Microbial transformation of nandrolone with Cunninghamella echinulata and Cunninghamella blakesleeana and evaluation of leishmaniacidal activity of transformed products

Therapeutic potential of nandrolone and its derivatives against leishmaniasis has been studied. A number of derivatives of nandrolone (1) were synthesized through biotransformation. Microbial transformation of nandrolone (1) with Cunninghamella echinulata and Cunninghamella blakesleeana yielded three new metabolites, 10β,12β,17β-trihydroxy-19-nor-4-androsten-3-one (2), 10β,16α,17β-trihydroxy-19-nor-4-androsten-3-one (3), and 6β,10β,17β-trihydroxy-19-nor-4-androsten-3-one (4), along with four known metabolites, 10β,17β-dihydroxy-19-nor-4-androsten-3-one (5), 6β,17β-dihydroxy-19-nor-4-androsten-3-one (6) 10β-hydroxy-19-nor-4-androsten-3,17-dione (7) and 16β,17β-dihydroxy-19-nor-4-androsten-3-one (8). Compounds 1–8 were evaluated for their anti-leishmanial activity. Compounds 1 and 8 showed a significant activity in vitro against Leishmania major. The leishmanicidal potential of compounds 1–8 (IC₅₀ = 32.0 ± 0.5, >100, 77.39 ± 5.52, 70.90 ± 1.16, 54.94 ± 1.01, 80.23 ± 3.39, 61.12 ± 1.39 and 29.55 ± 1.14 μM, respectively) can form the basis for the development of effective therapies against the protozoal tropical disease leishmaniasis.     

Platachromone A–D: Cytotoxic 2-styrylchromones from the bark of Platanus × acerifolia (Aiton) Willd.

Four novel 2-styrylchromones, 4′,5,7-trihydroxy-6-isopentene-2-styrylchromone (1), 4′,5,7-trihydroxy-8-isopentene-2-styrylchromone (2), 4′,5,7-trihydroxy-6-(2-hydroxy-3-methylbut-3-enyl)-2-styrylchromone (3) and 4′,5,7-trihydroxy-8-(2-hydroxy-3-methylbut-3-enyl)-2-styrylchromone (4), were isolated from shed bark of Platanus × acerifolia (Aiton) Willd., as well as four known compounds, 4′,5,7-trihydroxy-2-styrylchromone (5), scutellarein (6), 4′,5,7-trihydroxy-6-prenylflavone (7), and 4′,5,7-trihydroxy-8-prenylflavone (8). The structures of compounds 1–4 were established by direct interpretation of their spectral data, mainly high resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D and 2D NMR (¹H–¹H COSY, HSQC and HMBC). The cytotoxicity of the compounds 1–8 was evaluated in four human carcinoma cell lines, including HepG2, SMMC-7721, MDA-MB-231, and KB. Compounds 1–4 exhibited significantly cytotoxic activity toward HepG2 and KB cells, with IC₅₀ values ranging from 3.0 to 9.7 μM.     

Phytochemical and cytotoxic studies on the leaves of Calotropis gigantea

A new lignan, 9′-methoxypinoresinol (1), and two new glycosylated 5-hydroxymethylfurfurals, calofurfuralside A (2), and calofurfuralside B (3), together with nine known compounds (4–12) have been isolated from the active fractions, CHCl₃ (IC₅₀, 0.32 μg mL^?1) and EtOAc (IC₅₀, 0.55 μg mL^?1) fractions of the leaves of Calotropis gigantea. Their structures were elucidated based on NMR and MS data. Among the isolated compounds, compounds 1 and 9 exhibited potent cytotoxicity against PANC-1 human pancreatic cancer cell line under the normoglycemic condition with IC₅₀ values of 3.7 and 3.3 μM, respectively. 9′-Methoxypinoresinol (1) significantly inhibited the colony formation of PANC-1 cells in a concentration-dependent manner.     

Vasodilatory actions of xanthones isolated from a Tibetan herb,Halenia elliptica

In this study, six major xanthones, isolated and identified from Halenia elliptica were investigated for their vasodilatory actions in isolated rat coronary artery. The xanthones, including 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1), 1-hydroxy-2,3,4,7-tetramethoxy-xanthone (HM-2), 1-hydroxy-2,3,4,5-tetramethoxy-xanthone (HM-3), 1,7-dihydroxy–2,3,4,5-tetramethoxy-xanthone (HM-4), 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) and 1,7-dihydroxy-2,3-dimethoxy-xanthone (HM-7) caused vasodilation in the coronary artery pre-contracted with 1 μM 5-hydroxytryptamine (5-HT), with EC₅₀ values ranging from 1.4±0.1 μM (HM-1) to 6.6±1.4 μM (HM-2). The EC₅₀ values of the other xanthones were between those of HM-1 and HM-2. Removal of endothelium of the coronary artery led to decreases in the vasorelaxant effects of HM-1, HM-7 but not HM-2, HM-3, HM-4 and HM-5. Our results showed that xanthones isolated from Halenia elliptica are vasoactive substances which exhibit either endothelium-dependent or endothelium-independent mechanisms in rat coronary artery. The potency and mechanism(s) of the vasorelaxant effects of these xanthones may be relevant to the structure–activity differences in the level and the position of the substituent groups with the primary xanthone structure.     

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.     

Sesquiterpenes and triterpenoids from the rhizomes of Alisma orientalis and their pancreatic lipase inhibitory activities

Five new terpenoids, including three sesquiterpenes 11-hydroxy-8-ox-alismoxide (1), 11-oxo-13-nor-alismol (2), and 1β,11-dihydroxy-β-cyperone (3), and two protostane-type triterpenoids 16β-acetoxy alisol B (4) and 16α-acetoxy alisol B (5) were isolated from the rhizomes of Alisma orientalis together with 11 known compounds. Their structures were established using 1D and 2D NMR and HRESIMS spectroscopic analyses. The isolated compounds were assayed for their inhibitory activities against pancreatic lipase. Compounds 6 and 13 showed inhibitory effects with IC₅₀ values of 64.4 and 45.5 μM, respectively.     

Two new anti-HBV lignans from Herpetospermum caudigerum

Two new lignans, named (+)-(7′S, 7″S, 8′R, 8″R)-4, 4′, 4″-trihydroxy-3, 5′, 3″-trimethoxy-7-oxo-8-ene [8-3′, 7′-O-9″, 8′-8″, 9′-O-7″] lignoid (1) and (1S)-4-Hydroxy-3-[2-(4-hydroxy-3-methoxy-phenyl)-1-hydroxymethyl-2-oxo-ethyl]-5-methoxy-benzaldehyde (2), along with five known (3–7) ones, have been isolated from the 95% ethanol extract of the seeds of Herpetospermum caudigerum Wall. The structures of the new compounds, including the absolute configurations, were elucidated by spectroscopic and CD analysis. Compounds 1, 2, and 7 displayed inhibitory activities on HBsAg secretion with IC₅₀ values of 20.5, 0.34, and 4.89 μM, while 1, 2, and 7 displayed inhibitory activities on HBeAg secretion with IC₅₀ values of 3.54, 4.83 × 10⁻⁴, and 8.02 μM, and cytotoxicity on HepG 2.2.15 cells with CC₅₀ values of 12.7, 2.96 × 10⁵, and 11.4 μM, respectively.     

Polyoxygenated xanthones of Centaurium littorale

Two apolar tetra-oxygenated xanthones (1,8-dihydroxy-3,5-dimethoxyxanthone and 1-hydroxy-3,5,8-trimethoxyxanthone) and two hexaoxygenated xanthones (1,8-dihydroxy-3,5,6,7-tetramethoxyxanthone and 1-hydroxy-3,5,6,7,8-pentamethoxyxanthone) have been isolated from the root of Centaurium littorale. The isolation and structure of these xanthones are reported and details of the TLC analysis are given. The ¹³C NMR and high resolution EIMS spectra of the two hexaoxygenated xanthones are reported. The xanthones found within the genus Centaurium Hill are reviewed.     

Two new flavonols from flowers of Getonia floribunda Roxb.

Phytochemical investigation of the EtOAc and MeOH extracts from flowers of Getonia floribunda Roxb., a Thai herbal medicine, resulted in the isolation of two new flavonols, 4′-hydroxy-6,7,8,3′-tetramethoxyflavonol (1) and 4′-hydroxy-6,7,8-trimethoxyflavonol (2), along with a known pachypodol (3). Their structures were elucidated by spectroscopic methods including UV, IR, 1D and 2D NMR techniques and MS analysis. Compound 1 showed cytotoxicity against the oral cavity cancer (KB) cell line with an IC₅₀ value of 8.99 ± 2.00 μg/ml.     

A new homoisoflavonoid and the bioactivities of some selected homoisoflavonoids from the inter-bulb surfaces of Scilla nervosa subsp. rigidifolia

Seven homoisoflavonoids and one stilbenoid, 3-(4′-methoxybenzyl)-6,7-dihydroxy-5-methoxychroman-4-one (1) which is new; 3-(4′-methoxybenzyl)-6-hydroxy-5,7-dimethoxychroman-4-one (2); 3-(4′-methoxybenzyl)-5,7-dimethoxychroman-4-one (3); 3-(3′-hydroxy-4′-methoxybenzyl)-5,7-dimethoxychroman-4-one (4); 3-(4′-methoxybenzylidene)-5,7-dihydroxy-6-methoxychroman-4-one (5); 3-(4′-hydroxybenzylidene)-5,7-dihydroxy-6-methoxychroman-4-one (6); 3-(4′-hydroxybenzylidene)-5,7-dihydroxychroman-4-one (7) and 4,3′,5′-trihydroxy-3-methoxystilbene (8), were isolated from the yellow inter-bulb deposits from Scilla nervosa. The structures of these compounds were elucidated by 1D- and 2D-NMR and mass spectrometry. A number of extracts, fractions and compounds tested displayed bacterostatic activity with MICs ranging between 0.156 and 1.250 mg/ml. Two extracts displayed significant α-glucosidase inhibitory activity and a number of extracts, fractions and compounds showed strong antioxidant activity with, compounds 1, 2 and 8 displaying lower MECs than the positive control ascorbic acid (0.0156 mg/ml).     

Two new cycloartane-type triterpenoids and one new flavanone from the leaves of Dasymaschalon dasymaschalum and their biological activity

Two new cycloartane-type triterpenoids, 3β-hydroxy-21-O-acetyl-24-methylenecycloartane (3) and 3β,21-dihydroxy-24,31-epoxy-24-methylenecycloartane (4), one new flavanone, 7-hydroxy-6,8-dimethoxyflavanone (5), two new natural products, 2-hydroxybenzyl benzoate (7) and 2-phenyl-2-acetoxyethyl benzoate (8), and ten known compounds, 3β-hydroxy-24-methylenecycloartane (1), 3β,21-dihydroxy-24-methylenecycloartane (2), desmosdumotin B (6), artabotrene (9), (?)-senepoxide (10), (+)-crotepoxide (11), (?)-1,6-desoxypipoxide (12), rotundol (13), cassipourol (14) and (+)-spathulenol (15) were isolated from the leaves of Dasymaschalon dasymaschalum. The structures of the new compounds were elucidated by spectroscopic analysis and of the known compounds by comparison of their physical, UV, IR, ¹H and ¹³C NMR data with those of published compounds. Antimycobacterial, antiplasmodial and cytotoxic activities of the isolates, except 8 and 10 were evaluated. Compounds 1, 4, 5, 11, 12 and 15 exhibited potent cytotoxic activities against human lung cancer cell lines (NCI-H187) with respective IC₅₀ values of 4.67, 7.82, 1.85, 6.33, 3.07 and 6.68 μg/mL.     

Bioactive compounds from Stuhlmannia moavi from the Madagascar dry forest

Bioassay-directed fractionation of the leaf and root extracts of the antiproliferative Madagascar plant Stuhlmannia moavi afforded 6-acetyl-5,8-dihydroxy-2-methoxy-7-methyl-1,4-naphthoquinone (stuhlmoavin, 1) as the most active compound, with an IC₅₀ value of 8.1 μM against the A2780 human ovarian cancer cell line, as well as the known homoisoflavonoid bonducellin (2) and the stilbenoids 3,4,5′-trihydroxy-3′-methoxy-trans-stilbene (3), piceatannol (4), resveratrol (5), rhapontigenin (6), and isorhapontigenin (7). The structure elucidation of all compounds was based on NMR and mass spectroscopic data, and the structure of 1 was confirmed by a single crystal X-ray analysis. Compounds 2?5 showed weak A2780 activities, with IC₅₀ values of 10.6, 54.0, 41.0, and 74.0 μM, respectively. Compounds 1?3 also showed weak antimalarial activity against Plasmodium falciparum with IC₅₀ values of 23, 26, and 27 μM, respectively.     

Cytotoxic glucosydic iridoids from Veronica americana

Fractionation guided by the cytotoxic activity of the methanolic extract of Veronica americana led to the isolation of two new iridoids identified as 4β-hydroxy-6-O-(p-hydroxybenzoyl)-tetrahydrolinaride (1) and 10-O-protocatechuyl-catalpol (2), together with four known aromatic acids, veratric acid (3) p-methoxybenzoic acid (4), p-hydroxybenzoic acid (5) and protocatechuic acid (6). The structure of these compounds was determined by spectroscopic analysis. Iridoid glycosides 1 and 2 showed selective cytotoxic activity against the human cancer cell lines HF-6 (IC₅₀ = 0.031 and 0.066 μM, respectively) and PC-3 (IC₅₀ = 0.721 and 0.801 μM, respectively), with less sensitivity in normal MRC-5 cells (IC₅₀ = 77.103 and 1451.562 μM, respectively). Compound 1 was 9.9 times more potent than camptothecin against HF-6 cell line, while compound 2 was 4.7 times, more potent, against the same cell line, than camptothecin. The found biological efficacy of 1 and 2 allow us to propose these compounds as candidates for the development of effective anticancer therapeutic agents.     

Vasodilatory actions of xanthones isolated from a Tibetan herb,Halenia elliptica

In this study, six major xanthones, isolated and identified from Halenia elliptica were investigated for their vasodilatory actions in isolated rat coronary artery. The xanthones, including 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1), 1-hydroxy-2,3,4,7-tetramethoxy-xanthone (HM-2), 1-hydroxy-2,3,4,5-tetramethoxy-xanthone (HM-3), 1,7-dihydroxy–2,3,4,5-tetramethoxy-xanthone (HM-4), 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) and 1,7-dihydroxy-2,3-dimethoxy-xanthone (HM-7) caused vasodilation in the coronary artery pre-contracted with 1 μM 5-hydroxytryptamine (5-HT), with EC₅₀ values ranging from 1.4±0.1 μM (HM-1) to 6.6±1.4 μM (HM-2). The EC₅₀ values of the other xanthones were between those of HM-1 and HM-2. Removal of endothelium of the coronary artery led to decreases in the vasorelaxant effects of HM-1, HM-7 but not HM-2, HM-3, HM-4 and HM-5. Our results showed that xanthones isolated from Halenia elliptica are vasoactive substances which exhibit either endothelium-dependent or endothelium-independent mechanisms in rat coronary artery. The potency and mechanism(s) of the vasorelaxant effects of these xanthones may be relevant to the structure–activity differences in the level and the position of the substituent groups with the primary xanthone structure.     

Cytotoxicity of cardenolides and cardenolide glycosides from Asclepias curassavica

A new cardenolide, 12β,14β-dihydroxy-3β,19-epoxy-3α-methoxy-5α-card-20(22)-enolide (6), and a new doubly linked cardenolide glycoside, 12β-hydroxycalotropin (13), together with eleven known compounds, coroglaucigenin (1), 12β-hydroxycoroglaucigenin (2), calotropagenin (3), desglucouzarin (4), 6′-O-feruloyl-desglucouzarin (5), calotropin (7), uscharidin (8), asclepin (9), 16α-hydroxyasclepin (10), 16α-acetoxycalotropin (11), and 16α-acetoxyasclepin (12), were isolated from the aerial part of ornamental milkweed, Asclepias curassavica and chemically elucidated through spectral analyses. All the isolates were evaluated for their cytotoxic activity against HepG2 and Raji cell lines. The results showed that asclepin (9) had the strongest cytotoxic activity with an IC₅₀ value of 0.02 μM against the two cancer cell lines and the new compound 13 had significant cytotoxic activity with IC₅₀ values of 0.69 and 1.46 μM, respectively.     

Cytotoxicity and modes of action of 4′-hydroxy-2′,6′-dimethoxychalcone and other flavonoids toward drug-sensitive and multidrug-resistant cancer cell lines

IntroductionResistance of cancer to chemotherapy is a main cause in treatment failure. Naturally occurring chalcones possess a wide range of biological activities including anti-cancer effects. In this work, we evaluated the antiproliferative activity of three chalcones [4′-hydroxy-2′,6′-dimethoxychalcone (1), cardamomin (2), 2′,4′-dihydroxy-3′,6′-dimethoxychalcone (3)], and four flavanones [(S)-(–)-pinostrobin (4), (S)-(–)-onysilin (5) and alpinetin (6)] toward nine cancer cell lines amongst which were multidrug resistant (MDR) types.MethodsThe resazurin reduction assay was used to detect the antiproliferative activity of the studied samples whilst flow cytometry for the mechanistic studies of the most active molecule (1).ResultsIC₅₀ values in a range of 2.54 μM against CEM/ADR5000 leukemia cells to 58.63 μM toward hepatocarcinoma HepG2 cells were obtained with 1. The lowest IC₅₀ values of 8.59 μM for 2 and 10.67 μM for 3 were found against CCRF-CEM cells leukemia cells, whilst the corresponding values were above 80 μM for 4 and 6. P-glycoprotein-expressing and multidrug-resistant CEM/ADR5000 cells were much more sensitive toward compound 1 than toward doxorubicin and low cross-resistance or even collateral sensitivity was observed in other drug-resistent cell lines to this compound. Normal liver AML12 cells were more resistant to the studied compounds than HepG2 liver cancer cells, indicating tumor specificity at least to some extent. Compound 1 arrested the cell cycle between Go/G1 phase, strongly induced apoptosis via disrupted mitochondrial membrane potential (MMP) and increased production of reactive oxygen species (ROS) in the studied leukemia cell line.ConclusionsChalcone 1 was the best tested cytotoxic molecule and further studies will be performed in order to envisage its possible use in the fight against multifactorial resistant cancer cells.     

Three new benzophenone glycosides with MAO-A inhibitory activity from Hypericum thasium Griseb.

Purification of n-BuOH fraction from 80% ethanol extract of Hypericum thasium Griseb. resulted in the isolation of three new compounds 3′,4,5′-trihydroxy-6-methoxy-2-O-α-l-arabinosylbenzophenone (1), 3′,4,5′,6-tetrahydroxy-2-O-α-l-arabinosylbenzophenone (2), and 3′,4-dihydroxy-5′-methoxy-2-O-α-l-arabinosyl-6-O-β-d-xylosylbenzophenone (3) along with a known flavonoid glycoside quercetin-3-O-α-l-arabinofuranoside (4). The structures of the new compounds were elucidated by 1D and 2D NMR analysis as well as HRESIMS. The isolated compounds (1–4), as well as quercetin, and kaempferol previously isolated from EtOAc fraction were screened against MAO-A inhibitory activity. When tested against the MAO-A quercetin and kaempferol displayed IC₅₀ values of 19.6, and 17.5 μM, respectively. The IC₅₀ values for MAO-A inhibition by compounds (1–4) were 310.3, 111.2, 726.0, and 534.1 μM, respectively. Standard inhibitor (clorgyline) exhibited MAO-A inhibition with an IC₅₀ value of 0.5 μM.     

Microbial transformation of bavachin by Absidia coerulea

Microbial transformation of bavachin (1), one of the major bioactive components of Psoralea corylifolia L., was performed by using Absidia coerulea. Three oxidized metabolites were obtained in the biotransformation of 1, and their structures were elucidated as bavachinone A (2), (2S)-4′-hydroxy-6,7-[(R)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofurano]flavanone (3), and (2S)-4′,7-dihydroxy-6-(2,3-dihydroxy-3-methylbutyl)flavanone (4) based on the spectroscopic analyses. Among them, metabolites 3 and 4 were new compounds. The biotransformation study suggested that 1 was fully oxidized to its metabolites within 5 days. Thus, biotransformation by A. coerulea can be used as a promising method for oxidation of bavachin.     

An unusual lanostane-type triterpenoid,spiroinonotsuoxodiol, and other triterpenoids from Inonotus obliquus

An unusual lanostane-type triterpenoid, spiroinonotsuoxodiol (1), and two lanostane-type triterpenoids, inonotsudiol A (2) and inonotsuoxodiol A (3), were isolated from the sclerotia of Inonotus obliquus. Their structures were determined to be (3S,7S,9R)-3,7-dihydroxy-7(8 → 9)abeo-lanost-24-en-8-one (1), lanosta-8,24-dien-3β,11β-diol (2), and (22R)-3β,22-dihydroxylanosta-8,24-dien-11-one (3) on the basis of NMR spectroscopy, including 1D and 2D (¹H–¹H COSY, NOESY, HMQC, HMBC) NMR, and FABMS. Compounds 1–3 showed moderate activity against cultured P388, L1210, HL-60 and KB cells.     

Isoflavones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Three new isoflavones, 4′,8-dihydroxy-6,7-dimethoxyisoflavone (1), 4′,6-dihydroxy-8-methoxycarbonyl-7-methoxyisoflavone (2), 4′,7-dimethoxy-8-hydroxymethyl-6-hydroxyisoflavone (3), together with three known flavones (4–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1–3 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–3 (at the concentration of 20 μM) exhibited anti-TMV activities with inhibition rates of 25.2, 22.6, and 27.4%, respectively.