Phenolic acid glycosides from Parmentiera cereifera Seem. (Candle tree)

Two new phenolic acid glycosides, parmentins A (1) and B (2) were isolated from the methanolic extract of the leaves and stems of candle tree (Parmentiera cereifera Seem). These compounds were accompanied by a mixture of β-sitosterol and stigmasterol (3), β-sitosterol glucoside (4), isovanillic acid (5), vanillic acid (6), and p-hydroxybenzoic acid (7). The structures of the isolated compounds were determined on the basis of physical and spectroscopic analyses, including 1D and 2D NMR (¹H, ¹³C, COSY, HSQC and HMBC) and mass spectrometry (HR-ESI-MS).     

Chemical constituents from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. (Lauraceae)

Phytochemical investigation of the ethanolic extract from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. led to the isolation of (3R, 4R, 3′R, 4′R)-6,6′-dimethoxy-3, 4, 3′, 4′-tetrahydro-2H, 2′H-[3, 3′]bichromenyl-4, 4′-diol (1), 4-hydroxybenzaldehyde (2), 1,2,4-trihydroxybenzene (3), kaempferol-3-O-α-l-rhamnoside (4), herbacetin (5), quercetin-3-O-α-l-rhamnoside (6), daucosterol (7), and β-sitosterol (8). The structures were established by extensive analysis of their MS and NMR spectroscopic data and comparison with literature data. In the present research, all of the isolated compounds 1–8 are reported for the first time in the species C. parthenoxylon. Compounds 1–6 were firstly isolated from genus Cinnamomum. Compounds 1, 3, 5 and 6 have not been reported from any species in Lauraceae family. The chemotaxonomic significance of the isolated compounds is discussed.     

Two new antioxidant flavones from the twigs of Eriosema robustum (Fabaceae)

Phytochemical study of the ethanol extract of the twigs of Eriosema robustum, a Cameroonian medicinal plant resulted to the isolation of two new flavones, 2′,3′,5′,5,7-pentahydroxy-3,4′-dimethoxyflavone (1) and 2′,3,5′,5,7-pentahydroxy-4′-methoxyflavone (2), along with five known compounds: 6-prenylpinocembrin (3), 1-O-heptatriacontanoyl glycerol (4), β-sitosterol (5), stigmasterol (6) and 3-O-β-d-glucopyranoside of sitosterol (7). The structure of the isolated compounds were elucidated on the basis of their NMR, UV and MS data, and by comparison with those reported in the literature. The ethanol crude extract, fractions and some isolated compounds (1–4) were evaluated for their radical scavenging capacity using 2,2-diphenyl-1-picryhydrazyl (DPPH). The crude extract, fraction II, the new compounds namely robusflavones A (1) and B (2) exhibited significant antioxidant activity.     

Chemical constituents from Lespedeza cuneata G. Don (Leguminosae)

Phytochemical investigation of Lespedeza cuneata led to the isolation of seventeen compounds including three steroids (β-sitosterol 1, β-sitosterol-6′-linolenoyl-3-O-β-d-glucopyranoside 3, and β-sitosterol glucoside 13), nine flavonoids (quercetin 4, kaempferol 5, isovitexin 8, hirsutrin 9, nicotiflorin 10, vitexin 11, astragalin 12, trifolin 14, and isorhamnetin 17), two phenolics (benzyl-β-d-glucopyranoside 7 and homovanillyl alcohol 16), one carotenoid (loroxanthin 2), one lignin (7R,8S–dihydrodehydrodiconiferyl alcohol 15), and one hexose (pinitol 6) on the basis of their spectroscopic data. Among these compounds, 2, 3, 7, 15 and 16 were reported for the first time from the genus Lespedeza. The taxonomic significance of these isolated compounds was also summarized.     

Bioactive flavones of Sida cordifolia

Two new flavones: 5,7-dihydroxy-3-isoprenyl flavone (1) and 5-hydroxy-3-isoprenyl flavone (2), along with two known compounds β-sitosterol and stigmasterol have been isolated from the chloroform extract of Sida cordifolia. Their structures were established on the basis of spectroscopic analysis. Flavones were tested for their analgesic and anti-inflammatory activity.     

Unusual lipids and acylglucosylsterols from the roots of Livistona chinensis

A 70% ethanol extract from the roots of Livistona chinensis has been investigated, led to the isolation of 18 compounds, including two new 6′-O-acyl-β-d-glucosyl-β-sitosterols, 6′-O-(2″-hydroxyheptadecanoyl)-β-d-glucosyl-β-sitosterol (1) and 6′-O-(icosa-9″Z,12″Z-dienoyl)-β-d-glucosyl-β-sitosterol (2), two new keto esters, ethyl 16-(dodeca-4″′Z,7″′Z-dienyl)-29-oxo-15-(tetradeca-5″Z,8″Z,11″Z-trienyl) triacontanoate (7), and 16-hydroxy-8-oxohexadecyl tetradecanoate (9), a new unsaturated fatty acid, tetracosa-(11Z,14Z,18Z)-trienoic acid (8), as well as a new fatty alcohol, 10-decylnonadecane-1,19-diol (10). The structures of new compounds were elucidated, based on spectroscopic and chemical methods. The antiproliferative activity against four human tumor cell lines (K562, HL-60, HepG2, and CNE-1) was evaluated. Four compounds (1–3, 5) showed potent antiproliferative effects with the IC₅₀ of 10–100 μM. To our knowledge, this is the first report of the occurrence of 6′-O-acyl-β-d-glucosyl-β-sitosterol and 3-O-acyl-β-sitosterol in the genus Livistona. Keto fatty acids and their esters are also rare in higher plant.     

Phytochemistry and antiglycation activity of Aloe sinkatana Reynolds

A new anthraquinone along with 10 known compounds were isolated from the leaves of Aloe sinkatana Reynolds (Aloaceae), and their structures were elucidated as the new compound 2,8-dihydroxy-6-(hydroxymethyl)-1-methoxyanthracene-9,10-dione (1) and the known compounds Aloe-emodin (2), feralolide (3), 1-hydroxy-5-methoxy-3-methyl-9,10 dihydroanthracene 9,10-dione (4), β-sitosterol (5), β-sitosterol with glycosidic bond (6), microdontin (7), homoaloins A (8) and B (9) and aloins A (10) and B (11). Characterization of compounds 1–9 was based on spectral analyses and comparison with reported data, particularly the new compound 1 was identified by 1D- and 2D NMR, mass spectroscopic and X-ray crystallography analyses. Antiglycation activity of the extracts and isolated compounds were carried out using the hemoglobin-δ-gluconolactone and glucose–bovine serum albumin assays. The results obtained showed that MeOH and EtOAc extracts as well as compound 1 showed an inhibitory effect on early stage protein glycation. Compound 1 also showed significant inhibitory effects against glucose-induced advanced glycation end-products.     

Two new compounds with antimicrobial activities from the seeds of Voacanga africana

Two new compounds, (R)-4-(2-methylpentyl)-4H-dithieno[2,3-b:3′,2′-e]pyran (1) and 4-(2-ethylbutyl)-4H-dithieno[2,3-b:3′,2′-e]pyran (2) were extracted from the seeds of Voacanga africana. The molecular structures of these compounds were measured with the help of broad spectroscopic (1D and 2D-NMR, IR, ESI-TOF-MS, HR-MS) analyses. The primary pharmacological operations of these compounds were brought to evaluation by applying the antibacterial extrasomatic test. The results revealed that compound 1 and 2 were in an effective position to stop the growth of Escherichia coli, Streptococcus and Salmonella typhi. On the other hand, the inhibitory impacts on Staphylococcus aureus as well as Pseudomonas aeruginosa were not apparent.     

Secondary metabolites of Sophora mollis subsp. griffithii (Stocks) Ali

Two new compounds, (+)-3,5,7-trihydroxy-3-[3′-hydroxy-2′,4′-dimethoxy-5-(3-methyl-2-butenyl)]-phenyl-(3R)-4H-1-benzopyran-4-one (1) and (?)-3-hydroxy-8,9-methylenedioxy-(6aR,11aS)-pterocarpan (2), were isolated from the methanolic extract of Sophora mollis subsp. griffithii. Two known compounds, β-sitosterol (3) and 19βH-lupeol-methyl-ether (4), were also obtained for the first time from this plant. The structures of 1–4 were identified through their spectroscopic data. CD Spectroscopy was also utilized for the structure elucidation of compounds 1 and 2. Compounds 1, 3 and 4 were studied for their effects on immune cells and only 1 was found to be substantially active.     

A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, kaempferol-3-O-α-l-arabinofuranoside, (+)-catechin, epicatechin, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-α-arabinopyranoside, quercetin-3-O-β-arabinopyranoside, quercetin-3-β-glucopyranoside, kaempferol, quercetin-3-O-β-galactopyranoside, β-sitosterol, α-amyrin, β-amyrin, and the ester derivatives of these two amyrins. Compound 1 exhibited weak inhibition of acetylcholinesterase. Structural identification was performed using IR, ESIHRMS and one- and two-dimensional NMR data analyses and confirmed by comparison with literature data.     

The regulation of inflammatory cytokine secretion in macrophage cell line by the chemical constituents of Rhus sylvestris

In our preliminary screening study on the anti-inflammatory activity, eight triterpenes, one sterol, and one chalcone were isolated from the CH₂Cl₂-soluble extract of the stems and leaves of Rhus sylvestris Siebold and Zucc (Anacardiaceae). On the basis of their spectroscopic data, these compounds were identified as 10α-cucurbitadienol (1), glut-5-en-3-ol (2), β-amyrin acetate (3), β-amyrin (4) and lupeol (5), cycloart-24-en-3-one (6), cycloart-25-en-3,24-dione (7), 24-hydroxycycloart-25-en-3-one (8), β-sitosterol (9), and 2′-hydroxy-4,4′-dimethoxychalcone (10). All of them were isolated from this plant for the first. Furthermore, the compounds in non-cytotoxic concentrations (0–1.0 μM) were tested for their ability to block inflammatory cytokine secretion in the presence of LPS in the murine RAW264.7 macrophage cell line. Among the compounds that were tested, compounds 8 and 9 reduced the LPS-induced secretion of IL-6, as well as TNF-α, in a mouse RAW264.7 macrophage cell line. Moreover, compounds 2, 3, 7, and 10 specifically diminished only the secretion of TNF-α even in 0.01 μM concentrations. It is thus suggested that they are potential therapeutics of TNF-α-related diseases and conditions, such as transplant rejection, type II diabetes, and atherosclerosis.     

Chemical constituents from the roots of Acanthus ilicifolius var. xiamenensis

Chemical investigation of Acanthus ilicifolius var. xiamenensis led to the isolation of eleven compounds, and their structures were identified to be 2-benzoxazolinone (1), 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one (2), (2R)-2-O-β-d-glucopyranosyl-2H-1,4-benzox azin-3(4H)-one (3), (2R)-2-O-β-d-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (4), (2R)-2-O-β-d-glucopyranosyl-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one (5), lyoniside (6), 3′-methoxy-luteolin-7-O-β-d-glucopyranoside (7), β-sitosterol-3-O-β-d-glucopyranoside (8), stigmasterol octadecanoate (9), β-sitosterol octadecanoate (10), stigmasterol-3-O-β-d-glucopyranoside (11) on the basis of mass and NMR spectra. This is the first report on the occurrence of compound 6 and 7 in Acanthaceae. This work also represents the first phytochemical work on the roots of A. ilicifolius var. xiamenensis.     

A lignan from Lonicera hypoleuca

A new lignan characterised as (-)-4-hydroxy-2,6-di-(4′-hydroxy-3′-methoxy)phenyl-3,7-dioxabicyclo-(3.3.0)octane along with n-10-nonacosanol, scopoletin, syringic acid, β-sitosterol and its glucoside, has been isolated from the aerial parts of Lonicera hypoleuca. The stereochemistry of the lignan has been established by its spectroscopic analysis and those of its derivatives, and by its conversion to (+)-pinoresinol. β-Sitosterol-β-D-glucoside displayed good spasmolytic activity.     

Madangones A and B: Two new neolignans from the stem bark of Beilschmiedia madang and their bioactivities

Two new neolignans, madangones A (1) and B (2), together with (+)-kunstlerone (3), vanillin, vanillic acid, betulin, β-sitosterol and β-sitostenone, were isolated from the stem bark of Beilschmiedia madang (Lauraceae). The structures of the compounds were determined by spectroscopic means. The compounds were tested for antioxidant, acetylcholinesterase inhibitory and anti-inflammatory activities. Compound (3) displayed the strongest DPPH radical-scavenging activity with an IC₅₀ value of 68.7 μM. Compound (2) exhibited the highest level of activity on the COX-2 model and acetylcholinesterase inhibition assay, with IC₅₀ values of 27.4 and 70.3 μM, respectively.     

Further constituents of Galianthe thalictroides (Rubiaceae) and inhibition of DNA topoisomerases I and IIα by its cytotoxic β-carboline alkaloids

A new cytotoxic β-carboline alkaloid, 1-methyl-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-β-carbolin-1-yl)-cyclopentanol (1), was isolated from roots of Galianthe thalictroides, together with the alkaloid 1-(hydroxymethyl)-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-β-carbolin-1-yl)-cyclopentanol (2), the anthraquinones 1-methyl-alizarin and morindaparvin-A, the coumarin scopoletin, homovanillic alcohol, (−)-epicatechin, and the steroids stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, 6-β-hydroxy-stigmast-4-en-3-one, stigmasterol, campesterol, β-sitosterol, and β-sitosterol-3-O-β-d-glucopyranoside. Among the previously known compounds, homovanillic alcohol is a novel finding in Rubiaceae, while 1-methyl-alizarin, morindaparvin-A, scopoletin, stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, and 6-β-hydroxy-stigmast-4-en-3-one is reported for the first time in the genus Galianthe. The cytotoxic β-carboline alkaloids 1 and 2 exhibited potent antitopoisomerase I and IIα activities and strong evidence is provided for their action as topoisomerase IIα poisons and redox-independent inhibitors.     

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.     

A new cycloartane-type triterpene and a new eicosanoic acid ester from fruits of Paullinia pinnata L.

A phytochemical study of the MeOH-soluble portion from the CH₂Cl₂/MeOH extract of the fruits of Paullinia pinnata resulted in the isolation of a new triterpenoid, cyclopinnatol (1), and a new eicosanoic acid ester, paulliniester (2), together with five known compounds including cycloart-22(E)-ene-3β,25-diol (3), cycloartenol (4), β-sitosterol (5), betulonic acid (6) and oleanonic acid (7). The structures of the new compounds were elucidated by spectroscopic analyses (NMR and MS) and comparisons with published data. Cyclopinnatol (1) and the MeOH-soluble portion exhibited significant and weak antibacterial activities against Staphylococcus aureus, with MICs of 32 and 50 μg/mL, respectively.     

New 19α-hydroxyursane-type triterpenes from the leaves of Meyna spinosa (= Vangueria spinosa), Rubiaceae

Two new 19α-hydroxyursane-type triterpenes, 2α,3α,19α,24,28-pentahydroxyurs-12-ene (1) and meyanthic acid, 3β-acetoxy-2β,19α,23-trihydroxyurs-12-en-28-oic acid (2) along with one new aliphatic ester, myricyl pentadecanoate (3) and five known compounds, 19α-hydroxyasiatic acid (4), oleanolic acid (5), myricyl alcohol (6), β-sitosterol (7) and its glycoside (8) were isolated from the methanolic leaf extract of Meyna spinosa Roxb. ex Link (= Vangueria spinosa Roxb., Rubiaceae). The structures of the new compounds were elucidated on the basis of extensive spectroscopic (including 2D NMR) analysis and comparison with literature. Except oleanolic acid, isolation of known compounds was reported for the first time from this plant.     

Production of 20-carboxy-pregna-1,4-dien-3-one from sterols by mutants of Rhodococcus sp

By selection of microorganisms which preferentially attack the side-chain of either cholesterol or β-sitosterol (campesterol) we isolated five mutants of Rhodococcus sp. strain k-3 was obtained from the wild-type strain MIL 1037 and μ-9, μ-11, and μ-12 from MIL 1038, by mutagenic treatment and produced preferentially 20-carboxy-pregna-1,4-dien-e-one from β-sitosterol (campesterol) or cholesterol in good yield. The other mutant, μ-7, isolated from the wild-type strain MIL 1038 produced a new compound identified as 7aβ-methyl-1β-[1′,5′-dimethyl-6′-hydroxy-hexyl]-5-oxo-3aα-hexahydro-4-indanpropionic acid from cholesterol. A temporary accumulation of this compound was observed during the transformation of cholesterol. This compound could be used as an intermediate for the chemical synthesis of steroids with unnatural configurations.