along with five known phenylethanoid glycosides (verbascoside, isoverbascoside, forsythoside B, jionoside D and leucosceptoside B). These last compounds were all active against DPPH. The structures were determined by means of spectrometric and chemical methods, including 1D and 2D NMR experiments and MS analysis.     

Four new immunomodulating steroidal glycosides from the stems of Stephanotis mucronata

Four new C-21 steroidal glycosides, mucronatosides E (1), F (2), G (3), and H (4), were isolated from the stems of Stephanotis mucronata. Two of them had the rare aglycone with a double bond between C-6 and C-7. Their structures were elucidated on the basis of spectroscopic data and chemical evidence. These isolated compounds were assayed for their immunological activities in vitro against concanavalin A (Con A)- and lipopolysaccharide (LPS)-induced proliferation of mice splenocytes. Compounds 2 and 4 showed immunosuppressive activities in a dose-dependent manner, while compounds 1 and 3 possessed immunoenhancing activities.     

Antioxidative flavan-3-ol glycosides from stems of Rhizophora stylosa

Two flavan-3-ol glycosides together with seven flavan-3-ols were isolated from stems of the mangrove plant, Rhizophora stylosa. Their structures were established as glabraoside A (7) and glabraoside B (8) by spectroscopic and chemical methods. The antioxidative activity of these isolated compounds evaluated by the diphenylpicrylhydrazyl (DPPH) radical scavenging reaction was higher than that of L-ascorbic acid.     

Composition and stereochemistry of ephedrine alkaloids accumulation in Ephedra sinica Stapf

Ephedra sinica Stapf (Ephedraceae) is a widely used Chinese medicinal plant (Chinese name: Ma Huang). The main active constituents of E. sinica are the unique and taxonomically restricted adrenergic agonists phenylpropylamino alkaloids, also known as ephedrine alkaloids: (1R,2S)-norephedrine (1S,2S)-norpseudoephedrine, (1R,2S)-ephedrine, (1S,2S)-pseudoephedrine, (1R,2S)-N-methylephedrine and (1S,2S)-N-methylpseudoephedrine. GC–MS analysis of freshly picked young E. sinica stems enabled the detection of 1-phenylpropane-1,2-dione and (S)-cathinone, the first two putative committed biosynthetic precursors to the ephedrine alkaloids. These metabolites are only present in young E. sinica stems and not in mature stems or roots. The related Ephedra foemina and Ephedra foliata also lack ephedrine alkaloids and their metabolic precursors in their aerial parts. A marked diversity in the ephedrine alkaloids content and stereochemical composition in 16 different E. sinica accessions growing under the same environmental conditions was revealed, indicating genetic control of these traits. The accessions can be classified into two groups according to the stereochemistry of the products accumulated: a group that displayed only 1R stereoisomers, and a group that displayed both 1S and 1R stereoisomers. (S)-cathinone reductase activities were detected in E. sinica stems capable of reducing (S)-cathinone to (1R,2S)-norephedrine and (1S,2S)-norpseudoephedrine in the presence of NADH. The proportion of the diastereoisomers formed varied according to the accession tested. A (1R,2S)-norephedrine N-methyltransferase capable of converting (1R,2S)-norephedrine to (1R,2S)-ephedrine in the presence of S-adenosylmethionine (SAM) was also detected in E. sinica stems. Our studies further support the notion that 1-phenylpropane-1,2-dione and (S)-cathinone are biosynthetic precursors of the ephedrine alkaloids in E. sinica stems and that the activity of (S)-cathinone reductases directs and determines the stereochemical branching of the pathway. Further methylations are likely due to N-methyltransferase activities.     

氮离子注入对草麻黄成熟胚诱导愈伤组织的影响

以草麻黄为材料,研究了不同剂量的N^＋注入对成熟胚诱导愈伤的影响,并对激素配比进行了优化实验。结果显示：对于草麻黄成熟胚愈伤诱导及继代培养,最佳激素配比为2mg／L2,4-D＋2mg／L 6-BA。剂量为3．0～5．0×10^16 ions／cm^2的氮离子注入成熟胚后,其存活率与对照相比显著下降;2．0×10^16ions／cm^2的氮离子注入处理能显著提高愈伤组织的诱导率;此外,各继代时段,1．0～4．0×10^16ions／cm^2的4个氮离子注入处理其愈伤组织增长速度均高于对照,且随着注入剂量的增加而加快。     

Structural and Functional Grounds for Ephedra sinica Expansion in Mongolian Steppe Ecosystems

Morphological and structural characteristics of photosynthetic organs, diurnal changes in photosynthetic and transpiration rates, and the efficiency of water use were studied in three plant species from mountain-steppe ecosystems in Mongolia, Ephedra sinica Stapf, Stipa glareosa P. Smirn., and Allium polyrhizum Furcz. ex Regel. The species studied differed in the structural and functional mechanisms for the adaptation of photosynthetic apparatus to arid conditions. E. sinica has thick, vertical assimilating shoots, which are characterized by a high density (620 mg/cm³) and a small proportion of photosynthetic tissues (13%). The proportion of meso-phyll in the leaves of A. polyrhizum and S. glareosa was two and three times higher, respectively. The low content of phototrophic tissues in E. sinica shoot was compensated for by a high photosynthetic activity of single chloroplasts (25 mg CO₂/(10⁹ chloroplast h)), which was six times higher, than in two other species. Daily course of photosynthesis and transpiration inE. sinica differed from those of A. polyrhizum and S. glareosa by the absence of the midday depression. E. sinica had the highest efficiency of water use (45 mg CO₂/g H₂O) due to a low transpiration rate (0.25 g/g fr wt h). It is concluded that, in E. sinica, the main strategy for adaptation to arid stress is to develop in the shoot a few photosynthesizing cells of high assimilation activity. Such structural organization of photosynthetic organs in ephedra contributes to its higher efficiency of water use and stability of physiological characteristics under changing environmental conditions. These specific features of the structure of assimilating organs and their functional features contribute to a greater expansion of E. sinica with increasing climate aridization in Mongolia.     

Alkaloidal,lignan and phenolic constituents of Ephedra alata

In addition to the known p-coumaric acid, the furanofuran lignan (±)-syringaresinol and the digalloylglucose, nilocitin, were obtained from the whole plant of Ephedra alata. A new natural alkaloid, ephedralone, was also isolated. The structures were determined mostly by mass, ¹H and ¹³CNMR spectroscopy.     

Asymmetrical development of biovulate cones resulting in uniovulate cones in Ephedra rhytidosperma (Ephedraceae)

Female cone morphology in Ephedra, including the number of initiated ovules and mature seeds per cone, provides important taxonomic characters used in sectional or species delimitation within Ephedra. Recent molecular phylogenies have indicated, however, that seed number per cone has changed repeatedly during the evolution of the genus. This study reports on the development of the female cone of E. rhytidosperma, based on a large sample of dissected cones studied under SEM. All cones were initially biovulate, and in the majority of cases, both female reproductive units (FRUs) developed a micropylar tube and formed mature seeds. In a few cases, the FRU pair developed asymmetrically in a cone, with one of them eventually aborting. There was no evidence of fusion of the FRU pair. Phylogenetically, E. rhytidosperma is in a clade with E. equisetina, which has uniovulate cones, and E. gerardiana and E. minuta, which have biovulate cones that also become unispermous via abortion. The biovulate condition may thus be ancestral in this clade.     

草麻黄雌性生殖器官的个体发生和畸形式样研究

用扫描电镜观察并分析了草麻黄（Ephedra sinica Stapf)雌性生殖器官的个体发生及畸形式样。该种雌球花个体发生式样与麻黄属其他具双胚朱球果的类群基本一致。外珠被以一对近轴侧突起物出现以及该突起物与苞片成交互排列的发育式样支持前人关于该构造叶性本质的论述,而内珠被与珠心的发育相关,因此可能是真正的珠被,基于返祖性畸形三胚珠球花的出现及其他形态特征,认为麻黄属胚珠数目减少是该属内物种特化的一个趋势;利用雌球花发育的畸形现象及外珠被的形态学本质提出麻黄属的雌球果为复轴性构造,雌性生殖单位是由类似于科达类的次级生殖枝构造经系统发育变态,融合,简化成现存的生胚珠构造式样,每一可育苞片及其腋内雌性生殖单位共同组成了麻黄属的苞鳞－种鳞复合体。     

几种外源含氮化合物对草麻黄愈伤组织增殖和麻黄碱含量的影响

在20和40mg·L-1的亚硝酸钠以及50mg·L-1的苯丙氨酸处理下草麻黄茎段愈伤组织增殖量增大,而酪氨酸和蛋氨酸处理的愈伤组织增殖量则下降,且随着这类外源物质浓度的增大其下降幅度也增大。60mg·L-1蛋氨酸、20mg·L-1酪氨酸和50mg·L-1苯丙氨酸可以有效提高草麻黄愈伤组织中麻黄碱的生成量。     

Variant secondary growth in old stems of Ephedra campylopoda G. A. Mey

LEV-YADUN, S. & ALONI, R., 1993. Variant secondary growth in old stems of Ephedra campylopoda C. A. Mey. Ephedra campylopoda C. A. Mey is a woody climber of the Ephedraceae. The vascular rays of old, thick stems of E. campylopoda differ greatly from the known ray structure found in young stems of the same species, and from the common ray structure of other woody species. The large rays in thick stems include xylem in various orientations, and they intermingle with the axial system. We suggest that this is a variant secondary growth, a common characteristic of climbers.     

Five new C21 steroidal glycosides from the stems of Marsdenia tenacissima

Five new C₂₁ steroidal glycosides (1-5) were isolated from the stems of Marsdenia tenacissima. The chemical structures and relative configurations of the new compounds were elucidated by mass spectrometry and NMR spectroscopy. Cellular assay of these compounds showed that they are weak cytotoxic to various cell lines.     

Transcriptome Profiling of Khat (Catha edulis) and Ephedra sinica Reveals Gene Candidates Potentially Involved in Amphetamine-Type Alkaloid Biosynthesis

Amphetamine analogues are produced by plants in the genus Ephedra and by khat (Catha edulis), and include the widely used decongestants and appetite suppressants (1S,2S)-pseudoephedrine and (1R,2S)-ephedrine. The production of these metabolites, which derive from L-phenylalanine, involves a multi-step pathway partially mapped out at the biochemical level using knowledge of benzoic acid metabolism established in other plants, and direct evidence using khat and Ephedra species as model systems. Despite the commercial importance of amphetamine-type alkaloids, only a single step in their biosynthesis has been elucidated at the molecular level. We have employed Illumina next-generation sequencing technology, paired with Trinity and Velvet-Oases assembly platforms, to establish data-mining frameworks for Ephedra sinica and khat plants. Sequence libraries representing a combined 200,000 unigenes were subjected to an annotation pipeline involving direct searches against public databases. Annotations included the assignment of Gene Ontology (GO) terms used to allocate unigenes to functional categories. As part of our functional genomics program aimed at novel gene discovery, the databases were mined for enzyme candidates putatively involved in alkaloid biosynthesis. Queries used for mining included enzymes with established roles in benzoic acid metabolism, as well as enzymes catalyzing reactions similar to those predicted for amphetamine alkaloid metabolism. Gene candidates were evaluated based on phylogenetic relationships, FPKM-based expression data, and mechanistic considerations. Establishment of expansive sequence resources is a critical step toward pathway characterization, a goal with both academic and industrial implications.     

Ephedra sinica Stapf (Ephedraceae): The fleshy bracts of seed cones used in Mongolian food and its nutritional components

Ephedra sinica Stapf (commonly, Chinese ephedra) grows mainly in Mongolia, Inner Mongolia, and other regions of northern China. The stems of Chinese ephedra have been called the world’s oldest medicine; other uses remain to be reported. Among the Mongolian people, in addition to medical applications, the fleshy bracts of the seed cones (or “fruit”) are traditionally used as food, fresh or dried, in several ways; for example, the fruit is used as a refined sugar, a cheese condiment, and a tea substitute. In this paper, we analyze the fruit’s nutritional components: moisture, crude protein, crude fat, crude fiber, carbohydrate, ash, pectin, vitamins, fatty acids, mineral elements, and amino acids. Ethnobotanical and nutritional component information may indicate that the plant has potential for development as a special food plant     

苍白秤钩风中脱皮甾酮类化学成分的研究

从中国广西药用植物苍白秤钩风(Diploclisia glaucescens)藤茎的95％乙醇提取物中分离得到5个脱皮甾酮类化合物(1-5)。通过NMR、MS以及化学沟通等方法分别将其结构鉴定为paristerone C-20,22-monoacetonide(1),paristerone(2),eodysterone(3),makisterone C(4)和capisterone(5)。化合物1为首次从自然界分得的天然产物,2,4,5亦为首次从该植物中分得。