Graptophyllum pictum is a tropical plant noticeable for its variegated leaves and exploited for various medicinal purposes. In this study, seven compounds, including three furanolabdane diterpenoids, i.e., Hypopurin E, Hypopurin A and Hypopurin B, as well as with Lupeol, β-sitosterol 3-O-β-d-glucopyranoside, stigmasterol 3-O-β-d-glucopyranoside and a mixture of β-sitosterol and stigmasterol, were isolated from G. pictum, and their structures were deduced from ESI-TOF-MS, HR-ESI-TOF-MS, 1D and 2D NMR experiments. The compounds were evaluated for their anticholinesterase activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BchE), as well as their antidiabetic potential through inhibition of α-glucosidase and α-amylase. For AChE inhibition, no sample had IC50 within tested concentrations, though the most potent was Hypopurin A, which had a percentage inhibition of 40.18 ± 0.75%, compared to 85.91 ± 0.58% for galantamine, at 100 µg/mL. BChE was more susceptible to the leaves extract (IC₅₀ = 58.21 ± 0.65 µg/mL), stem extract (IC₅₀ = 67.05 ± 0.82 µg/mL), Hypopurin A (IC₅₀ = 58.00 ± 0.90 µg/mL), Hypopurin B (IC₅₀ = 67.05 ± 0.92 µg/mL) and Hypopurin E (IC₅₀ = 86.90 ± 0.76 µg/mL). In the antidiabetic assay, the furanolabdane diterpenoids, lupeol and the extracts had moderate to good activities. Against α-glucosidase, lupeol, Hypopurin E, Hypopurin A and Hypopurin B had appreciable activities but the leaves (IC₅₀ = 48.90 ± 0.17 µg/mL) and stem (IC₅₀ = 45.61 ± 0.56 µg/mL) extracts were more active than the pure compounds. In the α-amylase assay, stem extract (IC₅₀ = 64.47 ± 0.78 µg/mL), Hypopurin A (IC₅₀ = 60.68 ± 0.55 µg/mL) and Hypopurin B (IC₅₀ = 69.51 ± 1.30 µg/mL) had moderate activities compared to the standard acarbose (IC₅₀ = 32.25 ± 0.36 µg/mL). Molecular docking was performed to determine the binding modes and free binding energies of Hypopurin E, Hypopurin A and Hypopurin B in relation to the enzymes and decipher the structure–activity relationship. The results indicated that G. pictum and its compounds could, in general, be used in the development of therapies for Alzheimer’s disease and diabetes.

The ethyl acetate fraction, the stem bark and the residual methanolic extracts from the leaves of Cola heterophylla (Sterculiaceae) led to the isolation of two new compounds: Heterophynone (1) and methyl ester of Colic acid (6), along with four known triterpenes: betulinic acid (2), oleanolic acid (3), ursolic acid (4) and chletric acid (5). Structures of compounds were established by different spectroscopic methods that included 1D and 2D NMR experiment. The antimicrobial activity of isolated compounds was evaluated against two yeasts, Candida Albicans NR 29456 and Candida Krusei 1415; and five Gram-positive bacterial, Salmonella enteric Serovar Muenchem, Salmonella enteric Serovar Thyphimurium, Staphylococcus aureus NR 46003, Staphylococcus aureus NR46374 and Pseudomonas aeruginosa HM 601). Among tested compounds, Heterophynone was found to be the most active with significant antimicrobial activity against Salmonella enteric Serovar Thyphimurium (MIC = 7.82 μg/mL and MBC = 62.5 μg/mL) and good activity against Candida Albicans NR 29456 (MIC = 62.5 μg/mL).

A phytochemical investigation of the aqueous-MeOH extract of Allanblackia floribunda (Guttifereae) pods was conducted to isolate five compounds (1-5). The structures were established based on the interpretation of their HRMS-ES, HRMS-LD⁺ and NMR data. The absolute configurations of 1-3 were determined using DFT-based ECD (electronic circular dichroism) data. To explore the therapeutic potential of this plant for microbial diseases, the inhibitory and cytotoxic activities of the extract and the isolated compounds were evaluated against a panel of human pathogens. An in silico molecular docking study was performed on isolated compounds using the DNA gyrase-bound crystal structures 7C7N and 5CDP, enzymes implicated against E. coli and S. aureus resistance. Three unreported compounds i.e. (+)-nlongboflavone A (1), (+)-nlongboflavone B (2) and florinone (3), together with two known compounds: morelloflavone (4) and morelloflavone-7"-O-β-glucopyranoside (5) were identified. Potent activity against Staphylococcus aureus NR 46003 was observed for the crude extract, ethyl acetate and residual fractions, with MICs of 12.5, 10.60 and 16.34 μg/mL as well as (+)-nlongboflavone A (1), also exhibited activity at 17.5 μM. . Compound (1) exhibited a favorable binding energy (ΔG = -11.7 kcal/mol) against S. aureus DNA gyrase, suggesting that its antibacterial activity may be mediated through DNA gyrase inhibition. This research supports the traditional use of Allanblackia floribunda to treat microbial ailments.