Article

Antiplasmodial and antimicrobial activities of e nt -abietane diterpenoids from the roots of Suregada zanzibariensis

Taylor & Francis
Natural Product Research
Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

The root extract of Suregada zanzibariensis Baill. afforded six previously described ent-abietane diterpenoids, namely 7-oxo-ent-abieta-5(6),8(14),13(15)-trien-16,12-olide (1), mangiolide (2), 8,14β:11,12α-diepoxy-13(15)-abietane-16,12-olide (3), 7β,11β,12β-trihydroxy-ent–abieta-8(14),13(15)-diene-16,12-olide (4), 8α,14-dihydro-7-oxo-jolkinolide E (5), jolkinolide A (6), together with 3β-sitosterol (7), scopoletin (8) and vanillin (9). Their structures were deduced through 1D and 2D NMR spectroscopic techniques, and HRESIMS, as well as by comparison of the NMR data with those reported in the literature. The crude extract and compounds 1–9 were evaluated for their antiplasmodial, antifungal and antibacterial activities. Mangiolide (2) showed strong in vitro antiplasmodial activity against chloroquine sensitive (D6) and resistant (W2) strains of Plasmodium falciparum with IC50 values of 0.79 and 0.87 µg/mL, respectively, while 3 (IC50 1.24 and 1.17 µg/mL) was less active than 2. Compound 2 also displayed antimicrobial activity against Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) with IC50 values of 1.20, 3.90 and 7.20 µg/mL, respectively.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

Article
Full-text available
Relevant biological activities of both naturally occurring and semi-synthetic bi- and tricyclic diterpenoids, in the context of infection, are highlighted in this review alongside significant structure–activity relationships.
Article
Full-text available
The leaf extract of Suregada zanzibariensis gave two new modified ent-abietane diterpenoids, zanzibariolides A (1) and B (2), and two known triterpenoids, simiarenol (3) and β-amyrin (4). The structures of the isolated compounds were elucidated based on NMR and MS data analysis. Single-crystal X-ray diffraction was used to establish the absolute configurations of compounds 1 and 2. The crude leaf extract inhibited the infectivity of herpes simplex virus 2 (HSV-2, IC50 11.5 μg/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC50 52 μg/mL. The isolated compounds 1–3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at ≥100 μM.
Article
Full-text available
Besides a known Coumarin derivative, Scopoletin, the iridoids gardenoside was isolated for the first time from an Ipomoea species, namely Ipomoea reniformis (Convolvulaceae). Its structure was established on the basis of its spectroscopic data.
Article
Full-text available
A new (1) and two known (2-3) diterpene lactones belonging to a rare class of diepoxy abietaneolide, were isolated from the cytotoxic extract of Suregada multiflora. New compound 1 is characterized as 3-hydroxy-8,14:11,12-diepoxy-13(15)-abietane-16,12-olide, on the basis of extensive spectral studies. This is the first report describing 2D NMR studies of this unique class of diepoxy abietaneolide.
Article
Full-text available
The family Polygonaceae is known for its traditional use in the management of various neurological disorders including Alzheimer’s disease (AD). In search of new anti-AD drugs, β-sitosterol isolated from Polygonum hydropiper was subjected to in vitro, in vivo, behavioral and molecular docking studies to confirm its possibility as a potential anti-Alzheimer’s agent. The in vitro AChE, BChE inhibitory potentials of β-sitosterol were investigated following Ellman’s assay. The antioxidant activity was tested using DPPH, ABTS and H2O2 assays. Behavioral studies were performed on a sub-strain of transgenic mice using shallow water maze (SWM), Y-maze and balance beam tests. β-sitosterol was tested for in vivo inhibitory potentials against cholinesterase’s and free radicals in the frontal cortex (FC) and hippocampus (HC). The molecular docking study was performed to predict the binding mode of β-sitosterol in the active sites of AChE and BChE as inhibitor. Considerable in vitro and in vivo cholinesterase inhibitory effects were observed in the β-sitosterol treated groups. β-sitosterol exhibited an IC50 value of 55 and 50 μg/ml against AChE and BChE respectively. Whereas, the activity of these enzymes were significantly low in FC and HC homogenates of transgenic animals. Molecular docking studies also support the binding of β-sitosterol with the target enzyme and further support the in vitro and in vivo results. In the antioxidant assays, the IC50 values were observed as 140, 120, and 280 μg/ml in the DPPH, ABTS and H2O2 assays respectively. The free radicals load in the brain tissues was significantly declined in the β-sitosterol treated animals as compared to the transgenic-saline treated groups. In the memory assessment and coordination tasks including SWM, Y-maze and balance beam tests, β-sitosterol treated transgenic animals showed gradual improvement in working memory, spontaneous alternation behavior and motor coordination. These results conclude that β-sitosterol is a potential compound for the management of memory deficit disorders like AD.
Article
Full-text available
In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents.
Article
Full-text available
The diterpene ent-12-hydroxy-12[R]-abieta-8(14),13(15)-dien-16,12-olide was isolated from the tubers of Euphorbia sessiliflora Roxb., together with four known ent-abietadienolides, four known cycloartane triterpenes and ellagic acid-beta-D-glucopyranoside. Two of these metabolates displayed moderate antibacterial activities.
Article
In the framework of phytochemical studies on Greek endemic Inula species, Inula candida subsp. candida and Inula candida subsp. decalvans have been analyzed. The aerial parts were extracted with increasing polarity solvents and sixteen secondary metabolites from I. candida subsp. candida and eight from I. candida subsp. decalvans were isolated. From I. candida subsp. decalvans a sesquiterpene lactone (3aS,8aR)-6-methyl-3-methylidene-7-(3-oxobutyl)-3a,4,5,8a-tetrahydro-2H-cyclohepta[b]furan-2,8(3H)dione (1), was determined as a new natural product, additionally to five known triterpenes: β-amyrin (2), dammaradienol (3), dammaradienyl acetate (4), epifriedelanol (5), stigmasterol (6) and two known lactones: inusoniolide (7) and tomentosine (8). The chemical investigation of I. candida subsp. candida resulted in the isolation of ten known triterpenes: β-amyrin (2), stigmasterol (6), β-sitosterol (9), α-amyrone (10), α-amyrin (11), friedelin (12), lupenone (13), 3β-acetoxy-24-hydroxydammara-20,25-diene (14), 3β-acetoxy-25-hydroxydammara-20,23-diene (15), 3β-acetoxy-24-oxo-dammara-20,25-diene (16), as well as five lactones: inusoniolide (7), 4-O-dihydroinusoniolide (17), 9β-(3-hydroxyisovaleryloxy) parthenolide (18), 9β-hydroxyparthenolide (19), 9β-(3-hydroxy-2-methylbutyryloxy) parthenolide (20), together with the phenolic aldehyde: vanillin (21). The crude extracts and the isolated compounds were also evaluated for their antimicrobial activity against a panel of selected human pathogenic bacteria and fungi showing that the new lactone (1) and 9β-hydroxyparthenolide (19) showed the strongest activity against the tested bacteria (MIC 3•10⁻²–5•10⁻¹ μg/ml), while (1) and tomentosin (8) appeared as the most active against the assayed fungi (MIC 2,5•10⁻²–12•10⁻² μg/ml). The antiproliferative effect for the new lactone was also evaluated in vitro against the human non-small-cell bronchopulmonary carcinoma cell line NSCLC-N6 and the epidermoid lung cancer cell line A549.
Article
The stem bark extract of Suregada zanzibariensis afforded a previously undescribed ent-abietane diterpenoid trivially named mangiolide (1) and a known jolkinolide B (2) via anticancer bioassay-guided fractionation. The CH2Cl2:MeOH extract of S. zanzibariensis was initially analysed for its anticancer properties against three cancer cell lines, renal (TK10), melanoma (UACC62), and breast (MCF7) and was found to be potent at low μg/mL ranges. Compound 1, 6α-acetoxy-14-keto-ent-abieta-7(8),13(15)-diene-16,12-olide (mangiolide) inhibited the growth of renal (TK10) with a GI50 of 0.02 μg/mL; a GI50 of 0.03 μg/mL for melanoma (UACC62) and a GI50 of 0.05 μg/mL for breast (MCF7) cancer cell lines. Compound 2, 8,13-diepoxy-13,15-ent-abietene-16,12-olide (jolkinolide B) inhibited the growth (GI50) of the cell lines at 3.31 μg/mL for renal (TK10), 0.94 μg/mL for melanoma (UACC62) and 2.99 μg/mL for the breast (MCF7). The structures were established on the basis of their spectroscopic analysis and the absolute stereostructures assigned using electronic circular dichroism (ECD).
Article
Six tigliane-type diterpenoids (1-6) were isolated from the roots of Euphorbia fischeriana. Their structures were elucidated by various spectral analyses. Among them, compounds 1 and 3 were new, and compounds 2, 4, and 5 were naturally obtained for the first time. All compounds were tested against two human cancer cell lines, MDA-MB-231 and HepG2, and one human immortalized cell line, and only compound 6 showed cytotoxicity for MDA-MB-231 cells with an IC(50) value of 6.694 μM.
Article
Indigenous rural communities in the tropics manage parasitic diseases, like malaria and leishmaniasis, using herbal drugs. The efficacy, dosage, safety and active principles of most of the herbal preparations are not known. Extracts from 6 selected plant species, used as medicinal plants by indigenous local communities in Kenya, were screened for in vitro anti-plasmodial and anti-leishmanial activity, against 2 laboratory-adapted Plasmodium falciparum isolates (D6, CQ-sensitive and W2, CQ-resistant) and Leishmania major (IDU/KE/83=NLB-144 strain), respectively. The methanol extract of Suregada zanzibariensis leaves exhibited good anti-plasmodial activity (IC(50) 4.66+/-0.22 and 1.82+/-0.07 microg/ml for D6 and W2, respectively). Similarly, the methanol extracts of Albizia coriaria (IC(50) 37.83+/-2.11 microg/ml for D6) and Aspergillus racemosus (32.63+/-2.68 and 33.95+/-2.05 microg/ml for D6 and W2, respectively) had moderate anti-plasmodial activity. Acacia tortilis (IC(50) 85.73+/-3.36 microg/ml for W2) and Albizia coriaria (IC(50) 71.17+/-3.58 microg/ml for W2) methanol extracts and Aloe nyeriensis var kedongensis (IC(50) 87.70+/-2.98 and 67.84+/-2.12 microg/ml for D6 and W2, respectively) water extract exhibited mild anti-plasmodial activity. The rest of the extracts did not exhibit any anti-plasmodial activity. Although the leishmanicidal activity of extracts were lower than for pentosam (80%), reasonable activity was observed for Aloe nyeriensis methanol (68.4+/-6.3%), Albizia coriara water (66.7+/-5.0%), Maytenus putterlickoides methanol (60.0+/-6.23%), Asparagus racemosus methanol and water (58.3+/-8.22 and 56.8+/-6.58%, respectively), Aloe nyeriensis water (53.3+/-5.1%) and Acacia tortilis water (52.9+/-6.55%) extracts at 1000 microg/ml. Leishmania major infected macrophages treated with methanol extracts of Suregada zanzibariensis and Aloe nyeriensis var kedongensis and pentostam had infection rates of 28+/-2.11, 30+/-1.22 and 40+/-3.69%, respectively at 1000 microg/ml, indicating better anti-leishmanial activity for the extracts. The methanol extract of Albizia coriara (44.0+/-3.69%) and aqueous extracts of Asparagus racemosus (42+/-3.84%) and Acacia tortilis (44+/-5.59%) had similar activity to pentosam. Multiplication indices for Leishmania major amastigotes treated with methanol extracts of Albizia coriaria, Suregada zanzibariensis and Aloe nyeriensis var kedongensis, aqueous extract of Acacia tortilis and pentosam were 28.5+/-1.43, 29.4+/-2.15, 31.1+/-2.22, 35.9+/-3.49 and 44.0+/-3.27%, respectively, at 1000 microg/ml, confirming better anti-leishmanial activity for the extracts. Aqueous extracts of Aloe nyeriensis (46.7+/-3.28%) and Albizia coriaria (47.5+/-3.21%) had similar activity level to pentosam. The plant extracts have better inhibitory activity while pentosam has better leishmanicidal activity. All extracts exhibited very low cytotoxicity (CC(50) > 500 microg/ml) against human embryonic lung fibroblast (HELF) cells. The investigations demonstrated the efficacy and safety of some extracts of plants that are used by rural indigenous communities for the treatment of parasitic diseases.
Article
Twelve ENT-abietane and ENT-kaurane type diterpenoids, 1- 12, including five new compounds 1- 5, were isolated from the roots of Suregada glomerulata. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR and other spectroscopic studies, and the structures of 1 and 2 were confirmed by X-ray crystallography. Cytotoxic activities against five human tumor cell lines were evaluated.
Article
In addition to widespread flavonoids, a collection of Euphorbia characias from Sardinia afforded 13 oxygenated diterpenoids of the atisane, abietane, pimarane, and kaurane type. Four of these compounds (1, 3a, 7a,b) are new. The accumulation of substantial amounts of biologically active diterpenoids of limited availability, like ent-atisanes endowed with anti-HIV activity and ent-abietanolides active on the central nervous system, makes E. characias an interesting source of lead compounds for biomedical research.
Article
From the dried roots of Euphorbia fischeriana, seven new diterpenoids, 3alpha,17-dihydroxy-ent-pimara-8(14),15-diene (1), 7beta,11beta,12beta-trihydroxy-ent-abieta-8(14),13(15)-dien-16,12-olide (2), 17-acetoxyjolkinolide B (3), 13beta-hydroxy-ent-abiet-8(14)-en-7-one (4), 12-deoxyphorbaldehyde-13-acetate (5) 12-deoxyphorbaldehyde-13-hexadecacetate (6), and 12-deoxyphorbol-13-(9Z)-octadecanoate-20-acetate (7), and two known compounds, 12-deoxyphorbol-13-decanoate (8) and prostratin (9), were isolated. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. The structure of compound 1 was confirmed by single-crystal X-ray crystallography. Compounds 3 and 8 exhibited potent cytotoxic activity to Ramos B cells with IC50 values of 0.023 and 0.0051 microg/mL, respectively.
Article
Six new diterpenoids, 7beta,8alpha-dihydroxy-12-oxo- ent-abietan-16,14-olide ( 1), 3,4,18beta-cyclopropa-7beta,17-dihydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 2), 3alpha,7beta-dihydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 3), 3-oxo-8beta,14beta-epoxy- ent-abieta-11,13(15)-dien-16,12-olide ( 4), 17-hydroxy- ent-pimara-8(14),15-dien-3-one ( 5), and 3alpha,6beta-dihydroxy- ent-kaur-16-ene ( 6), and two known compounds, 7beta-hydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 7) and jolkinolide B, were isolated from roots of Suregada glomerulata. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR and other spectroscopic studies. The structure of compound 1 was confirmed by X-ray crystallography. Cytotoxic activities were evaluated against five human tumor cell lines.
Isolation and structure elucidation of scopoletin from Ipomoea reniformis (Convolvulaceae)
  • B Mehul
  • D Kishor
  • Mehul B