Germacra-12,6β-olides from Montanoa revealii and M. mollissima

Montanoa revealii and M. mollissima yielded a series of germacra-12,6β-olides similar to those previously reported from M. hibiscifolia and M. pteropoda.     

Sesquiterpene lactones of Montanoa guatemalensis and Montanoa tomentosa subsp. Xanthiifolia

New 4,5-epoxygermacra-12,6β-olides from Montanoa guatemalensis and a Guatemalan disjunct collection of M. tomentosa subsp. xanthiifolia are reported. These compounds were unlike those from the 10 other Mexican collections of M. tomentosa previous investigated.     

Elemanolides from Zinnia peruviana

Zinnia peruviana from Honduras afforded two new acetal-type elemanolides as well as a mixture consisting primarily of zinaflorin III.     

Ent-kauranes and 10α-methyl-eudesman-8αh,12-olides from wedelia calycina and wedelia hispida

The aerial parts of Wedelia hispida furnished small amounts of three new 10α-methyl-eudesman-8α,12-olides as well as some known ent-kauranes. Wedelia calycina yielded various ent-kaurane derivatives, several of them new.     

Diterpenoids from galeopsis angustifolia

The structures of two new diterpenoids, galeopsin and pregaleopsin, isolated from aerial parts of Galeopsis angustifolia (Labiatae) have been shown to be 8β-acetoxy-15,16-epoxy-9α-hydroxylabda-13(16),14-dien-7-one and 8β-acetoxy-9α,13R; 15,16-diepoxylabd-14-en-7-one, respectively, by chemical and spectroscopic studies. The previously known diterpenoid hispanolone (15,16-epoxy-9α-hydroxy-8α-labda-13(16),14-dien-7-one) has been also obtained from the same source. A thermal retroaldol reaction in the absence of solvent experienced by these 9-hydroxy-7-keto-labdanes is also described.     

Diterpenoids from Salvia oxyodon and Salvia lavandulifolia

Three new diterpenoids have been detected in Salvia oxyodon and identified as 3β-hydroxy-dehydroabietic acid, 3β-acetoxy-abieta-8(14)-en-18-oic acid 9α,13α-endoperoxide and 3β-hydroxy-abieta-8(14)-en-18-oic acid 9α,13α-endoperoxide. Salvia lavandulifolia yielded two known compounds ursolic acid and galdosol.     

Humirianthenolides,new degraded diterpenoids from Humirianthera rupestris

The tuber of Humirianthera rupestris (Icacinaceae) contains the degraded diterpenoids 3β,20-epoxy-30α- hydroxy- 14-oxo-9β-podocarpan-19,6β-olide (humirianthenolide A), 3β,20-epoxy-3α,14α-dihydroxy-9β-podocarpan-19,6β- olide (humirianthenolide B), 3β,20; 16,14-diepoxy-3α-hydroxy-17-nor-15-oxo-9β-abiet-13-en-19,6β-olide (humirianthenolide C), 3β,20-epoxy-3α,14-dihydroxy-13-oxo-9β-podocarp-8(14)-en-19,6β-olide (humirianthenolide D), 3β,20-epoxy-3α-hidroxy-14-oxo-8α,9β-podocarpan-19,6β-olide (humirianthenolide E) and 3β,20-epoxy-3α,14β- dihydroxy-8α,9β-podocarpan-19,6β-olide (humirianthenolide F). ¹H NMR and ¹³C NMR spectroscopy were efrective for the determination of the humirianthenolide structures.     

Sesquiterpene lactones from Calea leptocephala

Chemical analysis of Calea leptocephala yielded seven sesquiterpene lactones three of which had not been previously reported as natural products. The new compounds were represented by a furanoheliangolide, 8β-angeloyloxy-9α-acetoxycalyculatolide, the germacranolide desacetylcalein A, and a guaianolide, 8β-angeloyloxyleptocephalide. The structures of the new compounds were established by spectroscopic methods.     

Efficient synthesis of 17-acetyl-13-(p-bromophenyl)-3-methoxy-11,11-bis(methoxycarbonyl)gona-1,3,5(10)-trienes

We described an efficient synthesis of (8β,9β,14β)-17β-acetyl-13β-p-bromophenyl-11,11-di(methoxycarbonyl)-3-methoxygona-1,3,5(10)-triene, (8β,9α,14β)-17β-acetyl-13β-p-bromophenyl-11,11-di(methoxycarbonyl)-3-methoxygona-1,3,5(10)-triene, (8β,9β,14β)-13 β-p-bromophenyl-11,11-di(methoxycarbonyl)-17β-(2-hydroxyethyl)-3-methoxygona-1,3,5(10)-triene, and (8β,9β,14β)-13β-p-bromophenyl-11,11-di(methoxycarbonyl)-17β-(2-oxoxyethyl)-3-methoxygona-1,3,5(10)-triene in five or six steps from 1-iodo-4-methoxybenzocyclobutene and readily available materials.     

8-Diazoguanosine, 2,8-Diaminoadenosine and Other Purine Nucleosides Derived from Guanosine

Abstract

Diazotization of 8-aminoguanosine gave 8-diazoguanosine (2) which is stable in neutral and basic media, but decomposes to D-ribose and 8-diazoguanine in acidic conditions. 2-Amino-6,8-dichloro-9-(2,3,5-tri-0-acetyl-β-D-ribo-furanosyl)purine (5) was employed to synthesize 9-β-D-ribofuranosyl-2,6,8-triaminopurine (8) and a number of N6-alkyl-2-amino-8-chloro-9-β-D-ribofuranosylpurines.     

黑柄炭角菌的化学成分

从黑柄炭角菌(Xylaria nigripe)子实体中分离得到10个化合物,通过波谱分析等方法分别鉴定为(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(1)、5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(2)、脑苷酯B(3)、脑苷酯D(4)、stearic acid(5)、甘油的亚油酸三酯(trilinolein,6)、α-kojibiose(7)、D-阿洛糖醇(8)、L-氨基丙酸(9)和尿囊素(10)。所有化合物均为首次从该子实体中分离得到。     

Polydom/SVEP1 is a ligand for integrin α9β1

A variety of proteins, including tenascin-C and osteopontin, have been identified as ligands for integrin α9β1. However, their affinities for integrin α9β1 are apparently much lower than those of other integrins (e.g. α3β1, α5β1, and α8β1) for their specific ligands, leaving the possibility that physiological ligands for integrin α9β1 still remain unidentified. In this study, we found that polydom (also named SVEP1) mediates cell adhesion in an integrin α9β1-dependent manner and binds directly to recombinant integrin α9β1 with an affinity that far exceeds those of the known ligands. Using a series of recombinant polydom proteins with N-terminal deletions, we mapped the integrin-binding site to the 21st complement control protein domain. Alanine-scanning mutagenesis revealed that the EDDMMEVPY sequence (amino acids 2636-2644) in the 21st complement control protein domain was involved in the binding to integrin α9β1 and that Glu(2641) was the critical acidic residue for the integrin binding. The importance of this sequence was further confirmed by integrin binding inhibition assays using synthetic peptides. Immunohistochemical analyses of mouse embryonic tissues showed that polydom colocalized with integrin α9 in the stomach, intestine, and other organs. Furthermore, in situ integrin α9β1 binding assays using frozen mouse tissues showed that polydom accounts for most, but not all, of the integrin α9β1 ligands in tissues. Taken together, the present findings indicate that polydom is a hitherto unknown ligand for integrin α9β1 that functions as a physiological ligand in vivo.     

A germacranolide from Inula indica

Chemical investigation of Inula indica has yielded a new germacranolide, 1β,10α-epoxy-2α,9β-dihydroxy-5β-acetoxy-6α(2-methylbutyryloxy)-germacran-8α,12-olide, whose structure and stereochemistry have been established from the spectral characteristics of the compound and its derivatives.     

Synthesis and acetylcholinesterase inhibitory activity of 2β,3α-disulfoxy-5α-cholestan-6-one

Disodium 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (8) has been synthesized using cholesterol (1) as starting material. Sulfation was performed using trimethylamine-sulfur trioxide complex in dimethylformamide as the sulfating agent. The acetylcholinesterase inhibitory activity of compound 8 was evaluated and compared to that of disodium 2β,3α-dihydroxy-5α-cholestane disulfate (10) and diols 7 and 9. Compounds 8 and 10 were active with IC(50) values of 14.59 and 59.65 μM, respectively. Diols 7 and 9 showed no inhibitory activity (IC(50)>500 μM).     

The structure of leocardin,two epimers of a diterpenoid from Leonurus cardiaca

From the aerial part of Leonurus cardiaca a new labdane diterpenoid, leocardin, has been isolated and its structure was established by spectroscopic and chemical means. It has been shown to be 8β-acetoxy-9α,13α,15,16-bisepoxy-15-hydroxy-7-oxo-labdan-6β,19-olide present as a C-15 epimeric mixture.     

水红木中两个新的酚苷成分

从水红木（Viburnum cylindricum）植物中分离出2个新化合物,1-phlomglucinyl-（6-methybutyryl）-β-D-glucopyranoside命名为cylindrin A（1）,1-[4-（3-hydroxyl-propyl）]-pyrocatechol-（6-methybutyryl）-β-D—glucopyranoside,命名为cylindrin B（2）。以及7个已知化合物tachioside（3）,syingic acid-4-β-D-glucopyran oside（4）,1-β-D—glucopyanosyloxy-3-methoxy-5-hydroxybenzene（5）,4-hydroxy-3-methoxyphenol-1-O-β-D-glucoside（6）,4-hydroxy-2,6-dimethoxyphen-1-O-β-D-glucoside（7）,phlorogluc inol-1-O-β-D-glucoside（8）,1-β-D-glucosyloxy-2-（3-nrethoxy-4-hydroxyphenyl）propane-1,3-diol（9）．它们的结构经波谱方法得到鉴定。3—9为首次从该种植物中分离得到。     

白粉藤的木脂素和三萜成分

从白粉藤（Cissus repens Lank）地上部分分离得到5个木脂素和8个三萜,其中一个木脂素是新化合物,它的结构通过波谱分析和碱水解的方法鉴定为：（＋）-异落叶松树脂醇-9′-（2-对-香豆酰）-O-β-D-吡喃木糖苷（1）。其余化合物分别是：（＋）-异落叶松树脂醇-9′-O-β-D-吡喃木糖苷（2）,（＋）-Lyoniside（3）,（—）-开环异落叶松树脂醇-9-O-β-D-吡喃木糖苷（4）,（7′R,8′S）-4′-hydroxy-3′,5-dimethoxy-7,8′-dihydrobenzofuran-1-propanolneolignan-9′-O-β-D-xylopyranoside（5）,木栓酮（6）,表木栓醇（7）,蒲公英赛醇乙酸酯（8）,熊果酸（9）,2α-羟基乌索酸（10）,积雪草酸（11）,Niga-ichigoside F1（12）,羽扇豆醇（13）。这些化合物都是首次从该植物中分离得到。     

蓝柄丽齿菌的化学成分

从担子菌亚门蓝柄丽齿菌(Calodon suaveolens)中首次分离得到8个化合物,通过波谱学技术并借助必要的化学方法最终确定结构,它们是：(22E,24R)-麦角甾-7,22-二烯-3β-醇(1),(22E,24R)-5α,8α-过氧麦角甾-6,22-二烯．3β-醇(2),(22E,24R)-麦角甾．5,7,22-三烯-3β-醇(3),(22E,24R)-3β-羟基麦角甾-5,22-二烯-7-酮(4),对羟基苯甲酸(5),尿嘧啶(6),polyozellin(7),(4E,BE）-2-N-(2’-羟基棕榈酰)-1-O-β-D-吡喃葡萄糖基-9-甲基-4,8-sphingadienine(8)。     

Furanoheliangolides and flavonoids from Lourteigia ballotaefolia

The aerial parts of Lourteigia ballotaefolia afforded, in addition to three known flavonoids, two furanoheliangolides. The structures and stereochemistries were determined by chemical and spectroscopic means and were established as the 8- and 9-acetylsarracinoyl esters of 1-keto-8β-9β-dihydroxygermacra-2,4,11(13)-trien-3, (10β)-oxo-6α,12-olide. The chemotaxonomic situation is discussed briefly.