New acylphloroglucinol derivatives from the leaves of Baeckea frutescens

Three new acylphloroglucinols, baeckenones A–C (1–3), were isolated from the chloroform extract of the leaves of Baeckea frutescens together with three known compounds 4–6. The structures of the isolated compounds were determined using extensive spectroscopic analyses including IR, NMR, and HRMS. Baeckenone B (2) exhibited a moderate antibacterial activity against Bacillus subtilis with an MIC value of 40 μM.     

Polyprenylated polycyclic acylphloroglucinol: Angiogenesis inhibitor from Garcinia multiflora

A new polyprenylated polycyclic acylphloroglucinol, garcimultiflorone K (1), has been isolated from the stems of Garcinia multiflora, together with two known compounds, garcimultiflorone A (2) and garcimultiflorone B (3). The structure of new compound 1 was determined through spectroscopic methods including 1D and 2D NMR and MS analyses. The anti-angiogenic and anti-cancer effects of compounds 1–3 were evaluated in human endothelial progenitor cells (EPCs) and cancer cells. Of these, garcimultiflorone K (1) displayed the most potent anti-angiogenic property by suppressing cell growth and tube formation of EPCs. Compound 1 also exhibited growth-inhibitory activities against human hepatocellular carcinoma cell line SK-Hep-1 and hormone refractory prostate cancer cell line PC-3 with GI₅₀ values of 4.3?±?1.6 and 6.6?±?0.4?μM, respectively.     

Petiolins J–M,prenylated acylphloroglucinols from Hypericum pseudopetiolatum var. kiusianum

Four new prenylated acylphloroglucinols, petiolins J?M (1?4), were isolated from aerial parts of Hypericum pseudopetiolatum var. kiusianum, and the structures were elucidated by spectroscopic data and a single-crystal X-ray diffraction analysis. Petiolin J (1) exhibited antimicrobial activity.     

Novel degraded polycyclic polyprenylated acylphloroglucinol and new polyprenylated benzophenone from Hypericum sampsonii

Norhypersampsone A (1), a novel degraded polycyclic polyprenylated acylphloroglucinol (PPAP) derivative, 3-(2-hydroxy-7-methyl-3-methyleneoct-6-enyl)-5-isoprenyl-2,4,6-trihydroxybenzophenone (2), a new polyprenylated benzophenone derivative, and nine known compounds (3–11) were isolated from Hypericum sampsonii. Their structures were elucidated by comprehensive spectroscopic techniques. Compound 1 represents a novel cyclohexenone monocyclic-PPAP formed by losing the fragment of C-2–C-4 and the side chains at C-3 and C-5 in the phloroglucinol ring. The results of the inhibitory effects of compounds 1–11 on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages showed that compounds 1, 6–8, and 10 exhibited weak activities with IC₅₀ values in the range of 20.3–37.1 μM.     

Antimicrobial constituents of peel and seeds of camu-camu (Myrciaria dubia)

Various antimicrobial constituents of camu-camu fruit were isolated. Acylphloroglucinol (compound 1) and rhodomyrtone (compound 2) were isolated from the peel of camu-camu (Myrciaria dubia) fruit, while two other acylphloroglucinols (compounds 3 and 4) were obtained from camu-camu seeds. The structures of the isolated compounds were characterized by spectrophotometric methods. Compounds 1 and 4 were confirmed to be new acylphloroglucinols with different substituents at the C7 or C9 position of 2, and were named myrciarone A and B, respectively. Compound 3 was determined to be isomyrtucommulone B. This is the first report of the isolation of 3 from a natural resource. The antimicrobial activities of compounds 1, 3, and 4 were similar to those of 2, and the minimum inhibitory concentrations were either similar to or lower than that of kanamycin. These results suggest that the peel and seeds of camu-camu fruit could be utilized for therapeutic applications.     

Isoswinholide B and swinholide K,potently cytotoxic dimeric macrolides from Theonella swinhoei

Chemical investigation of an Indonesian specimen of Theonella swinhoei afforded the new dimeric macrolides isoswinholide B (5) and swinholide K (6), along with the known swinholides A (1), B (2) and D (3) and isoswinholide A (4). Isoswinholide B showed an unprecedented 21/19′ lactonization pattern, while swinholide K included an sp² methylene attached at C-4 and an additional oxymethine group at C-5, whose configuration has been determined through application of J-based configuration analysis. The isolated swinholides (1–6), with the exception of isoswinholide B, showed a cytotoxic activity on HepG2 (hepatocarcinoma cell line) in the nanomolar range.     

Hyperpatulols A–I,spirocyclic acylphloroglucinol derivatives with anti-migration activities from the flowers of Hypericum patulum

Nine new spirocyclic acylphloroglucinol derivatives, hyperpatulols A–I (1–9), were characterized from the flowers of Hypericum patulum. Their structures were elucidated by the basic analysis of the obtained spectroscopic data, and their absolute configurations were assigned by both the electronic circular dichroism (ECD) exciton chirality method and ECD calculation. The evaluation of their anti-migration effects on U2-OS human osteosarcoma cells showed that compound 4 exhibited moderate inhibitory activity in a dose-dependent manner. Further pharmacological studies revealed that 4 could regulate the expression of the proteins Vimentin and E-cadherin.     

Anti-mycobacterial alkaloids,cyclic 3-alkyl pyridinium dimers,from the Indonesian marine sponge Haliclona sp.

Three new dimeric 3-alkyl pyridinium alkaloids, named haliclocyclamines A–C (1–3), were isolated together with five known congeners, cyclostellettamines A (4), B (5), C (6), E (7), and F (8), from the Indonesian marine sponge Haliclona sp. The structures of 1–3 were assigned based on their spectroscopic data (1D and 2D NMR, HRFABMS, ESIMS/MS, UV, and IR). Compounds 1–8 exhibited antimicrobial activities against Mycobacterium smegmatis with inhibition zones of 17, 10, 13, 14, 8, 8, 12, and 12 mm, respectively, at 10 μg/disc. Compounds 3 and 8 also modestly inhibited the activity of vaccinia H-1-related phosphatase (VHR), a dual-specificity phosphatase, at 17–18 μM.     

Two new polycyclic polyprenylated acylphloroglucinols from Hypericum curvisepalum N. Robson

Phytochemical investigation of the whole plant of Hypericum curvisepalum led to the isolation of nine polycyclic polyprenylated acylphloroglucinols (1–9). Among them, curvisepalumiones A (1) and B (2) are two new compounds and their structures were elucidated based on extensive spectroscopic data analysis combined with Rh₂(OCOCF₃)₄-induced electronic circular dichroism experiment. Cytotoxic assay showed that all the tested compounds except for 1 was moderately cytotoxic against human hepatocarcinoma cell line SMMC-7721 cell line, while compounds 3 and 4 also exhibited cytotoxicity toward MGC-803 cells. In addition, compound 2 exhibited weak inhibitory activity against Bacillus subtilis.     

Chemical constituents from the stems of Tripterygium regelii

Phytochemical investigation on the stems of Tripterygium regelii resulted in the isolation of fourteen compounds, including six flavonoids (1–6), seven lignans (7–13), and one cyanogenic glycoside (14). This is the first report of the four dimeric flavonoids bis-8, 8′-catechinylmethane (2), bis (8-epicatechinyl) methane (3), bis-6, 8′-catechinylmethane (4) and montahomobisflavan B (5) from a species of Tripterygium. Previously, these dimeric flavonoids have been mainly identified from species of gymnosperms. This research has shown that the main secondary metabolisms identified in T. regelii were flavonoids and lignans. These data enable this species to be differentiated from T. wilfordii and T. hypoglaucum that contain the triptolide-resembling diterpenoids.     

Two dimeric lignans with an unusual α,β-unsaturated ketone motif from Zanthoxylum podocarpum and their inhibitory effects on nitric oxide production

Two new dimeric lignans, zanthpodocarpins A (1) and B (2), and five known lignans, eudesmin (3), (1R,2R,5R,6S)-2-(3,4-dimethoxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (4), dimethoxysamin (5), rel-(1R,5R,6S)-6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-one (6), and magnone A (7), were isolated from the barks of Zanthoxylum podocarpum. Their structures were identified by using spectroscopic methods. Compounds 1 and 2 are rare dilignans bearing an unusual α,β-unsaturated ketone group from a natural source. Bioassay showed that compounds 1 and 2 could inhibit nitric oxide (NO) production in LPS stimulated RAW 264.7 cells with IC₅₀ values of 5.31 μM and 12.15 μM, respectively.     

New prenylated C6–C3 compounds from the roots of Illicium henryi

One new dimeric prenylated C₆–C₃ compound, namely, illihendione A (1), two prenylated C₆–C₃ compounds, illihenryifunone C (2) and illihenryipyranone A (3), and one known dimeric prenylated C₆–C₃ compound, illicidione A (4), were isolated from the roots of Illicium henryi. The structures and absolute configurations of these compounds were determined by extensive spectroscopic and chemical analyses, including nuclear magnetic resonance (NMR), circular dichroism (CD) and a modified Mosher method. Compound 1 exhibited a weak inhibitory ratio for β-glucuronidase release induced by platelet-activating factor (PAF) in rat polymorphonuclear leukocytes (PMNS) in vitro.     

Japonicones A–D,bioactive dimeric sesquiterpenes from Inula japonica Thunb.

Four new dimeric sesquiterpene lactones japonicones A?D (1?4), comprised by eudesmane and guaiane sesquiterpenes, were isolated from the aerial part of Inula japonica Thunb. The structures and stereochemistry of 1?4 were elucidated by use of 2D NMR spectroscopic techniques, X-ray crystallography and modified Mosher method. Japonicone A (1) showed the most potent cytotoxicities against four tumor cell lines, A549, LOVO, CEM and MDA-MB-435.     

Acylphloroglucinols from the fruits of Callistemon viminalis

Five new acylphloroglucinols, callistenones L-P (1–5), and three known compounds watsonianone A, callistenones F and H were isolated from the fruits of Callistemon viminalis. Callistenones L and M possessed a bisfuran fused-ring skeleton. Compounds 3–5 were acylphloroglucinol condensed with a β-triketone moiety via a pyrane. Their structures were established from analyses of NMR spectra, CD spectra and X-ray crystallography. Compound 8 showed antibacterial activity against S. aureus with MIC value of 20.3 μg/mL and E. coli with MIC value of 15.6 μg/mL.     

Stilbene glucosides from the bulbs of Iris tingitana

Two new dimeric stilbene glucosides, tingitanol A (1) and tingitanol B (2) together with trans-resveratrol 3-O-glucopyranoside (3) in addition to three known isoflavones, 5-O-methylgenistein (4), 5-O-methylgenistein 7-O-β-d-glucopyranoside (5) and betavulgarin (6) have been isolated for the first time from the fresh bulbs of Iris tingitana Boiss. & Reut. Their structures were established on the basis of the spectral data and direct comparison with values from previously identified analogues. Additionally, the isolated compounds (1–6) were evaluated for the free radical scavenging activity.     

Three new flavonoids from Millettia pachyloba

Two new prenylated isoflavones, pachyloisoflavone A (1), pachyloisoflavone B (2), and a new pterocarpan, pachylobin A (3), together with ten known flavonoids (4–13), were isolated from the vine stems and leaves of Millettia pachyloba. The structures of new compounds were elucidated on the basis of extensive spectroscopic data interpretation, including 1D, 2D NMR and HREIMS. The absolute configuration of 2 was established by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra.     

Mannic acid,a new ent-kaurane dimer diterpenoid and other chemical constituents from different parts of Diospyros mannii

A new dimeric ent-kaurane diterpene, mannic acid (1), and 19 known compounds were isolated from the methanol extract of the stems, roots and leaves of Diospyros mannii Hiern (Ebenaceae). Their structures were established by NMR and MS data. This is the first report of asperglaucide from the family Ebenaceae, while mannic acid (1) and xylopic acid (2) are the first ent-kaurane diterpenes isolated from this family. Their chemotaxonomic value is discussed.     

Melanogenesis inhibitory daphnane diterpenoids from the flower buds of Daphne genkwa

Two new daphnane-type diterpene esters, daphneresiniferins A (1) and B (2), along with seven known diterpenes, yuanhuacine (3), yuanhuadine (4), yuanhuahine (5), genkwadaphnin (6), genkwanine A (7), genkwanine F (8), and genkwanine H (9), were isolated from the methanol extract of the flower buds of Daphne genkwa. Their structures were elucidated on the basis of spectroscopic methods, especially 2D NMR spectra such as HMQC, HMBC, and NOESY. All the isolates were evaluated for their inhibitory effects of the melanogenesis against α-melanocyte stimulating hormone (α-MSH)-activated B16 melanoma cells.     

Three new koninginins from Trichoderma neokongii 8722

Three new fungal metabolites, named koninginins I (1), J (2) and K (3) together with four known koninginins A (4), B (5), D (6) and E (7), were isolated from solid fermentation products of Trichoderma neokongii 8722. Three new structures were elucidated by extensive spectroscopic methods, including 1D NMR and 2D NMR, and HR-ESI–MS experiments.     

A pair of new sesquiterpene isomers containing spiro heterocyclic skeleton from plant-derived fungus Botryosphaeria dothidea

A pair of new sesquiterpene isomers containing a spiro heterocyclic skeleton, dothimes A (1) and B (2), together with six known compounds, quindoline (3), (S)-3-(3-indolyl)lactic acid methyl ester (4), dankasterone B (5), dibutyl phthalate (6), (1S,3R,4R,7S)-3,4-dihydroxy-α-bisabolol (7), and p-hydroxybenzaldehyde (8), were isolated from the plant-derived fungus Botryosphaeria dothidea. The structures of all isolated compounds were determined based on extensive spectroscopic analyses, including 1D/2D nuclear magnetic resonance (NMR), and high resolution electrospray ionization mass spectrometry (HRESIMS) data, as well as by comparison with literature reports. Compounds 1 and 2 exhibited inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production with IC₅₀ values of 63.66 and 58.29 μM, respectively.