欧洲凤尾蕨中C14蕨素类成分分离与鉴定

目的研究欧洲凤尾蕨Pteris cretica中蕨素类化学成分。方法结合蕨素UV特征吸收及MSn裂解规律,采用硅胶柱色谱、Sephadex LH-20柱、C18半制备柱等多种柱色谱进行蕨素类成分目标分离纯化,并应用理化性质和波谱数据对分离的化合物进行结构鉴定。结果从欧洲凤尾蕨乙醇提取物中分离得到19个C14蕨素类化合物,分别鉴定为(2S,3S)-蕨素T(1)、(2S,3S)-蕨素C 3-O-β-D-葡萄糖苷(2)、(2R,3S)-蕨素C 3-O-β-D-葡萄糖苷(3)、(2S)-蕨素B 14-O-β-葡萄糖苷(4)、6-(1,2-二羟乙基)-2,5,7-三甲基-1-茚-1(5)、(2R,3S)-蕨素C(6)、(2S,3S)-蕨素C(7)、(2S)-蕨素P(8)、(2R,3S)-蕨素S(9)、(2S,3S)-蕨素S(10)、(2R,3S)-蕨素Q(11)、(2S,3S)-蕨素Q(12)、(2S,3S)-蕨素C 14-O-β-D-葡萄糖苷(13)、(2R,3S)-蕨素C 14-O-β-D-葡萄糖苷(14)、(2S,3S)-蕨素S 14-O-β-D-葡萄糖苷(15)、脱氢蕨素B(16)、(2R,3S)-蕨素Q 3-O-β-D-葡萄糖苷(17)、(2S,3S)-蕨素Q3-O-β-D-葡萄糖苷(18)、(2S,3S)-蕨素T14-O-β-D-葡萄糖苷(19)。结论化合物2~5、10、11、14~19为首次从欧洲凤尾蕨中分离得到。     

Mode of action of epoxyphomalins A and B and characterization of related metabolites from the marine-derived fungus Paraconiothyrium sp

Epoxyphomalins A (1) and B (2) are highly potent cytotoxic fungal metabolites. During the course of purifying larger quantities of 1 and 2 from Paraconiothyrium sp. fermentation extracts, three new epoxyphomalins (3-5) were isolated and characterized, showing modifications to the oxidation pattern of the cyclohexene moiety or of C-9 of the decalin system. IC(50) values for cytotoxicity against a panel of 36 human tumor cell lines were determined for all new compounds. Compound 4 was found to be cytotoxic particularly toward prostate PC3M (IC(50) = 0.72 μM) and bladder BXF 1218 L (IC(50) = 1.43 μM) cancer cell lines. In addition, inhibition of chymotrypsin-, caspase-, and trypsin-like activity of purified 20S proteasomes was determined for epoxyphomalins A (1) and B (2). The results indicate that compounds 1 and 2 exert their cytotoxic effect through potent inhibition of the 20S proteasome.     

Hippolides A-H, acyclic manoalide derivatives from the marine sponge Hippospongia lachne

Eight new acyclic manoalide-related sesterterpenes, hippolides A-H (1-8), together with two known manoalide derivatives, (6E)-neomanoalide (9) and (6Z)-neomanoalide (10), were isolated from the South China Sea sponge Hippospongia lachne. The absolute configurations of 1-8 were established by the modified Mosher's method and CD data. Compound 1 exhibited cytotoxicity against A549, HeLa, and HCT-116 cell lines with IC50 values of 5.22×10(-2), 4.80×10(-2), and 9.78 μM, respectively. Compound 1 also showed moderate PTP1B inhibitory activitiy with an IC50 value of 23.81 μM, and compound 2 showed moderate cytotoxicity against the HCT-116 cell line and PTP1B inhibitory activity with IC50 values of 35.13 and 39.67 μM, respectively. In addition, compounds 1 and 5 showed weak anti-inflammatory activity, with IC50 values of 61.97 and 40.35 μM for PKCγ and PKCα, respectively.     

Abietane and C20-norabietane diterpenes from the stem bark of Fraxinus sieboldiana and their biological activities

Fourteen new abietane (1-14) and seven new C(20)-norabietane (15-21) diterpenes, together with five known analogues, have been isolated from the stem bark of Fraxinus sieboldiana. Their structures were elucidated by spectroscopic data analysis. In the in vitro assays, at 10(-5) M, compounds 8, 16, and 22 showed inhibitory activity against the release of β-glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor, with 59.7 ± 4.8%, 56.1 ± 5.6%, and 65.9 ± 3.1% inhibition, respectively. Compound 23 was active against H5N1 avian influenza virus with an IC(50) value of 4.8 μM. Compounds 3 and 5 exhibited selective cytotoxic activities against A2780 (IC(50) 1.7 μM) and A549 (IC(50) 6.0 μM), respectively.     

Bioactive hydroanthraquinones and anthraquinone dimers from a soft coral-derived Alternaria sp. fungus

Five new hydroanthraquinone derivatives, tetrahydroaltersolanols C-F (1-4) and dihydroaltersolanol A (5), and five new alterporriol-type anthranoid dimers, alterporriols N-R (12-16), along with seven known analogues (6-11 and 17), were isolated from the culture broth and the mycelia of Alternaria sp. ZJ-2008003, a fungus obtained from a Sarcophyton sp. soft coral collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods including 1D and 2D NOE spectra as well as single-crystal X-ray crystallography. Compound 13 represents the first isolated alterporriol dimer with a C-4-C-4' linkage, and the absolute configuration of 4 was determined using the modified Mosher's method. Compounds 1 and 15 exhibited antiviral activity against the porcine reproductive and respiratory syndrome virus (PRRSV), with IC?? values of 65 and 39 μM, respectively. Compound 14 showed cytotoxic activity against PC-3 and HCT-116 cell lines, with IC?? values of 6.4 and 8.6 μM, respectively.     

蕨的化学成分研究

 目的 研究蕨（Pteridium aquilinum var.latiusculum）的化学成分。方法 采用多种色谱进行分离,通过波谱方法结合理化性质鉴定其化学结构。结果 从蕨中分离鉴定了16个化合物,分别为：（2R）-蕨素B（1）、（2S,3S）-蕨素C（2）、反式乌毛蕨酸（3）、苏铁蕨酸（4）、槲皮素（5）、异槲皮苷（6）、芦丁（7）、异鼠李素-3-O-（6″-O-E-p-香豆酰基）-β-D-葡萄糖苷（8）、紫云英苷（9）、山柰酚-3-O-芸香糖苷（10）、椴树苷（11）、原儿茶酸（12）、莽草酸（13）、苯甲酸（14）、胡萝卜苷（15）、β-谷甾醇（16）。结论 化合物3、4、8、10、12~14为首次从该植物中分离得到,其中化合物3和4为首次从蕨科植物中发现。     

Claurailas A-D, cytotoxic carbazole alkaloids from the roots of Clausena harmandiana

Four new carbazole alkaloids, claurailas A-D (1-4), as well as 12 known carbazoles and three known coumarins were isolated from the roots of Clausena harmandiana. Heptaphylline (6) and 7-methoxyheptaphylline (7) showed strong cytotoxicity against NCI-H187 and KB cell lines with IC(50) values ranging from 1.3 to 2.7 μM. Compound 7 showed no cytotoxicity against Vero cells.     

Ring B aromatic norpimarane glucoside from a Xylaria sp

A novel 20-norpimarane glucoside, xylopimarane (1), together with the known sphaeropsidin C (2) and clonostachydiol (3), was isolated from the fungus Xylaria sp. BCC 4297. Compound 1 exhibited cytotoxicity to cancer cell lines KB, MCF-7, and NCI-H187 with respective IC(50) values of 1.0, 13, and 65 μM.     

Camphoratins A-J, potent cytotoxic and anti-inflammatory triterpenoids from the fruiting body of Taiwanofungus camphoratus

Ten new triterpenoids, camphoratins A-J (1-10), along with 12 known compounds were isolated from the fruiting body of Taiwanofungus camphoratus. Their structures were established by spectroscopic analysis and chemical methods. Compound 10 is the first example of a naturally occurring ergosteroid with an unusual cis-C/D ring junction. Compounds 2-6 and 11 showed moderate to potent cytotoxicity, with EC(50) values ranging from 0.3 to 3 μM against KB and KB-VIN human cancer cell lines. Compounds 6, 10, 11, 14-16, 18, and 21 exhibited anti-inflammatory NO-production inhibition activity with IC(50) values of less than 5 μM, and were more potent than the nonspecific NOS inhibitor N(ω)-nitro-L-arginine methyl ester.     

Alboatisins A-C, ent-atisene diterpenoids from Isodon albopilosus

Three biogenetically interesting ent-kaurane-derived metabolites, alboatisins A-C (1-3), featuring a C-13-oxygenated ent-atisane skeleton, have been isolated from the aerial parts of Isodon albopilosus. Their structures were determined on the basis of spectroscopic evidence. Compound 2 exhibited cytotoxicity against A549 and HT-29 human cancer cells, with IC50 values of 8.3 and 7.9 microM, respectively.     

HLE-inhibitory alkaloids with a polyketide skeleton from the marine-derived fungus Coniothyrium cereale

The marine endophytic fungus Coniothyrium cereale produces the structurally unusual polyketide-type alkaloids (-)-cereolactam (1) and (-)-cereoaldomine (3), incorporating a lactam and an imine functionality, respectively, as well as the related metabolite (-)-trypethelone (2). Compounds 1 and 3 showed selective inhibition of human leukocyte elastase with IC50 values of 9.28 and 3.01 μM, respectively. Compound 2 was found to be inhibitory toward Mycobacterium phlei, Staphylococcus aureus, and Escherichia coli and also cytotoxic against mouse fibroblast cells (IC50=7.5 μM).     

Prenylated Polyhydroxy-p-terphenyls from Aspergillus taichungensis ZHN-7-07

Six new prenylated polyhydroxy-p-terphenyl metabolites, named prenylterphenyllins A-C (1-3) and prenylcandidusins A-C (5-7), and one new polyhydroxy-p-terphenyl with a simple tricyclic C-18 skeleton, named 4'-dehydro-3-hydroxyterphenyllin (4), were obtained together with eight known analogues (8-15) from Aspergillus taichungensis ZHN-7-07, a root soil fungus isolated from the mangrove plant Acrostichum aureum. Their structures were determined by spectroscopic methods, and their cytotoxicity was evaluated using HL-60, A-549, and P-388 cell lines. Compounds 1 and 8 exhibited moderate activities against all three cell lines (IC50 1.53-10.90 μM), whereas compounds 4 and 6 displayed moderate activities only against the P-388 cell line (IC50 of 2.70 and 1.57 μM, respectively).     

7-Nor-ergosterolide, a pentalactone-containing norsteroid and related steroids from the marine-derived endophytic Aspergillus ochraceus EN-31

7-Nor-ergosterolide (1), a rare 7-norsteroid with an unusual pentalactone B-ring system, and two new steroid derivatives, 3β,11α-dihydroxyergosta-8,24(28)-dien-7-one (2) and 3β-hydroxyergosta-8,24(28)-dien-7-one (3), were characterized from the culture extract of Aspergillus ochraceus EN-31, an endophytic fungus isolated from the marine brown alga Sargassum kjellmanianum. In addition, nine known related steroids were isolated and identified. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configuration of the new steroids (1-3) was determined by application of the modified Mosher's method. Compound 1, which represents the first example of a 7-nor-ergosteroid possessing a pentalactone B-ring system in a naturally occurring steroid, displayed cytotoxicity against NCI-H460, SMMC-7721, and SW1990 cell lines with IC(50) values of 5.0, 7.0, and 28.0 μg/mL, respectively. Compound 2 also displayed cytotoxicity against the SMMC-7721 cell line with an IC(50) value of 28.0 μg/mL.     

Trigoflavidols A-C, degraded diterpenoids with antimicrobial activity, from Trigonostemon flavidus

Trigoflavidols A (1) and B (2), tetranorditerpenoid dimers possessing a rearrangement skeleton with a spiroketal core moiety, and trigoflavidol C (3), a hexanorditerpenoid, have been isolated from Trigonostemon flavidus along with two known compounds. Compounds 1 and 2 showed moderate antimicrobial activities (MIC values: 3.12-6.25 μg/mL) against Staphylococcus aureus, 8(#)MRSA, and 82(#)MRSA, and 1, 2, and 5 showed weak activities (IC(50) values: 3.75-28.99 μM) against various human tumor cell lines.     

Bioactive quassinoids from the seeds of Brucea javanica

Six new quassinoids (1-6) and eight known compounds of this type (7-14) were isolated from the seeds of Brucea javanica. Their structures were elucidated by analysis of their spectroscopic data and from chemical evidence. Compounds 1-5 were found to be unusual quassinoids with a 2,3-seco A ring. The configurations at C-4 in 4 and 5 were determined by a difference circular dichroism method. In in vitro bioassays, 8 and 10 showed inhibitory activities for nitric oxide production in LPS-activated macrophages, with IC(50) values of 1.9 and 5.0 μM, respectively, while compounds 6, 8-11, 13, and 14 exhibited cytotoxicity against five human tumor cell lines (HCT-8, HepG2, BGC-823, A549, and SKVO3), having IC(50) values in the range 0.12-9.3 μM.     

Radical scavenging and antioxidant activities of isocoumarins and a phthalide from the endophytic fungus Colletotrichum sp

Five known isocoumarins, monocerin (1), derivative 2, and fusarentin derivatives 3-5, and a new phthalide (6) were isolated from the endophytic fungus Colletotrichum sp. 2 selectively exhibited cytotoxic activity toward the HepG2 cell line. Compounds 2 and 4 scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals (IC(50) values of 23.4 and 16.4 μM, respectively) and inhibited superoxide anion radical formation (IC(50) values of 52.6 and 4.3 μM, respectively). The C-7 hydroxyl group in 2 and 4 might be important for radical scavenging activities. Isocoumarins 1-3 and phthalide 6 showed potent antioxidant activity.     

Phrygiasterol, a cytotoxic cyclopropane-containing polyhydroxysteroid, and related compounds from the pacific starfish Hippasteria phrygiana

The new cyclopropane-containing steroid phrygiasterol (1) and steroid glycoside phrygioside B (2), along with previously known borealoside C (2a) and (20R,24S)-5alpha-cholesta-3beta,6alpha,8,15alpha,24-pentaol (3), have been isolated from the Pacific starfish Hippasteria phrygiana. On the basis of spectroscopic analyses, using 1D and 2D NMR techniques and some chemical transformations, the structures of 1 and 2 have been established as (20R,24R,25R)-24,26-cyclo-5alpha-cholesta-3beta,6alpha,8,15alpha,16beta,27-hexaol (1) and the sodium salt of (20R,24S)-24-O-(3-O-methyl-4-O-sulfate-beta-d-xylopyranosyl)-5alpha-cholesta-3beta,6alpha,8,15alpha,24-pentaol (2), respectively. Compound 1 inhibited the growth of Ehrlich carcinoma cells with an IC(50) of 50 microg/mL, whereas 2 induced apoptosis of the same cells (EC(50)=70 microg/mL) and inhibited Ca(2+) influx into mouse spleenocytes (EC(50)=20microg/mL).     

Cucurbitane glucosides from the root of Machilus yaoshansis

Seven new cucurbitane triterpene glucosides (1-5, 8, and 9) and five known analogues (6, 7, 10, cucurbitacin I 2-O-β-d-glucopyranoside, and khekadaengoside K) have been isolated from an ethanol extract of roots of Machilus yaoshansis. Compounds 1 and 2 have an unusual 16,23:22,25-diepoxy unit, 4 is an uncommon cucurbitane 25-carbamate with the carbamoyl amino group attached at C-24 to form an oxazolidinone ring in the side chain, and 8 is the first example of a trinorcucurbitane derivative. The configurations in several pairs of C-24 epimeric cucurbitacins with 24,25-dihydroxy-22-one side chains were assigned, and the validity of J(23a,24) and J(23b,24) values to differentiate the configuration at C-24 in these cucurbitane derivatives is discussed. Compounds 2-4 showed in vitro activity against protein tyrosine phosphatase 1B with IC50 values of 8.63, 2.81, and 4.26 μM, respectively. Cucurbitacin E 2-O-β-d-glucopyranoside (10) showed selective cytotoxicity against BGC-823 and A549 cancer cells with IC50 values of 4.98 and 3.20 μM, respectively.     

Cytotoxic steroidal alkaloids from Kibatalia laurifolia

Four new steroids, 3-epi-gitingensine (1), N-acetylgitingensine (6), kibalaurifoline (7) and kibalaurifenone (8), along with the known paravallarine (2), 7α-hydroxyparavallarine (3), gitingensine (4), and N-methylgitingensine (5) were isolated from the leaves of Kibatalia laurifolia. Their structures were determined primarily from mass spectrometry and 2D NMR analyses. On the basis of the known absolute configurations of 2 and 4, the absolute configurations of the new compounds were proposed. Due to the structural relationships of compounds 1-8, a biosynthetic pathway was suggested. Compound 2 was cytotoxic to KB cells (IC50 12.8 μM), followed by 1 with IC50 21.2 μM.     

Ashwagandhanolide, a bioactive dimeric thiowithanolide isolated from the roots of Withania somnifera

A new dimeric withanolide, ashwagandhanolide (1), was isolated from the roots of an Ayurvedic medicinal herb, Withania somnifera. A detailed spectroscopic evaluation revealed its identity as a dimer with an unusual thioether linkage. Compound 1 displayed growth inhibition against human gastric (AGS), breast (MCF-7), central nervous system (SF-268), colon (HCT-116), and lung (NCI H460) cancer cell lines, with IC50 values in the range 0.43-1.48 microg/mL. In addition, it inhibited lipid peroxidation and the activity of the enzyme cyclooxygenase-2 in vitro.