Chromones from the tubers of Eranthis cilicica and their antioxidant activity

Chemical studies on the constituents of Eranthis cilicica led to isolation of ten chromone derivatives, two of which were previously known. Comprehensive spectroscopic analysis, including extensive 1D and 2D NMR data, and the results of enzymatic hydrolysis allowed the chemical structures of the compounds to be assigned as 8,11-dihydro-5-hydroxy-2,9-dihydroxymethyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, 5,7-dihydroxy-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-2-methyl-4H-1-benzopyran-4-one, 5,7-dihydroxy-2-hydroxymethyl-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-4H-1-benzopyran-4-one, 7-[(β-d-glucopyranosyl)oxy]-5-hydroxy-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-2-methyl-4H-1-benzopyran-4-one, 7-[(β-d-glucopyranosyl)oxy]-5-hydroxy-2-hydroxymethyl-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-4H-1-benzopyran-4-one, 9-[(O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]methyl-8,11-dihydro-5,9-dihydroxy-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, 8,11-dihydro-5,9-dihydroxy-9-hydroxymethyl-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, and 7-[(O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]methyl-4-hydroxy-5H-furo[3,2-g][1]benzopyran-5-one, respectively. The isolated compounds were evaluated for their antioxidant activity.     

(2S)-Prenylflavanones and taraxerane triterpenoids from Mallotus mollissimus

Three prenylflavanones, (2S)-5,7-dihydroxy-4′-methoxy-8-(3″,3″-dimethylallyl)flavanone (3), (2S)-5,4′-dihydroxy-7-methoxy-6-(3″,3″-dimethylallyl)flavanone (6), 8-prenylnaringenin (11), and a new epimeric pair (2″S/2″R)-(2S)-5,7-dihydroxy-4′-methoxy-6-(2″-hydroxy-3″-methylbut-3″-enyl)flavanones (4a/4b) were isolated together with taraxerone, taraxerol, epitaraxerol, β-sitosterol, oleanolic acid, 1-O-docosanoyl glycerol, apigenin, and apigenin 7-O-β-D-glucopyranoside from the MeOH extract of the leaves of Mallotus mollissimus. The structures of the isolated compounds were determined on the basis of 1D/2D NMR and HR-MS spectroscopic data; the 2S configuration of the prenylflavanones 3, 4, and 6 was deduced from CD spectroscopic data. The presence of three taraxerane triterpenoids reinforces the inclusion of M. mollissimus (syn. Croton mollissimus) in Mallotus genus. Among species of Mallotus the occurrence of the (2S)-prenylflavanones 3, 4, and 6 is confined to M. mollissimus.     

Chemical constituents from the roots of Cichorium glandulosum Boiss. et Huet (Asteraceae)

A phytochemical investigation of the roots extract of Cichorium glandulosum led to the isolation and characterization of fourteen compounds, including five sesquiterpene lactones (1–5), five flavonoids (6–10), and four lignans (11–14). Their structures were determined by spectroscopic data analysis and comparison with the literatures. This is the first report of the crystal data of lactucopicrin (1). This is the first time to report the isolation of 6,8,11-epi-desacetylmatricarin (2), desacetylmatricarin (3), ixerisoslde C (4), magnodelavin (5), 2ʹ,4-dihydroxy-4ʹ-methoxy-6ʹ-O-β-glucopyranoside dihydrochalcone (6), (−)-evofolin B (7), isoquercitrin (8), myricetin 7-methyl-ether-3-O-glucoside (9), (+)-medioresinol (12), 4-O-methylcedrusin [2-(3ʹ,4ʹ-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-hydroxybenzofuran-5-propan-1-ol] (13), and (2R,3S)-samwirin A (14) from C. glandulosum. Among them, compounds 5, 9, 13, and 14 were obtained from Asteraceae family for the first time. The chemotaxonomic significance of all the isolates 1–14 was discussed.     

Phytochemical investigation of Millettia dorwardi Coll. et Hemsl

The first phytochemical investigation on the vine stems of Millettia dorwardi Coll. et Hemsl led to the isolation of ten flavonoids (isoafrormosin 1, formononetin 2, afrormosin 3, padmakastein 4, liquiritigenin 5, 4H-1-Benzopyran-4-one,7-hydroxy-5,8-dimethoxy-3-(4-methoxyphenyl)-isoflavone 6, 4H-1-Benzopyran-4-one,7-hydroxy-3-(3-hydroxy-5-methoxyphenyl)-6-methoxy 8, 4H-1-Benzopyran-4-one,6-methoxy-3-(4-methoxyphenyl)-6,4′-dimethoxyisoflavone 9, irisolidone 10, prunetin 11), one heterocycle (5-5′-dibuthoxy-2-2′-bifuran 7) and one new isoflavone glycoside (4H-1-Benzopyran-4-one,5-hydroxymethyl-3-(4-methoxyphenyl)-6-β-d-glucopyranoside-isoflavone 12). Their structures were determined by extensive analysis of their spectroscopic data. Among them, compounds 4, 6–10, 12 were for the first time isolated from this genus. The chemotaxonomic importance of these compounds was also summarized.     

Tyrosinase inhibitory activity of three new glycosides from Breynia fruticosa

Two new flavanone glycoside derivatives and one new sulfur-containing spiroacetal glycoside, (2R, 3R)-3-acetyl-7-methoxy-(−)-epicatechin 5-O-(6-isobutanoyl)-β-d-glucopyranoside (1), (2R, 3R)-3-acetyl-7-methoxy-(−)-epicatechin 5-O-[6-(2-methylbutanoyl)]-β-d-glucopyranoside (2) and 4-[(carboxymethyl)thio]-5′-hydroxy-phyllaemblic acid O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside ester (3), along with twelve known flavonoids and one known sulfur-containing spiroacetal glycoside, were isolated from Breynia fruticosa. Their structures were elucidated by the use of extensive spectroscopic methods (UV, IR, HR-ESI-MS, 1D and 2D NMR, and CD). The in vitro inhibition of tyrosinase activity by all of these compounds was also evaluated, and we concluded that the flavanol-containing 5-O- and 7-O-sugar moieties possessed more potent effects than the other compounds examined herein.     

Steroidal constituents of Solanum xanthocarpum

From the extract of the fruits of Solanum xanthocarpum (Solanaceae), five new steroidal compounds were isolated and characterized: 4α-methyl-24ξ-ethyl-5α-cholest-7-en-3β,22ξ-diol (1), 3β,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (2), 3β-benzoxy-14β,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (3), 3β-benzoxy-14α,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (4) and 3β-(p-hydroxy)-benzoxy-22ξ-hydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (5).     

Sesquiterpenoids and lignans from the fruits of Illicium simonsii Maxim

Twenty-two known compounds were isolated from the 95% alcohol extract of the fruits of Illicium simonsii Maxim, including seven sesquiterpenoids (16–22) and fifteen lignans (1–15). In the present research, compounds 3 ((7S,8R,8′S)-3,3′-dimethoxy-4,4′,9-trihydroxy-7,9′-epoxylignan-7′-one), 4 ((−)-(7′S,8S,8′R)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxylignan-9′-ol-7-one), 5 ((+)-8-hydroxypinoresinol), 6 ((+)-8-hydroxymedioresinol), 8 ((2R,3R)-2β-(4″-hydroxy-3″-methoxybenzyl)-3α-(4′-hydroxy-3′-methoxybenzyl)-γ-butyrolactone 2-O-(β-D-glucopyranoside), 12 ((+)-8-methoxyisolariciresinol), 13 (α-conidendrin), 14 (boehmenan) and 15 (7R,8R,7′E-7′,8′-didehydro-4,7,9,9′- tetrahydroxy-3-methoxy-8-O-4′-neolignan) were reported from the Illicium genus for the first time, and compounds 1 (simulanol), 7 ((+)-secoisolariciresinol monoglucoside), 10 ((+)-9-O-β-D-glucopyranosyl lyoniresinol), 11 ((+)-isolariciresinol), 18 (neoanisatin), 19 (veranisatin A), 20 (4,5-d₂-8′-oxo-dihydrophaseic acid) and 22 (Oligandrumin A) were firstly isolated from the plant. Their structures were elucidated on the basis of NMR spectroscopic and mass spectrometric data. Moreover, the chemotaxonomic significance of the isolated compounds is discussed.     

Two new coumarin derivatives from the whole plant of Spermacoce latifolia

Six coumarin derivatives including two new, 2-acetyl-4-hydroxy-6H-furo[2,3-g]chromen-6-one (1) and 2-(1',2'-dihydroxypropan-2'-yl)-4-hydroxy-6H-furo[2,3-g]chromen-6-one (2), and four known ones, 7H-furo [3,2-g][1]benzopyran-7-one (3), esculetin (4), isoscopoletin (5) and 7,8-dihydroxy-6-methoxycoumarin (6), were isolated for the first time from the whole plant of Spermacoce latifolia. Their structures were determined by detailed spectroscopic analysis and comparison with literature reported data. In vitro antibacterial assay indicated that compounds 1, 2 and 4 were active toward bacteria Staphyloccocus aureus, Bacillus subtilis and Bacillus cereus with MIC values ranging from 7.81 to 62.5 ug/mL.     

Monoterpenoids from the aerial parts of Aruncus dioicus var. kamtschaticus and their antioxidant and cytotoxic activities

The aerial parts of Aruncus dioicus var. kamtschaticus afforded five new monoterpenoids (1-5): 4-(erythro-6,7-dihydroxy-9-methylpent-8-enyl)furan-2(5H)-one (1, aruncin A), 2-(8-ethoxy-8-methylpropylidene)-5-hydroxy-3,6-dihydro-2H-pyran-4-carboxylic acid (2, aruncin B), 4-(hydroxymethyl)-6-(8-methylprop-7-enyl)-5,6-dihydro-2H-pyran-2-one-11-O-β-d-glucopyranoside (3, aruncide A), (3S,4S,5R,10R)-3-(10-ethoxy-11-hydroxyethyl)-4-(5-hydroxy-7-methylbut-6-enyl)oxetan-2-one-11-O-β-d-glucopyranoside (4, aruncide B), and (3S,4S,5R,7R)-5-(9-methylprop-8-enyl)-1,6-dioxabicyclo[3,2,0]heptan-2-one-7-(hydroxymethyl)-12-O-β-d-glucopyranoside (5, aruncide C). Compound 2 showed potent cytotoxicity against Jurkat T cells with an IC₅₀ value of 17.15 μg/mL. In addition, compounds 7 and 10 exhibited moderate antioxidant activity with IC₅₀ values of 46.3 and 11.7 μM, respectively.     

Cycloartane glycosides from Astragalus gombo

Six new cycloartane-type triterpene glycosides named 3-O-[β-d-glucopyranosyl(1 → 2)-β-d-xylopyranosyl]-3β,16β,23(R),24(R),25-pentahydroxycycloartane (1), 3-O-[β-d-glucopyranosyl(1 → 2)-β-d-xylopyranosyl]-3β,16β,23(R),24(R)-tetrahydroxy-25-dehydrocycloartane (2), 3-O-[β-d-xylopyranosyl]-6α-acetoxy-23α-methoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (3), 3-O-[β-d-xylopyranosyl]-6α-acetoxy-23α-butoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (4), 3-O-[β-d-glucopyranosyl(1 → 2)]-β-d-xylopyranosyl]-6α-acetoxy-23α-methoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (5), 3-O-[β-d-glucopyranosyl(1 → 2)]-β-d-xylopyranosyl]-23α-methoxy-16β,23(R)-epoxy-4,25,26,27-tetranorcycloartane (6), in addition to three known secondary metabolites consisting of another cycloartane triterpene glycoside and two flavonol glycosides, were isolated from the aerial parts of Astragalus gombo Coss. & Dur. (Fabaceae). The structures of the isolated compounds were established by spectroscopic methods, including 1D and 2D-NMR, mass spectrometry and comparison with literature data.     

Secondary metabolites from Calotropis procera (Aiton)

Three new metabolites, 5-hydroxy-3,7-dimethoxyflavone-4′-O-β-glucopyranoside (1), 2β,19-epoxy-3β,14β-dihydroxy-19-methoxy-5α-card-20(22)-enolide (4) and β-anhydroepidigitoxigenin-3β-O-glucopyranoside (5), along with two known compounds, uzarigenine (2) and β-anhydroepidigitoxigenin (3), were isolated from Calotropis procera (Asclepiadaceae). The structure elucidation was accomplished mainly by nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric methods. To examine putative antimicrobial or cytotoxic activities, various bioassays were performed. Uzarigenine (2) demonstrated moderate cytotoxicity.     

Naphthofuran precursors of sesquiterpenoid aldehydes in diseased Gossypium

Crude terpenoid fractions from stele tissues of Gossypium barbadense infected with Verticillium dahliae contained two prominent compounds that were nonaldehydic, but readily autooxidized to the terpenoid aldehydes hemigossypol and 6-methoxyhemigossypol. Spectral analyses, chemical studies, and comparisons with model compounds showed that these compounds were the sesquiterpenoids 3,4-dihydroxy-5-isopropy]-7-methy]-2H-naphtho[1,8-bc]furan (1a) and 3-hydroxy-5-isopropyl-4-methoxy-7-methyl-2H-naphtho[1,8-bc]furan (1b). The trivial names desoxyhemigossypol and desoxy-6-methoxyhemigossypol are proposed for (1a) and (1b). The sesquiterpenoid, previously isolated and named vergosin, is apparently desoxy-6-methoxyhemigossypol.     

Eudesmane-type sesquiterpenes from the liverwort Apomarsupella revolute

Phytochemical investigation of the Et₂O extract of liverwort Apomarsupella revolute led to isolation and identification of five new eudesmane-type sesquiterpenoids, 6β-hydroxy-9β-acetoxy-eudesma-4,11-dien (1), 6β-hydroxy-9β-acetoxy-eudesma-4,11-dien-3-one (2), 5α,6β-dihydroxy-9β-acetoxy-eudesma-4(15),11-dien (3) 4β-hydroxy-9β-acetoxy-11,12,13-trinor-5-eudesmen-7-one (4) and 4β-methox-9β-acetoxy-11,12,13-trinor-5-eudesmen-7-one (5), two of which were trinorsesquiterpenoids. Their structures were established unequivocally on the basis of spectroscopic data analysis. All compounds were preliminary bioscreened for their cytotoxicities and antifungal activities.     

Steroidal saponins and homoisoflavanone from the aerial parts of Sansevieria cylindrica Bojer ex Hook.

Phytochemical study on the methanolic extract of Sansevieria cylindrica aerial parts lead to the isolation, characterization and structure elucidation of a new steroidal saponin, 1β-hydroxy-kryptogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside (1), a new homoisoflavanone, (3S)-3,7-dihydroxy-8-methoxy-3-(3′,4′-methylenedioxybenzyl) chroman-4-one (2) and the known saponin alliospiroside A (3). To the best of our knowledge, the genin 1β-hydroxy-kryptogenin is reported here for the first time. The structures of the new compounds were determined by UV, IR, EIMS, HRESIMS together with 1D (¹H and ¹³C) and 2D (HSQC and HMBC) NMR spectral analysis. The isolated compounds 1–3 were tested for their radical scavenging activity (DPPH). Compound 2 exhibited activity compared to that of ascorbic acid as a standard. The cytotoxicity of the isolated compounds and the standard doxorubicin was tested against the three human tumor cell lines HT116, MCF-7 and PC-3. The results showed that the isolated compounds were inactive.     

New cytotoxic dihydrochalcone and steroidal saponins from the aerial parts of Sansevieria cylindrica Bojer ex Hook

A new dihydrochalcone, 2‘,4‘-dihydroxy-3‘-methoxy-3,4-methylenedioxy-8-hydroxymethylene dihydrochalcone 1 and two new steroidal saponins, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside 2, (25S)-ruscogenin-3-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranoside 3, together with three known steroidal saponins (25S)-ruscogenin-3-O-β-d-glucopyranoside 4, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 5 and (25R)-26-O-β-d-glucopyranosyl-furost-5-ene-1β,3β,22α,26-tetrol-1-O-α-L-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 6 were isolated from the aerial parts of Sansevieria cylindrica. The structures of the new compounds were established by UV, IR, EI-MS, HR-ESI–MS as well as 1D (¹H,¹³C and DEPT-135) and 2D (HSQC, HMBC and TOCSY) NMR spectral analysis. The isolated compounds 1-6 were assayed for in vitro cytotoxicities against the three human tumor cell lines HT116, MCF7 and HepG2. Compound 1 showed a moderate cytotoxicity against MCF7. Compounds 2, 3 and 6 exhibited moderate cytotoxicities against the three used cell lines and compound 5 showed marked cytotoxicities against all used cell lines.     

Chemical constituents from the roots of Fallopia multiflora var. Ciliinerve

Phytochemical investigations on the roots of Fallopia multiflora var. Ciliinerve led to the isolation of eighteen compounds, including six chromones [2-methyl-5- carboxymethyl-7-hydroxychromone (1), 2-methyl-5-methylcarboxymethyl-7- hydroxychromone (2), 2,5-dimethyl-7-hydroxychromone (3), 2-methyl-5-hydroxymeth-yl-7-hydroxychromone (4), 2-methyl-5-carboxylicacid-7-hydroxy-chromone (5), and 2,5-dimethyl-7-hydroxychromone-7-O-β-D-glucopyranoside (6)], three lignans [Isolariciresinol (8), 5-[4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl]-1,3-benzodioxole (9), and isolariciresinol-9-O-β-D-xylopyranoside (10)], four anthraquinones [physcion-8-O-β-D-glucopyranoside (11), emodin-8-O-β-D-glucopyranoside (12), Rhein (13), and Chrysophanol (14)], three isobenzofurans [5,7-dihydroxy-isobenzofuran (15), 5-methoxy-7-hydroxy-isobenzofuran (16), and 5-methoxy-isobenzofuran-7-O-β-D-glucoside (17)], one phenolic acid [2,5-diacethylhy-droquinone (7)], and one pyran [Zanthopyranone (18)]. Among them, compounds 1, 3, 6, 13 and 14 were reported from F. multiflora var. Ciliinerve for the first time, compounds 2, 8, 10 and 15–17 were isolated from the genus Fallopia for the first time, and compounds 4, 9 and 18 were isolated for the first time from Polygonaceae family. Furthermore, the isolation of compounds 5 and 7 were reported for the first time in plants. Their structures were identified by spectroscopic methods and compared with those previously published. The chemotaxonomic significance of these isolated compounds has also been discussed.     

Inhibition of ABCG2-mediated drug efflux by naphthopyrones from marine crinoids

Five new naphthopyrones (1–5) along with the known compounds TMC-256A1, 5,8-dihydroxy-6-methoxy-2-propyl-4H-naphtho[2,3-b]pyran-4-one, TMC-256C1, comaparvin, 6-methoxycomaparvin, and 6-methoxycomaparvin 5-methyl ether (6–11) were isolated from crinoids of the family Comasteridae. All compounds were tested for their ability to inhibit the multidrug transporter ABCG2, which plays a role in drug resistance. Six of the seven angular naphthopyrones showed moderate activity with <60% inhibition of ABCG2-mediated transport as compared to the positive control fumitremorgin C. None of the linear naphthopyrones inhibited ABCG2-mediated efflux.     

Three further naphthoquinones produced by Fusarium solani

Three naphthoquinone pigments are described which were produced by Fusarium solani. They are 2,3-dihydro-5,8-dihydroxy-6-methoxy-2-hydroxymethyl-3-(2-hydroxypropyl)-1,4-naphthalenedione, 2,3-dihydro-5-hydroxy-4-hydroxymethyl-8-methoxy-naphtho[1,2-b]furan-6,9-dione and 5,8-dihydroxy-2-methoxy-6-hydroxymethyl-7-(2-hydroxypropyl)-1,4-naphthalenedione. One of these pigments was shown to be the precursor of the other two.     

Biotransformation of dianabol with the filamentous fungi and β-glucuronidase inhibitory activity of resulting metabolites

Biotransformation of the anabolic steroid dianabol (1) by suspended-cell cultures of the filamentous fungi Cunninghamella elegans and Macrophomina phaseolina was studied. Incubation of 1 with C. elegans yielded five hydroxylated metabolites 2–6, while M. phaseolina transformed compound 1 into polar metabolites 7–11. These metabolites were identified as 6β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (2), 15α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (3), 11α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (4), 6β,12β,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (5), 6β,15α,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (6), 17β-hydroxy-17α-methylandrost-1,4-dien-3,6-dione (7), 7β,17β,-dihydroxy-17α-methylandrost-1,4-dien-3-one (8), 15β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (9), 17β-hydroxy-17α-methylandrost-1,4-dien-3,11-dione (10), and 11β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (11). Metabolite 3 was also transformed chemically into diketone 12 and oximes 13, and 14. Compounds 6 and 12–14 were identified as new derivatives of dianabol (1). The structures of all transformed products were deduced on the basis of spectral analyses. Compounds 1–14 were evaluated for β-glucuronidase enzyme inhibitory activity. Compounds 7, 13, and 14 showed a strong inhibition of β-glucuronidase enzyme, with IC₅₀ values between 49.0 and 84.9 μM.     

Microbial transformation of 3β-acetoxypregna-5,16-diene-20-one by Penicillium citrinum

The biotransformation of 3β-acetoxypregna-5,16-diene-20-one (1) by using a filamentous fungus Penicillium citrinum resulted in the production of four metabolites 2–5. The structures of these compounds were elucidated by different spectroscopic analysis (1D- and 2D-NMR) and HR-ESI-MS as 3β,7β-dihydroxy-pregn-5,16(17)-dien-20-one (2), 3β-hydroxy-7α-methoxy-pregn-5,16(17)-dien-20-one (3), 3β,7β,11α-trihydroxy-pregn-5,16(17)-dien-20-one (4), and a known 3β,7α-dihydroxy-pregn-5,16(17)-dien-20-one (5). The 7-O-methylation is a novel reaction in the field of microbial transformation of pregnane steroids.