Pyranonaphthoquinones and Naphthoquinones from the Stem Bark of Ventilago harmandiana and Their Anti-HIV-1 Activity

Seven previously undescribed compounds, including five pyranonaphthoquinones (ventilanones L-P) and two naphthoquinones (ventilanones Q and R), along with 15 known compounds were isolated from the stem bark of Ventilago harmandiana (Rhamnaceae). The structures were established by extensive analysis of their spectroscopic data. The absolute configuration of ventilanone L was established from single crystal X-ray crystallographic analysis using Cu Kα radiation and from its electronic circular dichroism data. Anti-HIV-1 activity using a syncytium inhibition assay and the cytotoxic activities of some isolated compounds were evaluated. Compounds 12, 13, 15, and 16 showed activity against syncytium formation with half maximal effective concentration (EC₅₀) values ranging from 9.9 to 47 μM (selectivity index (SI) 2.4-4.5).

Boesenmaxane Diterpenoids from Boesenbergia maxwellii

Three new diterpenoids, boesenmaxanes A-C (1-3), with an unprecedented core skeleton consisting of an unusual C-C bond between C-12 and an exo-cyclic methylene C-13, were isolated from the rhizome extracts of Boesenbergia maxwellii. The structures were elucidated by analysis of spectroscopic and X-ray diffraction data. Electronic circular dichroism spectra were used to determine the absolute configuration. All the isolates were evaluated for their cytotoxic effects, anti-HIV activity, and antimicrobial activity. Boesenmaxanes A and C (1 and 3) showed significant inhibitory activity in the syncytium reduction assay, with EC₅₀ values of 55.2 and 27.5 μM, respectively.

Cytotoxic compounds from the leaves and stems of the endemic Thai plant Mitrephora sirikitiae

Context: Mitrephora sirikitiae Weeras., Chalermglin & R.M.K. Saunders (Annonaceae) is a plant endemic to Thailand. Its constituents and their biological activities are unknown.Objective: Isolation and identification of the compounds in the leaves and stems of M. sirikitiae and determination of their cytotoxicity.Materials and methods: Methanol extracts of the leaves and stems of M. sirikitiae were separated by chromatography, and spectroscopic methods were used to determine the structures of the components. The cytotoxicity of the extracts and pure compounds was evaluated using the sulforhodamine B assay with several cell lines. The cells were treated with the compounds at concentrations of 0.16-20 µg/mL for 48 or 72 h.Results: The investigation of the extracts of M. sirikitiae leaves and stems resulted in the isolation of a new lignan, mitrephoran, and 15 known compounds. Among these compounds, 2-(3,4-dimethoxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, ciliaric acid, 6-methoxymarcanine A, and stepharanine were isolated from this genus for the first time. The alkaloids liriodenine and oxoputerine exhibited strong cytotoxicity against all tested cells (IC₅₀ values of 6.59-11.02 µM). In contrast, magnone A, 3',4-O-dimethylcedrusin, and 6-methoxymarcanine A inhibited the growth of some of the tested cells (IC₅₀ values of 2.03-19.73 µM). Magnone A and 6-methoxymarcanine A showed low toxicity for Hek 293 cells (IC₅₀ >20 µM).Discussion and conclusions: M. sirikitiae is a source of cytotoxic lignans and alkaloids. Among the cytotoxic compounds, magnone A and 6-methoxymarcanine A are potentially useful lead compounds for the further development of anticancer agents because of their selective inhibitory effects on cancer cell lines.

Siphonagarofurans A-J: Poly-O-acylated β-dihydroagarofuran sesquiterpenoids from the fruits of Siphonodon celastrineus

Ten poly-O-acylated β-dihydroagarofuran sesquiterpenoids, siphonagarofurans A-J, were obtained from the fruits of Siphonodon celastrineus using chromatographic techniques. Their structures were elucidated by extensive use of 2-D NMR spectroscopic methods. The absolute configurations of siphonagarofurans A-J were assigned following analysis of calculated and experimental ECD spectra. The absolute configuration of siphonagarofuran A was also confirmed by X-ray crystallographic analysis. Selected compounds were evaluated for their cytotoxic activity against KB, Vero and Hela cell lines with siphonagarofuran J identified as the most active compound, with IC₅₀ values ranging from 14 to 27 μM.

Pyranonaphthoquinone and anthraquinone derivatives from Ventilago harmandiana and their potent anti-inflammatory activity

The chemical study on the heartwoods extract of Ventilago harmandiana (Rhamnaceae) resulted in the isolation of ten previously undescribed pyranonaphthoquinones (ventilanones A-J), an undescribed anthraquinone (ventilanone K), together with eight known anthraquinone derivatives. Their structures were elucidated by extensive analysis of their spectroscopic data. The absolute configuration of ventilanone A was established from single crystal X-ray crystallographic analysis of its p-bromobenzenesulfonate ester derivative using Cu Kα radiation. The absolute configurations of the other related compounds were identified by comparison of their ECD data with those of ventilanone A and related known compounds. Cytotoxic and anti-inflammatory activities of some of the isolated compounds were evaluated. Ventilanone A and ventilanone C exhibited moderate cytotoxicity against P-388 cell line. Ventilanone D exhibited significant anti-inflammatory activity while ventilanone A and ventilanone C showed moderate activity.

Cytotoxic polyoxygenated cyclohexene derivatives from the aerial parts of Uvaria cherrevensis

Three previously undescribed polyoxygenated cyclohexene derivatives named cherrevenol M (1), cherrevenol N (2), and cherrevenone (3), together with nine related known analogues 4-12 were isolated from the ethyl acetate fraction partitioned from the methanol extract of the aerial parts of Uvaria cherrevensis (Annonaceae). The determination of the structures and their relative configurations of the isolated compounds were established by spectroscopic techniques, electronic circular dichroism (ECD) analysis as well as comparison with the literature data. For cherrevenone (3), the relative and absolute configurations were also confirmed by using X-ray diffraction and ECD techniques, respectively. Compounds isolated except for compounds 8 and 10 were evaluated for their cytotoxic activity and cherrevenone (3) showed moderate cytotoxic activity against all cancerous cell lines except for ASK cell line with ED₅₀ values ranging from 1.04 ± 0.13 to 10.09 ± 4.31 μM.

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark of Ziziphus cambodiana

Six new 14-membered ring cyclopeptide alkaloids, cambodines A–F (1–6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Ziziphus cambodiana Pierre. Their structures and configurations were established based on 1D and 2D NMR, HRMS, ECD, and X-ray crystallographic data. Compounds 1 and 3 are rare 5(14)-type cyclopeptide alkaloids that possess an imidazolidin-4-one ring in the terminal unit. The cyclopeptides were tested for their in vitro antiplasmodial, antitubercular, and cytotoxic effects against three cancer cell lines. Compound 3 showed significant antiplasmodial activity against the malarial parasite Plasmodium falciparum, with an IC₅₀ value of 6.09 μM.

Six new 14-membered ring cyclopeptide alkaloids, cambodines A–F (1–6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Ziziphus cambodiana Pierre.

A chromogenic and fluorogenic rhodol-based chemosensor for hydrazine detection and its application in live cell bioimaging

A rhodol-based fluorescent probe has been developed as a selective hydrazine chemosensor using levulinate as a recognition site. The rhodol levulinate probe (RL) demonstrated high selectivity and sensitivity toward hydrazine among other molecules. The chromogenic response of RL solution to hydrazine from colorless to pink could be readily observed by the naked eye, while strong fluorescence emission could be monitored upon excitation at 525 nm. The detection process occurred via a ring-opening process of the spirolactone initiated by hydrazinolysis, triggering the fluorescence emission with a 53-fold enhancement. The probe rapidly reacted with hydrazine in aqueous medium with the detection limit of 26 nM (0.83 ppb), lower than the threshold limit value (TLV) of 10 ppb suggested by the U.S. Environmental Protection Agency. Furthermore, RL-impregnated paper strips could detect hydrazine vapor. For biological applicability of RL, its membrane-permeable property led to bioimaging of hydrazine in live HepG2 cells by confocal fluorescence microscopy.

A thiourea-appended rhodamine chemodosimeter for mercury(II) and its bioimaging application

A rhodamine-thiourea conjugate RTP with an o-phenylenediamine linker was developed as a fluorogenic chemodosimeter for Hg²⁺ detection. In the presence of Hg²⁺, a colorless solution of RTP turned pink with a maximum absorption band at 555nm and with a 62-fold fluorescence enhancement at 578nm (Φ=0.34). RTP is highly selective to Hg²⁺ among other metal ions with a detection limit of 1.6nM (0.3ppb). A similar rhodamine analog with a flexible ethylenediamine spacer was less selective and less sensitive than RTP. Hg²⁺ induced cyclic guanylation to yield a benzimidazole moiety and a subsequent ring-opening of the spirolactam unit resulted in chromogenic and fluorogenic changes. The membrane-permeable RTP probe was successfully demonstrated in monitoring of Hg²⁺ in cultured HeLa cells.

Anti-HIV and cytotoxic biphenyls, benzophenones and xanthones from stems, leaves and twigs of Garcinia speciosa

Eleven previously undescribed compounds, including four benzophenones (garciosones A-D), four xanthones (garciosones E-H) and three biphenyls (garciosines A-C), along with eighteen known compounds were isolated from the stems, leaves and twigs of Garcinia speciosa Wall. (Clusiaceae). Their structures were established by extensive spectroscopic analysis. For garciosines A-C, the structures were confirmed by single crystal X-ray diffraction analysis. Most of the isolated compounds were evaluated for their cytotoxic activity and anti-HIV-1 activity using the syncytium inhibition assay and HIV-1 reverse transcriptase (RT) assay. The known compounds, 4,6,3',4'-tetrahydroxy-2-methoxybenzophenone and macluraxanthone, displayed significant cytotoxic activity with the ED₅₀ in the range of 1.85-11.76 μM. 1,5-Dihydroxyxanthone exhibited the most potent anti-HIV activity against syncytium formation with EC₅₀ < 17.13 μM (SI > 25.28) and 2-(3,3-dimethylallyl)-1,3,7-trihydroxyxanthone was the most active compound in the HIV-1 reverse transcriptase assay with IC₅₀ value of 58.24 μM. Structure-activity relationship of some isolated compounds were also discussed.

Polycyclic polyprenylated acylphloroglucinols and biphenyl derivatives from the roots of Garcinia nuntasaenii Ngerns. & Suddee

Seven previously undescribed compounds, including three polycyclic polyprenylated acylphloroglucinols (garcinuntins A-C), three biphenyl derivatives (garcinuntabiphenyls A-C) and a lanostane triterpene (garcinuntine), along with thirteen known compounds were isolated from the root of Garcinia nuntasaenii Ngerns. & Suddee. Their structures were elucidated on the basis of spectroscopic techniques. For garcinuntins A-C, the absolute configurations were confirmed by the combination of single X-ray crystallography and ECD calculations. Anti-HIV activity using anti-HIV-1 reverse transcriptase and syncytium inhibition assays, and cytotoxic activity against a panel of cultured mammalian cancer cell lines of isolated compounds were investigated.

F-THENA: a chiral derivatizing agent for the determination of the absolute configuration of secondary aromatic alcohols with a self-validating system

F-THENA is designed as an alternative fluorine-containing chiral derivatizing agent (CDA). The fluorine atom functions exclusively as a reporter which can directly sense an anisotropic effect from an aromatic substituent of a chiral alcohol. In combination with chemical shift differences from both ¹⁹F NMR and ¹H NMR, the F-THENA method can successfully be used for determining the absolute configuration of chiral secondary aromatic alcohols with a self-validating system.

A rhodol-based fluorescent chemosensor for hydrazine and its application in live cell bioimaging

A rhodol cinnamate fluorescent chemosensor (RC) has been developed for selective detection of hydrazine (N₂H₄). In aqueous medium, the rhodol-based probe exhibited high selectivity for hydrazine among other molecules. The addition of hydrazine triggered a fluorescence emission with 48-fold enhancement based on hydrazinolysis and a subsequent ring-opening process. The chemical probe also displayed a selective colorimetric response toward N₂H₄ from colorless solution to pink, readily observed by the naked eye. The detection limit of RC for hydrazine was calculated to be 300nM (9.6ppb). RC is membrane permeable and was successfully demonstrated to detect hydrazine in live HepG2 cells by confocal fluorescence microscopy.

Anti-inflammatory 12,20-Epoxypregnane and 11,12-seco-Pregnane Glycosides from the Stems of Hoya kerrii

Five 12,20-epoxypregnane glycosides (1-3, 5, and 6) and two 11,12-seco-pregnane glycosides (4 and 7) with spirodilactone motifs, as well as spirodilactone cleavage products 8 and 9, were isolated from the stems of Hoya kerrii. The relative configurations of the three related skeletons were supported by ROESY experiments and X-ray crystallographic analyses. The isolates were evaluated for their anti-inflammatory activity based on the inhibition of NO production in RAW264.7 cells, and some showed IC₅₀ values ranging from 12.6 to 96.5 μM. The most potent compound, 9a, was also examined for its anti-inflammatory mechanism against mRNA expression and was found to down-regulate mRNA expression of iNOS and COX-2 in a dose-dependent manner.

Characterization of the selective alkylation site in hemoglobin A by dihydroartemisinin with tandem mass spectrometry

The reaction between the antimalarial drug dihydroartemisinin (DHA) and hemoglobin A (HbA) was investigated in vitro. A fluorescein-tagged artemisinin analog reacted with HbA and fluorescent HbA-drug adducts could be visualized on SDS-PAGE to confirm stable covalent reaction adducts and necessity of the endoperoxide moiety and Fe(II). Mass spectrometric analyses revealed that DHA favourably alkylated protein part rather than heme and the modification site was identified to be at Tyr35 of the beta globin chain.

Cytotoxic lanostanes from fruits of Garcinia wallichii Choisy (Guttiferae)

Five new lanostanes, wallichinanes A-E (1-5) together with a known lanostane derivative 6 were isolated from the cytotoxic hexanes extract of fruits of Garcinia wallichii Choisy (Guttiferae). The structures of the isolated compounds were established by analysis of spectroscopic data, X-ray diffraction technique as well as comparison with the literature data. The cytotoxicity of all isolated compounds against a panel of cultured cancer cell lines was evaluated. Compound 4 exhibited good cytotoxicity with ED₅₀ values ranging from 3.91 to 7.63μM.

Rhodol-based fluorescent probe for Au3+ detection and its application in bioimaging

A propargyl–rhodol conjugate is a highly selective reaction-based fluorescent chemosensor for Au³⁺.

Phenalenone derivatives and the unusual tricyclic sesterterpene acid from the marine fungus Lophiostoma bipolare BCC25910

Ten compounds including nine phenalenone derivatives (five bipolarides and four bipolarols) and a sesterterpene acid (bipolarenic acid), were isolated from a marine isolated of the fungus Lophiostoma bipolare (BCC25910), along with the known compounds, (-)-scleroderolide, (-)-sclerodin, and oxasetin. Chemical structures were elucidated based on NMR spectroscopic data and HRESIMS analysis. In addition, the absolute configurations of the phenalenones were resolved using specific rotations and chemical means, while the relative configuration of bipolarenic acid was confirmed by X-ray crystallographic analysis. The compounds were evaluated for biological activity against the Plasmodium falciparum K-1 strain, Candida albicans, and Bacillus cereus, and for cytotoxicity against both cancerous and non-cancerous cells.

Aromadendrane and cyclofarnesane sesquiterpenoids from cultures of the basidiomycete Inonotus sp. BCC 23706

Twelve aromadendrane sesquiterpenoids, inonotins A-L, and a previously unknown cyclofarnesane, i.e., inonofarnesane, together with two known compounds, were isolated from cultures of the wood-rotting basidiomycete Inonotus sp. BCC 23706. Inonotin I is identical to a previously reported compound with an incorrect structure. Structures of the compounds were elucidated by spectroscopic analysis and X-ray crystallography. The absolute configurations of inonotin D and inonofarnesane were determined by application of the modified Mosher's method.

Polyoxygenated cyclohexene derivatives isolated from Dasymaschalon sootepense and their biological activities

Six new naturally occurring polyoxygenated cyclohexene derivatives together with eight related known derivatives, two known alkaloids, and two known flavonoid derivatives were isolated from bioassay-guided fractionation of the ethyl acetate extract of the leaves and twigs of Dasymaschalon sootepense. The structure elucidation and determination of absolute configurations were established by various spectroscopic methods, X-ray diffraction techniques as well as comparison with the literature data. Several isolated compounds were evaluated for their cytotoxic, anti-HIV-1 RT and anti-inflammatory activities.

Crystal structure of 1-(2,4-dihy-droxy-6-methyl-phen-yl)ethanone

The title compound, C9H10O3, is a bioactive secondary metabolite, isolated from the endophytic fungus Nodulisporium sp. The compound exhibits an intra-molecular O-H⋯O hydrogen bond between the phenolic H atom and the carbonyl O atom of the adjacent acetyl group. In the crystal, mol-ecules are linked by hydrogen bonds involving the 4-phenolic H atom and a symmetry-related carbonyl O atom of a neighboring mol-ecule, resulting in extended supra-molecular chains along the a-axis direction. Aromatic π-π stacking inter-actions between the nearly parallel benzene rings of adjacent chains [centroid-centroid distance = 3.7478 (8) Å] further stabilize the three-dimensional supra-molecular framework.

Crystal structure of 4,6-di-amino-2,2-dimethyl-3-[3-(2,4,5-tri-chloro-phen-oxy)prop-oxy]-2,3-di-hydro-1,3,5-triazin-1-ium chloride methanol monosolvate

In the title methanol-solvated salt, C₁₄H₁₉Cl₃N₅O₂⁺·Cl⁻·CH₃OH, the triazine mol­ecule is protonated at one of the triazine N atoms. In the crystal, the triazine cations are linked through a pair of N—H⋯N hydrogen bonds, with graph-set R₂²(8), forming an inversion dimer. The protonated N atom and the 2- and 4-amino groups of the triazine cation inter­act with the chloride anion through N—H⋯Cl hydrogen bonds, leading to the formation of a tape structure running along the b-axis direction. A short Cl⋯Cl contact [3.2937 (9) Å] is observed in the tape. The methanol mol­ecule is linked to the chloride anion and the triazine cation, respectively, by an O—H⋯Cl hydrogen bond and a C—H⋯O inter­action.

Pyridine–triazole ligands for copper-catalyzed aerobic alcohol oxidation

Effects of triazole configuration and substituents on reaction rates of aerobic oxidation of benzyl alcohol to benzaldehyde were investigated.

Cytotoxic hydroanthraquinones from the mangrove-derived fungus Paradictyoarthrinium diffractum BCC 8704

Two new hydroanthraquinones, paradictyoarthrins A (1) and B (2), were isolated from the mangrove-derived fungus Paradictyoarthrinium diffractum BCC 8704. Structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. The absolute configuration of 1 was determined by X-ray crystallography. These compounds exhibited cytotoxic activities.

Triterpene lactones from cultures of Ganoderma sp. KM01

A revised structure of colossolactone G (1), seven new triterpene lactones, ganodermalactones A-G (2-8), and five known triterpene lactones, colossolactone I (9), schisanlactone B (10), colossolactone B (11), colossolactone E (12), and colossolactone IV (13), and ergosterol have been isolated from cultured biomass of the macrofungi Ganoderma sp. KM01. Their structures were identified by spectroscopic methods. Structures and relative configurations of 3, 7, and 8 were confirmed by X-ray crystallographic analysis. Compounds 7, 10, and 12 exhibited antimalarial activity against Plasmodium falciparum in the range 6.0-10.0 μM (IC50).

Anti-inflammatory activity of compounds from Boesenbergia longiflora rhizomes

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Boesenbergia longiflora (Wall.) Kuntze have been traditionally used in treatment of inflammatory bowel disease, ulcerative colitis, aphthous ulcer and abscess. Our previous study indicated that CHCl3 fractions of Boesenbergia longiflora had potential on anti-inflammatory properties. In the present study, we investigated the active constituents of this plant for anti-inflammatory activity in order to support its traditional use.

MATERIAL AND METHODS

The CHCl3 fraction was isolated using chromatographic techniques. Isolated compounds were tested using relevant in vitro anti-inflammatory assays against LPS-induced NO and TNF-α releases as well as their mechanisms in transcription levels in murine macrophage RAW264.7 cells.

RESULTS

The isolation of the CHCl3 fraction from Boesenbergia longiflora rhizomes led to the isolation of three new daucane sesquiterpenes, which were identified as 8-hydroxy-dauca-9, 11-diene-7-one (longiferone A; 1), dauca-8, 11-diene-7-one (longiferone B; 2) and dauca-8, 11-diene-7, 10-dione (longiferone C; 3); together with four known flavonoids, six known diarylheptanoids as well as one sterol. The longiferone B (2) and longiferone C (3) showed anti-inflammatory activity against NO release with IC50 values of 21.0 and 31.3µM, respectively. Longiferone B (2) also suppressed the iNOS and COX-2 mRNA expression. Moreover, the flavonoids and diarylheptanoids inhibited NO and TNF-α production in a dose dependent manner.

CONCLUSION

This study demonstrated that sesquiterpenes, diarylheptanoids and some methoxyflavonoids found in Boesenbergia longiflora are responsible for anti-inflammatory activity.

Bridged tricyclic sesquiterpenes from the tubercle nudibranch Phyllidia coelestis Bergh

A new sesquiterpene, 1-formamido-10(1→2)-abeopupukeanane (1), was isolated from the tubercle nudibranch Phyllidia coelestis Bergh, along with 2-formamidopupukeanane (2), which is reported here as a natural product for the first time. A rearrangement pathway toward the unprecedented tricyclo[4.4.0.0(2,8)]decane skeleton is proposed. Both compounds showed antiproliferative activity when targeting HeLa, MCF-7, KB, and HT-29 cancer cell lines in the range 0.05-10 μM.

Parviflorals A-F, trinorcadalenes and bis-trinorcadalenes from the roots of Decaschistia parviflora

Trinorcadalenes, parviflorals A and B (1 and 2), and four bis-trinorcadalenes, parviflorals C-F (3-6), together with the known trinorcadalenes, syriacusins A (7) and C (8), scopoletin (9) and stigmasterol were isolated from roots of Decaschistia parviflora. Their structures were established by spectroscopic techniques. The CD spectra of the bis-trinorcadalenes (3-6) established their absolute configurations at the binaphthyl axis. Further, structure 6 was confirmed by a single-crystal X-ray crystallographic analysis. Compounds 2 and 6 showed antimalarial activity against Plasmodium falciparum with IC50 values of 11.45 and 6.85 μM, respectively. Compounds 1, 5, 7 and 8 also exhibited weak antifungal activity against Candida albicans, with IC50 values in the range of 37.03-197.68 μM. Compounds 1-3 and 5-8 showed weak antimycobacterial activity against Mycobacterium tuberculosis with MIC values in the range of 54.30-192.13 μM. In addition, several of these compounds possessed cytotoxicity towards the cancer cell lines, KB, MCF7 and NCI-H187 with IC50 values in the range of 2.20-90.09 μM.

Synthesis, Structural Characterisation, and Preliminary Evaluation of Non-Indolin-2-one-based Angiogenesis Inhibitors Related to Sunitinib (Sutent®)

The indolin-2-one fused-ring system and the 2,4-dimethylpyrrole unit represent key structural motifs in the anticancer drug sunitinib (Sutent®) and predecessor angiogenesis inhibitors that have undergone anticancer clinical trials (e.g. semaxanib, SU5416). In pursuit of novel anti-angiogenic scaffolds, we were interested in identifying whether the indolin-2-one group in these structures could be modified without losing activity. This paper describes novel condensation chemistry used to prepare a test series of (E)- and (Z)-alkenes related to SU5416 that retain the 2,4-dimethylpyrrole unit while incorporating ring-opened indolin-2-ones. Unique structural characteristics were identified in the compounds, such as intramolecular hydrogen bonds in the (Z)-alkenes, and several examples were shown to possess significant anti-angiogenic activity in a rat aorta in vitro model of angiogenesis. The work demonstrates that the indolin-2-one moiety is not an absolute requirement for angiogenesis inhibition in the sunitinib/SU5416 class.

Lanostane and hopane triterpenes from the entomopathogenic fungus Hypocrella sp. BCC 14524

Seven new lanostane-type triterpenes, hypocrellols A-G (1-7), and six new hopane-type triterpenes, 7β,15α-dihydroxy-22(29)-hopene (8), 3β,7β-dihydroxy-22(29)-hopene (9), 3β-acetoxy-15α-hydroxy-22(29)-hopene (10), 3β,7β,15α,22-tetrahydroxyhopane (11), 3β-acetoxy-7β,15α,22-trihydroxyhopane (12), and 7β,15α,22-trihydroxyhopane (13), were isolated from the scale insect pathogenic fungus Hypocrella sp. BCC 14524. The structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. The structure of 1 was confirmed by X-ray crystallography.

Antiplasmodial sesquiterpene alkaloids from the roots of Maytenus mekongensis

Eight new sesquiterpene alkaloids (1-8) and four known sesquiterpene alkaloids (9-12) have been isolated from the roots of Maytenus mekongensis. Structures were determined using extensive spectroscopic methods. The relative configuration of 7-epi-mekongensine (2) was established by single-crystal X-ray crystallographic analysis. The alkaloids were evaluated for antiplasmodial activity against Plasmodium falciparum, K1 strain, and for cytotoxicity using a panel of cell lines.

Antiplasmodial and antimycobacterial cyclopeptide alkaloids from the root of Ziziphus mauritiana

Investigation of the MeOH extract obtained from the root of the Ziziphus mauritiana grown in Thailand resulted in the isolation of two 14- and 13-membered cyclic alkaloids, mauritine L (1) and mauritine M (2), and three known cyclopeptide alkaloids, nummularines H (3), B (4) and hemsine A (5). Their structures were elucidated on the basis of extensive NMR spectroscopic analysis. The first single crystal X-ray diffraction study of the 13-membered ring cyclopeptide, nummularine B methiodide (4'), revealed all S configurations on the amino acid residues. The isolated alkaloids exhibited potent antiplasmodial activity against the parasite Plasmodium falciparum with the inhibitory concentration (IC50) ranging from 3.7 to 10.3 μM. Compounds 2 and 3 also demonstrated antimycobacterial activity against Mycobacterium tuberculosis with the MIC of 72.8 and 4.5 μM, respectively.

Cytotoxic pentacyclic and tetracyclic aromatic sesquiterpenes from Phomopsis archeri

Three new sesquiterpenes, named phomoarcherins A-C (1-3), and four known compounds, kampanol A (4), R-mevalonolactone, ergosterol, and ergosterol peroxide, were isolated from the endophytic fungus Phomopsis archeri. These structures were established on the basis of spectroscopic evidence. The structure and absolute configuration of 1 were confirmed by X-ray crystallographic analysis of its p-bromobenzoate derivative (1a). Compounds 1-4 showed cytotoxicity against five cholangiocarcinoma cell lines (0.1-19.6 μg/mL), while 1 and 2 exhibited weak cytotoxicity against the KB cell line with IC(50) values of 42.1 and 9.4 μg/mL, respectively. In addition, compound 2 showed antimalarial activity against Plasmodium falciparum with an IC(50) value of 0.79 μg/mL.

Bis[2,6-bis-(2-meth-oxy-phen-yl)pyridinium] di-μ-bromido-bis-[dibromidocuprate(II)]

The title salt, (C₁₉H₁₈NO₂)₂[Cu₂Br₆], was obtained from an attempt to synthesize the copper(II) complex of 2,6-bis­(2-meth­oxy­phen­yl)pyridine (L) from a reaction between CuBr₂ and one equivalent of L in CH₂Cl₂ at room temperature. The resulting compound is the salt of the 2,6-bis­(2-meth­oxy­phen­yl)pyridinium cation and 0.5 equivalents of a hexa­bromido­dicuprate(II) dianion. Both meth­oxy groups of the cationic pyridinium moiety are directed towards the N atom of the pyridine ring as a result of intra­molecular N—H⋯O hydrogen bonds. The centrosymmetric hexabromidodicuprate dianion possesses a distorted tetra­hedral geometry at the copper ion. The Cu—Br bond lengths are 2.3385 (7) and 2.3304 (7) Å for the terminal bromides, whereas the bond length between the Cu atom and two bridging bromides is slightly longer [2.4451 (6) Å].

Anti-HIV-1 and anti-inflammatory lupanes from the leaves, twigs, and resin of Garcinia hanburyi

Two new lupanes, 2 alpha-acetoxy-3 beta-hydroxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (2-acetoxyalphitolic acid) ( 1) and 2 alpha-hydroxy-3 beta-acetoxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (3-acetoxyalphitolic acid) ( 2), together with the known betulinic acid ( 3), betulin ( 4), and stimasterol-3- O- beta- D-glucopyranoside ( 5), were isolated from the leaves and twigs of GARCINIA HANBURYI. Compounds 1- 3 were also isolated from the resin of this plant. The structure of 2 was confirmed by single-crystal X-ray diffraction analysis. All of the lupanes ( 1- 4) displayed anti-HIV-1 activities in the anti-HIV-1 reverse transcriptase (IC (50) values 16.3-116.9 microg/mL) and syncytium assays (EC (50) 5.6-73.6 microg/mL, SI 1.7-3.3). Moreover compounds 1- 4 exhibited anti-inflammatory activity in an ethyl phenylpropiolate (EPP)-induced ear edema model.