Highly oxygenated germacrane-type sesquiterpenoids from the whole plant of Salvia cavaleriei H.Lév. and their biological activities.

The entire plant Salvia cavaleriei H.Lév. (Lamiaceae) is used as a traditional Chinese herbal medicine. Its leaves are edible, and the flowers can be soaked in water to make a health-care tea. In an effort to find natural bioactive chemical components, twelve undescribed germacrane-type sesquiterpenoids, salcavalins A-L, were isolated from the whole plant of S. cavaleriei and were identified as analogs. This is the first study to isolate highly oxygenated germacrane-type sesquiterpenoids from this plant. The structures of these undescribed compounds were elucidated by various spectroscopic methods, and their absolute configurations were confirmed by single-crystal X-ray diffraction analysis with Cu Kα radiation and electronic circular dichroism calculations. The biological activity of these undescribed compounds on the production of tumor necrosis factor-alpha in lipopolysaccharide induced NR8383 cells was evaluated, and salcavalins I and K showed anti-inflammatory activity to some extent. Salcavalins A-C, F and L were found to be neuroprotective with antiparkinsonic potential in a nematode (Caenorhabditis elegans) model. In addition, salcavalins F and I displayed marked phytotoxic activity against radish seeds at a low concentration of 50 ppm. Our findings provide scientific justification to show that bioactive sesquiterpenoids from the edible herb have anti-inflammatory in vitro, neuroprotective and phytotoxic activities.

Antimicrobial diterpenoids from the leaves and twigs of Croton kongensis Gagnepain.

Croton kongensis Gagnepain. belongs to the genus Croton, the Euphorbiaceae family, mainly distributed in Hainan and southern Yunnan, China. The aim of present study was to acquire secondary metabolites of the ethanol extract obtained from the leaves and twigs of C. kongensis. Three new abietane-type diterpenoids, crokongenolides A-C (1-3), together with seven known diterpenoids (4-10), were isolated from the leaves and twigs of C. kongensis. The structures of the new compounds were determined by extensive spectroscopic methods (1D and 2D NMR, IR, and HRESIMS), and their absolute configurations were confirmed by single-crystal X-ray diffraction analysis or electronic circular dichroism (ECD) calculations. The absolute configuration of 4 was determined for the first time by single-crystal X-ray diffraction analysis with Cu-Kα irradiation. Some compounds were evaluated for their antimicrobial properties by assessing their inhibitory effects on Staphylococcus aureus, Candida albicans, and Escherichia coli. Compound 10 showed significant antimicrobial activity against S. aureus with MIC value of 1.56 µg/ml.

Diterpenoids with α-glucosidase inhibitory activities from the fruits of Vitex trifolia Linn.

Viticis Fructus, known as "Man-jing-zi", are the fruits of the traditional Chinese medicine Vitex trifolia Linn. and its variant Vitex trifolia Linn. var. simplicifolia. These fruits are used as folk medicines to treat various diseases. Although V. trifolia is useful for treating diabetes, the antidiabetic effect of its purified constituents is still under investigation. The phytochemical investigation on the ethanol extract of the fruits of V. trifolia yielded four new labdane diterpenoids vitetrolins A-D (1-4), together with seven (5-11) known analogs. The structures of these compounds were elucidated by spectroscopy techniques and the absolute configuration of 4 was determined by electronic circular dichroism (ECD) calculations. The isolated diterpenoids were evaluated for their α-glucosidase inhibitory activities. Compounds 5, 6, 8, and 9 exhibited moderate inhibitory activities against α-glucosidase with IC50 values ranging from 44.9 ± 6.1 to 70.5 ± 5.5 µM.

Two new aromatic derivatives from Codonopsis pilosula and their α-glucosidase inhibitory activities.

The ethanol extract of the roots of Codonopsis pilosula was subjected to chromatographic fractionation, which result in the isolation and characterization of two new aromatic derivatives 2,3-dihydroxypropyl 2,4-dihydroxy-3,6-dimethylbenzoate (1) and 2-oxopropyl 3-hydroxy-4-methoxybenzoate (2), along with three known compounds pilosulinene A (3), pollenfuran B (4) and (+)-pinoresinol (5). Their structures were demonstrated by HRESIMS and spectroscopic methods including NMR and IR. It is worth noting that compound 4 was isolated for the first time from the genus Codonopsis. The potential hypoglycemic properties of compounds 2-5 were evaluated by measuring their α-glucosidase inhibitory effects. As a result, compounds 2 and 3 showed weak α-glucosidase inhibitory activities with IC50 values of 154.8 ± 11.0 µM and 24.0 ± 2.2 µM, respectively.[Formula: see text].

Polyoxygenated sesquiterpenoids from Salvia castanea and their potential anti-Alzheime's disease bioactivities.

Salvia castanea (Family Labiatae), a perennial fragrant herb with castaneous flowers, is mainly distributed in areas with an altitude of 2500-3750 m. The roots of this plant were used as a tea drink by local residents to strengthen physical health. The aim of present study was to acquire secondary metabolites of the ethanol extract obtained from the whole plant of S. castanea and to evaluate their potential anti-Alzheimer's disease. Six new sesquiterpene lactones, salcastanins A-F (1-6), together with three known guaiane-type sesquiterpenoids nubiol (7), nubdienolide (8), and nubenolide (9), were separated from the whole plant of S. castanea. The structures of these compounds were determined by HRESIMS and NMR experiments. The absolute configurations of 1-6 were ascertained by electronic circular dichroism (ECD) experiments. The humanized Caenorhabditis elegans AD pathological model was used to evaluate anti-Alzheimer's disease (AD) activities of 1-9. The results showed the compounds 1-3 and 7 significantly delayed AD-like symptoms of worm paralysis phenotype, which could be used as novel anti-AD candidates.

Cadinane-type sesquiterpenes from the resinous exudates of Commiphora myrrha and their anti-Alzheimer's disease bioactivities.

Commiphoins A-C (1-3), three new cadinane-type sesquiterpenes, together with two known cadinane-type sesquiterpenes (4 and 5) were isolated from the resinous exudates of Commiphora myrrha. Their structures and relative configurations were established on the basis of comprehensive spectroscopic methods, including HRESIMS, 1D and 2D NMR analyses. Compounds 1 and 3-5 were screened for anti-Alzheimer's disease (AD) activities using the AD pathological model in Caenorhabditis elegans. The results showed that they all had significant anti-AD activities.

Cytotoxic and antibacterial activities of iridoids and sesquiterpenoids from Valeriana jatamansi.

Three new iridoids, valejatanins A-C (1-3), and one new natrual iridoid (4), together with four known sesquiterpenoids (5-8), were isolated from the roots of Valeriana jatamansi Jones. Compounds 3 and 4 are C(4)-epimers. Their structures were elucidated by extensive spectroscopic analysis (IR, HRESIMS, 1D and 2D NMR) and by comparison of their NMR data with those of related compounds. The absolute configuration of 5 was determined for the first time by single-crystal X-ray diffraction analysis with Cu-Kα irradiation. The cytotoxic activities of all compounds were evaluated against HT29, K562 and B16 cancer cell lines in vitro by MTT assay. Valejatanin A (1) showed noteworthy cytotoxic activities with IC50 values of 22.17, 15.26, 3.53µg/mL against three cancer cell lines. The antibacterial activities of all compounds against bacteria were tested in vitro. Compound 6 exhibited antibacterial activities against Staphylococcus aureus and Pseudomonas aeruginosa.

Eremophilane-type Sesquiterpenes from the Leaves of Ligularia virgaurea.

A phytochemical study of the ethanolic extract of the leaves of Ligularia virgaurea led to the isolation of a new eremophilane-type sesquiterpene lactone, (4S,5R,6S,8S,lR)-6ß-angeloyloxy-eremophil-7(l l)-en-10ßH-8α,12-olide (1), along with a known eremophilane-type sesquiterpene, (4S,5R,6S,lOS)-6ß- angeloyloxy-10ßH-furanoeremophil-9-one (2). Their structures were elucidated by extensive spectroscopic methods, including ID and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry experiments, and the absolute configurations were confirmed by single-crystal X-ray diffraction analysis using the anomalous scattering of Cu Ka radiation.

A New Succinate Derivative from Ajuga decumbens.

A new succinate derivative, ethyl (5-formylfuran-2-yl)methyl succinate (1), along with three known compounds (2-4) have been isolated from the whole plants of Ajuga decumbens Thunb. Their structures were elucidated by extensive spectroscopic (1D and 2D NMR) and HR-ESI-MS data analysis, and literature values. Compound 1 was isolated as a new succinate derivative, and compounds 2 and 3 were for the first time separated from A. decumbens.

A Novel Norclerodane Diterpenoid from the Roots of Croton crassifolius.

A chemical investigation of Croton crassifolius afforded a novel norclerodane diterpenoid (1) with an unprecedented six-membered oxygen ring between C-1 and C-12, together with three known compounds. The structure of the new compound was elucidated based on spectroscopic (IR, 1D, and 2D NMR) and HR-ESI-MS techniques. This report describes the first example of a natural norclerodane with a 4H-chromene ring system.

Eremophilane-type sesquiterpene derivatives from Ligularia hodgsonii.

Eight new highly oxygenated eremophilane-type sesquiterpene derivatives (1- 8), including two norsesquiterpenes, were isolated from an extract of the roots and the aerial parts of Ligularia hodgsonii Hook. Their structures and relative configurations were elucidated by spectroscopic methods, including IR, UV, HR-ESI-MS, and 1D and 2D NMR techniques, as 3 beta-acetoxy-10 beta-hydroxy-6 beta,8 beta-dimethoxyeremophil-7(11)-en-8 alpha,12-olide (1), 3 beta-acetoxy-10 beta-hydroxy-6 beta-methoxyeremophil-7(11),8(9)-dien-8,12-olide (2), 3 beta-acetoxy-10 beta-hydroxy-6 beta,8 alpha-dimethoxyeremophil-7(11)-en-8 beta,12-olide (3), 6 beta-(2'-methylbutanoyloxy)-3 beta-acetoxy-10 beta-hydroxy-8 alpha-methoxyeremophil-7(11)-en-8 beta,12-olide (4), 6 beta-(2'-methylbutanoyloxy)-3 beta-acetoxy-10 beta-hydroxyeremophil-7(11)-en-8 beta,12-olide (5), 3 beta-acetoxy-8-oxoeremophil-6(7),9(10)-dien-12-oic methyl ester (6), 3 beta-acetoxy-6 alpha,7 alpha-epoxy-9(10)-en-8-oxoeremophil-12-nor-11-one (7), and 2-acetyl-5 beta-acetoxy-3a,4,5,6,7,7a-hexahydro-7a beta-hydroxy-3a beta,4 beta-dimethyl-1H-indene (9).

The sesquiterpenes from the roots of Cacalia roborowskii.

A new sesquiterpene cacaroborin (1) was isolated from the roots of Cacalia roborowskii, together with three known ones, cinalbicol (2), isopetasin (3), and 3alpha-angeloyloxylactone (4). The structure of compound 1 was elucidated as 1beta,10alpha-dihydroxy-8alpha-methoxyeremophil-7(11)-en-8beta,12-olide on the basis of spectral evidence (1D, 2D NMR, IR, EI-MS, and HR-ESI-MS) and X-ray diffraction analysis.

Antimicrobial triterpenoids from Vladimiria muliensis.

A new triterpenoid with a rearranged ursane skeleton, 3beta-acetoxyl-11alpha-methoxybauer-8-en-7alpha-ol ( 1), two new ursane triterpenoids, 1alpha,5alpha-dioxy-11alpha-hydroxyurs-12-en-3-one ( 2) and urs-3beta,13alpha,18beta-triol ( 3), together with three known ursane triterpenoids ( 4- 6) were isolated from the rhizome of Vladimiria muliensis. Their structures were elucidated on the basis of spectroscopic methods (IR, EIMS, HRESIMS, 1D and 2D NMR, and X-ray crystallography diffraction). Compounds 2 and 4 exhibited modest antimicrobial activity against Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Enterococcus faecalis, Bacillus cereus, and Staphylococcus aureus.

Eremophilane-type sesquiterpenes from Senecio nemorensis.

Three new highly oxygenated eremophilane-type sesquiterpenes, 1 beta,10 beta(8,12)-diepoxy-7 beta,11 beta-dihydroxy-8 beta,12 alpha-dimethoxyeremophilane (1), 1 beta,10 beta-epoxy-7 beta-hydroxy-8 alpha-methoxyeremophil-11 alphaH-12,8 beta-olide (2), and 6 beta-isobutyryloxy-8 alpha-hydroxy-1-oxoeremophil-7(11),9-dien-12,8 beta-olide (3), together with nine known compounds (4-12) were isolated from the roots and aerial parts of Senecio nemorensis L. (Compositae). Structures of compounds 1-3 were elucidated on the basis of spectroscopic evidence including IR, HR-ESI-MS, 1D and 2D NMR techniques and were unequivocally confirmed by single-crystal X-ray diffraction experiments. The antimicrobial activity of the isolated compounds 1-3 and 8-12 was tested against Staphylococcus aureus and Candida albicans.

Eremophilane-type sesquiterpene derivatives from the roots of Ligularia lapathifolia.

Six new highly oxygenated eremophilane-type sesquiterpene derivatives (1-6), including a norbisesquiterpene, were isolated from an extract of the roots of Ligularia lapathifolia, and their structures were elucidated by spectroscopic methods. The structure of 1 was confirmed by single-crystal X-ray crystallography. In addition, the cytotoxicity of compounds 1, 2, 3, 5, and 6 was evaluated against selected cancer cell lines, including human stomach carcinoma (MGC-803), human hepatoma (HEP-G2), and murine sarcoma (S-180) cell lines.

Bisabolane sesquiterpenes from the roots of Ligularia cymbulifera.

Eight new highly oxygenated bisabolane sesquiterpenes (1-8), of which one contains a chlorine atom, were obtained in a phytochemical investigation of the roots of Ligularia cymbulifera, and their structures were elucidated by interpretation of spectroscopic data. Their relative configurations were clarified by a detailed analysis of (1)H NMR coupling constants and by NOE experiments. Compounds 1-8 were evaluated for antimicrobial activity against three bacterial cultures and a yeast culture.