Inhibition of leukotriene biosynthesis by stilbenoids from Stemona species

Fifteen stilbenoids and two alkaloids from Stemona collinsae, S. tuberosa, and S. peirrei were tested alongside the commercially available stilbenoids resveratrol and pinosylvin for inhibition of leukotriene formation in an ex vivo test system based on activated human neutrophilic granulocytes. The stilbenoids resveratrol (1), pinosylvin (2), dihydropinosylvin (3), stilbostemin A (4), stilbostemin B (5), stilbostemin D (6), stilbostemin F (7), stilbostemin G (8), stemofuran B (9), stemofuran C (10), stemofuran D (11), stemofuran G (12), stemofuran J (13), stemanthrene A (14), stemanthrene B (15), stemanthrene C (16), and stemanthrene D (17) showed structure-dependent activities with IC(50) values ranging from 3.7 to >50 microM. The alkaloids tuberostemonine (18) and neotuberostemonine (19) were inactive at a concentration of 50 microM.     

对叶百部化学成分研究

目的研究百部科百部属对叶百部Stemonatuberosa的化学成分。方法采用反相C18、硅胶、凝胶柱色谱、制备型HPLC等方法进行分离纯化,通过理化性质、光谱数据结合参考文献鉴定化合物结构。结果从对叶百部根部甲醇提取物中分离鉴定10个化合物,分别鉴定为6-甲氧基-3-甲基-2H-吡喃-2-酮(1)、stilbostemin A(2)、stilbostemin K(3)、stilbostemin P(4)、stilbostemin Q(5)、stilbostemin R(6)、stilbostemin T(7)、stilbostemin W(8)、stilbostemin X(9)、stilbostemin Y(10)。结论化合物1为新的吡喃酮,命名为对叶百部吡喃酮A,化合物2、3为首次从该植物中分离得到。     

竹叶兰中联苄类化学成分和抗肿瘤活性研究

目的:进行竹叶兰干燥根茎中的化学成分和体外抗肿瘤活性研究。方法:乙醇提取,硅胶、SephadexLH-20及ODS柱色谱分离,采用UV,NMR和MS等方法确定化合物的结构。采用MTT法测试化合物对人肝癌细胞Bel-7402和人胃癌细胞BGC-823抗肿瘤药理活性。结果:分得6个化合物,分别为2,7-二羟基-1-(对-羟基苄基)-4-甲氧基-9,10-二氢菲(2,7-di-hydroxy-1-(p-hydroxylbenzyl)-4-methoxy-9,10-dihydrophenanthrene,1),4,7-二羟基-1-(对-羟基苄基)-2-甲氧基-9,10-二氢菲[4,7-dihydroxy-1-(p-hydroxylbenzyl)-2-methoxy-9,10-dihydrophenanthrene,2],3,3’-二羟基-5-甲氧基-联苄(3,3’-dihydroxy-5-me-thoxybibenzyl,3),反式阿魏酸二十四烷酯[(2E)-2-propenoic acid,3-(4-hydroxy-3-methoxyphenyl)-tetracosyl ester,4],反式阿魏酸二十五烷酯[(2E)-2-propenoic acid,3-(4-hydroxy-3-methoxyphenyl)-pentacosyl ester,5],十五烷酸(pentadecyl acid,6)。体外抗肿瘤实验表明,联苄类化合物具有一定的抗肿瘤活性。结论:除化合物3外,另5个化合物均为首次从竹叶兰中分离得到,联苄类化合物均表现出一定的体外细胞毒活性,开环型联苄类化合物3的抗肿瘤活性强于闭环型联苄类化合物1和2。     

Phytochemical studies on Stemona aphylla: isolation of a new stemofoline alkaloid and six new stemofurans

A new stemofoline alkaloid, (2'S)-hydroxy-(11S,12R)-dihydrostemofoline (3), new stemofurans M-R (8-13), and known compounds stemofoline (1), (2'S)-hydroxystemofoline (2), stemofuran E (4), stemofuran F (5), stemofuran J (6), and stilbostemin F (7) have been isolated from the root extracts of Stemona aphylla. The structures and relative configurations of these new compounds have been determined by spectroscopic data interpretation and from semisynthetic studies. These natural and semisynthetic alkaloids were tested for acetylcholinesterase inhibitory activities and were found to be 10-20 times less active than 1',2'-didehydrostemofoline itself. Stemofurans 4, 6, 8, 11, and 13 were tested for their antibacterial and antifungal activities. Three of these showed antibacterial activities against MRSA with MIC values of 15.6 μg/mL.     

Triterpene glycosides from the deep-water North-Pacific sea cucumber Synallactes nozawai Mitsukuri

Five non-sulfated triterpene glycosides, synallactosides A(1) (1), A(2) (2), B(1) (3), B(2) (4), and C (5), have been isolated from the sea cucumber Synallactes nozawai. Their structures have been deduced by extensive analysis of NMR and mass spectra. The glycosides 2-5 are new glycosides. Glycosides 2-4 have carbohydrate chains without precedent in the glycosides from sea cucumbers. This is the first time glycosides are found in members of the family Synallactidae.     

连钱草的化学成分研究

采用硅胶柱色谱、Sephadex LH-20、ODS和HPLC等色谱技术对连钱草全草进行化学成分研究,得到14个化合物。通过理化数据和波谱等手段鉴定其结构,化合物分别鉴定为 stilbostemin B（1）,trilepisiumic acid（2）,3,4-二羟基苯基乙醇酮（3）,岩白菜素（4）,oresbiusin A（5）,norbergenin（6）,stilbostemin D（7）,ehretioside B（8）,阿魏酸乙酯（9）,反式对羟基肉桂酸（10）,没食子酸甲酯（11）,原儿茶酸（12）,对羟基苯乙酮（13）,E-3-2,4-二羟基苯基-2-丙烯酸（14）,其中化合物 1~10 及化合物 13为首次从该植物中分离得到。     

Triterpene glycosides from Antarctic sea cucumbers. 1. Structure of liouvillosides A1, A2, A3, B1, and B2 from the sea cucumber Staurocucumis liouvillei: new procedure for separation of highly polar glycoside fractions and taxonomic revision

Five new triterpene glycosides, liouvillosides A1 (1), A2 (2), A3 (3), B1 (4), and B2 (5), have been isolated from the Antarctic sea cucumber Staurocucumis liouviellei along with the known liouvilloside A(6), isolated earlier from the same species, and hemoiedemosides A (7) and B (8), isolated earlier from the Patagonian sea cucumber Hemioedema spectabilis. The isolation was carried out using a new chromatographic procedure including application of ion-pair reversed-phase chromatography followed by chiral chromatography on a cyclodextrin ChiraDex column. The structures of the new glycosides were elucidated using extensive NMR spectroscopy (1H and 13C NMR spectrometry, DEPT, 1H-(1)H COSY, HMBC, HMQC, and NOESY), ESI-FTMS, and CID MS/MS, and chemical transformations. Glycosides 1-3 are disulfated tetraosides and glycosides 4 and 5 are trisulfated tetraosides. Glycosides 2 and 3 contain 3-O-methylquinovose, found for the first time as a natural monosaccharide in sea cucumber glycosides. On the basis of analyses of glycoside structures a taxonomic revision is proposed.     

Triterpene glycosides from the Far Eastern sea cucumber Cucumaria conicospermium

Four new triterpene glycosides, cucumariosides A(2)-5 (1), A(3)-2 (2), A(3)-3 (3), and isokoreoside A (4), along with the previously isolated koreoside A (5), have been found in the sea cucumber Cucumariaconicospermium. Glycoside 1 was isolated as a native substance, while glycosides 2-5 were identified through their desulfated derivatives. Their structures have been deduced by extensive spectral analysis (NMR and MS) and chemical evidence. All the glycosides contain the same branched pentasaccharide carbohydrate chain but differ in the number and positions of the sulfate groups. Glycoside 1 has one, glycosides 2 and 3 have two, and glycosides 4 and 5 have three sulfate groups. Glycosides 2-5 are non-holostane derivatives; their aglycons lack the 18(20)-lactone and are characterized by shortened side chains, which is a very rare feature among the sea cucumber glycosides.     

Mollisosides A, B1, and B2: minor triterpene glycosides from the New Zealand and South Australian sea cucumber Australostichopus mollis

Three new monosulfated triterpene glycosides, mollisosides A (2), B(1) (3), and B(2) (4), have been isolated from the sea cucumber Australostichopus mollis. Their structures were determined by NMR and mass spectra. The presence of sulfated glycosides in sea cucumbers belonging to the family Stichopodidae is uncommon.     

Triterpene Glycosides from Sea Cucumber Holothuria scabra with Cytotoxic Activity

Objective To study the new triterpene glycosides from sea cucumber Holothuria scabra with cytotoxic activity.Methods Triterpene glycosides from H.scabra were separated and purified by chromatography on...     

Triterpene glycosides from the far eastern sea cucumber Pentamera calcigera II: disulfated glycosides

Three new triterpene glycosides, calcigerosides D(1) (1), D(2) (2), and E (3), have been isolated from the sea cucumber Pentamera calcigera. Their structures have been deduced from extensive spectral analysis (NMR and MS) and chemical evidence. All the compounds are disulfated pentaosides differing in aglycon structure and position of sulfate group, which were determined by the measurement of NT(1) values in the cases of glycosides 1 and 2. Glycoside 1 is a nonholostane derivative, that is, it lacks an 18(20)-lactone, which is very rare among the sea cucumber glycosides.     

西藏胡黄连的苯乙醇糖苷类化学成分研究

目的 :对西藏胡黄连Picrorhizascrophulariiflora根的苯乙醇糖苷类化学成分进行研究。方法 :采用色谱技术进行分离 ,通过¹H ,¹³C-NMR等波谱技术确定化合物的结构。结果 :分离并鉴定了 6个苯乙醇糖苷类化合物 :2-(3,4-二羟基苯基 )乙基-O/i>-β-D-吡喃葡萄糖苷 (1) ,2-(3-羟基-4-甲氧基苯基 )乙基 -O/i>-β-D- 吡喃葡萄糖基 (1→ 3)-β-D-吡喃葡萄糖苷 (2 ) ,scrosideB (3) ,hemiphrosideA (4) ,plantainosideD (5 ) ,scrosideA (6 )。结论 :其中化合物 1,2 ,4和 5系首次从该植物中分离得到 ,2为新的天然产物。     

Water-soluble glycosides from Ruta graveolens

An EtOH extract of the dried aerial parts of Ruta graveolens was suspended in water and then partitioned with EtOAc. Three new glycosides, 3'-sinapoyl-6-feruloylsucrose (4), methylcnidioside A (5), and methylpicraquassioside A (6), together with four known glycosides, 3',6-disinapoylsucrose (1), cnidioside A (2), rutin, and picraquassioside A (3), were isolated from the water-soluble part. Their structures were elucidated by interpretation of IR, MS, and 1D and 2D NMR spectra and comparison with literature data.     

Metabolic fate of orally administered phyllodulcin in rats

Naturally occurring phyllodulcin (1) was orally administered to rats to investigate its metabolic fate. Urinary metabolites were analyzed by three-dimensional HPLC. Phyllodulcin-3'-O-sulfate (2), phyllodulcin-3'-O-beta-glucuronide (3), 2-[2-(3,4-dihydroxyphenyl)ethyl]-6-hydroxybenzoic acid (4), and one novel bibenzyl derivative, 2-[2-(3-hydroxy-4-methoxyphenyl)ethyl]-6-hydroxybenzoic acid (5), together with thunberginol G (6) and hydrangenol (7) were isolated from the phyllodulcin-treated urine. 1 was extensively metabolized to 4-6 by a rat fecal suspension after incubation for 24 h. Urinary excretion of 4-6 in rats administered phyllodulcin orally was substantially reduced when the rats were treated with antibiotics to suppress their intestinal flora. On the other hand, the incubation of 1 with rat liver S-9 mix showed the presence of 7 together with 4 and 5.     

Neuroprotective constituents from Hedyotis diffusa

In a bioassay-guided search for neuroprotective compounds from medicinal plants, a MeOH extract of whole plants of Hedoytis diffusa yielded five flavonol glycosides, kaempferol 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (1), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (2), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-glucopyranoside (3), kaempferol 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (4), and quercetin 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (5), and four O-acylated iridoid glycosides (6-9). Compounds 1 and 2 are previously unreported natural products, and all nine compounds exhibited significant neuroprotective activity in primary cultures of rat cortical cells damaged by L-glutamate.     

Steroidal alkaloid glycosides from tomato (Lycopersicon esculentum)

Three new steroidal alkaloid glycosides, lycoperosides F-H (1-3), were isolated from tomato fruits (Lycopersicon sculentum) along with lycoperosides A-D, esculeoside A, and rutin. The structures of these glycosides were characterized as the 3-O-beta-lycotetraosides of 23(R)-23-acetoxy-27-hydroxy-27-O-beta-d-glucopyranosyltomatidine (1), (23S,24R)-23-acetoxy-24-O-beta-d-glucopyranosylsoladulcidine-24-ol (2), and 22-isopimpifolidine (3), by means of their spectroscopic data. Also obtained was the new natural product lycoperodine-1 (4).     

Steroidal glycosides from the leaves of Cestrum nocturnum

Further phytochemical analysis aimed at the steroidal glycoside constituents of the leaves of Cestrum nocturnum has resulted in the isolation of eight new steroidal glycosides (1-8), which were classified into a spirostanol saponin (1), a furostanol saponin (2), a pseudo-furostanol saponin (3), two pregnane glycosides (4, 5), two cholestane glycosides (6, 7), and pregnane-carboxylic acid gamma-lactone glycoside (8), and of two known spirostanol glycosides (9, 10). The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence.     

Antioxidant constituents of the aerial parts of Globularia alypum growing in Morocco

Three new phenolic compounds were isolated from the aerial parts of Globularia alypum. Their structures were determined as 6-hydroxyluteolin 7-O-laminaribioside (1), eriodictyol 7-O-sophoroside (2), and 6'-O-coumaroyl-1'-O-[2-(3,4-dihydroxyphenyl)ethyl]-beta-D-glucopyranoside (3). In addition, three phenylethanoid glycosides (acteoside, isoacteoside, and forsythiaside) and two flavonoid glycosides (6-hydroxyluteolin 7-O-beta-D-glucopyranoside and luteolin 7-O-sophoroside) were also isolated and are reported here for the first time in this plant. The structures of compounds 1-3 were established on the basis of their spectroscopic data analysis. Evaluation of the antioxidative activity, conducted in vitro, showed that the isolated phenylethanoids and flavonoid glycosides possess strong effects of this type.     

Synaptosides A and A1, triterpene glycosides from the sea cucumber Synapta maculata containing 3-O-methylglucuronic acid and their cytotoxic activity against tumor cells

Two novel triterpene holostane glycosides, synaptosides A ( 1) and A 1 ( 2), have been isolated from the Vietnamese sea cucumber Synapta maculata (Synaptida, Apodida). Their structures were elucidated by spectroscopic methods (NMR and MS) and chemical transformations. Glycosides 1 and 2 have rare branched pentasaccharide carbohydrate chains featuring a 3- O-methylglucuronic acid residue not previously reported in glycosides from sea cucumbers and a 6- O-sulfated glucose. Glycoside 2 has an oxo group at C-7 and a 8(9)-double bond. All these structural features are unknown in glycosides from sea cucumbers. Glycoside 1 has moderate cytotoxic activity (IC 50 8.6 microg/mL) and glycoside 2 is inactive against HeLa tumor cells.     

A new naphthopyrone derivative from Cassia quinquangulata and structural revision of quinquangulin and its glycosides

A novel naphthopyrone derivative, named quinquangulone (1), has been isolated from Cassia quinquangulata, along with the known compounds quinquangulin (2) and its two glycosides (3 and 4), rubrofusarin (5) and its two glycosides (6 and 7), nor-rubrofusarin (8) and its 6-O-glucoside (9), and three stilbenes (10-12). The structure of quinquangulone was established by spectral interpretation as 5,9-dihydroxy-8-methoxy-2,9-dimethyl-6-oxo-4H,6H,9H-naphtho-[2,3-b]pyran-4-one. Reinvestigation of the NMR spectra of quinquangulin led to revision of its structure as 5,6-dihydroxy-8-methoxy-2,9-dimethyl-4H-naphtho[2,3-b]pyran-4-one (2a). The structures of two quinguangulin glycosides, 3 and 4, were also revised accordingly. Compound 2a exhibited activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC, 3.125 and 6.25 microg/mL, respectively).