Search

The genus Lasianthus (Rubiaceae) consists of approximately 180 species, of which the greatest species diversity is found in tropical Asia. Some of the Lasianthus species have been used in folk medicine to treat tinnitus, arthritis, fever, and bleeding. Lasianthus verticillatus (Lour.) Merr. (Syn. Lasianthus trichophlebus auct. non Hemsl.) is a shrub, branchlets terete about 1.5&ndash, 3 m in height. This paper studies the chemical composition of the leaves of L. verticillatus for the first time, which resulted in the isolation of five undescribed iridoid glucosides, lasianosides A&ndash, E (1&ndash, 5), together with three known compounds (6&ndash, 8). The undescribed structures of isolated compounds (1&ndash, 5) were characterized by physical and spectroscopic data analyses, including one-dimensional (1D) and two-dimensional (2D) NMR, IR, UV, and high-resolution electrospray ionization mass spectra (HR-ESI-MS). Furthermore, the electronic circular dichroism data determined the absolute configurations of the new compounds. The free radical scavenging properties of isolated compounds was assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and their cytotoxicity was assessed toward human lung cancer cell line A549 by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Among the isolated compounds, 3 and 4 displayed potent radical scavenging activities with IC50 values of 30.2 &plusmn, 1.8 and 32.0 &plusmn, 1.2 &micro, M, which were comparable to that of Trolox (29.2 &plusmn, 0.39 &micro, M), respectively, while 5 possessed moderate activity with an IC50 value of 46.4 &plusmn, 2.3 &micro, M. None of the isolated compounds exerted cytotoxicity against human cell line A549. As a result, lasianosides C, D, and E have the potential to be non-toxic safe antioxidant agents.

From the EtOAc-soluble fraction of a MeOH extract of the leaves of Glochidion acuminatum, six new compounds along with five known ones were isolated. The structures of the new compounds were elucidated to be two gallates, a p-hydroxybenzoate and an (S)-2-(4-hydroxycyclohex-1-en-1-yl)acetate of a nitrile-containing phenolic glucoside, methyl 2-(2-hydroxyphenyl)acetate β-D-glucopyranoside, and (S)-methyl 2-[4-sulfooxycyclohex-1-en-1-yl]acetate on the basis of spectroscopic evidence.

From the 1-BuOH-soluble fraction of a methanol (MeOH) extract of the leaves of Croton cascarilloides, crotofolanes: crotocascarins I-K, nor-crotofolane: crotocascarin γ, isocrotofolane glucoside and phenolic glycoside were isolated by a combination of various separation techniques. Their structures were elucidated mainly from the NMR spectroscopic evidence. The structure of crotocascarin K was first elucidated by spectroscopic analysis and then was confirmed by X-ray crystallographic analysis. Its absolute structure was finally determined by the modified Mosher's method. Isocrotofolane glucoside was found to possess a new skeleton, however, its absolute structure remains to be determined.

From the branches of Microtropis japonica (Celastraceae), seven phenolic alcohol glucosides, named microtropins J-P (1-7), were isolated. The 6-position of glucose was esterified with 2-ethyl-2,3-dihydroxybutyric acid. Microtropin K (2) was hydrolyzed under a mild basic condition to give methyl (2S,3R)-2-ethyl-2,3-dihydroxybutyrate, whose absolute structure was determined by the comparison of NMR data and the optical rotation value with that reported.

From the branches of Schoepfia jasminodora collected in Okinawa, three new dihydrochalcone C-glycosides, one dihydrochalcone di-O-glucopyranoside, two flavanone C-glycosides, one flavanone O-glycoside and one flavone O-glycoside were isolated. Their structures were elucidated by extensive study of one- and two-dimensional NMR spectroscopic data.

From the 1-BuOH-soluble fraction of a methanol (MeOH) extract of the leaves of Croton cascarilloides, crotofolanes: crotocascarins I-K, nor-crotofolane: crotocascarin γ, isocrotofolane glucoside and phenolic glycoside were isolated by a combination of various separation techniques. Their structures were elucidated mainly from the NMR spectroscopic evidence. The structure of crotocascarin K was first elucidated by spectroscopic analysis and then was confirmed by X-ray crystallographic analysis. Its absolute structure was finally determined by the modified Mosher's method. Isocrotofolane glucoside was found to possess a new skeleton, however, its absolute structure remains to be determined.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Russelia equisetiformis, one new iridoid glucoside was isolated along with 24 known compounds, comprising iridoids and iridoid glucosides, phenyl propane glucosides, phenyl ethanoids, lignan glucosides, and flavonoid glucosides. The structure of the new compound was elucidated to be 10-O-cinnamoyl sinuatol. Of the 25 compounds isolated, rehmaglutin B exhibited moderate inhibitory activity toward NO production, which was not associated with cytotoxicity.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Schoepfia jasminodora collected from Okinawa Island, two new galloyl esters and 15 known compounds were isolated. The structures of the new compounds were elucidated by spectroscopic analysis to be isoorientin 4″-O-gallate and (2S)-1,2-propanediol 1-O-β-D: -glucopyranoside 6'-O-gallate. The compounds possessing galloyl or cathechol moieties showed equal radical scavenging activity.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Symplocos cochinchinensis var. philippinensis, 12 compounds were isolated. Spectroscopic analyses of compounds 1 - 3 established their structures to be megastig-mane glycosides, named symplocosionosides A-C. The absolute structure of 1 was determined by the modified Mosher’s method. Compound 4 was found to be a neolignan glucoside and named symplocosneolignan. The structures of com-pounds 5 and 6, named symplocosins A and B, were elucidated to be the saponins of hederagenin sugar esters. The structures of the remaining known compounds (7 - 12) were identified by comparison of spectroscopic data with those reported in the literature.

Further isolation work on the water-soluble fraction of a MeOH extract of Tricalysia dubia afforded one new megastigmane gentiobioside, named tricalysionoside A (1), and three sulfates, named sulfatricalysines A-C (2-4). Extensive isolation work on the 1-BuOH-soluble fraction of a MeOH extract of T. dubia yielded sulfatricalysines D-F (5-7) and three new ent-kaurane glucosides, named tricalysiosides X-Z (8-10). The structures of the new compounds were elucidated by analyses of one- and two-dimensional NMR spectroscopic data. The absolute stereochemistry of tricalysionoside A (1) was established by modified Mosher's method.

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Tarenna gracilipes, collected in Okinawa, six further new cycloartane glycosides, named tareciliosides H-M (1-6), were isolated. Their structures were established through a combination of spectroscopic analyses.

Two new flavonol glycosides were isolated from the 1-butanol (1-BuOH)-soluble fraction of a methanol (MeOH) extract of the leaves of Indigofera zollingeriana, along with four flavonol glycosides and three known megastigmane glucosides. The structures of the new compounds were elucidated by spectroscopic analyses as kaempferol 3-O-β-D-(2"-O-β-D-apiofuranosyl)glucopyranoside 7-O-α-L-rhamnopyranoside and 3-O-β-D-(2"-O-β-D-apiofuranosyl, 6"-O-α-L-rhamnopyranosyl)glucopyranoside 7-O-α-L-rhamnopyranoside.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Guettarda speciosa L., two new compounds (1, 2) were isolated together with six known compounds. Spectroscopic analysis of 1 and 2 established their structures to be derivatives of a glycerol α-glucuronide and a megastigmane glycoside, respectively. HPLC analysis of the hydrolyzate of 1 confirmed the presence of D-glucuronic acid in the structure, and the modified Mosher's method established the absolute structure of 2.

From a 1-BuOH-soluble fraction of a MeOH extract of Cananga odorata var. odorata, collected at the Botanical Garden of Chiang Mai University, a new megastigmane glucoside, named canangaionoside, and an irregular monoterpene were isolated. A known compound, breyniaionoside A, which has been obtained from the leaves of Breynia officinalis, was also isolated, and its absolute structure was substantiated for the first time in this study. On this occasion, the absolute stereochemistries of structurally related megastigmane glucosides, breyniaionosides B and C, isolated from B. officinalis were examined.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Grevillea robusta Allan Cunningham, two 5-alkylresorcinol glucosides, named grevillosides G and H (1, 2), and grevilloside E methyl ester (3) were isolated, along with one known megastigmane glucoside, staphylionoside D (4). The structures of the new compounds were elucidated by means of spectroscopic analyses. The structure of the related phenolic glucoside (1a) isolated from Veronica thymoides subsp. pseudocinerea was reported to be the same as that of 1. However, as judged on the close inspection of the spectroscopic data, its structure (1a) must be revised to 3,4-dihydroxyphenylethanol 3-O-glucoside.

The absolute stereochemistry of blumenol C glucoside and byzantionoside B was revised here as (6R,9S)- and (6R,9R)-9-hydroxymegastigman-4-en-3-one 9-O-beta-D-glucopyranosides, respectively, by modified Mosher's method. The empirical rules of (13)C-NMR chemical shift to determine the absolute stereochemistry of C-9 of 9-hydroxymegastigmane 9-O-beta-D-glucopyranoside were also discussed.

From a 1-BuOH-soluble fraction of the MeOH extract of the leaves of Crotalaria zanzibarica collected in the Okinawa Islands, three new megastigmane glucosides, named crotalionosides A-C, two new pterocarpan glucosides and a chalcone C-glucoside were isolated together with two known flavonoid glycosides and one known megastigmane glucoside. The structures of the new compounds were elucidated by a combination of spectroscopic analyses. The absolute configurations of allenic megastigmane glucosides were determined by application of the modified Mosher's method. Those of the allenic moieties were determined by interpretation of the circular dichroism (CD) spectra of the reduction products derived from citrosides A and B. The aglycones of pterocarpan glucosides were found to be melilotocarpan B and the absolute structure of the chalcone C-glucoside was determined by comparison of the CD spectral behavior with the reported values.

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Schefflera arboricola, collected in Okinawa, six new lupane glucosides, named schefflerins A-F (1-6) and one new dammarane glucoside, named schefflerin G (7), were isolated together with three known compounds, citroside A (8), and oleanane saponins, oleanolic acid (9) and echinocystic acid (10) 3-O-α-L-rhamnopyranosyl(1→4')-O-β-D-glucuronopynosides. Their structures were elucidated through a combination of spectroscopic analyses and the structure of schefflerin F (6) was determined by X-ray crystallographic method using SPring-8 synchrotron radiation.

A lignan glucoside, (+)-pinoresinol 4-O-[6''-O-galloyl]-beta-D-glucopyranoside (1), and two megastigmane glucosides, named macarangiosides E and F (2,3), together with 15 known compounds (4-18) were isolated from leaves of Macaranga tanarius (L.) Müll.-Arg. (Euphorbiaceae). Their structures were elucidated by spectroscopic and chemical analyses. In addition, the absolute stereochemistry of macarangiosides B and C isolated previously from the same plant was also determined for the first time. Compounds 1 and 2 were galloylated on glucose and possessed potent DPPH radical-scavenging activity.

Thirteen compounds (1-13) were isolated from a MeOH extract of leaves of Glochidion rubrum. The structures of four new compounds were elucidated to be (-)-isolariciresinol 2a-O-beta-D-glucopyranoside (1), (7R,8S)- and (7R,8R)-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-neolignan 7-O-beta-D-glucopyranosides (2 and 3, respectively), and tachioside 2'-O-4''-O-methylgallate (4) on detailed inspection of one- and two-dimensional NMR spectral data.

From a MeOH extract of leaves of Grevillea robusta, seven compounds (1-7) were isolated. One known compound (7) was identified with a benzyl glucoside, icariside F2. The structures of the six of these, named grevillosides A-F (1-6), were elucidated on detailed inspection of one- and two-dimensional NMR spectroscopic data as glucosides of 5-alkylresorcinols.

Sixteen compounds were isolated from the MeOH extract of leaves of Myoporum bontioides. Of the compounds isolated, five were found to be new. Their structures were elucidated to be a chlorine-containing iridoid, named myopochlorin, and an iridoid glucoside, an acylated iridoid glucoside, a linear acetogenin glucoside, and an acyclic monoterpene glucoside, named myobontiosides A-D, respectively, by means of spectroscopic analyses.

A new lignan glycoside, bridelioside, has been isolated from Bridelia glauca f. balansae. The structure of bridelioside was elucidated be (+)-isolariciresinol 2a-O-α-l-arabinopyranoside on the basis of spectral data.

Three rearranged ent-kaurane diterpenes with the cafestol-type framework have been isolated from the leaves of Tricalysia dubia. Two were found to be known diterpenoids, tricalysiolides B and C. Tricalysiolide B was isolated as colorless prisms in this experiment and its three-dimensional structure was determined by X-ray crystallography. The remaining diterpenoid was a new compound and was named tricalysiolide G. Two new ent-kaurane-type diterpenoids, given the trivial names tricalysiol A and tricalysiol B, were also isolated. The structures of the new compounds were elucidated from spectroscopic evidence.

Further extensive isolation work on the 1-BuOH-soluble fraction of a MeOH extract of Tricalysia dubia afforded five new ent-kaurane glucosides (4-8) and one new labdane glucoside (9), together with a known megastigmane glucoside, sammangaoside B (1), and monoterpene glucosides (2, 3). The structures of the new compounds were elucidated by analyses of one- and two-dimensional NMR spectroscopic data. The absolute configuration of the 9-position of sammangaoside B was revised to S and its total stereochemistry was established by the modified Mosher's method.

From the leaves of Helicia cochinchinensis, collected on Okinawa Island, seven phenolic glucosides and two terpenic glucosides were isolated. Five of the phenolic glucosides were previously known, being identified with p-coumaric and ferulic acids glucosyl esters, rhodioloside, helicidiol, and naringenin 5-O-beta-D-glucopyranoside. The structures of two other phenolic glucosides, named heliciosides A and B, were elucidated to be 5-O-beta-D-glucosides of 3-hydroxyflavanone, namely aromadendrin and taxifolin, by means of spectroscopic analyses. The two terpenic glucosides were identified with ampelopsisionoside and icariside C1.

Background and Objectives Virus inactivation and removal are important prerequisites to ensure the safety of plasma derivatives. For virus inactivation and removal in our coagulation factor VIII (FVIII) product, CROSS EIGHT M®, the production process consists of solvent–detergent (S/D) treatment, two chromatography steps and virus filtration with a 35-nm pore-size filter. However, the clearance of non-enveloped viruses was not as good as that of enveloped viruses because non-enveloped viruses are resistant to S/D treatment and are too small to be removed by the filter. In this study, in order to improve the viral safety of the FVIII products, we attempted to replace the 35-nm pore-size virus filter with a 20-nm filter. Materials and Methods The virus-filtration process was validated for the removal of enveloped and non-enveloped model viruses. Several factors that might affect the FVIII yield on filtration were investigated to obtain a higher recovery. The biochemical properties of the FVIII products produced with the 20-nm pore-size filter were compared with those produced by the 35-nm filter. Results Virus filters of 20-nm pore size effectively removed the small non-enveloped viruses when compared with the 35-nm pore-size virus filter. The permeability of FVIII through the 20-nm pore-size filter was inversely proportional to the concentration of FVIII at filtration, and directly proportional to the amount of postfiltration solution. No differences were observed in the biochemical properties of both FVIII products, such as the structure and stability of the FVIII, the contents and multimeric structure of von Willebrand factor (vWF), and FVIII activation by thrombin. Conclusions The virus-clearance efficiency of the FVIII product, CROSS EIGHT M®, was markedly increased, in particular against small non-enveloped viruses, by changing the virus filter pore size from 35 nm to 20 nm. It was possible to implement the 20-nm pore-size filter without variation of the biochemical properties or a serious loss of FVIII.

Trypanocidal constituents of Dracocephalum komarovi were investigated. Under guidance of the in vitro trypanocidal activity against epimastigotes of Trypanosoma cruzi, the causative agent of Chagas' disease, two new diterpenes, dracocequinones A ( 1 ) and B ( 2 ), and two known triterpene acids, ursonic acid and ursolic acid, were isolated as trypanocidal constituents, in addition to previously reported diterpenes, cyclocoulterone ( 4 ), komaroviquinone ( 5 ), dracocephalone A ( 6 ) and komarovispirone ( 7 ). Furthermore a new diterpene, komarovinone A ( 3 ), was isolated, together with four known terpenes. Among these compounds, komaroviquinone ( 5 ) showed the most potent activity with minimum lethal concentration of 0.4 μM. Structure elucidation of the new diterpenes 1–3 was described.

Six rearranged ent-kaurane diterpenes, tricalysiolides A–F, having the cafestol-type carbon framework were isolated from the wood of Tricalysia dubia (Rubiaceae). Their absolute structures were determined on the basis of the 2D NMR spectroscopy, X-ray crystallographic analysis, and chemical methods.

ステビアの抗酸化成分を同定するに当たり，ステビアをメタノール抽出し，その抽出物の溶媒分画のうち，特異的にDPPHラジカル消去活性の強かった酢酸エチル可溶画分から，3種の活性成分を単離・同定した．この単離物質は，すべて，脂質の酸化に対して十分な抗酸化性を有することが判明した．ステビアの抗酸化性はこれまでカリウム等の無機塩によるものとされてきたが2），今回の有機フェノール成分もステビア抗酸化性に十分に寄与している可能性が考えられた．

As a part of our research project on the elucidation of the chain-breaking antioxidant mechanism of natural phenolic compounds in food components, ferulic acid, a phenolic acid widely distributed in edible plants, especially grains, was investigated. An antioxidation reaction of ferulic acid methyl ester produced a main product when ethyl linoleate was used as the oxidation substrate. Isolation and structure determination of the main product revealed that it was a dimer having a dihydrobenzofuran moiety. On the basis of the formation pathway for the product, a radical scavenging reaction was suggested to occur between the 5′-position of one of the ferulate radicals and the 2-position of another of the ferulate radicals to terminate the radical chain oxidation of linoleate.

Eight ent-kaurane glucosides, named tricalysiosides H–O (1–8), were isolated from Tricalysia dubia. Tricalysioside H (1) possessed a hydroxyl group at the 1-position, to which the glucose moiety was attached. The structure was first elucidated by means of spectroscopic data analysis and finally confirmed by X-ray crystallography. Since acid hydrolysis of 1 gave d -glucose, the aglycone was proved to have an enantio-kaurane type skeleton. The structures of tricalysiosides I–O (2–8) were mainly elucidated from analysis of spectroscopic evidence.

Carnosol is one of the main antioxidants in sage and rosemary. Although carnosol quinone is the antioxidation product of carnosol and has a very weak antioxidant activity, its treatment in water-containing solvent restored its strong antioxidant activity. HPLC analysis of the water-stimulated recovery reaction of the antioxidant activity revealed that the strong activity was due to the reproduced carnosol. The analysis also showed that an almost equal amount of quinone derivatives of rosmanol (rosmanol quinone) was produced in the reaction along with the carnosol. The rosmanol was formed by the addition of 1 equiv of water and the following isomerization from carnosol quinone in the water-containing solvent. The formed rosmanol was also found to be oxidized by the remaining carnosol quinone to produce rosmanol quinone. At the same time, carnosol quinone was reduced to afford carnosol. This redox phenomenon is an important part of the mechanism for the recovery of the antioxidant activity from carnosol quinone under the water-containing conditions.

From the aerial parts of Crepidiastrum lanceolatum , six guaiane-type sesquiterpene glucosides, lanceocripidiasides A–F were isolated together with five known sesquiterpene glucosides, ixerin Y, crepidialanceosides A and B, and youngiasides A and D, two known megastigmane glucosides, icariside B 1 and corchoionoside A, and benzyl 6′- O -β- d -apiofuranosyl-β- d -glucopyranoside. Structures were elucidated by spectroscopic analyses.

The tyrosinase inhibitory activity of methanol extracts of the leaves of 39 plant species growing on the seashore of Iriomote island (Okinawa, Japan) was investigated. The extracts of Hibiscus tiliaceus, Carex pumila, and Garcinia subelliptica showed potent activity among them. The inhibitors in the extract of Garcinia subelliptica were purified by assay-guided fractionation to give two biflavonoids. These were known compounds (2R,3S-5,7,4',5'',7'',3''',4'''-heptahydroxy flavanone[3-8''] flavone and 5,7,4',5'',7'',3''',4'''-heptahydroxy[3-8''] biflavanone), although their strong inhibitory activity toward tyrosinase is revealed for the first time in this work. One of these biflavonoids (2R,3S-5,7,4',5'',7'',3''',4'''-heptahydroxy flavanone[3-8''] flavone) showed much stronger activity (IC50 2.5 microM) than that of kojic acid (IC50 9.1 microM) when L-tyrosine was used as the substrate.

The antioxidant reaction of carnosol, a phenolic diterpene of sage and rosemary, produced ortho- and para-quinone derivatives. Although the orthoquinone derivative of carnosol (CARQ) is stable in a lipophilic solution and has a very weak antioxidant activity, the thermal treatment of CARQ in lipid restored strong antioxidant activity. HPLC analysis of the thermal recovery reaction clarified that the strong activity was mainly due to the reproduced carnosol. A possible mechanism for the production of carnosol from CARQ is the self-redox reaction of CARQ. Two of the oxidation products from CARQ in the thermal recovery reaction were identified to be rosmariquinone and dehydrorosmariquinone. Copyright © 2004 Society of Chemical Industry

A new antifungal flavanone, muscanone (1), was isolated along with known naringenin (2) from Commiphora wightii (Arn.) Bhandari (Burseraceae) by directing the fractionation of an EtOH extract of the air-dried trunk of C. wightii with microbial sensitivity assay. The structures of 1 and 2 were determined from EIMS, HREIMS, DEPT, 1H–1H COSY, HSQC and HMBC spectral data. Muscanone (1) was identified as 3-O-(1″, 8″,14″-trimethylhexadecanyl)naringenin and was found to be active against Candida albicans. The isolation, structure elucidation, NMR spectral assignments, and bioactivities of 1 and 2 are reported.

A simple detection method for a powerful radical scavenging compound in a mixture containing a large variety of compounds, such as the raw extract of edible plants, was developed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the radical reagent. The method was established on the basis of the features of the typical chain-breaking antioxidation reaction mechanism, which suggests that the radical scavenging antioxidant should be converted to other stable nonradical compounds during the reaction. This method requires only a simple HPLC instrument, and the disappearance or decrease in the peak intensity, which is induced by the addition of DPPH. This change is monitored by the HPLC to detect the powerful radical scavenger from the complex mixture. The method was applied to the detection and identification of the most powerful antiradical compound in the extracts of three antioxidatively active plant extracts (Psidium guajava, Citrus depressa, and Hypericum chinense). The radical scavenging efficiency of a newly identified compound from H. chinense was also compared with that of Trolox and catechin using the method.

The ethyl acetate soluble extract of the dried roots of Ferula penninervis gave 17 new sesquiterpenes [15 of the guaiane-type, ferupennins A-O (1-15), and two of the eudesmane-type, 1alpha-hydroxy-2-oxo-5alpha,7beta,11betaH-eudesm-3-en-6alpha,12-olide (16) and penninervin (17)] and nine known sesquiterpenes. The structures of the new compounds were elucidated on the basis of spectroscopic evidence and X-ray analysis. The absolute configuration of ferupennin A (1) was determined by a modified Mosher method.

Two new icetexane diterpenes, cyclocoulterone (1) and komaroviquinone (2), and a novel 20-norabietane diterpene, dracocephalone A (3), were isolated from Dracocephalum komarovi. Their structures were elucidated by extensive analyses of spectral data. Komaroviquinone (2) showed strong trypanocidal activity against epmastigotes of Trypanosoma cruzi, the causative agent of American trypanosomiasis, with a minimum lethal concentration of 0.4 micro M.

Seven rearranged ent-kaurane glycosides, named tricalysiosides A-G (1-7), were isolated from the leaves of Tricalysia dubia collected on Okinawa Island. Their C-18 and 19 methyls were found to have rearranged to form an alpha,beta-unsaturated gamma-lactone ring, with other functional groups remotely located only on C-15, -16, and -17 of the five-membered ring. Information available from various kinds of two-dimensional NMR spectra was limited and insufficient to allow total characterization of the structures. Finally, using X-ray crystallographic analysis, the structure of tricalysioside A (1) was determined to be 4-nor-18-homo-ent-kauran-4(18)-en-15beta,16beta,17-triol-3beta,19-olide 16-O-beta-D-glucopyranoside (1). On the basis of the crystal structure of 1, the structures of the other tricalysiosides (2-7) were also established.

We have previously reported that ponicidin (PND), isolated from Rabdosia ternifolia, potentiates the cell-killing activity of antiherpes prodrugs acyclovir (ACV) and ganciclovir (GCV) in human cancer cells expressing herpes simplex virus thymidine kinase (HSV-TK). To extend these in vitro results to in vivo situations, HSV-TK-expressing HeLa cells were injected into nude mice. The in vivo growth of TK(+) HeLa cells was significantly inhibited by coadministration of PND and ACV, or of PND and GCV, compared with single use of ACV or GCV in spite of lower doses of 1 or 0.25 mg/mouse, respectively. These results indicate that there is a good correlation between this in vivo efficacy and previously reported in vitro efficacy. Because of the insufficiency of incorporation of genes into tumors, bystander cell killing has attracted special interest. In the present study, we determined the ability of PND to potentiate the bystander effects of ACV and GCV in both in vitro and in vivo systems. In vitro combined use of PND with ACV or GCV rendered tumor cells more sensitive to the prodrugs, demonstrating a 1.8- to 97-fold or 2.8- to 26-fold reduction in IC(50) compared with ACV or GCV only, respectively, in 1 to 20% of HSV-TK(+) cells. In the in vivo experiments using nude mice injected with 3 or 10% HSV-TK(+) cells, tumor volume was lower in mice treated with a combination of PND and ACV/GCV than in those treated with ACV or GCV only. No toxicity of PND was seen in mice even at a dose 10-fold higher than that used in the in vivo experiments. These novel strategies could provide benefit to ablative cancer gene therapy by making it feasible to use toxic GCV at lower doses and relatively nontoxic ACV.

Nine new polyprenylated benzoylphloroglucinol derivatives, hyperibones A-I (1-9), were isolated from the aerial parts of the Uzbekistan medicinal plant Hypericum scabrum. Their structures were determined mainly on the basis of spectroscopic evidence (2D NMR and HRMS). Compounds 1, 2, and 4 showed mild in vitro antibacterial activity against methicillin-resistance Staphylococus aureus (MRSA) and methicillin-sensitive Staphylococus aureus (MSSA).

The cytotoxic activity of methanol extracts of leaves collected from 39 seashore plants in Iriomote Island, subtropical Japan was examined on human leukaemia cells (K562 cells) using a flow cytometer with two fluorescent probes, ethidium bromide and annexin V-FITC. Five extracts (10 microg/mL) from Hernandia nymphaeaefolia, Cerbera manghas, Pongamia pinnata, Morus australis var. glabra and Thespesia populnea greatly inhibited the growth of K562 cells. When the concentration was decreased to 1 microg/mL, only one extract from H. nymphaeaefolia still inhibited the cell growth. A cytotoxic compound was isolated from the leaves by bioassay-guided fractionation and was identified as (-)-deoxypodophyllotoxin (DPT). The fresh leaves of H. nymphaeaefolia contained a remarkably high amount of DPT (0.21 +/- 0.07% of fresh leaf weight), being clarified by a quantitative HPLC analysis. DPT at 70-80 pM started to inhibit the growth of K562 cells in an all-or-none fashion and at 100 pM or more it produced complete inhibition in all cases. Therefore, the slope of the dose-response curve was very steep. DPT at 100 pM or more decreased the cell viability to 50%-60% and increased the number of cells undergoing apoptosis (annexin V-positive cells). The results indicate that DPT contributes to the cytotoxic action of the extract from the leaves of H. nymphaeaefolia on K562 cells.