Antiproliferative activity of compounds isolated from the root bark of Lannea acida in multiple myeloma cell lines.

Lannea acida A. Rich. is a native plant of West Africa used in traditional medicine against diarrhea, dysentery, rheumatism, and women infertility. Eleven compounds were isolated from the dichloromethane root bark extract using various chromatographic techniques. Among those, nine compounds have not been previously reported, i.e. one cardanol derivative, two alkenyl 5-hydroxycyclohex-2-en-1-ones, three alkenyl cyclohex-4-ene-1,3-diols, two alkenyl 7-oxabicyclo[4.1.0]hept-4-en-3-ols, and one alkenyl 4,5-dihydroxycyclohex-2-en-1-one, together with two known cardanols. The structure of the compounds was elucidated using NMR, HRESIMS, ECD, IR, and UV. Their antiproliferative activity was evaluated in three multiple myeloma cell lines: RPMI 8226, MM.1S, and MM.1R. Two compounds showed activity in all cell lines with IC50 values < 5 µM. Further investigations are needed to understand the mechanism of action.

Formulation of Nano/Micro-Carriers Loaded with an Enriched Extract of Coffee Silverskin: Physicochemical Properties, In Vitro Release Mechanism and In Silico Molecular Modeling.

Designing strategies for an effective transformation of food waste into high-value products is a priority to address environmental sustainability concerns. Coffee silverskin is the major by-product of the coffee roasting industry, being rich in compounds with health benefits. Such composition gives it the potential to be transformed into high-value products. In this study, coffee silverskin extracts were enriched, regarding caffeine and chlorogenic acid contents, by adsorbent column chromatography. The compounds content increased 3.08- and 2.75-fold, respectively, compared to the original extract. The enriched fractions were loaded into nano-phytosomes or cholesterol-incorporated nano-phytosomes (first coating layers) to improve the physiochemical properties and permeation rate. These nano-lipid carriers were also subjected to a secondary coating with different natural polymers to improve protection and stability against degradation. In parallel, and for comparison, different natural polymers were also used as first coating layers. The produced particles were evaluated regarding product yield, encapsulation efficiency, loading capacity, particle size, surface charge, and in vitro release simulating gastrointestinal conditions. All samples exhibited anionic surface charge. FTIR and molecular docking confirmed interactions between the phytoconstituents and lipid bilayers. The best docking score was observed for 5-caffeoylquinic acid (chlorogenic acid) exhibiting a stronger hydrogen binding to the lipid bilayer. Among several kinetic models tested, the particle release mechanism fitted well with the First-order, Korsmeyer-Peppas, and Higuchi models. Moreover, most of the formulated particles followed the diffusion-Fick law and anomalous transport.

Exploring Gunnera tinctoria: From Nutritional and Anti-Tumoral Properties to Phytosome Development Following Structural Arrangement Based on Molecular Docking.

Gunnera tinctoria, an underexplored invasive plant found in Azores, Portugal, was studied regarding its nutritional, antioxidant, and antitumoral properties. Higher antioxidant activity was found in baby leaves, followed by adult leaves and inflorescences. A phenolic fraction of the plant was enriched using adsorbent resin column chromatography (DiaionTM HP20LX, and Relite EXA90). Antitumoral effects were observed with the enriched fractions in breast (MCF-7) and pancreatic (AsPC-1) cancer cell lines, being more pronounced in the latter. To improve protection and membrane absorption rates of phenolic compounds, nano-phytosomes and cholesterol-conjugated phytosomes coated with natural polymers were loaded with the enriched fraction. The particles were characterized, and their physiochemical properties were evaluated and compared. All samples presented anionic charge and nanometer size in relation to the inner layer and micrometer size regarding the external layers. In addition, the molecular arrangement of phenolics within both types of phytosomes were studied for the first time by molecular docking. Polarity and molecular size were key factors on the molecular arrangement of the lipid bilayer. In conclusion, G. tinctoria showed to be an interesting source of nutrients and phenolic compounds with anti-tumoral potential. Moreover, phytosome loading with these compounds can increase their stability and bioavailability having in view future applications.

Nor-abietane Diterpenoids from Perovskia abrotanoides Roots with Anti-inflammatory Potential.

Fractionation of an EtOAc extract of the roots of Perovskia abrotanoides yielded 28 diterpenoids, including 12 new analogues, 1-12. The structures of these diterpenoids were established using comprehensive spectroscopic data analysis, including 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism spectroscopy, and comparison with literature data. The extract and some of the tested compounds showed significant anti-inflammatory activity on J774A.1 macrophage cells stimulated with E. coli lipopolysaccharide. In particular, the tested compounds significantly inhibited the release of nitric oxide and the expression of related proinflammatory enzymes, such as inducible nitric oxide synthase.

Unusual derivatives from Hypericum scabrum.

Three new compounds (1-3) with unusual skeletons were isolated from the n-hexane extract of the air-dried aerial parts of Hypericum scabrum. Compound 1 represents the first example of an esterified polycyclic polyprenylated acylphloroglucinol that features a unique tricyclo-[4.3.1.11,4]-undecane skeleton. Compound 2 is a fairly simple MPAP, but with an unexpected cycloheptane ring decorated with prenyl substituents, and compound 3 has an unusual 5,5-spiroketal lactone core. Their structures were determined by extensive spectroscopic and spectrometric techniques (1D and 2D NMR, HRESI-TOFMS). Absolute configurations were established by ECD calculations, and the absolute structure of 2 was confirmed by a single crystal determination. Plausible biogenetic pathways of compounds 1-3 were also proposed. The in vitro antiprotozoal activity of the compounds against Trypanosoma brucei rhodesiense and Plasmodium falciparum and cytotoxicity against rat myoblast (L6) cells were determined. Compound 1 showed a moderate activity against T. brucei and P. falciparum, with IC50 values of 3.07 and 2.25 µM, respectively.

Pyridine-4(1H)-one Alkaloids from Waltheria indica as Antitrypanosomatid Agents.

Twelve new pyridine-4(1H)-one derivatives, namely, 8-demethoxywaltherione F (1), waltheriones R-V (2, 6, 7, 10, and 11), 1-methoxywaltherione O (3), (S)-15-hydroxywaltherione G (4), (8R)-8-hydroxywaltherione M (5), (9S,13S)-2-hydroxymethylwaltherione C (8), (9S,10S,13S)-10-hydroxywaltherione C (9), and (S)-13-methoxywaltherione V (12), as well as melovinone (13) and 5'-methoxywaltherione A (14) were isolated from the CH2Cl2 extract of the aerial parts of Waltheria indica. Their chemical structures were determined by means of a comprehensive analysis including 1H NMR, DEPTQ, HSQC, HMBC, 1H-1H COSY, ROESY, and HRESIMS data. The absolute configurations were assigned via comparison of the experimental and calculated ECD data. In addition, the isolated constituents as well as the known waltheriones M-Q were evaluated for their in vitro antitrypanosomal activity. Compounds 2, 5, and 7 as well as waltheriones M, P, and Q showed potent growth inhibition toward Trypanosoma cruzi with IC50 values of 2.1, 0.8, 2.1, 1.3, 0.5, and 0.1 µM, respectively, and selectivity indices of >12, >33, >13, 5, 25, and 14. These findings further demonstrate that the waltheriones are a promising class of antichagasic compounds worthy of further investigations.

Generation of Stilbene Antimicrobials against Multiresistant Strains of Staphylococcus aureus through Biotransformation by the Enzymatic Secretome of Botrytis cinerea.

The biotransformation of a mixture of resveratrol and pterostilbene was performed by the protein secretome of Botrytis cinerea. Several reaction conditions were tested to overcome solubility issues and to improve enzymatic activity. Using MeOH as cosolvent, a series of unusual methoxylated compounds was generated. The reaction was scaled-up, and the resulting mixture purified by semipreparative HPLC-PDA-ELSD-MS. Using this approach, 15 analogues were isolated in one step. Upon full characterization by NMR and HRMS analyses, eight of the compounds were new. The antibacterial activities of the isolated compounds were evaluated in vitro against the opportunistic pathogens Pseudomonas aeruginosa and Staphylococcus aureus. The selectivity index was calculated based on cytotoxic assays performed against human liver carcinoma cells (HepG2) and the human breast epithelial cell line (MCF10A). Some compounds revealed remarkable antibacterial activity against multidrug-resistant strains of S. aureus with moderate human cell line cytotoxicity.

7-epi-Clusianone, a Multi-Targeting Natural Product with Potential Chemotherapeutic, Immune-Modulating, and Anti-Angiogenic Properties.

Targeted therapies have changed the treatment of cancer, giving new hope to many patients in recent years. The shortcomings of targeted therapies including acquired resistance, limited susceptible patients, high cost, and high toxicities, have led to the necessity of combining these therapies with other targeted or chemotherapeutic treatments. Natural products are uniquely capable of synergizing with targeted and non-targeted anticancer regimens due to their ability to affect multiple cellular pathways simultaneously. Compounds which provide an additive effect to the often combined immune therapies and cytotoxic chemotherapies, are exceedingly rare. These compounds would however provide a strengthening bridge between the two treatment modalities, increasing their effectiveness and improving patient prognoses. In this study, 7-epi-clusianone was investigated for its anticancer properties. While previous studies have suggested clusianone and its conformational isomers, including 7-epi-clusianone, are chemotherapeutic, few cancer types have been demonstrated to exhibit sensitivity to these compounds and little is known about the mechanism. In this study, 7-epi-clusianone was shown to inhibit the growth of 60 cancer cell types and induce significant cell death in 25 cancer cell lines, while simultaneously modulating the immune system, inhibiting angiogenesis, and inhibiting cancer cell invasion, making it a promising lead compound for cancer drug discovery.

Hypermongone C Accelerates Wound Healing through the Modulation of Inflammatory Factors and Promotion of Fibroblast Migration.

The physiology of wound healing is dependent on the crosstalk between inflammatory mediators and cellular components of skin regeneration including fibroblasts and endothelial cells. Therefore, strategies to promote healing must regulate this crosstalk to achieve maximum efficacy. In light of the remarkable potential of natural compounds to target multiple signaling mechanisms, this study aims to demonstrate the potential of hypermongone C, a polycyclic polyprenylated acylphloroglucinol (PPAP), to accelerate wound closure by concurrently enhancing fibroblast proliferation and migration, promoting angiogenesis, and suppressing pro-inflammatory cytokines. This compound belongs to a family of plants (Hypericum) that traditionally have been used to treat injuries. Nevertheless, the exact biological evidence to support the claims is still missing. The results were obtained using a traditional model of cell scratch assay and endothelial cell tube formation, combined with the analysis of protein and gene expression by macrophages. In summary, the data suggest that hypermongone C is a multi-targeting therapeutic natural compound for the promotion of tissue repair and the regulation of inflammation.

Phytochemical Study of Salvia leriifolia Roots: Rearranged Abietane Diterpenoids with Antiprotozoal Activity.

Phytochemical investigation of the lipophilic extract of the roots of Salvia leriifolia resulted in the isolation of the new rearranged abietane diterpenoids leriifoliol (1) and leriifolione (2), together with 10 known diterpenoids. Structure elucidations were performed via extensive NMR and HRESIMS data, and the absolute configurations of compounds 1 and 3-5 were established by evaluation of experimental and calculated ECD spectra. The antiplasmodial activity of the new isolates was assayed against Trypanosoma brucei rhodesiense, T. cruzi, Plasmodium falciparum, and Leishmania donovani and also toxicity against rat myoblast (L6) cells. Compound 1 displayed antimalarial and low cytotoxic activity with IC50 values of 0.4 and 33.6 µM, respectively, and a selectivity index of 84. Compound 2 displayed activity against T. brucei, T. cruzi, and L. donovani, with IC50 values of 1.0, 4.6, and 1.0 µM, respectively. Putative biosynthetic pathways toward the formation of 1, 2, and 3 are proposed. Leriifoliol (1) is the first 20- nor-9,10- seco-abietane, while 2 exhibits an uncommon 6-6-5 fused-ring system.

Antiprotozoal Diterpenes from Perovskia abrotanoides.

As part of a screening for new antiparasitic natural products from Iranian plants, n-hexane and ethyl acetate extracts from the aerial parts of Perovskia abrotanoides were found to exhibit strong inhibitory activity against Trypanosoma brucei rhodesiense and Leishmania donovani. The activity was tracked by high-performance liquid chromatography (HPLC)-based activity profiling. Preparative isolation by a combination of silica gel column chromatography and HPLC afforded 17 diterpenoids (1: -17: ), including 14 abietane-, two icetexane-, and one isopimarane-type derivatives. Among these, (5R,10S)-11-hydroxy-12-methoxy-20-norabieta-8,11,13-triene (2: ), 12-hydroxy-norabieta-1(10),8,11,13-tetraene-1,11-furan (6: ), and 12-methoxybarbatusol (9: ) were new compounds, the structure of which was established by comprehensive spectroscopic data analysis (one- and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism). The antiprotozoal activity of the isolated compounds was evaluated against T. b. rhodesiense, Trypanosoma cruzi, L. donovani, and Plasmodium falciparum. Selectivity indexes (SI) were calculated in comparison to cytotoxicity on rat myoblast (L6) cells. Particularly active were 7α-ethoxyrosmanol (4: ) with an IC50 of 0.8 µM against T. b. rhodesiense (SI 14.9) and an IC50 of 1.8 µM (SI 6.9) against L. donovani, ferruginol (8: ) with an IC50 of 2.9 µM (SI 19.2) against P. falciparum, and miltiodiol (10: ) with an IC50 of 0.5 µM (SI 10.5) against T. b. rhodesiense. None of the compounds exhibited selective toxicity against T. cruzi (SI ≤ 1.6).

Wound Healing Potential of Chlorogenic Acid and Myricetin-3-O-ß-Rhamnoside Isolated from Parrotia persica.

Wound healing is a complex physiological process that is controlled by a well-orchestrated cascade of interdependent biochemical and cellular events, which has spurred the development of therapeutics that simultaneously target these active cellular constituents. We assessed the potential of Parrotia persica (Hamamelidaceae) in wound repair by analyzing the regenerative effects of its two main phenolic compounds, myricetin-3-O-ß-rhamnoside and chlorogenic acid. To accomplish this, we performed phytochemical profiling and characterized the chemical structure of pure compounds isolated from P. persica, followed by an analysis of the biological effects of myricetin-3-O-ß-rhamnoside and chlorogenic acid on three cell types, including keratinocytes, fibroblasts, and endothelial cells. Myricetin-3-O-ß-rhamnoside and chlorogenic acid exhibited complementary pro-healing properties. The percentage of keratinocyte wound closure as measured by a scratch assay was four fold faster in the presence of 10 µg/mL chlorogenic acid, as compared to the negative control. On the other hand, myricetin-3-O-ß-rhamnoside at 10 µg/mL was more effective in promoting fibroblast migration, demonstrating a two-fold higher rate of closure compared to the negative control group. Both compounds enhanced the capillary-like tube formation of endothelial cells in an in vitro angiogenesis assay. Our results altogether delineate the potential to synergistically accelerate the fibroblastic and remodelling phases of wound repair by administering appropriate amounts of myricetin-3-O-ß-rhamnoside and chlorogenic acid.

Anti-Candida Cassane-Type Diterpenoids from the Root Bark of Swartzia simplex.

A dichloromethane extract of the roots from the Panamanian plant Swartzia simplex exhibited a strong antifungal activity in a bioautography assay against a genetically modified hypersusceptible strain of Candida albicans. At-line HPLC activity based profiling of the crude extract enabled a precise localization of the antifungal compounds, and dereplication by UHPLC-HRESIMS indicated the presence of potentially new metabolites. Transposition of the HPLC reversed-phase analytical conditions to medium-pressure liquid chromatography (MPLC) allowed an efficient isolation of the major constituents. Minor compounds of interest were isolated from the MPLC fractions using semipreparative HPLC. Using this strategy, 14 diterpenes (1-14) were isolated, with seven (5-10, 14) being new antifungal natural products. The new structures were elucidated using NMR spectroscopy and HRESIMS analysis. The absolute configurations of some of the compounds were elucidated by electronic circular dichroism spectroscopy. The antifungal properties of these compounds were evaluated as their minimum inhibitory concentrations in a dilution assay against both hypersusceptible and wild-type strains of C. albicans and by assessment of their antibiofilm activities. The potential cytological effects on the ultrastructure of C. albicans of the antifungal compounds isolated were evaluated on thin sections by transmission electron microscopy.

HPLC-based activity profiling for antiplasmodial compounds in the traditional Indonesian medicinal plant Carica papaya L.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaf decoctions of Carica papaya have been traditionally used in some parts of Indonesia to treat and prevent malaria. Leaf extracts and fraction have been previously shown to possess antiplasmodial activity in vitro and in vivo. MATERIALS AND METHODS: Antiplasmodial activity of extracts was confirmed and the active fractions in the extract were identified by HPLC-based activity profiling, a gradient HPLC fractionation of a single injection of the extract, followed by offline bioassay of the obtained microfractions. For preparative isolation of compounds, an alkaloidal fraction was obtained via adsorption on cationic ion exchange resin. Active compounds were purified by HPLC-MS and MPLC-ELSD. Structures were established by HR-ESI-MS and NMR spectroscopy. For compounds 5 and 7 absolute configuration was confirmed by comparison of experimental and calculated electronic circular dichroism (ECD) spectroscopy data, and by X-ray crystallography. Compounds were tested for bioactivity in vitro against four parasites (Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum), and in the Plasmodium berghei mouse model. RESULTS: Profiling indicated flavonoids and alkaloids in the active time windows. A total of nine compounds were isolated. Four were known flavonols--manghaslin, clitorin, rutin, and nicotiflorin. Five compounds isolated from the alkaloidal fraction were piperidine alkaloids. Compounds 5 and 6 were inactive carpamic acid and methyl carpamate, while three alkaloids 7-9 showed high antiplasmodial activity and low cytotoxicity. When tested in the Plasmodium berghei mouse model, carpaine (7) did not increase the survival time of animals. CONCLUSIONS: The antiplasmodial activity of papaya leaves could be linked to alkaloids. Among these, carpaine was highly active and selective in vitro. The high in vitro activity could not be substantiated with the in vivo murine model. Further investigations are needed to clarify the divergence between our negative in vivo results for carpaine, and previous reports of in vivo activity with papaya leaf extracts.

Manoyloxide Sesterterpenoids from Salvia mirzayanii.

Five new manoyloxide-type sesterterpenes were isolated from aerial parts of Salvia mirzayanii, a species endemic to Iran. The planar structures were established by means of 1D and 2D NMR and HRESIMS. Compounds 1-3 differed only in their configurations at C-13 and C-14. Assignment of relative and absolute configurations was achieved by NOESY experiments and by comparison of experimental and simulated ECD spectra of possible stereoisomers. The absolute configurations of 4 and 5 were established in a similar manner.

Abietane diterpenoids from Salvia sahendica--antiprotozoal activity and determination of their absolute configurations.

In a screening of Iranian plants for antiprotozoal activity, an n-hexane extract of the roots of Salvia sahendica potently inhibited the growth of Plasmodium falciparum K1 strain. Subsequent HPLC-based activity profiling led to the identification of seven known and one new abietane-type diterpenoid. Structure elucidation was achieved by analysis of spectroscopic data including 1D and 2D NMR. The absolute configuration of sahandol (7) and sahandone (8) were assigned by comparison of experimental ECD spectra with calculated ECD data, using time-dependent density functional theory and methanol as the solvent. In vitro biological activity against P. falciparum and Trypanosoma brucei rhodesiense STIB 900 strain and cytotoxicity in rat myoblast (L6) cells were determined. The IC50 values of the compounds ranged from 0.8 µM to over 8.8 µM against P. falciparum, and from 1.8 µM to over 32.3 µM against T. brucei rhodesiense. The cytotoxic IC50 values ranged from 0.5-15.5 µM. Selectivity indices for P. falciparum were 0.1 to 18.2, and 0.1 to 1.2 for T. brucei rhodesiense.

Cinnamoylphenethyl amides from Polygonum hyrcanicum possess anti-trypanosomal activity.

A methanolic extract from aerial parts of Polygonum hyrcanicum (Polygonaceae) showed high activity against Trypanosoma brucei rhodesiense (IC50 = 3.7 microg/mL). Bioassay-guided fractionation of the extract resulted in isolation of cinnamoylphenethyl amides, including N-trans-caffeoyltyramine (1), N-trans-p-coumaroyltyramine (7), and N-trans-feruloyltyramine (8) as the main active constituents (IC50s ranging from 2.2 to 13.3 microM). Some structurally related, but less active compounds, such as cannabisin B (2), tyrosol (3), p-coumaric acid (4), ferulic acid (5), and N-cis-feruloyltyramine (6) were also identified, along with N-trans-3,4-dimethoxycinnamoyldopamine (9). Cytotoxicity of the active compounds in L6 cells was determined, and selectivity indices (SI) of 7.9 to 33.4 were calculated.

Hydrangenone, a new isoprenoid with an unprecedented skeleton from Salvia hydrangea.

Hydrangenone, a new heptacyclic isoprenoid with a 6/7/6/5/5 membered carbon ring skeleton, was isolated from the aerial parts of Salvia hydrangea. The structure was established by extensive NMR spectroscopic methods. The relative and absolute configuration of 1 was assigned by NOESY and X-ray crystallographic analysis and by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compound 1 showed in vitro antiplasmodial activity, with an IC(50) value of 1.4 µM against P. falciparum. A plausible biosynthetic pathway of 1 was also proposed.

Triterpenoids with rare carbon skeletons from Salvia hydrangea: antiprotozoal activity and absolute configurations.

Salvadione C (1) and perovskone B (2), two new triterpenoids with rare carbon skeletons, were isolated from an antiplasmodial n-hexane extract of Salvia hydrangea. The absolute configuration was determined by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. In vitro activity against Plasmodium falciparum K1 strain, Trypanosoma brucei rhodesiense STIB 900 strain, and cytotoxicity in rat myoblast (L6) cells were determined. Compounds 1 and 2 showed in vitro antiplasmodial activity, with IC50 values of 1.43 and 0.18 µM and selectivity indices (SI) of 86.2 and 69.6, respectively. IC50 values against T. brucei rhodesiense were found to be 4.33 and 15.92 µM, respectively.