Aromadendrane-type Sesquiterpenoid Research Articles

Chemical constituents with their alpha-glucosidase inhibitory activity from the whole plant of Ceratophyllum demersum

From Ceratophyllum demersum growing in Vietnam, twelve compounds were isolated and structurally elucidated, including six previously undescribed compounds, demersones A-D (1-4), acetylvelutins A and B (8 and 9), together with six known compounds, (+)-cyclocolorenone (5), 1-hydroxycyclocolorenone (6), 10-hydroxycyclocolorenone (7), retusin (10), betulinic acid (11), and lupeol (12). The chemical structures and stereochemistry of 1-12 were identified through analysis of spectroscopic data (1D and 2D NMR and HRESIMS), ECD data, and DFT calculation. Notably, this is the first time that humulene-type (1 and 2), guaiane-type (3), and aromadendrane-type sesquiterpenoids (4-7) have been reported in this genus. Compounds 8 and 9 are the first examples of 8-acetoxyflavones found in nature. Upon evaluation of the alpha-glucosidase of 1-3 and 5-12, it was found that 12 exhibited the highest potential with an IC50 value of 15.4 ± 1.1 μM. The molecular docking of 3 and 8 was further studied.

Structurally intriguing rearranged bicyclogermacrene-type sesquiterpenoid from Aphania oligophylla

An investigation on the aqueous ethanol extract of the powdered twigs of Aphania oligophylla has afforded a skeletal new sesquiterpenoid aphanoid A (1) and one new aromadendrane-type sesquiterpenoid aphanoid B (2), as well as six known sesquiterpenoids (3–8). Their structures including the absolute configurations were characterized based on spectroscopic data analysis and X-ray crystallography. Compound 1 featuring an unprecedented tricyclo[6.3.1.03,5]dodecane scaffold, is likely rearranged from the bicyclogermacrene-type sesquiterpenoid. Among those compounds, 2 at 10 μL showed moderate antimalarial effect.

Heterodimers of Aromadendrane Sesquiterpenoid with Benzoquinone from the Chinese Liverwort Mylia nuda.

Mylnudones A-G (1-7), unprecedented 1,10-seco-aromadendrane-benzoquinone-type heterodimers, and a highly rearranged aromadendrane-type sesquiterpenoid (8), along with four known analogs (9-12), were isolated from the liverwort Mylia nuda. Compounds 1-6 and 7, bearing tricyclo[6.2.1.02,7] undecane and tricyclo[5.3.1.02,6] undecane backbones, likely formed via a Diels-Alder reaction and radical cyclization, respectively. Their structures were determined by spectroscopic analysis, computational calculation, and single-crystal X-ray diffraction analysis. Dimeric compounds displayed cytoprotective effects against glutamic acid-induced neurological deficits.

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa.

One new aromadendrane-type sesquiterpenoid, namely ximaocavernosin P [(+)-1], and three new cadinane-type sesquiterpenoids, namely (+)-maninsigin D [(+)-4], (+)- and (−)-ximaocavernosin Q [(+)- and (−)-5], together with five related known ones [2, 3, (−)-4, 6, and 7], were isolated from the Hainan sponge Acanthella cavernosa. Compounds 4 and 5 were isolated as racemic forms, which were further separated to the corresponding enantiomers [(+)-4/(−)-4 and (+)-5/(−)-5], respectively, by using chiral-phase HPLC. The structures of new compounds were elucidated by extensive spectroscopic analysis and comparison with the reported data. In addition, the absolute configuration of optically pure (+)-1 and 2 were determined by time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations or X-ray diffraction analysis. A plausible biosynthetic pathway of these sesquiterpenoids and their internal correlation were proposed and discussed. In an in vitro bioassay, (+)-aristolone (3) exhibited promising anti-inflammatory activity by the inhibition of LPS-induced TNF-α and CCL2 release in RAW 264.7 macrophages.

Three new sesquiterpenoids from the stems of Strophanthus divaricatus

Three new aromadendrane-type sesquiterpenoids (1–3) and five known compounds (4–8) were isolated from the stems of Strophanthus divaricatus. Their structures were determined by spectroscopic methods including HR-ESI-MS, 1D and 2D NMR. The absolute configurations of 1–3 was determined by comparison of the experimental and computed ECD spectra. Neridienone A (6) exhibited significant cytotoxicity against human cancer cell lines BEL-7402, SGC-7901, K562, A549, and HeLa with IC50 values of 3.30 ± 0.01, 2.25 ± 0.01, 2.02 ± 0.03, 1.55 ± 0.01, 4.73 ± 0.07 μM, respectively.

Cytotoxic Sesquiterpenoids from the Stem Bark of <i>Aglaia harmsiana</i> (Meliaceae)

Three aromadendrane-type sesquiterpenoids, spathulenol (1), 4β,10α-dihydroxyaromadendrane (2), and 4α,10α-dihydroxyaromadendrane (3) were isolated from the stem bark of Aglaia harmsiana (Meliaceae). Compound 3 was isolated for the first time from Aglaia genus. The chemical structures of isolated compounds were elucidated by various spectroscopic methods, including one and two-dimensional NMR, as well as mass spectroscopy analysis. These sesquiterpenoids 1-3 were evaluated for their cytotoxic activity against MCF-7 breast cancer cell lines. The IC50 value of compound 1-3 were 31.65 ± 0.1, 8.41 ± 0.04 and 2.80 ± 0.02 µM, respectively. Among the aromadendrane-type sesquiterpenoids, compounds 2 and 3, which do not have a double bond, showed higher activity than compound 1. Whereas, compound 3 showed the strongest activity indicate that α configuration of hydroxyl group increases the cytotoxic activity.

1,1,4,7-Tetramethyldecahydro-1H-cyclopropa[e]azulen-7-ol from the Stembark Chisocheton pentandrus

A new aromadendrane-type sesquiterpenoid, namely dehydrosphatulenol (1), has been isolated from the stembark of Chisocheton pentandrus. The chemical structure of 1 was characterized on the basis of spectroscopic evidences including mainly one dimension and two dimension Nuclear Magnetic Resonance, and Mass Spectroscopy as well as through a comparison with those related compounds previously reported.

New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava.

A detailed chemical investigation of the South China Sea soft corals Clavularia viridis and Lemnalia flava yielded four new halogenated laurane-type sesquiterpenoids, namely, isobromolaurenisol (1), clalaurenol A (2), ent-laurenisol (3), clalaurenol B (4), and the new aromadendrane-type sesquiterpenoid claaromadendrene (6), together with three known sesquiterpenoids (5, 7, and 8). Their structures were determined by extensive spectroscopic analysis and by comparison with the previously reported analogues. In a bioassay, compounds 1, 2 and 4 exhibited interesting inhibitory activities in vitro against PTP1B and NF-κB.

Sesquiterpenoids from the roots of Vladimiria muliensis

An unusual aromadendrane-type sesquiterpenoid with a rare hemiketal-containing 10/3 ring system, named vladimuliecin C (1), and one new eudesmane-type sesquiterpenoid, named vladimuliecin D (4), together with four known sesquiterpenoids, were isolated from the roots of Vladimiria muliensis. The structures of these compounds were elucidated by analysis of spectroscopic data. The absolute configuration of 1 was assigned by X-ray diffraction analysis. A possible biosynthetic process for the formation of 1 is proposed. Compound 1 showed moderate cytotoxicity against three human tumor cell lines.

Sesqui- and triterpenoids from the liverwort Lepidozia chordulifera inhibitors of bacterial biofilm and elastase activity of human pathogenic bacteria

Five dammarane-type triterpenoids, five pentacyclic triterpenoids (three of them carrying a carboxylic acid group), and two aromadendrane-type sesquiterpenoids were isolated from an Argentinian collection of the liverwort Lepidozia chordulifera. Compounds were characterized by comparison of their spectral data with those previously reported and tested in their ability to control bacterial growth, biofilm formation, bacterial Quorum Sensing process (QS), and elastase activity of Pseudomonas aeruginosa, as well as bacterial growth and biofilm formation of Staphylococcus aureus. The key role played by biofilm and elastase activity in bacterial virulence make them a potential target for the development of antibacterial agents. The aromadendrane-type sesquiterpenoid viridiflorol was the most potent biofilm formation inhibitor, producing 60% inhibition in P. aeruginosa and 40% in S. aureus at 50µg/ml. Ursolic and betulinic acids (two of the pentacyclic triterpenoids isolated) were able to reduce 96 and 92% the elastase activity of P. aeruginosa at 50µg/ml, respectively. Among the analyzed triterpenoids, those that carry a dammarane skeleton were the most potent inhibitors of the P. aeruginosa biofilm formation and were active against both P. aeruginosa and S. aureus. Subsequently, a computer-assisted study of the triterpenoid compounds was carried out for a better understanding of the structure-activity relationships.

Bioactive Sesquiterpenoids and Diterpenoids from the Liverwort Bazzania albifolia

One undescribed 6,7-secofusicoccane-type diterpene, albifolione (1), and one new aromadendrane-type sesquiterpenoid ketone, methyl 2-oxoaromadendra-1(10),3-dien-12-oate (2), along with four known compounds, δ-cuparenol (3), fusicoauritone (4), chiloscyphenols A and B (5 and 6, resp.), were isolated from the liverwort Bazzania albifolia Horik. The structures and relative configurations of 1 and 2 were established unequivocally on the basis of spectroscopic data analysis. Preliminary bioassay revealed that compound 5 showed quite strong cytotoxicity against the human tumor cell line MCF-7, with an IC(50) value of 5.6 μM.

Carbamate derivatives and sesquiterpenoids from the South China Sea gorgonian Melitodes squamata

Five carbamate derivatives, obtucarbamates C and D (1, 2), dimethyl ((carbonylbis(azanediyl))bis(2-methyl-5,1-phenylene))dicarbamate (3), obtucarbamates A and B (4, 5), and four aromadendrane-type sesquiterpenoids, (+)-4β-N-methenetauryl-10β-methoxy-1β,5α,6β,7β-aromadendrane (6), (−)-4β-N-methenetauryl-10β-methoxy-1β,5β,6α,7α-aromadendrane (7), (−)-4α,10β-aromadendranediol (8), (+)-4β,10β-aromadendranediol (9) were obtained from the South China Sea gorgonian coral Melitodes squamata Nutting. Compounds 1, 2, 6, and 7 were new, and their structures were established by spectroscopic analyses. Compounds 6 and 7 contained a taurine group that was rarely found in marine natural compounds, and 7 showed moderate antibacterial activity. The possible biosynthesis routes of 1–5 were conjectured.

Bioactive Sesqui- and Diterpenoids from the Argentine Liverwort Porella chilensis

Four fusicoccane-type diterpenoids (1-4), including the new 1 and 2; four pinguisane-type sesquiterpenoids (5-8); and two aromadendrane-type sesquiterpenoids (9 and 10) were isolated from an Argentine collection of the endemic liverwort Porella chilensis. The biofilm formation of the human pathogen Pseudomonas aeruginosa was inhibited by compounds 3 (53 and 47%), 9 (45 and 41%), and 10 (48 and 37%) at 50 and 5 μg/mL, respectively. Compounds 3, 9, and 10 also produced a slight decrease in bacterial growth and interfere with the process of quorum sensing at the same doses.

A New Diterpenoid Glucoside and Two New Diterpenoids from the Fruit of Vitex agnus-castus

A new labdane-type diterpenoid glucoside and two new labdane-type diterpenoids were isolated from the fruit (chasteberry) of Vitex agnus-castus L. (Verbenaceae) along with 14 known compounds comprising seven labdane-type diterpenoids, one halimane-type diterpenoid, two oleanane-type triterpenoids, two ursane-type triterpenoids, one aromadendrane-type sesquiterpenoid, and one flavonoid. Their structures were characterized on the basis of spectroscopic data as well as chemical evidence. Furthermore, the antioxidative activities of the flavonoid were evaluated using five different analyses.

Two new sesquiterpenoids from basidiomycete Agrocybe salicacola

Two new aromadendrane-type sesquiterpenoids (1 and 2), together with a known aromadendrane sesquiterpenoid (3), were isolated from the culture of basidiomycete Agrocybe salicacola. The structures and relative configurations of the new compounds were determined by spectroscopic methods and single-crystal X-ray crystallographic analysis.

Three New Diterpenoids from the Fruit of Vitex agnus-castus

Three new labdane-type diterpenoids, viteagnusins F, G, and H, were isolated from the hexane extract of fruit (chasteberry) of Vitex agnus-castus L. (Verbenaceae) along with seven known compounds including four labdane-type diterpenoids, one norlabdane-type diterpenoid, one aromadendrane-type sesquiterpenoid, and one flavonoid. The chemical structures of the three new labdane-type diterpenoids were determined on the basis of spectroscopic data as well as chemical evidence.

New Sesquiterpenoids from the New Zealand Liverwort Chiloscyphus subporosus

AbstractFor Abstract see ChemInform Abstract in Full Text.

Further labdane and kaurane diterpenoids and other constituents from Plectranthus fruticosus.

Eight new diterpenoids, one labdane and seven kaurane derivatives, and a new aromadendrane-type sesquiterpenoid have been isolated from the most polar chromatographic fractions of an acetone extract of Plectranthus fruticosus. The structures of the new compounds (1-9) were established mainly by 1D and 2D NMR studies and by some chemical transformations. Compounds 6 and 8 were characterized as their methyl ester derivatives (13 and 14, respectively). Most of the isolated compounds and some of their derivatives were tested as antimicrobial agents, but only 19 showed moderate inhibitory activity against Staphylococcus aureus.

New marine sesquiterpenoids and diterpenoids from the Okinawan soft coral Clavularia koellikeri.

Six new terpenoids (two maaliane-type sesquiterpenoids, 1 and 2, one aromadendrane-type sesquiterpenoid, 3, one noraromadendrane-type sesquiterpenoid, 4, and two neodolabellane-type diterpenoids, 5 and 6) were isolated from the Okinawan soft coral Clavularia koellikeri. The structures of these compounds were determined on the basis of the results of spectroscopic analysis, chemical conversion, and X-ray crystallographic analysis. Compound 6 exhibited modest growth-inhibition effect in vitro toward tumor cells.

New Sesquiterpenoids from the New Zealand Liverwort Chiloscyphus subporosus

A new aromadendrane-type sesquiterpenoid, 4(15)-aromadendren-12,5alpha-olide and an aromadendrane-guaianolide dimer have been isolated from the New Zealand liverwort Chiloscyphus subporosus. Their structures were established by extensive NMR techniques and X-ray crystallographic analysis.