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Two previously undescribed dihydrochalcones, 4,2′-dihydroxy- [2″, 2″-dimethylpyrano (3″, 4″: 4′, 5′]) dihydrochalcone (1) and 4, 2′, 4′, 2″-tetrahydroxy-5′-(3″-methylbut-3″-enyl) dihydrochalcone (2), along with six known compounds (3 - 8) were isolated from chloroform-methanol (1:1) extract of Baphia Massaiensis twigs. Their chemical structures were determined using NMR analysis, mass spectrometry, electronic circular dichroism (ECD), density functional theory (DFT) calculations, and a thorough comparison with reported data from the literature. All the isolated compounds (1−8) were assessed for their antioxidant activities, α-amylase and α-glucosidase inhibition effects. Dihydrochalcone 1 showed significant antioxidant activity with IC 50 value of 118.8 ± 2.95 µM, and a more potent antioxidant activity was exhibited by compounds 3 and 6 with IC 50 values of 84.3 ± 0.07 µM and 62.1 ± 1.59 µM, respectively, compared to the positive control, gallic acid with IC 50 value of 92.9 µM. Dihydrochalcone 2 showed moderate inhibition against α-amylase and α-glucosidase with IC 50 values of 44.0 ± 4.83 µM and 51.7 ± 9.72 µM compared to the standard acarbose with IC 50 values of 22.9 ± 0.92 µM and 31.5 ± 0.63 µM, respectively. Molecular docking studies of the new dihydrochalcones 1 and 2 , revealed the active binding sites which support the observed α-amylase and α-glucosidase inhibitory effects. [Display omitted] • Two undescribed dihydrochalcones were isolated from Baphia massaiensis. • The structures were confirmed by extensive spectroscopic analyses. • Compounds 1 and 2 showed significant inhibitory activities against α-amylase and α-glucosidase. • Compounds 1 , 3 and 6 also showed potent antioxidant activities. [ABSTRACT FROM AUTHOR]

Myricasalicifolia A Rich (Myricaceae) is a tree growing in Central and East Africa. Traditionally, the plant is used to treat malaria, respiratory disorders, inflammations, and infections. A new compound, 3β-O-trans-caffeoylisomyricadiol (7), was isolated from MeOH : CHCl3 (2 : 1) extract of the stem bark of Myrica salicifolia along with seven known compounds, namely, myricanone (1), myricanol (2), myricanol-11-O-β-D-xylopyranoside (3), taraxerone (4), taraxerol (5), myricadiol (6), and methyl-β-D-glucopyranoside (8). This is the first report of the isolation of taraxerene-type triterpenes from this plant. The structures were determined by a comprehensive analysis of 1D/2D NMR spectroscopy, HR-MS, and by comparison with literature data. The compounds showed a wide range of DPPH scavenging activities from very weak (IC50 value = 282.61 μM) to very strong (IC50 = 13.48 μM). Antibacterial activities of the compounds were evaluated using the disk diffusion agar method, where some of the compounds showed modest antibacterial activities against S. pyogenes and S. aureus at 250 μg/mL. Compounds 2, 3, and 7 were assessed for their in silico molecular docking analysis. The lowest binding affinity for compound 7 was found to be −7.26 to −10.35 kcal/mol against PqsA protein of P. aeruginosa, pyruvate kinase (PK) enzyme of S. aureus, LuxS protein of S. pyogenes, and DNA gyrase B of E. coli, which showed better binding affinity compared to the standard drug ampicillin (−7.36 to −8.03 kcal/mol) and ciprofloxacin (−6.19 to −6.83 kcal/mol). In silico ADMET predictions revealed that compounds 3 and 8 met all the requirements for pharmacokinetic properties. [ABSTRACT FROM AUTHOR]

A new polypyridyl ligand 4‐(4‐nitrophenoxy)‐N,N‐bis (pyridin‐2‐ylmethyl)aniline (L1) and its three ruthenium (II/III) complexes, [Ru (Cl)3L1] (C1), [Ru(L1)2]Cl (C2), and [RuCl (dpa)L1] (C3) where dpa = 2,2‐dipyridylamine, have been successfully synthesized and characterized using Fourier‐transform infrared spectroscopy (FTIR), elemental analysis, proton nuclear magnetic resonance (1H NMR), high‐resolution electrospray ionization mass spectrometry (HR‐ESI‐MS), thermal analysis (thermogravimetric analysis [TGA] and differential scanning calorimetry [DSC]), UV/Vis absorption, and magnetic susceptibility. The structures of the ligand and the complexes were optimized, and the structural characteristics were determined by density functional theory (DFT) using the B3LYP‐GD3/6‐311G++(d,p) method. Optimized FTIR vibrational frequencies and 1H NMR chemical shifts agreed well with the corresponding experimental FTIR and 1H NMR data. In vitro cytotoxicity of the ligand and the complexes were evaluated against the MCF‐7 breast cancer cell line. Ligand L1 was the most potent with an IC50 of 38.45 μM, followed by C2 with an IC50 of 45.23 μM. However, the ligand and the complexes showed low antiproliferative activity compared to cisplatin, which had an IC50 of 9.67 μM. To predict the reactivity trend of L1 and the complexes, frontier molecular orbital (FMO) analysis was performed. The FMO energy gap (Eg = ELUMO − EHOMO) for C2 was found to be 1.675 eV, which was the lowest among all the complexes or L1. In addition, molecular docking studies were carried out so as to predict the binding capacity of L1 and the complexes to estrogen receptor alpha (ER‐α). The results showed that C2 has the most negative binding energy score (−9.63 kcal/mol), which indicates more stable adducts with the key amino acid residues at the active sites of ER‐α. Furthermore, C2 displayed the lowest inhibition constant (Ki) of 0.09 μM compared to all the complexes or L1. These results are very promising and show that the novel complex C2 may help in the development of anticancer drugs. [ABSTRACT FROM AUTHOR]

Chemical investigation of the root wood of Erythrina livingstoniana led to the isolation of one previously undescribed isoflavan (3S,3″R)-7-hydroxy-2′-methoxy-[3″-hydroxy-2″,2″-dimethylpyrano (3′,4′)] isoflavan 1, together with eleven known compounds 2-12. The structure of compound 1 was elucidated on the basis of extensive spectroscopic and spectrometric analyses (1 D and 2 D-NMR and APCI-HRMS), with absolute configurations established by comparison of experimental and DFT calculated ECD data. The assignment of the absolute configurations of C-3 and C-3″ of compounds 2 and 3, respectively, were reported for the first time. Compounds 1 − 4 were evaluated for their antibacterial activities in vitro against E. coli ATCC 25922 and S. aureus ATCC 25923. Compound 1 exhibited moderate antibacterial activity with MIC value of 0.063 mg/mL against the clinically relevant risk-group 2 (RG-2) bacterium S. aureus. [ABSTRACT FROM AUTHOR]

The Combretum genus, with its few investigated members, has shown evidence-based justification for its extensive study in finding natural alternatives to various maladies. One of its species, Combretum platypetalum, has been traditionally used to treat diarrhea, pneumonia, dysmenorrhea, and infertility in women, with phytochemical investigations focusing on its leaves. The plant part(s) employed in the traditional practice are not explicitly mentioned in the literature, but several therapeutic properties have been confirmed. This study is a follow-up to previous metabolomic reports and a comprehensive biological investigation of the root extract, aimed at investigating the active compounds. The root was extracted by maceration, and compounds were isolated using various chromatographic techniques. Combrenorplatypta A, arjunolic acid, betulinic acid, and lupeol (2-4) were bioguidedly isolated from C. platypetalum root for the first time. The structures of the isolated compounds were established based on spectroscopic (1D NMR, 2D NMR, IR, UV, and ECD) and spectrometric (ESIMS) data as well as time-dependent density functional theory (TD-DFT) calculations. In vitro and computational antifungal activities of the compounds were investigated; after that, molecular docking analysis of structures (1-4) versus target (sterol 14α-demethylase) binding affinity for druggability was established. The MICs of in vitro bio-investigated compounds ranged from 2.30 µM to 15 µM, while computational antifungal investigations showed MICs from 4 nM to 49.86 nM. The compounds produced over six times the activity of fluconazole, a first-line antifungal drug. This study has identified the active sites and possible mechanisms of action of molecules against fungal pathogens. [ABSTRACT FROM AUTHOR]