Cellular uptake of Aib-containing amphipathic helix peptide.

Cell-penetrating peptides (CPPs) are useful tools for the delivery of hydrophilic bioactive molecules, such as peptides, proteins, and oligonucleotides, across the cell membrane. To realize the delivery of therapeutic macromolecules by CPPs, the CPPs are required to show resistance to protease and no cytotoxicity. In order to produce potent non-toxic and protease-resistant CPPs with high cellular uptake, we designed an amphipathic helix peptide using α-aminoisobutyric acid (Aib, U) and named it MAP(Aib). In the MAP(Aib) molecule, five Aib residues are aligned on the hydrophobic face of the helix and five lysine (K) residues are aligned on the hydrophilic face. MAP(Aib) showed potent resistance to trypsin and pronase compared with MAP, an amphipathic helix peptide formed by usual amino acids. Fluorescein-labeled MAP(Aib) efficiently traversed the A549 cell membrane, diffusing into the cytoplasm and slightly into the nucleus without exerting any cytotoxicity. In contrast, MAP was poorly taken up by the cell. These results indicate that the incorporation of Aib residues into CPPs markedly improves cellular uptake and MAP(Aib) may be a useful tool for the delivery of hydrophilic macromolecules.

Anti-tumor-initiating effects of phenolic compounds isolated from the bark of Picea jezoensis var. jezoensis.

We have previously reported the isolation of nine phenolic compounds including three new flavonostilbenes, jezonocinols A, B, and C, from the MeOH extract of the bark of Picea jezoensis var. jezoensis. Further investigation of the MeOH extract led to the isolation of three new stilbene-type compounds and one new 1,4-benzodioxane-type compound, together with seven known phenolic compounds. These compounds were tested for their inhibitory effects on the activation of (+/-)-(E)-methyl-2-[(E)-hydroxy-imino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor, as a primary screening test for anti-tumor initiators. All compounds tested exhibited potent inhibitory effects on NOR 1 activation. Furthermore, jezonocinol B, the most potent inhibitor of NOR 1 activation, showed remarkable anti-tumor-initiating activity in the in vivo two-stage mouse skin carcinogenesis test using peroxynitrite (ONOO(-); PN) as the initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as the promoter.

Potential anti-tumor-promoting activity of 3alpha-hydroxy-D:A-friedooleanan-2-one from the stem bark of Mallotus philippensis.

Four known friedelane-type triterpenoids, friedelin ( 1), 3-hydroxy-D:A-friedoolean-3-en-2-one ( 2), 2beta-hydroxy-D:A-friedooleanan-3-one ( 3), and 3alpha-hydroxy-D:A-friedooleanan-2-one ( 4), and two known lupane-type triterpenoids, lupeol ( 5) and betulin ( 6), were isolated from the stem bark of Mallotus philippensis. Isolates 1 - 4 and their synthetic analogues, 3-acetoxy-D:A-friedoolean-3-en-2-one ( 2A) and 3alpha-acetoxy-D:A-friedooleanan-2-one ( 4A), were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12- O-tetradecanoylphorbol 13-acetate (TPA). The inhibitory effect of compounds 2 (IC (50) = 292 mol ratio/32 pmol/TPA) and 4 (IC (50) = 288) was stronger than those of the other compounds tested and the positive control, curcumin (IC (50) = 343). Compound 4 strongly inhibited mouse skin tumor promotion in an IN VIVO two-stage carcinogenesis model. Studies have been conducted to identify the biologically active compounds extracted from the leaves, bark, and cones of trees that currently have no specific commercial use and are therefore treated as waste in the forestry industry.

Structures and radical-scavenging activities of phenolic constituents from the bark of Picea jezoensis var. jezoensis.

The MeOH extract of the bark of Picea jezoensis var. jezoensis was found to show scavenging activity for the DPPH radical. Bioassay-guided fractionation led to the isolation of two new flavonostilbenes named jezonocinols A ( 1) and B ( 2) and one nor-flavonostilbene named jezonocinol C ( 3) together with six known phenolic compounds. Their structures were elucidated by spectroscopic methods, and the absolute configurations of jezonocinols A ( 1) and B ( 2) were determined by Mosher's method, CD, and NOESY data.

Structure determination of inonotsuoxides A and B and in vivo anti-tumor promoting activity of inotodiol from the sclerotia of Inonotus obliquus.

Two new lanostane-type triterpenoids, inonotsuoxides A (1) and B (2) along with three known lanostane-type triterpenoids, inotodiol (3), trametenolic acid (4), and lanosterol (5), were isolated from the sclerotia of Inonotus obliquus (Pers.: Fr.) (Japanese name: Kabanoanakake) (Russian name: Chaga). Their structures were determined to be 22R,25-epoxylanost-8-ene-3beta,24S-diol (1) and 22S,25-epoxylanost-8-ene-3beta,24S-diol (2) on the basis of spectral data including single crystal X-ray analysis. These compounds except for 2 were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), as a test for potential cancer chemopreventive agents. The most abundant triterpene, inotodiol (3), was investigated for the inhibitory effect in a two-stage carcinogenesis test on mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter. Compound 3 was found to exhibit the potent anti-tumor promoting activity in the in vivo carcinogenesis test.

Isolation, DNA topoisomerase-II inhibition, and cytotoxicity of three new terpenoids from the bark of Macaranga tanarius.

One new pimarane-type diterpenoid (1) and two new taraxerane-based triterpenoids (2 and 3) were isolated from the bark of Macaranga tanarius, along with seven known compounds. Their structures were identified by spectroscopic methods including NMR and MS analyses. Compounds 1-5 were tested for their in vitro inhibition of DNA topoisomerase II, as well as for their cytotoxicities against human lung carcinoma A549 cells (Table 3). The triterpenoids 2-5 showed strong activities in both assays, but the diterpenoid 1 was only moderately active.

Potent antitumor activity of 3,4-seco-8betaH-Ferna-4(23),9(11)-dien-3-oic acid (EC-2) and 3,4-seco-Oleana-4(23),18-dien-3-oic acid (EC-4), evaluated by an in vitro human cancer cell line panel.

3,4-seco-8beta H-Ferna-4(23),9(11)-dien-3-oic acid (EC-2) (1) and 3,4-seco-oleana-4(23),18-dien-3-oic acid (EC-4) (2) isolated from the whole herb of Euphorbia chamaesyce L. were evaluated for their anti-tumor activities using a panel including 39 human cancer cell lines (HCC) coupled with a drug sensitivity database. Compounds 1 and 2 showed strong cytotoxicity against the HCC panel, even though alcohols 1A and 2A and methyl esters 1B and 2B were inactive.

A new seco-abietane-type diterpene from the stem bark of Picea glehni.

A new seco-abietane-type diterpenoid, 13S-hydroxy-9-oxo-9,10-seco-abiet-8(14)-en-18,10alpha-olide (1) along with a known lignan compound, pinoresinol (2) was isolated from the stem bark of Picea glehni (Fr. Schm.) Masters. Spectroscopic methods and chemical conversions were used to establish the structure of 1. In order to assess their cancer chemopreventive potential, the inhibition of Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) was examined for compound 1, its synthetic analogue, 9,10-seco-8S,13S-epoxy-abiet-8(14)-en-18,10alpha-olide (la) and 2. The inhibitory effect of la on EBV-EA induction was strong (0, 20.7, 67.1 and 89.2 % inhibition at 1000, 500,100 and 10 mol ratio/TPA). The IC50 of la was 226 mol ratio/32 pmol/TPA.

Potential anti-tumor promoting activity of lupane-type triterpenoids from the stem bark of Glochidion zeylanicum and Phyllanthus flexuosus.

Four known lupane-type triterpenoids, glochidonol (1), glochidiol (2), lup-20(29)-ene-1beta,3beta-diol (3) and glochidone (3) were isolated from the stem bark of Glochidion zeylanicum. Previously, lupeol (5), lup-20(29)-ene-3beta,24-diol (6) and betulin (7) were isolated from the stem bark of Phyllanthus flexuosus. This study reports the assays of these lupane-type triterpenoids: all isolates 1-7 and synthetic analogues, glochidonyl acetate (1a), lup-20(29)-ene-1,3-dione (1b) and lup-20(29)-ene 3beta,24-diacetate (6a) were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA). Among them, the effects of compounds 2 (IC50 = 290 mol ratio/32 pmol TPA) and 3 (IC50 = 300) were stronger than the others. In addition, compound 2 exhibited a strong inhibitory effect on mouse skin tumor promotion in an in vivo mouse two-stage carcinogenesis test.

Potential antitumor-promoting diterpenes from the cones of Pinus luchuensis.

A new nor-labdane-type diterpene, 15-nor-labda-8(17),12E-dien-13,19-dienoic acid (1), along with five known diterpenes, 15-nor-14-oxolabda-8(17),12E-dien-19-oic acid (2), trans-communic acid (3), sandaracopimaric acid (4), dehydroabietic acid (5), and abieta-8,11,13-triene-15,18-diol (6), was isolated from the cones of Pinus luchuensis. The structure of 1 was established by chemical and spectroscopic methods. Among these isolates, compounds 2, 4, and 6 showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.