Anti-HIV Macrocyclic Daphnane Orthoesters with an Unusual Macrocyclic Ring from Edgeworthia chrysantha.

Edgeworthianins A-E (1-5) were isolated from Edgeworthia chrysantha as a class of macrocyclic daphnane orthoesters with an unusual macrocyclic ring formed from a C14 aliphatic chain. Their structures were elucidated by extensive physicochemical and spectroscopic analyses. Compounds 2, 4, and 5 exhibited potent anti-HIV activity against HIV-1 infection of MT4 cells with EC50 values of 29.3, 8.4, and 2.9 nM, respectively. These compounds broaden the findings of the structure-activity relationship of macrocyclic daphnane orthoesters for further anti-HIV drug development.

Isolation, Structural Elucidation, and Anti-HIV Activity of Daphnane Diterpenoids from Daphne odora.

Five new [daphneodorins D-H (1, 5, and 10-12)] and seven known daphnane diterpenoids (2-4 and 6-9) were isolated from Daphne odora. The structures of the new compounds were elucidated by extensive physicochemical and spectroscopic analysis. The isolated compounds were evaluated for their anti-HIV activity against HIV-1 infection of MT4 cells. Nine daphnane diterpenoid orthoesters (1-9) showed potent anti-HIV activity with EC50 values of 1.5-7.7 nM.

Phellilane L, Sesquiterpene Metabolite of Phellinus linteus: Isolation, Structure Elucidation, and Asymmetric Total Synthesis.

A new cyclopropane-containing sesquiterpenoid, phellilane L (1), was isolated from the medicinal mushroom Phellinus linteus ("Meshimakobu" in Japanese), a member of the Hymenochaetaceae family and a well-known fungus that is widely used in East Asia. The planar structure of 1 was determined on the basis of spectroscopic analysis. The authors achieved the first total synthesis of 1. Our protecting group-free synthesis features a highly stereoselective one-pot synthesis involving an intermolecular alkylation/cyclization/lactonization strategy for construction of the key cyclopropane-γ-lactone intermediate. Additionally, our synthesis determined the absolute configuration of phellilane L (1).

Inhalation administration of the sesquiterpenoid aristolen-1(10)-en-9-ol from Nardostachys chinensis has a sedative effect via the GABAergic system.

Spikenard, the dried roots of Nardostachys chinensis, contains sesquiterpenoids and is widely used as an herbal tranquilizer. We previously demonstrated that spikenard vapor showed a sedative effect when administered by inhalation, and we identified hydrocarbon sesquiterpenoids as active components. Here we investigated the other components that contribute to the effects of spikenard. Six oxygenated sesquiterpenoids, including aristolane- and guaiane-types, were isolated from an acetone extract of spikenard. We evaluated the sedative activities of these oxygenated compounds using an inhalation administration method in a caffeine-treated excitatory mouse model. We identified aristolen-1(10)-en-9-ol and patchouli alcohol as highly effective sedative components. These compounds inhibited locomotion in mice by approximately 60% at a dose of 300 µg/cage. In addition, aristolen-1(10)-en-9-ol prolonged pentobarbital-induced sleep to the same extent as 1 mg/kg diazepam. This effect completely disappeared with the administration of the GABAA-benzodiazepine receptor antagonist flumazenil (3 mg/kg), suggesting that the sedative effect of aristolen-1(10)-en-9-ol is expressed via the GABAergic system. Furthermore, differently from diazepam, inhalation of aristolen-1(10)-en-9-ol for 1 h did not affect the motor coordination in the rota-rod test. In the present study, we identified active components and provided evidence supporting the traditional sedative use of spikenard. Our research suggests that aristolen-1(10)-en-9-ol may be an effective aromatherapy, providing mild sedation.

Evaluation of licorice flavonoids as protein tyrosine phosphatase 1B inhibitors.

Protein tyrosine phosphatase 1B (PTP1B) is a major negative regulator in insulin- and leptin-signaling cascades as well as a positive regulator in tumorigenesis, and much attention has been paid to PTP1B inhibitors as potential therapies for diabetes, obesity, and cancer. In the present study, the screening of a compound library of licorice flavonoids allowed for the discovery of several compounds, including licoagrone (3), licoagrodin (4), licoagroaurone (5), and isobavachalcone (6), as new PTP1B inhibitors. It was revealed that these compounds inhibit the activity of PTP1B in different modes and with different selectivities and that they exhibit different cellular activity in the insulin-signaling pathway. Glycybenzofuran (1), a competitive PTP1B inhibitor, showed both excellent inhibitory selectivity against PTP1B and cellular activity on the insulin-stimulated Akt phosphorylation level. The similarity of its action profiling in the insulin-signaling pathway suggested its potential as a new anti-insulin-resistant drug candidate.

Isolation, structure determination, and anti-HIV evaluation of tigliane-type diterpenes and biflavonoid from Stellera chamaejasme.

Five novel tigliane-type diterpenes, stelleracins A-E (3-7), a novel flavanone dimer, chamaeflavone A (8), and six known compounds were isolated from the roots of Stellera chamaejasme. Their structures were elucidated by extensive spectroscopic analyses. The isolated compounds were evaluated for anti-HIV activity in MT4 cells. New compounds 3-5 showed potent anti-HIV activity (EC90 0.00056-0.0068 µM) and relatively low or no cytotoxicity (IC50 4.4-17.2 µM). These new compounds represent promising new leads for development into anti-AIDS clinical trial candidates.

Clerodane diterpenoids from Tinospora sagittata (Oliv.) Gagnep.

Three new clerodane diterpene glycosides, tinospinosides A (1), B (2), and C (3) were isolated from the roots of Tinospora sagittata (Oliv.) Gagnep. Their structures were determined to be (2 S,4a R,6a R,9 R,10a S,10b S)-2-(3-furanyl)-9-( ß-D-glucopyranosyloxy)-1,4,4a,5,6,6a,9,10,10a,10b-decahydro-6a,10b-dimethyl-4-oxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester (1), (2 S,4a S,6a R,9 R,10a R,10b S)-2-(3-furanyl)-9-( ß-D-glucopyranosyloxy)-1,4,4a,5,6,6a,9,10,10a,10b-decahydro-4a-hydroxyl-6a,10b-dimethyl-4-oxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester (2) and (2 S,4a R,6a R,9 R,10a R,10b S)-2-(3-furanyl)-9-( ß-D-glucopyranosyloxy)-1,4,4a,5,6,6a,9,10,10a,10b-decahydro-4a-hydroxyl-6a,10b-dimethyl-4-oxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester (3), by various spectroscopic analyses, chemical reactions, and computer-assisted calculations. The inhibitory activities of NO production by these compounds and their chemical derivatives in lipopolysaccharide and TNF γ-activated macrophage-like cell line J774.1 were tested. Tinospin A, 12- EPI-tinospin A, tinospinoside B, and tinospinoside C showed inhibitory activities of NO production with the IC(50) values of 162, 182, 290, and 218 µM, respectively.

Tinospinosides D, E, and tinospin E, further clerodane diterpenoids from Tinospora sagittata.

Chemical investigation on the roots of Tinospora sagittata resulted in the isolation of three novel cis-clerodane diterpenoids, tinospinosides D, E, and tinospin E, together with two known compounds, columbin and columbin glucoside, and their structures were determined by extensive spectroscopic analyses, chemical reactions and computer-assisted calculations. The inhibitory activity of the isolated compounds and their chemical derivatives on nitric oxide production in lipopolysaccharide and interferon-γ activited J774.1 macrophage-like cells was also evaluated.

Secoiridoid glucosides and related compounds from Syringa reticulata and their antioxidant activities.

A 70% EtOH extract from the bark of Syringareticulata has shown significant antioxidant activity. Chemical study on the extract resulted in the isolation of seventeen compounds (1-17), including a novel oleoside-type secoiridoid glucoside, reticuloside (1), and the structures were elucidated on the basis of extensive spectroscopic analyses. Among the isolated compounds, jaspolyoside (2), oleuropein (4) and 2-(3,4-dihydroxy)-phenylethyl-ß-d-glucopyranoside (17), showed the most potent superoxide anion scavenging activity with the EC(50) values of 4.97, 2.57 and 4.97µM, respectively. The structure-activity relationship indicated that the presence of 2-(3,4-dihydroxyphenyl)-ethoxy group is important for exhibiting the activity.

Chemical constituents from Sambucus adnata and their protein-tyrosine phosphatase 1B inhibitory activities.

The MeOH extract from the whole plants of Sambucus adnata has shown significant protein-tyrosine phosphatase 1B (PTP1B) inhibitory activity. Chemical study on the extract resulted in the isolation of thirteen compounds, including a novel triterpene (1). The structure of 1 was determined to be 1α,3ß-dihydroxy-urs-12-en-11-one-3-yl palmitate on the basis of extensive spectroscopic analyses. Among the isolated compounds, ursolic acid, oleanolic acid and (±)-boehmenan showed the most potent PTP1B inhibitory activity in vitro with the IC(50) values of 4.1, 14.4 and 43.5 µm, respectively. The kinetic analysis indicated that (±)-boehmenan inhibits PTP1B activity in a competitive manner.

Two novel steroidal alkaloid glycosides from the seeds of Lycium barbarum.

Two novel steroidal alkaloid glycosides, lycioside A (1) and lycioside B (2) were isolated from the seeds of Lycium barbarum. Their structures were determined by various spectroscopic analyses. Compounds 1 and 2 showed inhibitory activities with the IC(50) values of 75.3 and 72.8 µM against rat intestinal sucrase, and 63.4 and 59.1 µM against rat intestinal maltase.

Prenylflavonoids from Glycyrrhiza uralensis and their protein tyrosine phosphatase-1B inhibitory activities.

Two new 2-arylbenzofurans, glycybenzofuran (1) and cyclolicocoumarone (2), together with 10 known flavonoids including licocoumarone (3), glycyrrhisoflavone (4), glisoflavone (5), cycloglycyrrhisoflavone (6), isoliquiritigenin (7), licoflavone A (8), apigenin (9), isokaempferide (10), glycycoumarin (11), and isoglycycoumarin (12), were isolated from the roots of Glycyrrhiza uralensis and their structures were determined by extensive spectroscopic analyses. Compounds 1 and 5 showed significant protein tyrosine phosphatase-1B (PTP1B) inhibitory activity in vitro with the IC50 values of 25.5 and 27.9 microM, respectively. The structure-activity relationship indicated that the presence of prenyl group and ortho-hydroxy group is important for exhibiting the activity. Kinetic analysis indicated that compound 1 inhibits PTP1B by a competitive mode, whereas compound 5 by a mixed mode.

Daphneodorins A-C, Anti-HIV Gnidimacrin Related Macrocyclic Daphnane Orthoesters from Daphne odora.

Three novel gnidimacrin related macrocyclic daphnanes (GMDs), daphneodorins A-C (2-4), were isolated from Daphne odora Thunb., together with gnidimacrin (1). Their structures were established by extensive physicochemical and spectroscopic analyses. Compounds 2 and 3 potently inhibited HIV-1 replication at subnanomolar concentrations (EC50 0.16 and 0.25 nM, respectively). Compounds 2-4 represent a novel type of GMDs that are highly oxygenated on the macrocyclic ring, suggesting good potential for anti-HIV drug development by further chemical modification.

Twelve pregnane glycosides from Cynanchum atratum.

Eleven new 14,15-seco-pregnane-type steroidal glycosides, cynanosides P1-P5, Q1-Q3, R1-R3, and a novel 12,13-seco-14,18-nor-pregnane-type steroidal glycoside, cynanoside S, were isolated from the roots of Cynanchum atratum, together with four known compounds, atratoside C, sublanceoside E3, chekiangensoside C and cynatroside B. Their structures were determined on the basis of spectroscopic analysis and chemical evidence.

Antimutagenic components in Spatholobus suberectus Dunn against N-methyl-N-nitrosourea.

BACKGROUND: An extract from Spatholobus suberectus (S. suberectus) Dunn has been reported to show potent antimutagenic effects against N-alkyl-N-nitrosoureas in umu screening. The aim of this study was to identify the antimutagenic components from extracts of S. suberectus against N-methyl-N-nitrosourea (MNU) in the Ames assay with Salmonella typhimurium strain TA1535 and to elucidate the antimutagenic mechanism of the flavonoids. RESULTS: From the ethyl acetate fraction obtained from fractionation of the methanol extract of S. suberectus Dunn, medicarpin, formononetin and isoliquiritigenin were successfully isolated through a combination of normal- and reversed-phase chromatography. Genistein and naringenin, which were already reported to be contained in S. suberectus Dunn, were also tested for their antimutagenicity towards MNU, along with formononetin, isoliquiritigenin and medicarpin. Our results demonstrated that genistein, isoliquiritigenin, medicarpin and naringenin were antimutagenic against MNU without showing cytotoxicity. MNU is reported to cause not only DNA alkylation but also induce reactive oxygen species. The hydroxyl radical scavenging capacity of the flavonoids was correlated with the antimutagenic capacity, indicating that the hydroxyl radical scavenging activity was involved in their antimutagenicity towards MNU. CONCLUSIONS: It is important to prevent DNA damage by N-nitrosamines for cancer chemoprevention. Genistein, isoliquiritigenin, medicarpin and naringenin were demonstrated to possess an antigenotoxic effects against carcinogenic MNU due to their radical scavenging activity.

Synthesis and Structure-Activity Relationship Correlations of Gnidimacrin Derivatives as Potent HIV-1 Inhibitors and HIV Latency Reversing Agents.

Currently, due to the HIV latency mechanism, the search continues for effective drugs to combat this issue and provide a cure for AIDS. Gnidimacrin activates latent HIV-1 replication and inhibits HIV-1 infection at picomolar concentrations. This natural diterpene was able to markedly reduce the latent HIV-1 DNA level and the frequency of latently infected cells. Therefore, gnidimacrin is an excellent lead compound, and its anti-HIV potential merits further investigation. Twenty-nine modified gnidimacrin derivatives were synthesized and evaluated in assays for HIV replication and latency activation to establish which molecular structures must be maintained and which can tolerate changes that may be needed for better pharmacological properties. The results indicated that hydroxyl substituents at C-5 and C-20 are essential, while derivatives modified at 3-OH with aromatic esters retain anti-HIV replication and latent activation activities. The half-lives of the potent GM derivatives are over 20 h, which implies that they are stable in the plasm even though they contain ester linkages. The established structure-activity relationship should be useful in the development of gnidimacrin or structurally related compounds as clinical trial candidates.

Isolation, Structural Elucidation, and Liquid Chromatography-Mass Spectrometry Analysis of Steroidal Glycosides from Polygonatum odoratum.

The rhizomes of Polygonatum odoratum represent a traditional Chinese medicine and functional food. A phytochemical investigation resulted in the isolation of eight steroidal glycosides (1-8), including two new compounds, polygonatumosides F (1) and G (2). The structures were elucidated by spectroscopic data and chemical reactions. Compound 7 showed antiproliferation activity against human hepatocellular carcinoma cell line HepG2 (IC50 of 3.2 µM). The chemical profile and contents of steroidal glycosides of P. odoratum rhizomes collected at different dates and geographical locations were also investigated, indicating that the rational harvest of P. odoratum in spring and autumn is preferable to obtain higher levels of steroidal glycosides. Compounds 1 and 7 showed the highest contents in all P. odoratum samples and have potential to serve as chemotaxonomic and chemical markers for quality control of this important plant material. 14-Hydroxylation may be a key step for the biosynthesis of compounds 1-7.

Identification, structural modification, and dichotomous effects on human immunodeficiency virus type 1 (HIV-1) replication of ingenane esters from Euphorbia kansui.

Euphorbia kansui showed potent anti-HIV-1 activity during screening of a library composed of plant extracts from Euphorbiaceae and Thymelaeaceae families. Bioassay-guided isolation led to identification of ingenane esters as the active compounds. Further chemical modification resulted in 3-(2-naphthoyl)ingenol (23), which exhibited the most potent anti-HIV-1 activity. Compound 23 also acted as an HIV-1-latency-reversing agent on activation of HIV-1 replication in a latently infected U1 cell model and a T cell latent HIV-1 model JLat-A2.

Corrigendum: γ-Ionylidene-type sesquiterpenoids possessing antimicrobial activity against Porphyromonas gingivalis from Phellinus linteus and their absolute structure determination.

This corrects the article DOI: 10.1038/ja.2017.35.

ent-Atisane diterpenoids from Euphorbia fischeriana inhibit mammosphere formation in MCF-7 cells.

The discovery of new drugs that target cancer stem cells (CSCs) is a critical approach to overcome the major difficulties of the metastasis, chemotherapeutic resistance and recurrence for successful cancer therapy. Chemical investigation of the roots of Euphorbia fischeriana resulted in the isolation of eight ent-atisane diterpenoids (1-8), including two new compounds: 19-O-ß-D-glucopyranosyl-ent-atis-16-ene-3,14-dione (7) and 19-O-(6-galloyl)-ß-D-glucopyranosyl-ent-atis-16-ene-3,14-dione (8). The structures were elucidated on extensive spectroscopic analyses, as well as chemical transformations. ent-3ß-Hydroxyatis-16-ene-2,14-dione (5), 7 and its aglycon, ent-19-hydroxy-atis-16-ene-3,14-dione (7a), showed significant inhibitory activity on mammosphere formation in human breast cancer MCF-7 cells at a final concentration of 10 µM.