Eudesmanolide sesquiterpenes and protein tyrosine phosphatase 1B inhibitory ent-kaurene diterpenes from aerial parts of Indonesian Wedelia prostata

Seven eudesmanolide sesquiterpenes (1–7) and two ent-kaurene diterpenes (8 and 9) including two new (9R)-eudesman-9,12-olides, named wedelolides I and J (1 and 2), were isolated from the aerial parts of Indonesian Wedelia prostata. The structures of 1 and 2 were assigned based on their spectroscopic data. Diterpenes 8 and 9 inhibited the activity of protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ values of 8.3 and 28 μM, respectively. Among sesquiterpenes 1–7, compound 4, wedelolide D, exhibited 32% inhibitory activity against PTP1B at 20 μM.     

Chemical constituents from Hovenia dulcis Thunb. And their chemotaxonomic significance

Phytochemical investigations on the fruit stalks and seeds of the plant Hovenia dulcis Thunb. led to the isolation of twenty-one compounds, including three triterpenes (1–3), two sterols (4–5), five flavonoids (6–10), two sesquiterpenes (11–12), one lignan (13), two phenylpropanoids (14–15), four benzoic acid derivatives (16–19), one acid amide (20) and one cerebroside (21). The structures of these compounds were elucidated on the basis of spectroscopic analysis and comparison with previous literatures. Among them, ten compounds (4, 11–12, 14–20) were isolated from familiy Rhamnaceae, two (13, 21) from the genus Hovenia, and three (5, 8, 10) from the species Hovenia dulcis Thunb. for the first time, respectively. The chemotaxonomic significance of these isolates was also discussed.     

Coumarin and terpenoids from Perezia alamani var. oolepis

Isoparvifolinone (2a), 8-hydroxypereflorine (3a) and diperezone (5) and the known sesquiterpenes cyperene and parvifoline (1a) were isolated from the roots of Perezia alamani var. oolepis. The structures of the new compounds were deduced from spectral data and tested by chemical correlation. Thus diperezone (5) was identical to the dimerization product of perezone (4a), isoparvifolinone (2a) was partially synthesized from parvifoline (1a) and 8-hydroxypereflorine (3a) was converted into the known 8-methoxypereflorine (3b).     

Terpenoids from Russula lepida and R. amarissima (Basidiomycota,Russulaceae)

Four aristolane sesquiterpenes were isolated from the fruiting bodies of Russula lepida and R. amarissima, namely (1R,2S)-1,2-dihydroxyaristolone (6), (2S,11S)-2,12-dihydroxy-aristolone (7), (1R,2S,11S)-1,2,12-trihydroxyaristolone (8), (1S,2S,11S)-1,2,12-trihydroxy-aristolone (9). In addition, a seco-cucurbitane triterpene, i.e. 3,4-secocucurbita-4,24E-diene-3-hydroxy-26-carboxylic acid (14) was isolated from both species. The configuration at C-2 of the already known rulepidol (2-hydroxyaristolone, 5) was corrected as S instead of R. Several more aristolane and nardosinane sesquiterpenes, as well as cucurbitane triterpenes, already reported both from European and Chinese samples of R. lepida, were also isolated. Compound 14 showed moderate cell growth inhibitory activity.     

Sesquiterpenes and nor sesquiterpenes from Schefflera leucantha R.Vig. (Araliaceae)

One new nor sesquiterpenes, Schesesquiterpene (1), together with nine reported sesquiterpenes and nor sesquiterpenes (2–10) were obtained from Schefflera leucantha R.Vig. (Araliaceae). The structures were determined according to spectroscopic data analysis and chemical evidence. Noteworthily, Compound 7 was isolated as a new natural product, and other compounds (2–6 and 8–10) were obtained from the family Araliaceae for the first time.     

Phytochemical investigation on the fruiting body of Russula aruea Pers

Phytochemical investigation of ethyl acetate fraction from Russula aruea Pers fruiting body led to the isolation and identification of one new isolactarane sesquiterpene (1) and 11 known compounds, including four sesquiterpenes (2-5), four sterols (6–9), one allitol (10), and two fatty acids (11–12). The structure of compound 1 was elucidated by means of spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, and X-Ray experiments. Compounds 1–3 and 5–12 are herein reported for the first time from Russula genus, while compound 4 is firstly described in R. aruea. The sesquiterpenes in R. aruea could serve as chemotaxonomic markers.     

Chemical constituents from Valeriana officinalis L. var. Iatifolia Miq. and their chemotaxonomic significance

Twenty-one compounds, including four monoterpenoids (1–4) (two new natural products, 1 and 2), four sesquiterpenes (5–8), two iridoids (9 and 10), four steroids (11–14), five phenolic compounds (15–19), and two alkaloids (20 and 21), were isolated from the roots of Valeriana officinalis L. var. Iatifolia Miq. Their chemical structures were established by spectroscopic methods and further confirmed by comparison with published data in the literature. Among them, eight compounds (1, 2, 6–8, 13, 18, and 21) are being reported from the family Valerianaceae for the first time, and compounds 9–12 were obtained from V. officinalis for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Quinoline alkaloids and sesquiterpenes from the roots of Dictamnus angustifolius

A new quinoline alkaloid named sonminine (1) along with nine known quinoline alkaloids dictamnine (2), isodictamnine (3), skimmianine (4), robustine (5), γ-fagarine (6), isopteleine (7), 5-methoxydictamnine (8), haplopine (9), 5-hydroxy-4,8-dimethoxy-furoquinoline (10) and two sesquiterpenes dictamnol (11), radicol (12) were obtained. Among them, compound 8 and 10 were isolated from the genus Dictamnus L. for the first time. Compounds 9, 11 and 12 were obtained from this species for the first time.     

Antifungal trichothecene sesquiterpenes obtained from the culture broth of marine-derived Trichoderma cf. brevicompactum and their structure-activity relationship

Two new trichothecene sesquiterpenes, trichobreols D (1) and E (2), were isolated from the culture broth of marine-derived Trichoderma cf. brevicompactum together with trichobreol A (3). The structures of 1 and 2 were assigned on the basis of their spectroscopic data. Compound 1 inhibited the growth of two yeast-like fungi, Candida albicans and Cryptococcus neoformans, with equivalent MIC values (6.3 μg/mL), while 2 gave MIC values of 12.5 and 25 μg/mL, respectively. The antifungal activities of five semisynthetic derivatives (4–8) prepared from 3 were evaluated and compared to investigate the preliminary structure-activity relationship.     

Two new guaiane sesquiterpenes from Datura metel L. with anti-inflammatory activity

Chemical investigation of an acidic methanol extract of the whole plants of Datura metel resulted in the isolation of two new guainane sesquiterpenes, 1β,5α,7β-guaiane-4β,10α,11-triol (1) and 1α,5α,7α-11-guaiene-2α,3β,4α,10α,13-pentaol (2), along with eight known compounds: pterodontriol B (3), disciferitriol (4), scopolamine (5), kaempferol 3-O-β-d-glucosyl(1 → 2)-β-d-galactoside 7-O-β-d-glucoside (6), kaempferol 3-O-β-glucopyranosyl(1 → 2)-β-glucopyranoside-7-O-α-rhamnopyranoside (7), pinoresinol 4′′-O-β-d-glucopyranoside (8), (7R,8S,7′S,8′R)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxy-lignan-4-O-β-d-glucopyranoside (9), and (7S,8R,7′S,8′S)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxylignan-4-O-β-d-glucopyranoside (10). Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and MS spectra. Compounds 2-4 and 6-10 were shown to have modest anti-inflammatory effects through inhibition of NO production in LPS-stimulated BV cells.     

Sesquiterpenoids from Pilea cavaleriei subsp. crenata

Three new humulane-type sesquiterpenes, 8-O-(p-coumaroyl)-5β-hydroperoxy-1(10)E,4(15)-humuladien-8α-ol (1), 8-O-(3-nitro-p-coumaroyl)-1(10)E,4(15)-humuladien-5β,8α-diol (2) and 8-O-(p-coumaroyl)-1(10)E,4(5)E-humuladien-8-ol (3), and a new copaborneol derivative, 1-O-p-coumaroyl-copaborneol (4), have been isolated from the methanol extract of Pilea cavaleriei Lévl. subsp. crenata C. J. Chen. Their structures were elucidated using spectroscopic methods. Cytotoxic and antimicrobial activities of the isolated compounds were evaluated.     

3-Oxo-γ-costic acid fungal-transformation generates eudesmane sesquiterpenes with in vitro tumor-inhibitory activity

While select eudesmane sesquiterpenes exhibit anti-neoplastic activity, tumor-inhibition for costic-acids has not been established. Here biological activity of 3-oxo-γ-costic acid (1), previously isolated from Chiliadenus montanus, as well as new sesquiterpenes (2–5) and the known derivative, 3-oxoeudesma-1,4,11(13)-trien-7-1061αH-l2-oic acid (6), all produced from 1 by the fungus Athelia rolfsii, are reported. Structures were elucidated using MS and NMR spectroscopy with activity-screening utilizing human colon- and lung-tumor lines, Caco-2 and A549 respectively. Compound 1 exhibited anti-proliferative activity against Caco-2 (IC₅₀ 39 µM) and 2 was active against A549 (IC₅₀ 74 µM) suggesting therapeutic potential for the original substrate and a bio-transformed product.     

Secondary metabolites from Saururus chinensis and their chemotaxonomic significance

Phytochemical investigation of the whole plants of Saururus chinensis resulted in the isolation of two sesquiterpenes (1 and 2), five lignans (3-7), one alkaloid (8) and two steroids (9 and 10). Among them, compound 3 has not been reported as a natural product before. Compounds 1, 2, 8 and 10 were firstly reported from the family Saururaceae. The possible biosynthesis pathway for sauchinone-like neolignans (6 and 11) was also firstly proposed. Furthermore, the chemotaxonomic significance of these compounds was summarized.     

Two new pterosin sesquiterpenes from Pteris multifida Poir

Two new pterosin sesquiterpenes named as 2R,3R-13-hydroxy-pterosin L 3-O-β-d-glucopyranoside (1) and 2R,3S-acetylpterosin C (2), along with a known one, 2S,3S-acetylpterosin C (3), were isolated from the whole plant of Pteris multifida and the 1D and 2D NMR data of 3 were reported for the first time in this paper. Their structures were elucidated on the basis of mass and spectral evidence. Compounds 1–3 showed cytotoxicity against HL 60 cells (human leukemia) with the IC₅₀ values of 14.6, 48.3 and 35.7 μM, respectively.     

Bisabolane and chamigrane sesquiterpenes from the soft coral Pseudopterogorgia rigida

A chemical investigation of the organic extract of the tropical soft coral Pseudopterogorgia rigida afforded 27 sesquiterpenes, among which one chamigrane (1) and seven bisabolanes (2–8) are new natural products. The structures of compounds 1–8 were deduced by analysis of their NMR and MS data. The full assignment of the spectroscopic data of four aromatic bisabolanes previously reported as semisynthetic products (11, 19, 22, 23) is reported.     

Chemical constituents of the Piper crocatum leaves and their chemotaxonomic significance

Chemical study of Piper crocatum leaves has led to isolation of a new megastigmane glucoside isomer (18), along with 23 known compounds including fifteen phenolic compounds (1–15), two monoterpenes (16 and 17), three sesquiterpenes (19–21), a phenolic amide glycoside (22), a neolignan (23), and a flavonoid C-glycoside (24). Structures of these compounds were identified via spectroscopic methods and compared with those reported in the literature. Seven compounds (7, 11, 13, 14, 17, 20, and 24) from the P. crocatum species and 17 others (1–6, 8–10, 12, 15–16, 18–19, and 21–23) from the Piper genus and Piperaceae family were isolated and reported for the first time. Furthermore, this study discusses chemotaxonomic relations between P. crocatum and other Piper species.     

Sesquiterpenes and triterpenoids from the rhizomes of Alisma orientalis and their pancreatic lipase inhibitory activities

Five new terpenoids, including three sesquiterpenes 11-hydroxy-8-ox-alismoxide (1), 11-oxo-13-nor-alismol (2), and 1β,11-dihydroxy-β-cyperone (3), and two protostane-type triterpenoids 16β-acetoxy alisol B (4) and 16α-acetoxy alisol B (5) were isolated from the rhizomes of Alisma orientalis together with 11 known compounds. Their structures were established using 1D and 2D NMR and HRESIMS spectroscopic analyses. The isolated compounds were assayed for their inhibitory activities against pancreatic lipase. Compounds 6 and 13 showed inhibitory effects with IC₅₀ values of 64.4 and 45.5 μM, respectively.     

Cytotoxic quinazoline alkaloids from the seeds of Peganum harmala

Seventeen quinazoline alkaloids and derivatives, containing two pairs of new epimers, named as (S)- and (R)-1-(2-aminobenzyl)-3-hydroxypyrrolidin-2-one β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (1, 2), (S)- and (R)-vasicinone β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (3, 4), and a new enantiomer (12b), together with six known ones (5–8, 10, and 12a), and three pairs of known enantiomers (9, 11, and 13), were isolated from the ethanol extracts of the seeds of Peganum harmala L.. Their structures including the absolute configuration were elucidated by using 1D and 2D NMR, and ECD calculation approaches. The cytotoxic activities of all isolated compounds were evaluated. 11 showed moderate cytotoxicity against PC-3 cells with an IC₅₀ value of 15.41?μM.     

Two new glycosides from the whole plant of Anemone rivularis var. flore-minore

Phytochemical investigation on the whole plant of Anemone rivularis var. flore-minore led to the isolation of a new labdane-type diterpene glycoside (1) and a new trihydroxyfuranoid lignanoid glycoside (2), together with three known triterpene and triterpenoid glycosides (3–5). The structures of the two new compounds were elucidated as β-d-glucopyranosyl (13S)-13-hydroxy-7-oxo-labda-8,14-diene-18-oate (1) and (7S,7′R,8R,8′S)-7′-butoxy-7,9′-epoxy-4,4′,9-trihydroxy-3,3′-dimethoxylignane 9-O-β-d-glucopyranoside (2), on the basis of extensive spectral analysis and chemical evidence. Compound 1 is characterized by a glucose (Glc) esterified C-18 carboxyl group, which is a rarely encountered labdane-type diterpene glycoside in nature. The two new compounds (1 and 2) reported here are the first examples of diterpene glycoside and lignanoid glycoside found in the genus Anemone, and the known triterpene and triterpenoid glycosides (3–5) are identified for the first time from the title plant.     

Diterpenoids from the South China Sea soft coral Sarcophyton solidum

Chemical investigation of the South China Sea soft coral Sarcophyton solidum has led to the isolation of one new (1) and seven known (2–8) diterpenoids, including three sarsolenanes (1–3), two capnosanes (4 and 5), and three cembranes (6–8). Sarsolilide B (4) was firstly confirmed by single-crystal X-ray diffraction. Compounds 1, 3, 4, and 6–8 were isolated from S. solidum for the first time, and 1, 2, and 4–7 were considered as the chemotaxonomic markers for the species S. solidum.