Glacins A and B: two novel bioactive mono-tetrahydrofuran acetogenins from Annona glabra

Acetogenins-Rich Fractions of Annona coriacea Suppress Human Glioblastoma Viability and Migration by Regulating Necroptosis and MMP-2 Activity In Vitro

Glioblastoma (GBM) is an incurable primary brain tumor with a poor prognosis. Resection, radiation therapy, and temozolomide (TMZ) are insufficient to increase survival, making the treatment limited. Thus, the search for more effective and specific treatments is essential, making plants a promising source for elucidating new anti-glioblastoma compounds. Accordingly, this study investigated the effects of four fractions of hexane and ethyl acetate extract of Annona coriacea Mart., enriched with acetogenins, against GBM cell lines. All four fractions were selectively cytotoxic to GBM cells when compared to TMZ. Moreover, A. coriacea fractions delayed cell migration; reduced cytoplasmic projections, the metalloproteinase 2 (MMP-2) activity; and induced morphological changes characteristic of necroptosis, possibly correlated with the increase in receptor-interacting protein kinase 1 and 3 (RIP-1 and RIP-3), apoptosis-inducing factor (AIF), and the non-activation of cleaved caspase 8. The present findings reinforce that fractions of A. coriacea Mart. should be considered for more studies focusing treatment of GBM.

GC/MS Analysis, Cytotoxicity, and Antiviral Activities of Annona glabra Hexane Extract Supported by In Silico Study

Annona glabra Linn is employed in conventional medicine to treat a number of human disorders, including cancer and viruses. In the present investigation, the significant phytochemical components of Annona glabra hexane extract were identified using gas chromatography-mass spectrometry (GC-MS) analysis. Three major compounds were identified in the hexane extract: tritriacontane (30.23%), 13, 17-dimethyl-tritriacontane (22.44%), and limonene (18.97%). MTT assay was used to assess the cytotoxicity of the extract on six human cancer cell lines including liver (HepG-2), pancreas (PANC-1), lung (A-549), breast (MCF-7, HTB-22), prostate (PC-3), and colon (CACO-2, ATB-37). The extract exhibited significant cytotoxic activity against both CACO-2 and A-549 cancer cell lines (IC₅₀ = 47 ± 0.74 μg/mL and 56.82 ± 0.92 μg/mL) in comparison with doxorubicin (IC₅₀ = 31.91 ± 0.81 μg/mL and 23.39 ± 0.43 μg/mL) and of SI of 3.8 and 3.1, respectively. It also induced moderate-to-weak activities against the other cancerous cell lines: PC-3, PANC-1, MCF-7, and HepG-2 (IC₅₀ = 81.86 ± 3.26, 57.34 ± 0.77, 80.31 ± 4.13, and 57.01 ± 0.85 μg/mL) in comparison to doxorubicin (IC₅₀ = 32.9 ± 1.74, 19.07 ± 0.2, 15.48 ± 0.84 and 5.4 ± 0.22 μg/mL, respectively) and SI of 2.2, 3.1, 2.2, and 3.1, respectively. In vitro anti-HSV1 (Herpes simplex 1 virus) and HAV (Hepatitis A virus) activity was evaluated using MTT colorimetric assay with three different protocols to test protective, anti-replicative, and anti-infective antiviral activities, and three separate replications of each experiment were conducted. The plant extract showed promising protective and virucidal activity against HSV1 with no significant difference with acyclovir (79.55 ± 1.67 vs. 68.44 ± 7.62 and 70.91 ± 7.02 vs. 83.76 ± 5.67), while it showed mild protective antiviral activity against HAV (48.08 ±3.46) with no significant difference vs. acyclovir (36.89 ± 6.61). The selected main compounds were examined for their bioactivity through in silico molecular docking, which exhibited that limonene could possess the strongest antiviral properties. These findings support Annona glabra's conventional use, which is an effective source of antiviral and anticancer substances that could be used in pharmaceuticals.

Acetogenins from Annonaceae family. Their potential biological applications

The aim of this contribution has been to continue with the knowledge about newly isolated acetogenins from Annonaceae family for the last fifteen years. This review will report classification, extraction, isolation, elucidation of the structure, biological activities and mechanism of action of such interesting natural products. In fact, out of the 532 compounds reviewed, 115 previously non-described annonaceous acetogenins have been added to the list of isolated compounds from 2005 to May 2019.

Acetogenins from Annonaceae

In recent decades, annonaceous acetogenins have become highly studied plant secondary metabolites in terms of their isolation, structure elucidation, synthesis, biological evaluation, mechanism of action, and toxicity. The aim of the present contribution is to summarize chemical and biological reports published since 1997 on annonaceous acetogenins and synthetic acetogenin mimics. The compounds are considered biologically in terms of their cytotoxicity for cancer cell lines, neurotoxicity, pesticidal effects, and miscellaneous activities.

Acetogenins from Annonaceae: recent progress in isolation, synthesis and mechanisms of action

The aim of the present review is to summarise the knowledge about newly isolated acetogenins (ACGs) in the last six years. It will also report the total syntheses that have allowed either the confirmation or the revision of some structures, together with the biological activities and mechanism of action of such interesting natural products. In fact, of the 417 isolated compounds reviewed, over 176 have been added during the period from 1998 to 2004.

Determination of the diterpenoid, kaurenoic acid, in Annona glabra by HPLC

The isolation of ent-kaur-16-en-19-oic acid (1) from the leaves and bark of Annona glabra and its determination by reversed-phase HPLC with a photodiode array detector is described. The results indicate that 1 accumulates in the bark of the plant with only very low concentrations in the leaves. Levels of 1 varied throughout the year being highest for bark and leaves in the autumn (5.29 +/- 0.23 and 0.27 +/- 0.01 mg/g dry weight, respectively) and lowest in the spring for bark and in the winter for leaves (4.00 +/- 0.25 and 0.11 +/- 0.01 mg/g dry weight, respectively).

Annonaceous acetogenins from the leaves of Annona montana

A novel Annonaceous acetogenin, montanacin F, with a new type of terminal lactone unit, was isolated from the leaves of Annona montana. Its structure was determined on the basis of spectral evidences and chemical methods, and a possible biosynthetic pathway was discussed. In addition, the cytotoxicity of montanacin F was evaluated in vitro against Lewis lung carcinoma (LLC) tumor cell lines. Furthermore, the previously isolated cytotoxic acetogenin annonacin against LLC was examined for in vivo antitumor activity with LLC tumor cells.

Molluscicidal properties of some species of Annona

In search for plant molluscicides for the vector control of schistosomiasis, ethanolic extracts from different parts of six species of the Annonaceae family were evaluated against adult forms and egg masses of Biomphalaria glabrata. Results from accurate experiments indicate that the majority of analyzed extracts possess properties lethal to Biomphalaria glabrata, some of them with significant LD90 values (< 20 ppm), as showed for Annona crassiflora M: [pulp and seed (LD50 = 13.21), steem (2.34), root bark (3.79)], Annona glabra L. [seed (17.02)], Annona muricata [leaf (8.75)]. Emphasis is held mainly into Annona muricata L. (leaf) and Annona squamosa Veil. (root) for presenting additional toxicity toward snail egg masses.