Norisoprenoids from Ulva lactuca

Five norisoprenoids were isolated from the green marine alga Ulva lactuca. Two new compounds were assigned to (3R,5R,6R,7E)3,5,6-trihydroxy-7-megastigmen-9-one (1) and (3S,5R,6S,7E)3,5,6-trihydroxy-7-megastigmen-9-one (2). The structures and absolute configurations of the five compounds were determined by analyses of NMR, MS and circular dichroism (CD).     

A novel sulphur glycoside from the seeds of Descurainia sophia (L.)

A new sulphur glycoside, named descurainoside (1), and the known compound sinapic acid (2) have been isolated from the seeds of Descurainia sophia (L.) Webb ex Prantl. The structure of 1 has been identified as (1R,6S,8R,9S,10S)-9,10-dihydroxy-4-[(4-hydroxy-3,5-dimethoxyphenyl)methylene]-8-(hydroxymethyl)-2,7-dioxa-5-thiabicyclo[4.4.0]decan-3-one by means of physico-chemical properties and spectroscopic methods (1D and 2D NMR, HRMS, ESI-MS).     

Chemical Constituents from the Leaves of Magnolia Denudata

20 compounds were isolated from the leaves of Magnolia denudata including 16 lignans, which belong to 6 structural types. Except for (7R, 8S, 1'S) -δ^8' - 1', 4' - dihydro - 5'- methoxy - 3, 4 -methylenedioxy - 4' - oxo -7.O.2', 8.1' - neolignan (6), magliflonenone (9), 2,5' - diene-2', 8'- epoxy - 5' - methoxy - 8 - methyl - 4' - oxo - 3,4-methylenedioxy - spiro (5,5) - undecane (10), veraguensin (16) and β-sitosterol (20), the other 15 compounds were obtained from this species for the first time. The absolute configurations of 3 compounds (1,4,10) were determined by CD spectroscopy for the first time. The anti-inflammatory activities of compounds 1, 2 and 16 were assessed and 2 was shown to have significant inhibition effect on mice hind-paw edema induced by carrageenan.     

杜仲叶中倍半萜及降碳倍半萜的分离与鉴定

目的 研究植物杜仲(Eucommia ulmoides Oliver)叶中的化学成分.方法 综合运用硅胶柱色谱、反相硅胶柱色谱和Sephadex LH-20凝胶柱色谱以及制备型高效液相色谱等方法进行系统分离,根据化合物的理化性质及其波谱数据确定化合物的结构.结果 从杜仲叶80％(体积分数)乙醇提取物中分离得到了12个倍...     

Anthraquinones from Gladiolus gandavensis

Five new anthraquinones have been obtained from the ethanolic extracts of the subterranean corms of Gladiolus gandavensis Van Houtt. Their structures were elucidated as 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone (gandavensin D, 1), methyl 3,8-dihydroxy-6,7-methylenedioxy-1-methyl-anthraquinone- 2-carboxylate (gandavensin E, 2), 2,3,8-trihydroxy-6-methoxy-1-methoxymethyl-anthraquinone (gandavensin F, 3), 8-hydroxy-3,6-dimethoxy-1-methyl-anthraquinone-2-carboxylic acid (gandavensin G, 4) and 1,7-dihydroxy-3,6-dimethoxy-anthraquinone (gandavensin H, 5) on the basis of spectral data. The known compounds isolated for the first time from this plant have been determined to be methyl 3,6,8-trihydroxy-7-methoxy-1-methyl-anthraquinone-2-carboxylate (6), methyl 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (7), 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylic acid (8), 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylic acid (9), 6,8-dihydroxy-3-methoxy-1-methyl-anthraquinone-2-carboxylic acid (10), methyl 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylate (11) and methyl 3,7,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (12).     

Xanthones from the roots of Cudrania fruticosa Wight

Chemical investigation on the roots of Cudrania fruticosa resulted in the isolation of two new xanthones, 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (1) and 3,6,7-trihydroxy-1-methoxyxanthone (2), together with three known ones, 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl)xanthone (3), 1,3-dihydroxy-6,7-dimethoxyxanthone (4) and 3,5,6-trihydroxy-1-methoxyxanthone (5), respectively. Their structures were elucidated on the basis of spectral and chemical techniques.     

A new amide from Asarum forbesii Maxim

A highly unsaturated new amide, (2E,4Z,8Z,10Z)-N-isobutyl-2,4,8,10-dodecatetraenamide (1), was isolated in very small quantities from the whole plant of Asarum forbesii Maxim. together with four known compounds, (2E,4E,8Z,10E)-N-isobutyl-2,4,8,10-dodecatetraenamide (2), (-)-sesamin (3), (-)-asarinin (4) andE)-asarone5). The Z/E isomers, 1 and 2, were separated successfully by developed silver-ion medium-pressure liquid chromatography (SIMPLC). Compound 2 and the two diastereoisomers, 3 and 4, were isolated from this plant for the first time. The characterization of these compounds was achieved by various spectroscopic methods.     

Three new xanthones from the roots of Polygala japonica Houtt.

Three new xanthones, 3, 6-dihydroxy-1, 2, 7-trimethoxyxanthone (2), 3, 7-dihydroxy- 1, 2-dimethoxyxanthone (4) and 1, 2, 7-trihydroxy-3-methoxyxanthone (9), together with seven known compounds were isolated from the roots of Polygala japonica Houtt. Their structures were determined on the basis of spectroscopic data.     

Rearranged abietane diterpenoids from Clerodendrum mandarinorum

Five new abietane derivatives which have a commonly rearranged abietane skeleton contained a 17(15 → 16),18(4 → 3)-diabeo-abietane framework, mandarones D-H, were isolated from the stem of Clerodendrum mandarinorum Diels (Verbenaceae). The structures were characterized as (16S)-12,16-epoxy-11-hydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13-pentaene-7-one (mandarone D, 1), 12,16-epoxy-11,14-dihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-7-one (mandarone E, 2), 12,16-epoxy-6,11,14-trihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-7-one (mandarone F, 3), 12,16-epoxy-11,14-dihydroxy-6-methoxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-2,7-dione (mandarone G, 4) and 12,16-epoxy-11,14-dihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-1,7-dione (mandarone H, 5) respectively, mainly based on the spectral analysis and by comparison with those of closely related compounds.     

Labdane diterpenes from the seeds of Platycladus orientalis

Two new labdane diterpenes, 14(R),15-dihydroxy-8(17),12(E)-labdadien-19-oic acid (1) and 16-methyl-12,15-epoxy-8(17),13-labdadien-19-oic acid (2), together with four known compounds, were isolated from the seeds of Platycladus orientalis. Their structures were established by spectroscopic methods. The stereochemistry of compound 1 was defined by X-ray crystallographic analysis.     

9, 10-Dihydrophenanthrene derivatives from Pholidota yunnanensis and scavenging activity on DPPH free radical

Three new 9,10-dihydrophenanthrene derivatives named phoyunnanins A-C, together with six known 9,10-dihydrophenanthrene constituents, 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (4), lusianthridin (5), eulophiol (6), 2,4,7-trihydroxy-9,10-dihydrophenanthrene (7) and imbricatin (8), were isolated from the 60% ethanolic extract of air-dried whole plant of Pholidota yunnanensis Rolfe. The structures of phoyunnanins A-C were established as 6-[2'-(3',3'-dihydroxy-5'-methoxybibenzy)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 6-[6'-(trans-3',3'-dihydroxy-5'-methoxystilbeny)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (2) and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,6'-biphenanthrene (3), respectively, on the basis of the spectroscopic analysis. All eight compounds (1-8) were found to show the DPPH free radical scavenging activity with EC₅₀ from 8.8 to 55.9 μM.     

Ether-soluble resin glycosides from the roots of Ipomoea batatas

Two new resin glycosides, batataosides I (1) and II (2), and five known compounds, friedelin (3), scopoletin (4), octadecyl caffeate (5), β-sistosterol (6) and daucosterol (7), were isolated from the roots of Ipomoea batatas. Their structures have been determined based on the chemical and spectral data. Batataosides I and II have novel structures because the core simonic acid B was esterised with cinnamic acid for the first time, and three different substituent esterification groups in one resin glycoside is scarce. The absolute configuration of the aglycone was elucidated to be S by Mosher's method.     

A New Bicoumarin from Stellera Chamaejasme L

Thirteen compounds were isolated from roots of Stellera chamaejasme L. (Thymelaeaceae). They are β-sitosterol (2), simplexin (3), pimelea factor P2 (4), daucosterol (5), (+)-3-hydroxy-1,5-diphenyl-1-pentanone (6), 4-ethoxy-benzoic acid (7), 2,4,6-Trimethoxy-benzoic acid (8), (+)-afzelechin (9), fumaric acid (10), N,N-dimethyl-L-aspartic acid (11), umbelliferone (12), daphniretin (13) and a novel bicoumarin named bicoumastechamin (1). Among the known compounds, 7, 8, 9, 10 and 11 were first isolated from this plant, and 6 was first isolated from the natural resources. Their structures have been elucidated on the basis of spectral data. In vitro bioassays showed that 4 inhibited cancer cell growth, 13 exhibited immunomodulatory activity, and 6 exhibited both immunomodulatory and anti-tumor activity.     

Coumarins from Coriaria nepalensis

Two new coumarins (1) and (2), along with seven known coumarins 3-9, were isolated from the leaves and stems of Coriaria nepalensis Wall. The two new compounds were established as 7-hydroxy-6-methoxy-3,8-bis(3-methyl-2-butenyl) coumarin (1) and 7-hydroxy-6-methoxy-3-(3-methyl-2-butenyl) coumarin (2), on the basis of 1D and 2D NMR techniques. The known compounds 3, 6-9 were isolated from this plant for the first time.     

Antibacterial constituents from Stemona sessilifolia

Bioassay-guided fractionation led to the isolation of eight compounds from Stemona sessilifolia. Of the eight isolates, three new bibenzyls, stilbostemins M-O (1-3), and a new tocopherol, 6-methoxy-3,4-dehydro-δ-tocopherol (4) were revealed together with four known compounds 3,5-dihydroxy-2'-methoxy bibenzyl (5), 3,5-dihydroxy bibenzyl (6), β-tocopherol (7), and γ-tocopherol (8). Compounds 5, 6, and 8 exhibited strong antibacterial activities against Staphylococcus aureus and S. epidermidis.     

A new diterpenoid and active stilbenes from Pinus armandii heartwood

8(17),13-Labdadien-16,14-olid-18-oic acid (1), a new diterpenoid, has been isolated from the heartwood of Pinus armandii Francher, along with seven known diterpenoids (2-8) and four known stilbenes (9-12). Their structures have been elucidated by spectral evidence. (E)-3-Hydroxy-5-methoxystilbene (9) showed significant inhibition against white-rot fungi.     

A new triterpenoid from Entodon okamurae Broth

One new triterpenoid, entokamurol (1), was isolated from Entodon okamurae Broth, together with other nine compounds, namely dryocrassol (2), chrysophamol (3), physcion (4), 10-nonacosamnol (5), n-hexadecanol (6), phthalic acid isodibutyl ester (7), curcumol (8), β-sitosterol (9) and daucosterol (10). Their structures were elucidated on the basis of extensive NMR (DEPT, DQF-COSY, HMQC, HMBC and NOESY), IR and MS studies. All the compounds were isolated and identified from the genus of Entodon for the first time, and it is also the first report of a guaiane-type sesquiterpenoid and compounds with anthraquinone skeleton in mosses.     

Phenolic glycosides from leaves of Hopiciopsis lobata

A new phenolic glycoside, 6'-[(E)-2'-hydroxymethyl, 2'-butenoyl] arbutin (1), and two known phenolic glycosides, 6'-[(E)-4'-hydroxycinnamoyl] arbutin (2) and 6'-[(E)-3',4'-dihydroxycinnamoyl] arbutin (3), were isolated from the leaves of Heliciopsis lobata (Merr.) Sleum. Their structures were elucidated by various spectroscopic methods including 2D NMR spectroscopy.     

A new thiaziedione from the fruits of Xanthium sibiricum

A novel sulphur-containing compound named xanthiazinone (1) was isolated from the ethanolic extract of the fruits of Xanthium sibiricum, along with four known compounds, xanthiazone (2), xanthiside (3), xanthienopyran (4) and 5-hydroxypyrrolidin-2-one (5). Their structures were determined on the basis of spectroscopic techniques.     

Heteroclitin H, a new lignan from Kadsura heteroclita

A new dibenzocyclooctadiene lignan, heteroclitin H (1), was isolated together with seven known compounds, heteroclitin D (2), interiorin B (3), interiorin (4), neokasuranin (5), interiotherin C (6), gomisin J (7) and (+)-anwulignan (8), from the stems of Kadsura heteroclita. Their structures were elucidated by spectroscopic methods. This is the first report of the isolation of compounds 3, 5, 6, 7 and 8 from K. heteroclita.