Identification of antidiabetic compounds from the aqueous extract of Sclerocarya birrea leaves

SUPPLEMENTARY MATERIALS : TABLE S1: 1H NMR and 13C NMR data of Myricetin (1) in methanol-d4 compared to those reported [35] in DMSO-d6; TABLE S2: 1H NMR and 13C NMR data of Myricetin-3-O-β-D-glucuronide (2) in methanol-d4 compared to those reported [36] in methanol-d4; TABLE S3: 1H NMR and 13C NMR data of Quercetin-3-O-β-D-glucuronide (3) in methanol-d4 compared to those reported by [37] in methanol-d4; FIGURE S4: Relative Glucose uptake activity of Marula fractions in C2C12 myocytes over a range of 0.01-100µg/ml. Activity is expressed relative % to the baseline glucose uptake (control) set at 0% and the positive control insulin (Ins) set at 100%. Active fraction (fraction 3) exhibited comparable potency to Insulin. p value < * p < 0.05, ** p < 0.01. *** p < 0.001; FIGURE S5: ESI negative-mode BPI chromatogram of compound 1 (Myricetin) isolated from Fraction 4; FIGURE S6: ESI negative-mode BPI chromatogram of compound 2 (Myricetin3-O-β-D-glucuronide) isolated from Fraction 3; FIGURE S7: ESI negative-mode BPI chromatogram of compound 3 (Quercetin-3-O-β-D-glucuronide) isolated from Fraction 3; FIGURE S8: MS fragmentation pattern of peak 1 overlaid with MSMS fragmentation pattern of peak 1; FIGURE S9: MS fragmentation pattern of peak 2 overlaid with MSMS fragmentation pattern of peak 2; FIGURE S10: MS fragmentation pattern of peak 3 overlaid with MSMS fragmentation pattern of peak 3; FIGURE S11: MS fragmentation pattern of peak 4 overlaid with MSMS fragmentation pattern of peak 4; FIGURE S12: MS fragmentation pattern of peak 5 overlaid with MSMS fragmentation pattern of peak 5; FIGURE S13: MS fragmentation pattern of peak 6 overlaid with MSMS fragmentation pattern of peak 6.DATA AVAILABILITY STATEMENT : All the data supporting the findings of this study are available within the article and/or its Supplementary Materials.Diabetes, a prevalent metabolic condition with a wide range of complications, is fast becoming a global health crisis. Herbal medicine and enhanced extracts are some of the therapeutic options used in the management of diabetes mellitus. The plant-derived molecules and their suitable structure modification have given many leads or drugs to the world such as metformin used as an antidiabetic drug. The stem extract of Sclerocarya birrea has been reported as a potent antidiabetic (glucose uptake) agent. However, the bioactive compounds have not been reported from S. birrea for treatment of diabetes. In this study, the spray-dried aqueous leaf extracts of S. birrea were investigated as an antidiabetic agent using a 2-deoxy-glucose (2DG) technique showing good stimulatory effect on glucose uptake in differentiated C2C12 myocytes with % 2DG uptake ranging from 110–180% that was comparable to the positive control insulin. Three compounds were isolated and identified using bioassay-guided fractionation of the spray-dried aqueous extract of S. birrea leaves: myricetin (1), myricetin-3-O- -D-glucuronide (2) and quercetin-3-O- -D-glucuronide (3). Their chemical structures were determined using NMR and mass spectrometric analyses, as well as a comparison of experimentally obtained data to those reported in the literature. The isolated compounds (1–3) were studied for their stimulatory actions on glucose uptake in differentiated C2C12 myocytes. The three compounds (1, 2 and 3) showed stimulatory effects on the uptake of 2DG in C2C12 myocytes with % 2DG uptake ranging from 43.9–109.1% that was better compared to the positive control insulin. Additionally, this is the first report of the flavonoid glycosides (myricetin-3-O- -D-glucuronide) for antidiabetic activity and they are the main bioactive compound in the extract responsible for the antidiabetic activity. This result suggests that the S. birrea leaves have the potential to be developed for treatment of diabetes.The Department of Science and Innovation, South Africa, University of KwaZulu-Natal, South Africa and Biomedical Research and Innovation Platform, South African Medical Research Council.https://www.mdpi.com/journal/moleculesam2023Chemistr

In vitro antiplasmodial activity-directed investigation and UPLC–MS fingerprint of promising extracts and fractions from Terminalia ivorensis A. Chev. and Terminalia brownii Fresen.

Please read abstract in the article.The Grand Challenges Africa programme is supported by the African Academy of Sciences (AAS), Bill & Melinda Gates Foundation (BMGF), Medicines for Malaria Venture (MMV), and Drug Discovery and Development Centre of University of Cape Town (H3D).https://www.elsevier.com/locate/jethpharm2023-07-09hj2023Chemistr

Extractives from the Meliaceae and Ptaeroxylaceae.

Thesis (M.Sc.)-University of Natal, Durban, 2001.This work is an account of the extractives from one member of the Meliaceae and one member of the Ptaeroxylaceae. In all, thirteen compounds have been isolated, of which four have not been described previously. Neobeguea mahafalensis belongs to the Neobeguea genus and has been classified into the Swietenieae subfamily of the Meliaceae. Neobeguea mahafalensis seeds obtained from Madagascar were investigated for the presence of limonoids. This is the first time extracts of the seeds were investigated. Previous work was done on the stem bark of this species. An andirobin-type limonoid, methyl angolensate (5), two mexicanolide-type limonoids, mexicanolide (6), khayasin (7), and three protolimonoids, sapelin E acetate (8), sapelin C (9) and grandifoliolenone (10), have been isolated in this work. One of these was novel. Cedrelopsis grevei belongs to the Cedrelopsis genus and has been classified into the Ptaeroxylaceae family. Extracts from the stem bark of Cedrelopsis grevei obtained from Madagascar yielded seven compounds, a triterpenoid, β-amyrin (15), a coumarin, scoparone (16), a limonoid, cedmiline (14), a triterpenoid derivative, cedashnine (17), a quassinoid, cedphiline (19), a lignan, cedpetine (18) as well as sitosteryl β-D-glucopyranoside (20). Three of these were novel

Extractives from samadera madagascariensis and toddaliopsis bremekampii.

Thesis (Ph.D.)-University of KwaZulu-Natal, 2004This work involves the isolation, structural elucidation and the biological screening of compounds from the Madagascan Samadera madagascariensis and Toddaliopsis bremekampii from South Africa. Samadera madagascariensis Jussieu (locally known as "fatriana") belongs to the Simaroubaceae family and is endemic to Madagascar. The leaves of Samadera madagascariensis are used in Madagascar for the treatment of stomach aches and dysentry, and the juice of the fresh leaves is used to treat wounds and burns. Samadera madagascariensis leaves were investigated in this work for the presence of quassinoids and triterpenoids. Eighteen compounds, including seven quassinoids: samaderine A (i), the novel 5~,6-dihydrosamaderine A (ii), the novel 2chlorosamaderine A (iii), the novel samaderine DN (iv), samaderine B (v), cedronin (vi) and the novel 3,4~-dihydrosamaderine C (vii), and eleven triterpenoids: the novel protosamaderine A (viii), 1,2-dihydrobruceajavanin A (ix), chisocheton compound A (x), the novel protosamaderine B (xi), the novel protosamaderine C (xii), the novel protosamaderine D (xiii), the novel protosamaderine E (xiv), the novel protosamaderine F (xv), the novel protosamaderine G (xvi), the novel protosamaderine H (xvii) and the novel protosamaderine I (xviii) were isolated from the Samadera madagascariensis leaves. The quassinoids isolated in this work are of the C18 and C19 classes, and only five of the C18 type have been published previously. Quassinoids exhibit a range of biological activities such as antileukemic, antiviral, antimalarial, anti-inflammatory, antifeedant and amoebicidal. 2-Chlorosamaderine A (iii), cedronin (vi) and 3,4~-dihydrosamaderine C (vii) were found to have anticarcinogenic properties. The triterpenoids isolated in this work are of the protolimonoid type and protolimonoids are known to exhibit anticarcinogenic and antifungal properties. Toddaliopsis bremekampii I. Verd. belongs to the Rutaceae family. Members of the Toddaliopsis genus are found in the warmer regions of southern Africa. The phytochemistry of this species and genus has not been investigated previously, however, other members of the Rutaceae have yielded a wide range of alkaloids and other compounds. The leaves and branches of Toddaliopsis bremekampii were investigated in this work and yielded four novel acridone alkaloids: 1,2,3trimethoxyacridone (i), 1,2,3-trimethoxy-1 O-acetoxymethylacridone (ii), 1-hydroxy-2,3-dimethoxy10- acetoxymethylacridone (iii) and 1,2,3-trimethoxy-1 O-methoxy methylacridone (iv). Acridone alkaloids are known to have antineoplastic and antitumour properties. These alkaloids were active in the chemiluminescence assay, which showed the suppression of the reactive oxygen species generated by polymorphonuclear leukocytes (PMNs) in humans. The PMNs play a key role in the host's defence. However, the reactive oxygen species generated as a result of this defence mechanism cause tissue damage

Apollonius and Callimachus on Heracles and Theiodamas: A Metapoetical Interpretation

Apollonius of Rhodes’ digression on Heracles and Theiodamas (Arg. 1.1211-20) alludes to Callimachus’ version of the story in his Aetia (fr. 24-5 Pf.). This article provides a metapoetical interpretation of the intertextual contact. The ways in which both poets deal with Heracles reveal the similar but different reactions of these “Callimachean” poets to the heroic-epic literary tradition

Additional file 4: of Anti-aging potential of extracts from Sclerocarya birrea (A. Rich.) Hochst and its chemical profiling by UPLC-Q-TOF-MS

Negative mode BPI chromatogram of quinic acid pure standard overlaid with that of Marula stem ethanol extract. A comparison of the retention time of quinic acid pure standard with that of peak 1 identified a quinic acid in Marula stem ethanol extract. (PPTX 85 kb

Additional file 11: of Anti-aging potential of extracts from Sclerocarya birrea (A. Rich.) Hochst and its chemical profiling by UPLC-Q-TOF-MS

MS/MS fragmentation pattern of epicatechin gallate pure standard overlaid with MS/MS fragmentation of peak 7. A comparison of the MS/MS fragmentation pattern of epicatechin gallate pure standard to that of peak 7 identified as epicatechin gallate in Marula stem ethanol extract. (PPTX 84 kb

Antiprotozoal Isoflavan Quinones from Abrus precatorius ssp. africanus

A library of 206 extracts from selected South African plants was screened in vitro against a panel of protozoan p arasites, Plasmodium falciparum, Trypanosoma brucei rhodesiense, and Leishmania donovani. A CH2Cl2/MeOH (1 : 1) extract of Abrus precatorius L. ssp. africanus strongly inhibited P. falciparum (98 %), T. b. rhodesiense (100 %), and L . donovani (76 %) when tested at a concentration of 10.0 m icrog/mL. The active constituents were tracked by HPLC-based activity profiling and isolated by preparative and semi preparative RP-HPLC chromatography. Structures were established by HR-ESIMS, and 1D and 2D NMR (1H, 13C, COSY, HMBC, HSQC, and NOE difference spectroscopy). Five compounds were obtained and identified as two isoflavan hydroquinones, abruquinone H (1) and abruquinone G (2), and three isofla van quinones, abruquinone I (3), abruquinone B (4), and 7, 8,3''5'-tetramethoxyisoflavan-1',4'-quinone (5). Compounds 1 and 3 were new natural products. The absolute configuration of compounds was determined by comparison of electronic circular dichroism spectra with calculated ECD data. Compounds 3 and 4 showed strong activity against T. b. rhodesiense (IC50 values of 0.30 and 0.16 microM, respectively) and good selectivity (selectivity indices of 73.7 and 50.5, respectively

Antitrypanosomal isoflavan quinones from Abrus precatorius

Human African trypanosomiasis is a neglected tropical disease in sub Saharan Africa that is fatal if left untreated. In a search for new natural products with antitrypanosomal activity, we recently identified abruquinones B and I from Abrus precatorius as potent in vitro trypanocidal compounds with high selectivity indices. To obtain sufficient compound for in vivo efficacy tests in mice, a second batch of plant material was re-collected and extracted. However, the chemical profiles of the two batches differed, and additional abruquinones were isolated and identified by HR-ESI-MS, and 1D and 2D NMR ((1)H, (13)C, COSY, HMBC, HSQC, and NOESY) spectroscopy. Abruquinones J (1), K (2), and L (3) were new, while abruquinones A (4) and D (5) were known from the first batch of plant material. The absolute configuration of compounds 1 to 3 was determined by comparison of electronic circular dichroism (ECD) spectra with calculated ECD data. Compounds 2 to 5 showed high in vitro activity against T. b. rhodesiense (IC50 of 0.01, 0.02, 0.02 and 0.01μM, respectively), and remarkable SIs of 508, 374, 1379, and 668, respectively

Bioassay-Guided Investigation of the Tanzanian Plant <i>Pyrenacantha kaurabassana</i> for Potential Anti-HIV-Active Compounds

Two new anti-HIV xanthones, 6,7,11-trihydroxy-10-methoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12<i>H</i>-benzo­[<i>b</i>]­xanthene-4-carboxylic acid (<b>1</b>) and 6,7-dihydroxy-10,11-dimethoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12<i>H</i>-benzo­[<i>b</i>]­xanthene-4-carboxylic acid (<b>2</b>), and a new hexadecahydrochrysen-3-ol (<b>3</b>) were isolated from the tubers of <i>Pyrenacantha kaurabassana</i>. Compounds <b>1</b> and <b>2</b> showed moderate anti-HIV activity when tested in the deCIPhR assay on HIV virus type NL4-3, with IC₅₀ values of 21 and 2 μg/mL, respectively