Inhibitory effects of dihydroagarofuran sesquiterpenes on Epstein-Barr virus activation

Cardiac glycosides from the roots of Streblus asper Lour. with activity against Epstein-Barr virus lytic replication

Cardiac glycosides (CGs) show potential broad-spectrum antiviral activity by targeting cellular host proteins. Herein are reported the isolation of five new (1-5) and eight known (7-13) CGs from the roots of Streblus asper Lour. Of these compounds 1 and 7 exhibited inhibitory action against EBV early antigen (EA) expression, with half-maximal effective concentration values (EC₅₀) being less than 60 nM, and they also showed selectivity, with selectivity index (SI) values being 56.80 and 103.17, respectively. Preliminary structure activity relationships indicated that the C-10 substituent, C-5 hydroxy groups, and C-3 sugar unit play essential roles in the mediation of the inhibitory activity of CGs against EBV. Further enzyme experiments demonstrated that these compounds might inhibit ion pump function and thereby change the intracellular signal transduction pathway by binding to Na⁺/K⁺-ATPase, as validated by simulated molecular docking. This study is the first report that CGs can effectively limit EBV lytic replication, and the observations made in this study may be of value for lead compound development.

Neuroprotective Dihydro-β-agarofuran-Type Sesquiterpenes from the Seeds of Euonymus maackii

Twenty-one dihydro-β-agarofuran derivatives were purified from the seeds of Euonymus maackii, and eight compounds (1-8) were identified as new natural products. Their structures were deduced by extensive spectroscopic analysis, X-ray diffraction studies, and comparison of observed and reported NMR data. Compounds 10, 12, 17, and 18 significantly increased the cell viability of Aβ_25-35-treated SH-SY5Y cells with effects similar to that of epigallocatechin gallate (EGCG). In addition, the abundant compound 9 reduced the seizure-like locomotor activity of zebrafish at 10 μM compared with a pentylenetetrazol-treated group.

Tripterfordins A-O, Dihydro-β-agarofuran Sesquiterpenoids from the Leaves of Tripterygium wilfordii

Fifteen new dihydro-β-agarofuran-type sesquiterpenoids, tripterfordins A-O, were obtained from the aqueous EtOH extracts of the leaves of Tripterygium wilfordii. These constituted a class of highly oxygenated tricyclic sesquiterpenoid polyesters with a cinnamoyloxy group at C-1. The assignments of their structures were conducted via extensive analyses of the spectroscopic data and comparison of experimental and calculated ECD data. The absolute configurations of compounds 1, 4, 9, and 10 were established via single-crystal X-ray diffraction data. Additionally, compounds 1, 4, 9, 10, and 13 exhibited pronounced inhibitory effects on nitric oxide production in RAW 264.7 murine macrophages stimulated by lipopolysaccharide with IC₅₀ values ranging from 11.9 to 31.0 μM.

Potential cancer chemopreventive and anticancer constituents from the fruits of Ficus hispida L.f. (Moraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus hispida L.f. (Moraceae) has been used as alternative for traditional medicine in the treatment of various ailments including cancer-cure. The aim of this study was to evaluate the cancer chemopreventive and anticancer activities of crude extracts of F. hispida, with the objective to screen the inhibition of Epstein-Barr virus early antigen, and cytotoxic active components, and provide foundation for potential applications of this promising medical plant.

MATERIALS AND METHODS

Compounds were isolated from the MeOH extract of F. hispida fruits, and their structure elucidation was performed on the basis of extensive spectroscopic analysis. The isolated compounds were evaluated for their inhibitory activities against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in Raji cells, and cytotoxic activities against human cancer cell lines (HL60, A549, SKBR3, KB, Hela, HT29, and HepG2) and a normal cell (LO2) using MTT method. For the compound with potent cytotoxic activity, its apoptosis inducing activity was evaluated by the observation of ROS generation level expression, and membrane phospholipid exposure and DNA fragmentation in flow cytometry. The mechanisms of the apoptosis induction were analyzed by Western blotting.

RESULTS

Nineteen compounds, 1-19, including two new isoflavones, 3'-formyl-5,7-dihydroxy-4'-methoxyisoflavone (2) and 5,7-dihydroxy-4'-methoxy-3'- (3-methyl-2-hydroxybuten-3-yl)isoflavone (3), were isolated from the MeOH extract of F. hispida fruits. Five compounds, isowigtheone hydrate (1), 2, 3, 9, and 19, showed potent inhibitory effects on EBV-EA induction with IC₅₀ values in the range of 271-340 molar ratio 32 pmol^-1 TPA. In addition, five phenolic compounds, 1-3, 10, and 13, exhibited cytotoxic activity against two or more cell lines (IC₅₀ 2.5-95.8μM), as well as compounds 1 and 3 were also displayed high selectivity for LO2/HepG2 (SI 23.5 and 11.8, respectively), while the compound 1-induced ROS generation leads to activated caspases-3, -8, and -9 apoptotic process in HL60 cells.

CONCLUSION

This study has established that the MeOH extract of F. hispida fruits contains isoflavones, coumarins, caffeoylquinic acids, along with other compounds including phenolics and steroid glucoside as active principles, and has demonstrated that the chemical constituents of F. hispida may be valuable as potential chemopreventive and anticancer agents.

Absolute Configuration of Dihydro-β-agarofuran Sesquiterpenes from Maytenus jelskii and Their Potential Antitumor-Promoting Effects

Chemoprevention of human cancer appears to be a feasible strategy for cancer control, especially when chemopreventive intervention is involved during early stages of the carcinogenesis process. As a part of our ongoing research program into new chemopreventive agents, herein are reported the isolation, structural elucidation, and biological evaluation of 10 new (1-10) and three known (11-13) sesquiterpenes with a dihydro-β-agarofuran skeleton from the leaves of Maytenus jelskii Zahlbr. Their stereostructures have been elucidated by means of spectroscopic analysis, including 1D and 2D NMR techniques, ECD studies, and biogenetic considerations. The isolated metabolites and eight previously reported sesquiterpenes (14-21) were screened for their antitumor-promoting activity using a short-term in vitro assay for Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Six compounds from this series (4, 5, 11, and 13-15) were found to exhibit higher efficacies than β-carotene, used as reference inhibitor for EBV-EA activation. In particular, promising antitumor activity was observed for compound 5, exhibiting inhibition even at the lowest concentration assayed (10 mol ratio/TPA). Preliminary structure-activity relationship analysis revealed that the acetate, benzoate, and hydroxy groups are the most desirable substituents on the sesquiterpene scaffold for activity in the EBV-EA activation assay.

Triptolide (TPL) improves locomotor function recovery in rats and reduces inflammation after spinal cord injury

In this study, we studied the effect of triptolide (TPL) on locomotor function in rats with spinal cord injury. A total of 40 rats were studied after dividing them in two major groups, one was experimental group denoted as TPL group while other was control group denoted as PBS group. Each group was subdivided in four subgroups having five rats each (n = 5). TPL was given intraperitonially at the rate of 5 mg/kg/day in TPL group while PBS was given at the same time interval in the same manner in control group for comparison. A reduction in the cavity area of tissue sections was observed by bright field microscopy from 0.22 ± 0.05 to 0.12 ± 0.05 mm(2) in experimental group after 28 days of treatment while BBB score also improved from 1 to 5 after 14 days of treatment. SPSS software, one way ANOVA, was used for recording statistical analysis and values were expressed as mean ± SEM where P value of <0.01 was considered significant. The expression of I-kBα and NF-kB p65 was also studied using western blotting and after recording optical density (OD) values of western blots. It was observed that treatment with TPL significantly reduced the expression of these factors after 28 days of treatment compared with controls.

Cancer chemopreventive effect of bergenin from Peltophorum pterocarpum wood

The aqueous extract of Peltophorum pterocarpum (Fabaceae) wood exhibited potent inhibitory effects against EpsteinBarr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and against melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 melanoma cells, as well as potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. Two phenolic acid derivatives, bergenin (1) and gallic acid (2), were isolated from the ethyl acetate (AcOEt)-soluble fraction obtained from the extract. Compound 1 exhibited potent inhibitory effect against EBV-EA activation and against skin tumor promotion in an in vivo two-stage mouse skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator, and with TPA as promoter. Both compounds 1 and 2 exhibited melanogenesis-inhibitory activities in α-MSH-stimulated B16 melanoma cells, and, in addition, compound 2 showed strong DPPH radical-scavenging activity.

Biological activities of phenolic compounds and triterpenoids from the galls of Terminalia chebula

Nine phenolic compounds, including two phenolic carboxylic acids, 1 and 2, seven hydrolyzable tannins, 3-9, eight triterpenoids, including four oleanane-type triterpene acids, 10-13, and four of their glucosides, 14-17, isolated from a MeOH extract of the gall of Terminalia chebula Retz. (myrobalan tree; Combretaceae), were evaluated for their inhibitory activities against melanogenesis in B16 melanoma cells induced by α-melanocyte-stimulating hormone (α-MSH), against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in Raji cells, and against TPA-induced inflammation in mice. Their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities and cytotoxic activities against four human cancer cell lines were also evaluated. Compounds 6-9 and 12 exhibited potent inhibitory activities against melanogenesis (39.3-66.3% melanin content) with low toxicity to the cells (74.5-105.9% cell viability) at a concentration of 10 μM. Western-blot analysis revealed that isoterchebulin (8) reduced the protein levels of MITF (=microphtalmia-associated transcription factor), tyrosinase, and TRP-1 (=tyrosine-related protein 1), mostly in a concentration-dependent manner. Eight triterpenoids, 10-17, showed potent inhibitory effects on EBV-EA induction with the IC50 values in the range of 269-363 mol ratio/32 pmol TPA, while these compounds exhibited no DPPH scavenging activities (IC50 >100 μM). On the other hand, the nine phenolic compounds, 1-9, exhibited potent radical-scavenging activities (IC50 1.4-10.9 μM) with weak inhibitory effects on EBV-EA induction (IC50 460-518 mol ratio/32 pmol TPA). The tannin 6 and seven triterpenoids, 10-16, have been shown to inhibit TPA-induced inflammation (1 μg/ear) in mice with the ID50 values in the range of 0.06-0.33 μmol/ear. Arjungenin (10) exhibited inhibitory effect on skin-tumor promotion in an in vivo two-stage mouse-skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator and with TPA as promoter. Compounds 1, 2, 4, 5, 7-9, 12, and 13, against HL60 cell line, compounds 1 and 4, against AZ521 cell line, and compounds 1, 11, and 12, against SK-BR-3 cell line, showed moderate cytotoxic activities (IC50 13.9-73.2 μM).

A new dihydroagarofuranoid sesquiterpene from the roots of Tripterygium hypoglaucum

A new sesquiterpene ester (1) has been isolated from the root bark of Tripterygium hypoglaucum. The structure was determined as 1α-acetoxy-6β,9β-dibenzoyloxy-4β-hydroxy-dihydroagarofuran by the extensive analysis of NMR data, and the absolute configurations were established as 1R, 4R, 6S, and 9R by application of the CD excitation chirality method. Compound 1 exhibited weak cytotoxicity against HeLa cells, with an IC₅₀ value of 30.2 μM.

Antiplasmodial sesquiterpenes from the seeds of Salacia longipes var. camerunensis

Phytochemical investigation of the seeds of Salacia longipes var. camerunensis led to the isolation of four sesquiterpenoid derivatives, salaterpene A (1) (1α,2β,8β-triacetoxy-6β,9β-dibenzoyloxy-4β-hydroxy-dihydro-β-agarofuran), salaterpene B (2) (1α,2β,8β-triacetoxy-9β-benzoyloxy-6β-cinnamoyloxy-4β-hydroxy-dihydro-β-agarofuran), salaterpene C (3) (1α,2β-diacetoxy-6β,9β-dibenzoyloxy-4β-hydroxy-dihydro-β-agarofuran) and salaterpene D (4) (2β-acetoxy-1α,6β-dibenzoyloxy-4β-hydroxy-9β-nicotinoyloxy-dihydro-β-agarofuran) together with two known compounds (5 and 6). The structures of the compounds were established by means of NMR spectroscopy. Compounds 1-4 and 6 were tested in vitro for their antiplasmodial activity against Plasmodium falciparum chloroquine-resistant strain W2. All the tested compounds exhibited a moderate potency with IC50 below 2.7 μM.

Semisynthesis and antifeedant activity of new derivatives of a dihydro-β-agarofuran from Parnassia wightiana

Five new derivatives (2-6) were semi-synthesized using compound 1, a dihydro-β-agarofuran sesquiterpene with C-2 ketone obtained from Parnassia wightiana, as the starting material by acylation, oxidation, reduction, esterification, and amination, respectively. Structures of 2-6 were confirmed by 1D- and 2D-NMR and HR-ESI-MS spectra. In addition, antifeedant activities of these compounds (1-6) were tested against the 3rd-instar larvae of Mythimna separata. Antifeedant effects of compounds 2 and 4 were greater than the parent compound 1 whereas other compounds exhibited low to no feeding deterrent effects against third instar M. separata larvae in lab bioassays. Therefore, our results suggest that acylated and reduced derivatives at C-8 and C-2, respectively, of 1 may improve the antifeeding effect. This preliminary information will be useful in designing new insect control agents against M. separata and other important pests.

Limonoids from the fruits of Melia azedarach and their cytotoxic activities

Thirty-one limonoids and one tirucallane-type triterpenoid were isolated from the fruits of Melia azedarach (Meliaceae). The structures of 14 of these isolated compounds were elucidated on the basis of spectroscopic analyses and comparison with literature. All of these compounds were evaluated for their cytotoxic activities against HL60, A549, AZ521, and SK-BR-3 human cancer cell lines. Meliarachin C (IC50 0.65 μM) and 3-O-deacetyl-4'-demethyl-28-oxosalannin (IC50 2.8 μM) exhibited potent cytotoxic activity against HL60 cells, and this was demonstrated mainly due to the induction of apoptosis by flow cytometry. Western blot analysis suggested that both compounds induced apoptosis via both the mitochondrial and death receptor-mediated pathways. In addition, 25 compounds were evaluated for their inhibitory effects against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells.

Impairment of triptolide on liver mitochondria in isolated liver mitochondria and HL7702 cell line

OBJECTIVE

To observe the impairing effects of triptolide on liver mitochondria in isolated rat-liver mitochondria and human normal liver HL7702 cell line.

METHODS

Rat-liver mitochondria were isolated from adult female Sprague-Dawley (SD) rats. Liver mitochondria were incubated with 0, 1.25, 2.5, 5 and 10 μmol/L triptolide for detecting mitochondrial swelling and with 0, 2.5, 5 and 10 μmol/L triptolide for mitochondrial permeability transition pore (MPTP) activity. Mitochondrial swelling was estimated by measuring the apparent absorbance change during 600 s in the mitochondrial suspensions at 520 nm with a mitochondrial swelling examining kit. The effect of triptolide on MPTP was determined with a fluorescence detection kit by detecting the fluorescence intensity at an excitation wavelength of 488 nm emitted at 527 nm. Human normal liver HL7702 cells were treated without or with 0.02, 0.1 and 0.5 μmol/L triptolide for 24 h for analyzing mitochondrial transmembrane potential (Δψm) and reactive oxygen species (ROS). Δψm was measured using the fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1). ROS was measured using fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH-DA). The cells were harvested and dyed with JC-1 and DCFH-DA, and analyzed by flow cytometry, respectively.

RESULTS

Incubation of isolated mitochondria with triptolide results in swollen mitochondria in a concentration-dependent manner. Moreover, triptolide significantly activated mitochondrial permeability transition at 5 and 10 μmol/L (P<0.05 and P<0.01). When HL7702 cells were exposed to a various concentration triptolide for 24 h, mitochondrial membrane depolarization and increase of ROS were caused by triptolide in a concentration-dependent manner. Triptolide significantly induced the mitochondrial membrane depolarization at 0.1 and 0.5 μmol/L (P<0.05 and P<0.01) and the increase of ROS at 0.1 and 0.5 μmol/L (P<0.05 and P<0.01).

CONCLUSION

Triptolide could induce mitochondrial impairment, which may be one of the mechanisms by which hepatotoxicity occurs.

Anti-inflammatory and anti-tumor-promoting effects of 5-deprenyllupulonol C and other compounds from Hop (Humulus lupulus L.)

A new phloroglucinol derivative, 5-deprenyllupulonol C (1), along with four other phloroglucinol derivatives, 2-5, five chalcones, 6-10, four flavanones, 11-14, two flavonol glycosides, 15 and 16, and five triterpenoids, 17-21, were isolated from the female inflorescence pellet extracts of hop (Humulus lupulus L.). Upon evaluation of these compounds against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in Raji cells, twelve compounds, i.e., 1-4, 11-14, 17-19, and 21, showed potent inhibitory effects on EBV-EA induction, with IC₅₀ values in the range of 215-393 mol ratio/32 pmol TPA. In addition, eleven compounds, i.e., 1-4, 6, 11, 12, 14, 17, 18, and 20, were found to inhibit TPA-induced inflammation (1 μg/ear) in mice, with ID₅₀ values in the range of 0.13-1.06 μmol per ear. Further, lupulone C (2) and 6-prenylnaringenin (14) exhibited inhibitory effects on skin-tumor promotion in an in vivo two-stage mouse-skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator and with TPA as promoter.

Cucurbitane triterpenoids from the leaves of Momordica charantia, and their cancer chemopreventive effects and cytotoxicities

Seventeen cucurbitane-type triterpenoids, 1-17, including six new compounds, (23E)-3β,25-dihydroxy-7β-methoxycucurbita-5,23-dien-19-al (1), (23S*)-3β-hydroxy-7β,23-dimethoxycucurbita-5,24-dien-19-al (6), (23R*)-23-O-methylmomordicine IV (7), (25ξ)-26-hydroxymomordicoside L (8), 25-oxo-27-normomordicoside L (9), and 25-O-methylkaravilagenin D (12), were isolated from a MeOH extract of the leaves of Japanese Momordica charantia. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Compounds 1-17 were examined for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, a known primary screening test for inhibitors of tumor promotion. Four compounds, 1, (23E)-3β,7β-dihydroxy-25-methoxycucurbita-5,23-dien-19-al (2), karavilagenin D (11), and 12, showed potent inhibitory effects on EBV-EA induction with IC(50) values in the range of 242-264 mol ratio/32 pmol TPA. In addition, compounds 1 and 11 exhibited inhibitory effects on skin-tumor promotion in an in vivo two-stage mouse skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator, and with TPA as a promoter. Furthermore, upon evaluation of the cytotoxic activities of compounds 1-17 against human cancer cell lines, compounds 2, 5-7, 9, and 14 showed potent activities against HL60 cell line, and compound 2 against SK-BR-3 cell line.

Simultaneous identification of multiple celangulins from the root bark of Celastrus angulatus using high-performance liquid chromatography-diode array detector-electrospray ionisation-tandem mass spectrometry

INTRODUCTION

Celangulins are a small family of β-dihydroagarofuran sesquiterpenoids endowed with diverse polyoxygenated polyol esters and various biological properties. Since our research focuses on celangulins, the development of rapid and sensitive online analytical methods to analyse and characterise them is of great significance.

OBJECTIVE

To develop an HPLC-DAD-ESI-MS/MS method capable of simple and rapid analysis of celangulins in crude extract of root bark of C. angulatus extracts.

METHODOLOGY

High-performance liquid chromatography coupled with a diode array detector and electrospray ionisation tandem mass spectrometry was established for the efficient and rapid identification of the celangulins. Chromatographic separations of celangulins were performed on a Hypersil Gold C(18) reverse-phase column by gradient elution with acetonitrile-water as mobile phase at a flow-rate 0.2 mL/min.

RESULTS

ESI/MS/MS analysis of sodium adduct ion ([M + Na](+) ) of each celangulin shows that all the celangulins produced very similar fragmentation profiles, and that the characteristic fragments at m/z 245, m/z 229 and m/z 231 were defined as the diagnostic ions for celangulins. Simultaneously, 46 components in the extracts of this plant were separated, and 36 of them were characterised as celangulins by online ESI/MS/MS and by comparing their retention times, UV and MS spectra with those of authentic compounds.

CONCLUSION

HPLC-DAD-ESI-MS/MS was demonstrated to be a powerful tool for the characterisation of minor celangulins in complex samples.

Isolation, biological evaluation and 3D-QSAR studies of insecticidal/narcotic sesquiterpene polyol esters

For the first time, a set of (43) natural sesquiterpene polyol esters isolated from the root bark of Celastrus angulatus Maxim and Euonymus japonicus Thunb were subjected to 3D-QSAR comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) studies, with the aim of proposing novel sesquiterpene-based compounds with optimal narcotic or insecticidal activities. The established 3D-QSAR models exhibit reasonable statistical quality and prediction capabilities, with internal cross-validated Q (2) values of ∼ 0.5 and external predicted R (2) values of >0.9, respectively. The relative contributions of the steric/electrostatic fields of the 3D-QSAR models show that the electronic effect governs the narcotic activities of the molecules, but the hybrid effect of the electrostatic and hydrophobic interactions is more influential in the insecticidal activities of the compounds. These findings may have valuable implications for the development of novel natural insecticides.

Antioxidant activity and protective effects of Tripterygium regelii extract on hydrogen peroxide-induced injury in human dopaminergic cells, SH-SY5Y

The present work was conducted to investigate the antioxidant activity and neuroprotective effects of Tripterygium regelii extract (TRE) on H₂O₂-induced apoptosis in human dopaminergic cells, SH-SY5Y. TRE possessed considerable amounts of phenolics (282.73 mg tannic acid equivalents/g of extract) and flavonoids (101.43 mg naringin equivalents/g of extract). IC₅₀ values for reducing power and DPPH radical scavenging activity were 52.51 and 47.83 μg, respectively. The H₂O₂ scavenging capacity of TRE was found to be 57.68 μM × μg⁻¹ min⁻¹. By examining the effects of TRE on SH-SY5Y cells injured by H₂O₂, we found that after incubation of cells with TRE prior to H₂O₂ exposure, the H₂O₂ induced cytotoxicity was significantly reversed and the apoptotic features such as change in cellular morphology, nuclear condensation and DNA fragmentation was inhibited. Moreover, TRE was very effective attenuating the disruption of mitochondrial membrane potential and apoptotic cell death induced by H₂O₂. TRE extract effectively suppressed the up-regulation of Bax, Caspase-3 and -9, and down-regulation of Bcl-2. Moreover, TRE pretreatment evidently increased the tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF) in SH-SY5Y cells. These findings demonstrate that TRE protects SH-SY5Y cells against H₂O₂-induced injury and antioxidant properties may account for its neuroprotective actions and suggest that TRE might potentially serve as an agent for prevention of neurodegenerative disease associated with oxidative stress.

Three New Insecticidal Sesquiterpene Polyol Esters from Celastrus angulatus

Three new insecticidal sesquiterpene polyol esters with dihydro-β-agarofuran skeletons, Kupiteng esters A (1), B (2) and C (3), were isolated from the methanol extracts of the root bark of Celastrus angulatus and their structures elucidated by analyses of MS and NMR spectral data. The insecticidal activities of these compounds against the 4th instar larvae of Mythimna separata were evaluated. The KD50 values of compounds 1-3, were 260.2, 445.5 and 1260.0 μg-g−1, respectively.

Anti-tumor-promoting effects of 25-methoxyporicoic acid A and other triterpene acids from Poria cocos

Nine new (1, 3, 5, 8, 12, 13, 15, 17, and 18) and nine known (2, 4, 6, 7, 9-11, 14, and 16) lanostane-type triterpene acids and a known diterpene acid (19) were isolated from the epidermis of the sclerotia of Poria cocos. The structures of the new compounds were established as 16alpha,27-dihydroxydehyrotrametenoic acid (1), 25-hydroxy-3-epitumulosic acid (3), 16alpha,25-dihydroxyeburiconic acid (5), 25-methoxyporicoic acid A (8), 26-hydroxyporicoic acid DM (12), 25-hydroxyporicoic acid C (13), poricoic acid GM (15), poricoic acid HM (17), and 6,7-dehydroporicoic acid H (18), on the basis of spectroscopic methods. On evaluation of the nine new and two of the known compounds, 4 and 19, against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, all of the compounds exhibited inhibitory effects, with IC(50) values in the range 187-348 mol ratio/32 pmol TPA. In addition, compound 8 exhibited an inhibitory effect on skin tumor promotion in an in vivo two-stage carcinogenesis test using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter. Further, 17 compounds, 1-14, 16, 18, and 19, were evaluated for their cytotoxic activity against two human tumor cell lines, HL60 (leukemia) and CRL1579 (melanoma).

Cucurbitane-type triterpenoids from the fruits of Momordica charantia and their cancer chemopreventive effects

Thirteen cucurbitane-type triterpene glycosides, including eight new compounds named charantosides I (6), II (7), III (10), IV (11), V (12), VI (13), VII (16), and VIII (17), and five known compounds, 8, 9, 14, 15, and 18, were isolated from a methanol extract of the fruits of Japanese Momordica charantia. The structures of the new compounds were determined on the basis of spectroscopic methods. On evaluation of these triterpene glycosides and five other cucurbitane-type triterpenes, 1-5, also isolated from the extract of M. charantia fruits, for their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, these compounds showed inhibitory effects on EBV-EA induction with IC(50) values of 200-409 mol ratio/32 pmol TPA. In addition, upon evaluation of compounds 1-5 for inhibitory effects against activation of (+/-)-(E)-methyl-2[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitrogen oxide (NO) donor, compounds 1-3 showed moderate inhibitory effects. Compounds 1 and 2 exhibited marked inhibitory effects in both 7,12-dimethylbenz[a]anthracene (DMBA)- and peroxynitrite (ONOO-; PN)-induced mouse skin carcinogenesis tests.

Triterpene acids from Poria cocos and their anti-tumor-promoting effects

The structures of six new lanostane-type triterpene acids isolated from the epidermis of the sclerotia of Poria cocos were established to be 15alpha-hydroxydehydrotumulosic acid (5), 16alpha,25-dihydroxydehydroeburicoic acid (9), 5alpha,8alpha-peroxydehydrotumulosic acid (10), 25-hydroxyporicoic acid H (11), 16-deoxyporicoic acid B (12), and poricoic acid CM (16) on the basis of spectroscopic methods. On evaluation of these six and 11 other known triterpene acids isolated from the sclerotium, 1-4, 6-8, 13-15, and 17, against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, all of the compounds except for 1, 3, 4, and 8 exhibited inhibitory effects with IC50 values of 195-340 mol ratio/32 pmol TPA. Compound 12 and poricoic acid C (13) exhibited inhibitory effects on skin tumor promotion in an in vivo two-stage carcinogenesis test using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

Cancer chemopreventive effects of cycloartane-type and related triterpenoids in in vitro and in vivo models

Forty-eight natural and semisynthetic cycloartane-type and related triterpenoids have been evaluated for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells as a primary screening test for anti-tumor promoters. In addition, these triterpenoids have been tested for their inhibitory effects on activation of (+/-)-(E)-methtyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor, as a primary screening test for anti-tumor initiators. All of the compounds tested exhibited inhibitory effects on both EBV-EA and NOR 1 activation. Six of these compounds having a C-24 hydroxylated side chain, viz., (24R)-cycloart-25-ene-3beta,24-diol (9), (24R)-cycloartane-3beta,24,25-triol (11), (24S)-cycloartane-3beta,24,25-triol (12), (24xi)-24-methylcycloartane-3beta,24,241-triol (14), (24xi)-241-methoxy-24-methylcycloartane-3beta,24-diol (15), and (24xi)-24,25-dihydroxycycloartan-3-one (27), showed higher inhibitory effects than the others tested on both EBV-EA (IC50 values of 6.1-7.4 nM) and NOR 1 activation. Furthermore, compounds 14 and 15 exhibited inhibitory effects on skin tumor promotion in an in vivo two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

Cucurbitane glycosides from the fruits of Siraitia gros venorii and their inhibitory effects on Epstein-Barr virus activation

Six new cucurbitane glycosides, mogroside II B (2), 11-deoxymogroside III (4), 7-oxomogroside II E (5), 7-oxomogroside V (6), 11-oxomogroside II A1 (7), and 11-oxomogroside IV A (8), and two known but new naturally occurring cucurbitane glycosides, mogroside II A1 (1) and mogroside III A2 (3), were isolated from an ethanol extract of the fruits of Siraitia grosvenorii. Upon evaluation of compounds 1-8 for inhibitory effects against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), all compounds exhibited inhibitory effects with IC50 values of 346-400 mol ratio/32 pmol TPA. In addition, compounds 1-8 showed weak inhibitory effects on activation of (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor.

Anti-inflammatory and anti-tumor-promoting effects of triterpene acids and sterols from the fungus Ganoderma lucidum

A series of lanostane-type triterpene acids, including eleven lucidenic acids (3, 4, 9, 10, 13-19) and six ganoderic acids (20-22, 24, 26, 27), as well as six sterols (28-33), all isolated from the fruiting bodies of the fungus Ganoderma lucidum, were examined for their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, a known primary screening test for anti-tumor promoters. All of the compounds tested, except for ganolactone (27) and three sterols (29-31), showed potent inhibitory effects on EBV-EA induction, with IC(50) values of 235-370 mol ratio/32 pmol TPA. In addition, nine lucidenic acids (1, 2, 5-8, 11, 12, 18) and four ganoderic acids (20, 23-25) were found to inhibit TPA-induced inflammation (1 microg/ear) in mice, with ID(50) values of 0.07-0.39 mg per ear. Further, 20-hydroxylucidenic acid N (18) exhibited inhibitory effects on skin-tumor promotion in an in vivo two-stage mouse-skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator, and with TPA as promoter.

The dihydro-β-agarofuran sesquiterpenoids

Dihydro-Beta-agarofuran sesquiterpenoids are a structurally diverse class of natural products based on tricyclic 5,11-epoxy-5Beta,10alpha-eudesman-4-(14)-ene skeleton. Between January 1990 and June 2006, 462 new dihydro-Beta-agarofuran sesquiterpenoids of 74 structural types have been isolated from about 64 species of Celastraceae, 3 species of Hippocrateaceae and one species of Lamiaceae. The present review covers the chemical and biological activity research of dihydro-Beta-agarofuran sesquiterpenoids in the past 16 years. The chemical research includes structural classification into sesquiterpene polyesters and macrolide sesquiterpene pyridine alkaloids, synthesis of dihydro-Beta-agarofuran as well as extraction, isolation and purification methods. The biological activity research includes activities such as multidrug resistance (MDR) reversal activity, HIV inhibition, cytotoxicity, antitumor activity, antifeedant activity and insecticidal activity with some insights to their modes of actions.

Preparation of monoclonal antibody against celangulin V and immunolocalization of receptor in the oriental armyworm, Mythimna separata walker (Lepidoptera: Noctuidae)

The botanical insecticide celangulin V (CA-V) is an insect digestive poison acting on midgut tissue of the target insect larvae. With the aim of localizing the receptor enacted by CA-V, monoclonal antibodies (MAbs) specific to the compound were developed. A hapten was synthesized by introducing a succinoyl into the CA-V structure and conjugated with three carrier proteins. From mice immunized with one conjugate, three MAbs were obtained with a potential capacity of detecting protein-bound residue forms of CA-V in the biological tissues. The oriental armyworm larvae ingested CA-V were examined by the technique of immuno-electron-microscopy (IEM) using the anti-CA-V MAb as the primary antibody and goat anti-mouse/IgG labeled with colloidal gold as the secondary antibody. Electron micrographs of the armyworm midgut tissues showed that the CA-V was associated with the midgut epithelia of the insects. These results demonstrated the existence of a receptor enacted by CA-V on the midgut cells of the oriental armyworm larvae.

Cancer Chemopreventive Effects and Cytotoxic Activities of the Triterpene Acids from the Resin of Boswellia carteri

Fifteen triterpene acids, viz., seven of the beta-boswellic acids (ursane-type) (1-7), two of the alpha-boswellic acids (oleanane-type) (8, 9), two of the lupeolic acids (lupane-type) (10, 11), and four of the tirucallane-type (12-14, 16), and two cembrane-type diterpenes (17, 18), isolated from the MeOH extract of the resin of Boswellia carteri (Burseraceae), together with a triterpene acid 15 (the acetyl derivative of 14), were examined for their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and on activation of (+/-)-(E)-methyl-2[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitrogen oxide (NO) donor, and cytotoxic activities against three human neuroblastoma cell lines, IMR-32, NB-39, and SK-N-SH in vitro. On evaluation against the EBV-EA activation induced by TPA, seven compounds, 2, 10, 11, and 13-16, showed potent inhibitory effects on EBV-EA induction. Upon evaluation against activation of NOR 1, five compounds, 7, 13, and 14-16, showed potent inhibitory effects. Further, fifteen compounds, 1-7, 9-11, 13-15, 17, and 18, exhibited potent cytotoxic activities with IC(50) values of 4.1-82.4 muM against all of the three human neuroblastoma cells tested.

Chalcones and other compounds from the exudates of Angelica keiskei and their cancer chemopreventive effects

Three new chalcones, xanthoangelol I (1), xanthoangelol J (2), and deoxydihydroxanthoangelol H (3), were isolated from an ethyl acetate-soluble fraction of exudates of the stems of Angelica keiskei, and their structures were established on the basis of spectroscopic methods. Nine aromatic compounds of known structure, 4-12, and a diacetylene, 13, were also isolated and identified from this same fraction. On evaluation of these compounds for their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, 1, 2, 4, and 9-12 showed potent inhibitory effects on EBV-EA induction. In addition, upon evaluation of the inhibitory effects against activation of (+/-)-(E)-methyl-2[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitrogen oxide (NO) donor, six compounds, namely, 1, 2, 4, 9, 11, and 12, exhibited potent inhibitory effects. Further, isobavachalcone (4) exhibited inhibitory effects on skin tumor promotion in an in vivo two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

Acerogenin M, a Cyclic Diarylheptanoid, and Other Phenolic Compounds from Acer nikoense and Their Anti-inflammatory and Anti-tumor-Promoting Effects

A new cyclic diarylheptanoid, acerogenin M (1), has been isolated along with nine known diarylheptanoids, 2-10, and two known phenolic compounds, 11 and 12, from a MeOH extract of the stem bark of Acer nikoense MAXIM. (Aceraceae). The structure of 1 was determined on the basis of a spectroscopic method. Upon evaluation of the inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 microg/ear) in mice of nine of the compounds (2-6, 8, 10-12), six (2, 4-6, 8, 10) showed a marked anti-inflammatory effect with a 50% inhibitory dose (ID(50)) of 0.26-0.81 mg per ear. In addition, upon an evaluation against the Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA for all of the compounds, all exhibited moderate inhibitory effects against EBV-EA induction (IC(50) values of 356-534 mol ratio/32 pmol TPA).

Azaphilones, furanoisophthalides, and amino acids from the extracts of Monascus pilosus-fermented rice (red-mold rice) and their chemopreventive effects

Six azaphilones, monascin (1), ankaflavin (2), rubropunctatin (3), monascorburin (4), rubropunctamine (5), and monascorburamine (6), two furanoisophthalides, xanthomonasin A (7) and xanthomonasin B (8), and two amino acids, (+)-monascumic acid (9) and (-)-monascumic acid (10), isolated from the extracts of Monascus pilosus-fermented rice (red-mold rice) were evaluated for their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice, on the induction of Epstein-Barr virus early antigen (EBV-EA) by TPA in Raji cells, and on the activation of (+/-)-(E)-methyl-2[(E)-hydroxy-imino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor. Among the compounds tested, seven compounds (1-6 and 10) on TPA-induced inflammation, and six compounds (1, 3-5, 9, and 10) on EBV-EA activation, exhibited potent inhibitory effects. All of the compounds tested showed moderate inhibitory effects on NOR 1 activation.