| 1. |
- Kalenga, T. M., et al.
(författare)
-
Modified ent-Abietane Diterpenoids from the Leaves of Suregada zanzibariensis
- 2022
-
Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 85:9, s. 2135-2141
-
Tidskriftsartikel (refereegranskat)abstract
- 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 fi-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 mu g/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC50 52 mu g/ mL. The isolated compounds 1-3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at >= 100 mu M.
|
|
| 2. |
- Maeda, Gasper, et al.
(författare)
-
A Meroisoprenoid, Heptenolides, and C-Benzylated Flavonoids from Sphaerocoryne gracilis ssp. gracilis
- 2020
-
Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 83:2, s. 316-322
-
Tidskriftsartikel (refereegranskat)abstract
- A new meroisoprenoid (1), two heptenolides (2 and 3), two C-benzylated flavonoids (4 and 5), and 11 known compounds (6-16) were isolated from leaf, stem bark, and root bark extracts of Sphaerocoryne gracilis ssp. gracilis by chromatographic separation. The structures of the new metabolites 1-5 were established by NMR, IR, and UV spectroscopic and mass spectrometric data analysis. (Z)-Sphaerodiol (7), (Z)-acetylmelodorinol (8), 7-hydroxy-6-hydromelodienone (10), and dichamanetin (15) inhibited the proliferation of Plasmodium falciparum (3D7, Dd2) with IC50 values of 1.4-10.5 mu M, although these compounds also showed cytotoxicity against human embryonic kidney HEK-293 cells. None of the compounds exhibited significant disruption in protein translation when assayed in vitro.
|
|
| 3. |
- Nyandoro, Stephen S., 1975, et al.
(författare)
-
A New Benzopyranyl Cadenane Sesquiterpene and Other Antiplasmodial and Cytotoxic Metabolites from Cleistochlamys kirkii
- 2019
-
Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 24:15
-
Tidskriftsartikel (refereegranskat)abstract
- Phytochemical investigations of ethanol root bark and stem bark extracts of Cleistochlamys kirkii (Benth.) Oliv. (Annonaceae) yielded a new benzopyranyl cadinane-type sesquiterpene (cleistonol, 1) alongside 12 known compounds (2-13). The structures of the isolated compounds were established from NMR spectroscopic and mass spectrometric analyses. Structures of compounds 5 and 10 were further confirmed by single crystal X-ray crystallographic analyses, which also established their absolute stereochemical configuration. The ethanolic crude extract of C. kirkii root bark gave 72% inhibition against the chloroquine-sensitive 3D7-strain malaria parasite Plasmodium falciparum at 0.01 mu g/mL. The isolated metabolites dichamanetin, (E)-acetylmelodorinol, and cleistenolide showed IC50 = 9.3, 7.6 and 15.2 mu M, respectively, against P. falciparum 3D7. Both the crude extract and the isolated compounds exhibited cytotoxicity against the triple-negative, aggressive breast cancer cell line, MDA-MB-231, with IC50 = 42.0 mu g/mL (crude extract) and 9.6-30.7 mu M (isolated compounds). Our findings demonstrate the potential applicability of C. kirkii as a source of antimalarial and anticancer agents.
|
|
| 4. |
- Begum, Sartaz, et al.
(författare)
-
Antiplasmodial, Antimicrobial and Cytotoxic Activities of Extracts from Selected Medicinal Plants Growing in Tanzania
- 2020
-
Ingår i: Journal of Biologically Active Products from Nature. - : Taylor & Francis Group. - 2231-1866 .- 2231-1874. ; 10:2, s. 165-176
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the evaluation of antiplasmodial, antimicrobial and cytotoxic activities of extracts from eleven plant species traditionally used by some Tanzanian coastal communities for treatment of malaria, microbial infections and related ailments. Crude extracts from selected plant species namely Acacia zanzibarica, Danais xanthorrhoea, Diospyros loureiriana ssp. rufescens, Erythrina sacleuxii, Newtonia paucijuga, Pentas lanceolata, Scorodophloeus fischeri, Stuhlmannia moavi, Tarenna pavettoides, Tessmannia burttii and Toussaintia orientalis growing in Tanzania were investigated using an imaging-based assay (antiplasmodial), well diffusion and microplate dilution methods (antimicrobial) and human embryonic kidney cells (HEK 293) and brine shrimp larvae assays (toxicity). The extracts exhibited activities of varying potencies and cytotoxicity with IC 50 values ranging from 0.45±0.09 to 75.70±24.19 μg/mL against Plasmodium falciparum (3D7 strain), MIC ranging from 0.25 to 2.0 mg/mL (against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Cryptococcus neoformans), LC 50 ranging from 0.75 to 1000 μg/mL against brine shrimp larvae (Artemia salina) and IC 50 ranging from 4.02±1.05 to more than 289 μg/mL against HEK 293 cells. The observed bioactivities of some of the investigated plant extracts validate their ethnomedicinal use and are indicative of the presence of bioactive ingredients for further phytochemical investigations.
|
|
| 5. |
- Kalenga, Thobias M, et al.
(författare)
-
Antibacterial and cytotoxic biflavonoids from the root bark of Ochna kirkii
- 2021
-
Ingår i: Fitoterapia. - : Elsevier BV. - 1873-6971 .- 0367-326X. ; 151
-
Tidskriftsartikel (refereegranskat)abstract
- The new isoflavonoid kirkinone A (1) and biflavonoid kirkinone B (2) along with six known compounds (3-8) were isolated from the methanolic extract of the root bark of Ochna kirkii. The compounds were identified by NMR spectroscopic and mass spectrometric analyses. Out of the eight isolated natural products, calodenin B (4) and lophirone A (6) showed significant antibacterial activity against the Gram-positive bacterium Bacillus subtilis with MIC values of 2.2 and 28μM, and cytotoxicity against the MCF-7 human breast cancer cell line with EC50 values of 219.3 and 19.2μM, respectively. The methanolic crude extract of the root bark exhibited cytotoxicity at EC50 8.4μg/mL. The isolated secondary metabolites and the crude extract were generally inactive against the Gram-negative Escherichia coli (MIC ≥400μg/mL). Isolation of biflavonoids and related secondary metabolites from O. kirkii demonstrates their chemotaxonomic significance to the genus Ochna and to other members of the family Ochnaceae.
|
|
| 6. |
- Kalenga, Thobias M, et al.
(författare)
-
Biflavanones, Chalconoids, and Flavonoid Analogues from the Stem Bark of Ochna holstii.
- 2021
-
Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 1520-6025 .- 0163-3864. ; 84:2, s. 364-372
-
Tidskriftsartikel (refereegranskat)abstract
- Two new biflavanones (1 and 2), three new bichalconoids (3-5), and 11 known flavonoid analogues (6-16) were isolated from the stem bark extract (CH3OH-CH2Cl2, 7:3, v/v) of Ochna holstii. The structures of the isolated metabolites were elucidated by NMR spectroscopic and mass spectrometric analyses. The crude extract and the isolated metabolites were evaluated for antibacterial activity against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) as well as for cytotoxicity against the MCF-7 human breast cancer cell line. The crude extract and holstiinone A (1) exhibited moderate antibacterial activity against B. subtilis with MIC values of 9.1 μg/mL and 14 μM, respectively. The crude extract and lophirone F (14) showed cytotoxicity against MCF-7 with EC50 values of 11 μg/mL and 24 μM, respectively. The other isolated metabolites showed no significant antibacterial activities (MIC > 250 μM) and cytotoxicities (EC50 ≥ 350 μM).
|
|
| 7. |
- Maeda, Gasper, et al.
(författare)
-
Oxygenated Cyclohexene Derivatives from the Stem and Root Barks of Uvaria pandensis
- 2021
-
Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 84:12, s. 3080-3089
-
Tidskriftsartikel (refereegranskat)abstract
- Five new cyclohexene derivatives, dipandensin A and B (1 and 2) and pandensenols A-C (3-5), and 16 known secondary metabolites (6-21) were isolated from the methanol-soluble extracts of the stem and root barks of Uvaria pandensis. The structures were characterized by NMR spectroscopic and mass spectrometric analyses, and that of 6-methoxyzeylenol (6) was further confirmed by single-crystal X-ray crystallography, which also established its absolute configuration. The isolated metabolites were evaluated for antibacterial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus epidermidis and the Gram-negative bacteria Enterococcus raffinosus, Escherichia coli, Paraburkholderia caledonica, Pectobacterium carotovorum, and Pseudomonas putida, as well as for cytotoxicity against the MCF-7 human breast cancer cell line. A mixture of uvaretin (20) and isouvaretin (21) exhibited significant antibacterial activity against B. subtilis (EC50 8.7 μM) and S. epidermidis (IC50 7.9 μM). (8'α,9'β-Dihydroxy)-3-farnesylindole (12) showed strong inhibitory activity (EC50 9.8 μM) against B. subtilis, comparable to the clinical reference ampicillin (EC50 17.9 μM). None of the compounds showed relevant cytotoxicity against the MCF-7 human breast cancer cell line.
|
|
| 8. |
- Maeda, Gasper, et al.
(författare)
-
Polyoxygenated cyclohexene derivatives and flavonoids from the leaves of Uvaria pandensis.
- 2022
-
Ingår i: Fitoterapia. - : Elsevier BV. - 1873-6971 .- 0367-326X. ; 158
-
Tidskriftsartikel (refereegranskat)abstract
- Three new oxygenated cyclohexene derivatives, pandensenol D - F (1-3), two new flavanoids, pandensone A and B (4-5), and seven known compounds (6-12) were isolated from the methanol extract of the leaves of Uvaria pandensis Verdc. (Annonaceae). The structures were characterized by NMR spectroscopic and mass spectrometric analyses. The isolated metabolites were evaluated for their antibacterial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus epidermidis and the Gram-negative bacteria Enterococcus raffinosus, Escherichia coli, Paraburkholderia caledonica, Pectobacterium carotovorum and Pseudomonas putida, and for cytotoxicity against the MCF-7 human breast cancer cell line. Out of the tested compounds, pandensenol D (1) and (6',7'-dihydro-8'α,9'β-dihydroxy)-3-farnesylindole (12) showed weak whereas (8'α,9'β-dihydroxy)-3-farnesylindole (11) strong activity against B. subtilis. Four of the isolated compounds (1, 4, 11 and 12) showed moderate cytotoxicity against MCF-7 breast cancer cells (EC50>100μM).
|
|
| 9. |
- Nyandoro, Stephen S., 1975, et al.
(författare)
-
N-Cinnamoyltetraketide Derivatives from the Leaves of Toussaintia orientalis
- 2015
-
Ingår i: Journal of natural products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 78:8, s. 2045-2050
-
Tidskriftsartikel (refereegranskat)abstract
- Seven N-cinnamoyltetraketides (1–7), including the new Z-toussaintine E (2), toussaintine F (6), and toussaintine G (7), were isolated from the methanol extract of the leaves of Toussaintia orientalis using column chromatography and HPLC. The configurations of E-toussaintine E (1) and toussaintines A (3) and D (5) are revised based on single-crystal X-ray diffraction data from racemic crystals. Both the crude methanol extract and the isolated constituents exhibit antimycobacterial activities (MIC 83.3–107.7 μM) against the H37Rv strain of Mycobacterium tuberculosis. Compounds 1, 3, 4, and 5 are cytotoxic (ED50 15.3–105.7 μM) against the MDA-MB-231 triple negative aggressive breast cancer cell line.
|
|
| 10. |
- Aronsson, Per, et al.
(författare)
-
Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis.
- 2016
-
Ingår i: Diseases (Basel, Switzerland). - : MDPI AG. - 2079-9721. ; 4:1
-
Tidskriftsartikel (refereegranskat)abstract
- As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8'-oxo-biplumbagin (1) was isolated along with the known tetralones trans-isoshinanolone (2) and cis-isoshinanolone (3), and the naphthoquinones plumbagin (4) and 3,3'-biplumbagin (5). Compounds 2, 4, and 5 showed cytotoxicity (IC50 520-82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC50 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC50 59.6 μg/mL). The radical scavenging activity of the isolated constituents (1-5) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.
|
|
