Olivier Placide NOTE

Guineenoside B a triterpenoid saponin from Piper guineense (Piperaceae) triggers apoptosis and PI3K/Akt/mTOR inactivation and inhibits metastasis

Eutrophe Le Doux Kamto, Anne Offermann, Olivier Placide Noté, Joséphine Ngo Mbing, Mohamed Haddad, Dieudonné Emmanuel Pegnyemb et 4 autre(s)

BMC Complementary Medicine and Therapies

BACKGROUND: Over 1.4 million new cases of prostate cancer (PCa) and 375,304 deaths were recorded in 2020. Piper guineense Schum and Thonn is used to treat various diseases including cancer. Three triterpenoid saponins namely guineenosides (Guin) A, B & C were recently isolated from this plant. This study marks the initial documentation of the anticancer potential of these compounds. METHODS: Anti-cell growth (MTT), proliferation (CCK-8), clonogenic assays were evaluated. Furthermore, the most potent compound (Guin-B) was investigated for its potential to induce apoptosis, inhibit cell migration/invasion as well as cell adhesion. Some key proteins in cell proliferation and migration were evaluated. RESULTS: Out of the 3 saponins isolated from P. guineense, Guin-B exhibited significant and concentration-dependent inhibition of PC3 (IC50 =10 µg/mL or ~ 4.82 × 10− 6 µM) and LNCaP (IC50 = 8 µg/mL or 3.86 × 10− 6 µM) cell growth and proliferation as well as a potent inhibition (p < 0.001) of PC3 cell clone formation. Guin-B induced a potent (near 50%) increment of apoptotic cell population in PC3 and LNCaP cells at both 5 and 10 µg/mL; which was accompanied by a significant increase in caspase-3 activity. Guin-B induced a potent inhibition of PC3 cell migration and invasion and an increase in adherence of PC3 cells to the extracellular collagen and fibronectin matrix. A decrease in the expression of pAKT, AKT, mTOR and VEGF proteins was noticed following the treatment with Guin-B. CONCLUSION: Guineenosides B triggers apoptosis via mitochondrial pathway and PI3K/Akt/mTOR inactivation and inhibits metastasis at a low concentration, thus encouraging future investigation of this saponin.

• #piperaceae chemical and biological studies
• #traditional and medicinal uses of annonaceae
• #oral health pathology and treatment
• #lncap

A new acylated phytosterol glucoside from the stem bark of Acacia polyacantha Willd (Fabaceae): molecular docking studies with phytopathogenic proteins as targets

Jean Atangana, Lin Marcellin Messi, Hilaire Tendongmo, Aymard Didier Tamafo Fouégué, Bolomigui Boyomo, Joséphine Ngo Mbing et 4 autre(s)

Biochemical Systematics and Ecology

• #natural products and biological research
• #cholesterol and lipid metabolism
• #bioactive natural compounds
• #phytosterol

Massularosides A-D, new triterpenoid saponins from the stem bark of Massularia acuminata with an N-acetylglucosamine residue and their antifungal properties

Charles Roberto Bilongo, Lin Marcellin Messi, Jean Atangana, Andreas Dietl, Joséphine Ngo Mbing, Dieudonné Emmanuel Pegnyemb et 3 autre(s)

Fitoterapia

C-DEPTq) and 2D (COSY, ROESY, HSQC and HMBC) NMR spectroscopy and by comparison with literature data to be 3-O-[α-L-rhamnopyranosyl-(1 → 3)-2-acetamido-2-deoxy-β-d-glucopyranosyl] oleanolic acid (1); 3-O-[α-L-rhamnopyranosyl-(1 → 3)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-28-O-[β-d-glucopyranosyl] oleanolic acid (2); 3-O-[α-L-rhamnopyranosyl-(1 → 3)-[β-d-glucopyranosyl-(1 → 6)]-2-acetamido-2-deoxy-β-d-glucopyranosyl]-28-O-[β-d-glucopyranosyl] oleanolic acid (3) and 3-O-[β-d-glucopyranosyl (1 → 4)-α-L-rhamnopyranosyl-(1 → 3)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-28-O-[β-d-glucopyranosyl] oleanolic acid (4), respectively. The antifungal activity of the butanol-soluble fraction, saponins-enriched fractions and compounds 1 and 3 was evaluated against a series of plant pathogenic fungi and oomycetes. The butanol-soluble fraction (>60 % inhibition at 125 μg/mL) and two saponins-enriched fractions (>65 % inhibition at 62.5 μg/mL) showed inhibitory activity against the oomycetes Pythium myriotylum and Phytophtora megakarya. Compound 1 inhibited the growth of P. myriotylum with a minimum inhibitory concentration (MIC) of 125 μg/mL.

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #pharmacological effects of natural compounds
• #oleanolic acid

Corrigendum to “Triterpenoid saponins from Calliandra calothyrsus Meisn. and their antiproliferative activity against two digestive carcinoma human cell lines” [Fitoterapia volume 146 (2020) p1-9/article 104669]

Lin Marcellin Messi, Olivier Placide Noté, Joséphine Ngo Mbing, Pierre Lavedan, Marc Vedrenne, Noufou Ouédraogo et 4 autre(s)

Fitoterapia

• #natural product bioactivities and synthesis
• #traditional medicine
• #triterpenoid
• #biology

A New Triterpenoid Saponin from Albizia zygia Induced Apoptosis by Reduction of Mitochondrial Potential Status in Malignant Melanoma Cells

Line Made Simo, Lin Marcellin Messi, Joséphine Ngo Mbing, Christian D. Muller, Fabrice Fekam Boyom, Aime-Didier Boyogueno Begoude et 3 autre(s)

Planta Medica

. Their structures were established based on extensive analysis of 1D and 2D NMR data, HR-ESI-MS analysis, and by chemical degradation. The proapoptotic effect of zygiaoside E (1: ) was evaluated on human malignant melanoma (A375), human epidermoid cancer (A431), and normal Homo sapiens skin tissue (TE 353.SK.) cell lines by cytometric analysis. Zygiaoside E (1: ) induced apoptosis of the two human cancer cell lines (A375 and A431) in a dose-dependent manner at 1 µM but did not induce apoptosis in noncancerous skin cells (TE 353.Sk), even when treated with concentrations up to 15 µM. The underlying mechanism of the apoptosis induction activity of zygiaoside E (1: ) on the mitochondrial membrane potential status in A375 cells was further assessed by monitoring the uptake rate of DiOC6, a mitochondrial specific and voltage-dependent fluorescent dye. The number of malignant melanoma cells emitting high fluorescence levels was decreased when cells were treated with 3 or 5 µM of zygiaoside E (1: ) during either 12 or 24 h, thereby revealing a drop of mitochondrial membrane potential in A375 cells upon treatment, which indicated mitochondrial perturbation.

• #natural product bioactivities and synthesis
• #phytochemical studies and bioactivities
• #nf-κb signaling pathways
• #apoptosis

Glycosides of polygalacic acid from the stem barks of Piper guineense Schum and Thonn

Eutrophe Le Doux Kamto, Olivier Placide Noté, Mc Jésus Kinyok, Anke Wilhelm, Joséphine Ngo Mbing, Cyril Antheaume et 5 autre(s)

Carbohydrate Research

• #natural product bioactivities and synthesis
• #traditional and medicinal uses of annonaceae
• #essential oils and antimicrobial activity
• #chemistry

Farnesyl glycosides and one new triterpenoid saponin from the roots of Lecaniodiscus cupanioides Planch. ex Benth

Lin Marcellin Messi, Olivier Placide Noté, Joséphine Ngo Mbing, Marieke Vansteelandt, Pierre Lavedan, Marc Vedrenne et 2 autre(s)

Carbohydrate Research

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #traditional chinese medicine analysis
• #chemistry

Lebbeckoside C, a new triterpenoid saponin from the stem barks of Albizia lebbeck inhibits the growth of human glioblastoma cells

Olivier Placide Noté, Joséphine Ngo Mbing, Marie‐Claude Kilhoffer, Dieudonné Emmanuel Pegnyemb, Annelise Lobstein

Natural Product Research

One new acacic acid-type saponin, named lebbeckoside C (1), was isolated from the stem barks of Albizia lebbeck. Its structure was established on the basis of extensive analysis of 1D and 2D NMR (1H, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as 3-O-[β-d-xylopyranosyl-(l→2)-β-d-fucopyranosyl-(1→6)-[β-d-glucopyranosyl(1→2)]-β-d-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-β-d-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28 O-[β-d-quinovopyranosyl-(l→3)-[α-l-arabinofuranosyl-(l→4)]-α-l-rhamnopyranosyl-(l→2)-β-d-glucopyranosyl] ester. The isolated saponin (1) displayed significant cytotoxic activity against the human glioblastoma cell line U-87 MG and TG1 stem-like glioma cells isolated from a patient tumor with IC50 values of 1.69 and 1.44 μM, respectively.

• #natural product bioactivities and synthesis
• #biological activity of diterpenoids and biflavonoids
• #plant biochemistry and biosynthesis
• #saponin

A new flavanolignan and a new alkane from the Stem bark of Newtonia griffoniana

Mc Jésus Kinyok, Susan L. Bonnet, Olivier Placide Noté, Joséphine Ngo Mbing, Eutrophe Le Doux Kamto, Jan H. van der Westhuizen et 1 autre(s)

Natural Product Research

Two new compounds a flavanolignan (1), and an alkane (2) along with four known compounds including two fatty acid esters (3-4) and two isocoumarins (5-6) were isolated from the methanolic extract of the stem bark of Newtonia griffoniana. Their structures were elucidated using spectroscopic methods including extensive 1-D and 2-D NMR experiments.

• #sesquiterpenes and asteraceae studies
• #natural product bioactivities and synthesis
• #silymarin and mushroom poisoning
• #alkane

Two new triterpenoid saponins from the roots of Albizia zygia (DC.) J.F. Macbr.

Olivier Placide Noté, Line Made Simo, Joséphine Ngo Mbing, Dominique Guillaume, Sarah Ali Aouazou, Christian D. Muller et 2 autre(s)

Phytochemistry Letters

• #natural product bioactivities and synthesis
• #biological activity of diterpenoids and biflavonoids
• #plant biochemistry and biosynthesis
• #heteronuclear single quantum coherence spectroscopy

Phenotype-specific apoptosis induced by three new triterpenoid saponins from Albizia glaberrima (Schumach. &amp; Thonn.) Benth

Olivier Placide Noté, Sarah Ali Azouaou, Line Made Simo, Cyril Antheaume, Dominique Guillaume, Dieudonné Emmanuel Pegnyemb et 2 autre(s)

Fitoterapia

• #natural product bioactivities and synthesis
• #biological activity of diterpenoids and biflavonoids
• #phytochemistry and biological activities
• #oleanolic acid

Triterpenoid saponins from Albizia lebbeck (L.) Benth and their inhibitory effect on the survival of high grade human brain tumor cells

Olivier Placide Noté, Jihu Dong, Cyril Antheaume, Maria Zeniou, Dieudonné Emmanuel Pegnyemb, Dominique Guillaume et 3 autre(s)

Carbohydrate Research

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #phytochemistry and biological activities
• #chemistry

Triterpenoid saponins from Albizia boromoensis Aubrév. &amp; Pellegr

Olivier Placide Noté, Jihu Dong, Cyril Antheaume, Dominique Guillaume, Dieudonné Emmanuel Pegnyemb, Marie Claude Kilhoffer et 1 autre(s)

Phytochemistry Letters

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #biological activity of diterpenoids and biflavonoids
• #phytochemical

Triterpenoid saponins from Piptadeniastrum africanum (Hook. f.) Brenan

Olivier Placide Noté, Azefack Léon Tapondjou, Anne‐Claire Mitaine‐Offer, Tomofumi Miyamoto, Dieudonné Emmanuel Pegnyemb, Marie‐Aleth Lacaille‐Dubois

Phytochemistry Letters

• #natural product bioactivities and synthesis
• #phytochemistry and bioactive compounds
• #plant biochemistry and biosynthesis
• #saponin

Labdane-type diterpenes and flavones from Dodonaea viscosa

Hippolyte K. Wabo, Philippe Chabert, Pierre Tane, Olivier Placide Noté, Michel Feussi Tala, Jean Peluso et 4 autre(s)

Fitoterapia

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #sesquiterpenes and asteraceae studies
• #labdane

A review of acacic acid-type saponins from Leguminosae-Mimosoideae as potent cytotoxic and apoptosis inducing agents

Marie‐Aleth Lacaille‐Dubois, Dieudonné Emmanuel Pegnyemb, Olivier Placide Noté, Anne‐Claire Mitaine‐Offer

Phytochemistry Reviews

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #toxin mechanisms and immunotoxins
• #moiety

Profiling of African Mimosaceae for the rapid identification of new triterpenoid electrophiles

Olivier Placide Noté, Aurélie Urbain, Cyril Antheaume, Annelise Lobstein

Planta Medica

Avicins are complex triterpenoid saponins isolated from an Australian Mimosaceae (Leguminosae), Acacia victoriae Benth. They are based on an acacic acid core, substituted by two glycosidic units and by a specific side chain at C-21 containing two monoterpene carboxylic acids and a quinovose moiety, conferring thereof particular electrophilic properties [1]. Avicins exhibit potent proapoptotic and anti-inflammatory activities, selectively inhibit the growth of tumor cells and thus appear as a new potential class of anticancer natural substances [2, 3]. In order to discover new avicins analogues and to identify the pharmacophore responsible for the activity, different African Mimosaceae species, including Acacia, Albizia, and Entada genera, were selected to screen their saponins content. Chemical profiling of saponin-enriched fractions, based on a LC-UV-MS/MS dereplication method and NMR experiments, has pointed out the presence of avicins analogues in the different studied species. Characteristic structural features of avicins consisting of an acacic acid aglycone, a tri- or tetra-saccharide moiety at C-28, a sugar residue at C-3, and the acylation of C-21 were highlighted by the developed method. These findings confirmed that some Mimosaceae species represent an alternative source for the discovery of new avicin analogues [4]. The dereplication approach enabled to quickly identify the compounds of interest, and so to focus on their specific isolation and saving a considerable amount of time. Structures of the isolated triterpenoids will be unambiguously elucidated on the basis of extensive analysis of NMR experiments and mass spectrometry, and further submitted to bioassays to study in depth their mechanism of action. References: 1. Jayatilake GS et al. (2003)J Nat Prod 66: 779–83. 2. Haridas V et al. (2001) Proc Natl Acad Sci USA 98: 11557–11562. 3. Gaikwad A et al. (2005) Clin Cancer Res 11: 1953–1962 4. Noté O et al. (2011) Phytochem Rev, in press

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #antioxidant activity and oxidative stress
• #electrophile

Structure elucidation of new acacic acid‐type saponins from Albizia coriaria

Olivier Placide Noté, Philippe Chabert, Dieudonné Emmanuel Pegnyemb, Bernard Weniger, Marie‐Aleth Lacaille‐Dubois, Annelise Lobstein

Magnetic Resonance in Chemistry

Three new acacic acid derivatives, named coriariosides C, D, and E (1-3) were isolated from the roots of Albizia coriaria. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry as 3-O-[β-D-xylopyranosyl-(1 → 2)-β-D-fucopyranosyl-(1 → 6)-2-(acetamido)-2-deoxy-β-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl- 6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-β-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1), 3-O-{β-D-fucopyranosyl-(1 → 6)-[β-D-glucopyranosyl-(1 → 2)]-β-D-glucopyranosyl}-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-β-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-α-L-rhamno pyranosyl-(1 → 2)-β-D-glucopyranosyl ester (2), and 3-O-[β-D-fucopyranosyl-(1 → 6)-β-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl)-β-D-quinovopyranosyl]octa-2,7-dienoyl}acacic acid 28-O-β-D-glucopyranosyl ester (3).

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #phytochemistry and biological activities
• #chemistry

Cytotoxic Acacic Acid Glycosides from the Roots of Albizia coriaria

Olivier Placide Noté, Anne‐Claire Mitaine‐Offer, Tomofumi Miyamoto, Thomas Paululat, Jean-François Mirjolet, Olivier Duchamp et 2 autre(s)

Journal of Natural Products

Two new oleanane-type saponins, coriariosides A (1) and B (2), along with a known saponin, gummiferaoside C (3), were isolated from the roots of Albizia coriaria. Their structures were established by extensive analysis of 1D and 2D NMR experiments (COSY, ROESY, TOCSY, HSQC, and HMBC) and mass spectrometry. Compounds 1 and 3 when tested for cytotoxicity against two colorectal human cancer cells showed activity against the HCT 116 (IC50 4.2 microM for 1 and 2.7 microM for 3) and HT-29 (IC50 6.7 microM for 1 and 7.9 microM for 3) cell lines.

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #phytochemistry and bioactive compounds
• #saponin

Tetrapterosides A and B, two new oleanane‐type saponins from Tetrapleura tetraptera

Olivier Placide Noté, Anne‐Claire Mitaine‐Offer, Tomofumi Miyamoto, Thomas Paululat, Dieudonné Emmanuel Pegnyemb, Marie‐Aleth Lacaille‐Dubois

Magnetic Resonance in Chemistry

From the stem bark of Tetrapleura tetraptera, two new oleanane-type saponins, tetrapteroside A 3-O-{6-O-[(2E,6S)-2,6-dimethyl-6-hydroxyocta-2,7-dienoyl]-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl}-3,27-dihydroxyoleanolic acid (1), and tetrapteroside B 3-O-{ beta-D-glucopyranosyl-(1 --> 2)-6-O-[(E)-feruloyl]-beta-D-glucopyranosyl-(1 --> 3)-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl}-3,27-dihydroxyoleanolic acid (2), were isolated. Further extractions from the roots led to the isolation of four known oleanane-type saponins. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments.

• #natural product bioactivities and synthesis
• #plant biochemistry and biosynthesis
• #phytochemistry and biological activities
• #chemistry