Phenolic acid derivatives with neuroprotective effect from the aqueous extract of Clerodendranthus spicatus

Two new phenolic acid helisterculins C (1) and D (2) were isolated from the whole plant of Clerodendranthus spicatus. Their structures were elucidated on the basis of 1D and 2D NMR, MS, and CD analysis. Compound 1 possesses an unusual bicyclol [2. 2. 2] octane moiety which is rare in the previously isolated phenolic acid derivatives. The two compounds were tested in vitro for neuroprotective activities against 6-OHDA-induced cell death in SH-SY5Y cells, and the result showed that compounds 1 and 2 displayed moderate neuroprotective activity with the IC₅₀ values of 17.4 and 21.3 μM, respectively.     

Two new unsaturated fatty acids from the whole plant of Pothos chinensis

Two new unsaturated fatty acids, (Z)-octadec-13-en-11-ynoic acid (1) and (Z)-octadec-16-en-12,14-diynoic acid (2), along with six known compounds were isolated from the whole plant of Pothos chinensis. The structures of these compounds were elucidated by detailed spectroscopic analysis, including 1D and 2D NMR data. Compound 2 showed moderate antibacterial activity against Staphylococcus aureus.     

Two new acylgluconic acids from the nearly ripe fruits of Evodia rutaecarpa

Two new acylgluconic acids, trans-feruloylgluconic acid (1) and trans-caffeoylgluconic acid (2), together with three known compounds, myo-inositol (3), phthalic acid dibutyl ester (4), and wuzhuyuamide-I (5), were isolated from the water soluble part of the dried nearly ripe fruits of Evodia rutaecarpa (Juss.) Benth. Their structures were determined by spectroscopic methods, including IR, UV, ESITOFMS, HRSIMS, 1D and 2D NMR spectral analyses.     

Sinapic acid derivatives from the seeds of Raphanus nussatirus L.

A new disulfide glycoside, raphthioglucoside (1), and a new sinapic acid derivative, sinapic acid 5-hydroxymethylfurfural ester (2), together with sinapic acid (3) have been isolated from the seeds of Raphanus nussatirus L. The structures of compounds 1-3 were determined based on chemical analysis and spectroscopic methods (UV, 1D and 2D NMR, HRFABMS, HREIMS and elemental analysis).     

Chemical constituents of the brown alga Dictyopteris divaricata

A novel sesquiterpene-substituted benzoic acid, named dictyvaric acid (1), together with nine known compounds (2–10), have been isolated from the brown alga Dictyopteris divaricata Okam. The structure of 1 was elucidated as 3-[(decahydro-2-hydroxy-2,5,5,8a-tetramethyl-1-naphthalenyl)-methyl]-4-hydroxybenzoic acid by spectroscopic methods, including IR, FABMS, HR-FABMS, 1D and 2D NMR techniques. All compounds were obtained from this species for the first time.     

Microbial transformation of asiatic acid by Alternaria longipes

Asiatic acid is a major pentacyclic triterpene isolated from Centella asiatica. It shows a variety of bioactivities. In order to obtain its derivatives, potentially useful for detailed pharmacological studies, the substrate was subjected to incubations with selected micro-organisms. In this work, asiatic acid was converted into three new compounds: 2α,3β,23,30-tetrahydroxyurs-12-ene-28-oic acid (1), 2α,3β,22β,23-tetrahydroxyurs-12-ene-28-oic acid (2), and 2α,3β,22β,23,30-pentahydroxyurs-12-ene-28-oic acid (3) by the fungus Alternaria longipes AS 3.2875. The structures of the three metabolites were determined by 1D and 2D NMR spectral data.     

Cameroonemide A: a new ceramide from Helichrysum cameroonense

From the extracts of all parts of the plant Helichrysum cameroonense, five compounds were isolated and identified. One of them, a ceramide, named cameroonemide A (1), is reported for the first time as a new natural product. Its structure was determined by comprehensive analyses of their 1D and 2D NMR and HR-EI-MS spectral data. The remaining four known compounds were identified by comparing their spectroscopic data with those reported in the literature as kaurenoic acid (2), 3-acetyloxykaurenoic acid (3), β-sitosterol (4), and β-sitosterol glucopyranoside (5). Preliminary studies showed that 3-acetyloxykaurenoic acid (3) inhibited the alga Chlorella fusca, while kaurenoic acid (2) showed strong antibacterial activity against Bacillus megaterium.     

Four new taraxastane-type triterpenoic acids from Cirsium setosum

Four new taraxastane-type triterpenoids acids 3β,22α-dihydroxy-20-taraxasten-30-oic acid (1), 3β-hydroxy-22-oxo-20-taraxasten-30-oic acid (2), 3-oxo-22α-hydroxy-20- taraxasten-30-oic acid (3), and 3β,19β-dihydroxy-20-taraxasten-30-oic acid (4) were isolated and characterized from Cirsium setosum (Willd.) MB. Their structures were determined by the combination of 1D and 2D NMR experiments (¹H-¹HCOSY, HSQC, HMBC and ROESY) and mass spectrometry. Compound 2 exhibited potent selective cytotoxicity against human ovarian cancer cell line A2780 with an IC₅₀ value of 3.9 μM.     

Diterpenoids from the freshwater green algae Rhizoclonium hieroglyphicum with antibacterial activity

Three new isopimarane diterpenes 7β-hydroxy-19α-methylmalonyloxy-isopimara-8(14),15-diene (1), 7β-hydroxy-14-oxo-isopimara-8(9),15-dien-19oic acid (2), and 7β-hydroxy-14-oxo-19α-methylmalonyloxy-isopimara-9(11),15-diene (3) in addition to the known compounds isopimaric acid (4), 7oxo-13-epi-pimara-14,15-dien-18oic acid (5), 7oxo-13-epi-pimara-8,15-dien-18oic acid (6), and 6β-hydroxyisopimaric acid (7) were isolated from the hexane extract of Rhizoclonium hieroglyphicum. The structures of compounds 1–7 were established by 1D and 2D NMR techniques. The isolated diterpenoids were screened for antimicrobial activity against gram-positive and gram-negative bacteria and yeast strains.     

Two new phenolic compounds and antitumor activities of asparinin A from Asparagus officinalis

Two new phenolic acid compounds, asparoffin C (1) and asparoffin D (2), together with four known compounds, asparenyol (3), gobicusin B (4), 1-methoxy-2-hydroxy-4-[5-(4-hydroxyphenoxy)-3-penten-1-ynyl] phenol (5), and asparinin A (6), have been isolated from the stems of Asparagus officinalis. The structures were established by extensive spectroscopic methods (MS and 1D and 2D NMR). Compound 6 has obvious antitumor activities both in vitro and in vivo.     

Microbial transformation of oleanolic acid by Trichothecium roseum

Microbial transformation of the oleanolic acid (1) using Trichothecium roseum (pers.) Link (M 95.56) has resulted in the isolation of two new hydroxylated type metabolites, characterized as 15α-hydroxy-3-oxo-olean-12-en-28-oic acid (2) and 7β,15α-dihydroxy-3-oxo-olean-12-en-28-oic acid (3). The structure elucidation of these metabolites was based primarily on HR-EIMS, 1D NMR, and 2D NMR analyses.     

A new ganoderic acid from Ganoderma lucidum mycelia

A new ganoderic acid (GA), 7-O-ethyl ganoderic acid O (GA-O) (1), together with two known compounds, GA-T (2) and GA-Me (3), was isolated and purified from fermented mycelia of Ganoderma lucidum. The structure of the new triterpenoid was elucidated on the basis of the interpretation of extensive spectroscopic data (HR-MS, IR, UV, 1D and 2D NMR) as 3α,15α,22-triacetoxy-7α-ethoxy-5α-lanost-8,24E-dien-26-oic acid. The new compound was found to contain a rare ethoxyl group at C-7. In addition, its cytotoxicity against 95D and HeLa human cancer cell lines was also evaluated.     

A new sesquiterpene lactone glycoside and a new quinic acid methyl ester from Patrinia villosa

A new sesquiterpene lactone glycoside (1) and a new quinic acid methyl ester (2) were isolated from Patrinia villosa, together with another two known compounds chlorogenic acid n-butyl ester (3), 3, 4-di-O-caffeoylquinic acid methyl ester (4). Their structures were established using 1D/2D-NMR spectroscopy, mass spectrometry, and comparing with spectroscopic data reported in the literature.     

A new <Emphasis Type="Italic">ent</Emphasis>-kaurane type diterpenoid glycoside from <Emphasis Type="Italic">Inula japonica</Emphasis> Thunb.

A new ent-kaurane type diterpenoid glycoside, 17-O-β-D-glucopyranosyl-16α-ent-kauran-19-oic acid (1), together with 17-hydroxy-16α-ent-kauran-19-oic acid (2), 16α,17-dihydroxyl-ent-kauran-19-oic acid (3), and 16α-hydroxy-17-acetoxy-ent-kauran-19-oic acid (4) were isolated from the aerial parts of Inula japonica Thunb. The structure of 1 was determined mainly by use of 1D and 2D NMR spectroscopic techniques including HSQC, ¹H-¹H COSY, HMBC, and NOESY. In addition, 4 exhibited significant inhibitory activity on NO production in LPS-stimulated RAW264.7 cells with IC₅₀ value of 14.3 μg/mL.     

Cryptoporic acid S,a new drimane-type sesquiterpene ether of isocitric acid from the fruiting bodies of Cryptoporus volvatus

A new drimane-type sesquiterpene with an isocitric acid moiety, cryptoporic acid S (1), together with six known compounds, cryptoporic acid D (2), β-sitosterol (3), β-daucosterol (4), stigmast-4-en-3-one (5), ergosterol (6), and (22E,24R)-ergosta-7,22-diene-3β,5α,6β-triol (7), was isolated from the fruiting bodies of Cryptoporus volvatus. The structures of these compounds were established on the basis of UV, IR, MS, 1D and 2D NMR analysis. In the meanwhile, compounds 1 and 2 were evaluated for antioxidant activity using the methods of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) assay, and they exhibited moderate antioxidant activities.     

Two new triterpenoids from the fungus Perenniporia maackiae

Two new triterpenoids, 3β-(2-methoxy-oxalyloxy)-24-methylene-lanost-8-en-21-oic acid (1) and 3β-(2-methoxy-oxalyloxy)-15α-hydroxy-24-methylene-lanost-8-en-21-oic acid (2), were isolated from cultures of the fungus Perenniporia maackiae, together with two previously known triterpenoids (3 and 4). Their structures were determined by spectroscopic methods, including 1D and 2D NMR, and MS analyses. All compounds were evaluated for their cytotoxic activities on five tumor cell lines.     

Two new triterpenoids from Callicarpa kwangtungensis

Two new triterpenoids, 2α,3β,16α,19α,23-pentahydroxyolean-12-en-28-oic acid (1) and 2α,3α,11α,21α,23-pentahydroxyurs-12-en-28-oic acid (2), were isolated from the aerial parts of Callicarpa kwangtungensis. Their structures were elucidated by 1D and 2D analyses, as well as MS and IR spectra.     

Two new compounds from a marine-derived Streptomyces sp.

Two new long-chain unsaturated compounds, (2E, 6E)-10-methoxy-3,7-dimethyl-10-oxodeca-2,6-dienoic acid (1) and (2E, 6E)-3,7,11-trimethyldodeca-2,6-dienedioic acid (2), together with seven known compounds were isolated from a marine-derived Streptomyces sp. Their structures were determined by spectroscopic methods, including 2D NMR techniques. Compounds 1 and 2 were investigated for their antibacterial activities.     

Polygosumic acid,a new cadinane sesquiterpene from <Emphasis Type="Italic">Polygonum viscosum</Emphasis>, inhibits the growth of drug-resistant <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA) in vitro

Three new sesquiterpenes, 6-hydroxy-7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid methyl ester (1, named viscozulenic acid methyl ester), 7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid 1-methyl ester (2, named viscoazucinic acid) and 3-oxo-1-epi-sclerosporin (3, named polygosumic acid), have been isolated from the chloroform extract of the aerial parts of Polygonum viscosum by reversed-phase preparative high performance liquid chromatography (HPLC). The structures of these compounds were established conclusively by ultraviolet (UV), mass spectrometry (MS) and a series of 1D and 2D nuclear magnetic resonance (NMR) analyses. The anti-bacterial properties of 1–3 against 12 pathogenic bacterial strains have also been assessed by the rapid and robust microtitre-plate-based serial dilution method incorporating resazurin as an indicator of cell growth. Polygosumic acid was the most active among the sesquiterpenes and inhibited the growth of penicillin-resistant Escherichia coli (minimum inhibitory concentration, MIC=0.05 mg/ml) and methicillin-resistant Staphylococcus aureus (MRSA) (MIC=0.10 mg/ml).     

Further polyoxypregnane glycosides from Marsdenia tenacissima

Three new polyoxypregnane glycosides, tenacigenosides F–H (1–3), were isolated from the stems of Marsdenia tenacissima. The structures of these new compounds were elucidated from 1D and 2D NMR spectra, as well as from HR-MS and acid hydrolysis.