Withanolides with antibacterial activity from Nicandra john-tyleriana

A Survey of Recently Discovered Naturally Occurring Organohalogen Compounds

The discovery of naturally occurring organohalogen compounds has increased astronomically in the 55 years since they were first discovered─from fewer than 50 in 1968 to a combined 7,958 described examples in three comprehensive reviews. The present survey, which covers the period 2021-2023, brings the number of known natural organohalogens to approximately 8,400. The organization is according to species origin, and coverage includes marine and terrestrial plants, fungi, bacteria, marine sponges, corals, cyanobacteria, tunicates, and other marine organisms.

Sesquiterpenes from the Fungus Antrodiella albocinnamomea with Cytotoxicity and Antibacterial Activity

Eight new sesquiterpenes, namely, albocinnamins A-H (1-8), along with two known ones (9 and 10), have been isolated from the fungus Antrodiella albocinnamomea. Compound 1 possesses a new backbone that might be derived from cadinane-type sesquiterpene. Structures of the new compounds were elucidated by detailed spectroscopic data analysis, single-crystal X-ray diffraction, and ECD calculations. Compounds 1a and 1b showed cytotoxicity against SW480 and MCF-7 cells, with IC₅₀ values ranging from 19.3 to 33.3 μM, while compound 2 displayed cytotoxicity against the HL-60 cell with an IC₅₀ value of 12.3 μM. In addition, compounds 5 and 6 exhibited antibacterial activity against Staphylococcus aureus with MIC values of 64 and 64 µg/mL, respectively.

Withaferin A-silyl ether analogs as potential anti-kinetoplastid agents targeting the programmed cell death

Current therapies of leishmaniasis and Chagas disease, two of the most widespread neglected tropical diseases, have limited efficacy and toxic side effects. In this regard, natural products play an important role in overcoming the current need for new antiparasitic agents. The present study reports the leishmanicidal and trypanocidal activities of twenty-four known silyl-ether derivatives of withaferin A. Eleven compounds from this series (4, 7, 8, 10, 12, 15, 17, 18, 20, 22 and 25) showed a potent dose-dependent inhibitory effect on the proliferation of Leishmania amazonensis promastigotes and Trypanosoma cruzi epimastigotes respectively, even higher than the references drugs, miltefosine and benznidazole. Among them, the most promising compound, derivative 10, exhibited approximately 34-fold higher leishmanicidal activity and 49-fold higher trypanocidal activity compared to the reference drugs, as well as lower cytotoxicity. Moreover, compounds 4, 7, 10, 12 and 15 were more active than the reference drugs against the amastigote forms of L. amazonensis, presenting a high selectivity index. Assays performed to study the ATP levels, mitochondrial membrane potential, plasma membrane permeability, chromatin condensation, reactive oxygen species and autophagy indicated that these withaferin A-silyl analogs appear to induce events characteristic of apoptosis-like and also autophagy leading to programmed cell death. These findings support the therapeutic potential of withaferin A-related steroids as anti-Leishmania and Trypanosoma agents.

Anti-inflammatory withajardins from the leaves of Athenaea velutina

Withajardins, uncommon modified withanolide-type steroids, have been isolated exclusively from plants of the Solanaceae family so far. Two undescribed withajardins and the known tuboanosigenin were isolated from the hexane/EtOAc 1:1 extract from Athenaea velutina leaves. Their structures were established by an extensive analysis of 1D and 2D-NMR and HRMS data. The absolute configuration was determined by X-ray diffraction (withajardin L and tuboanosigenin) and circular dichroism (CD) analyses (withajardin M). The anti-inflammatory activity of compounds was evaluated through the inhibition of the lipopolysaccharide (LPS)-induced nitric oxide (NO), TNF-α, and IL-6 release in RAW264.7 cells. The cell viability effects to RAW 264.7 cells showed IC₅₀ values of 74.4-354.4 μM. The compounds attenuated LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 in RAW264.7 cells.

Recent Advances in the Chemistry and Therapeutic Evaluation of Naturally Occurring and Synthetic Withanolides

Natural products are a major source of biologically active compounds that make promising lead molecules for developing efficacious drug-like molecules. Natural withanolides are found in many flora and fauna, including plants, algae, and corals, that traditionally have shown multiple health benefits and are known for their anti-cancer, anti-inflammatory, anti-bacterial, anti-leishmaniasis, and many other medicinal properties. Structures of these withanolides possess a few reactive sites that can be exploited to design and synthesize more potent and safe analogs. In this review, we discuss the literature evidence related to the medicinal implications, particularly anticancer properties of natural withanolides and their synthetic analogs, and provide perspectives on the translational potential of these promising compounds.

Natural withanolides, an update

Covering: March 2010 to December 2020. Previous review: Nat. Prod. Rep., 2011, 28, 705This review summarizes the latest progress and perspectives on the structural classification, biological activities and mechanisms, metabolism and pharmacokinetic investigations, biosynthesis, chemical synthesis and structural modifications, as well as future research directions of the promising natural withanolides. The literature from March 2010 to December 2020 is reviewed, and 287 references are cited.

Structure-Activity Relationships of Withanolides as Antiproliferative Agents for Multiple Myeloma: Comparison of Activity in 2D Models and a 3D Coculture Model

Multiple myeloma (MM) is a hematological cancer in which relapse and resistance are highly frequent. Therefore, alternatives to conventional treatments are necessary. Withaferin A, a withanolide isolated from Withania somnifera, has previously shown promising activity against various MM models. In the present study, structure-activity relationships (SARs) were evaluated using 56 withanolides. The antiproliferative activity was assessed in three MM cell lines and in a 3D MM coculture model to understand the in vitro activity of compounds in models of various complexity. While the results obtained in 2D allowed a quick and simple evaluation of cytotoxicity used for a first selection, the use of the 3D MM coculture model allowed filtering compounds that perform better in a more complex setup. This study shows the importance of the last model as a bridge between 2D and in vivo studies to select the most active compounds and ultimately lead to a reduction of animal use for more sustained in vivo studies. NF-κB inhibition was determined to evaluate if this could be one of the targeted pathways. The most active compounds, withanolide D (2) and 38, should be further evaluated in vivo.

Withanolides isolated from Tubocapsicum anomalum and their antiproliferative activity

Seven undescribed withanolides (1-7) and six artificial withanolides (8-13), along with 20 known compounds (14-33) were isolated from the aerial parts of Tubocapsicum anomalum. Their structures were confirmed by comprehensive spectroscopic analyses. The absolute configuration of compound 1 was defined by single-crystal X-ray crystallography. All isolates were evaluated for their antiproliferative effects against five human tumor cell lines (Hep3B, MDA-MB-231, SW480, HCT116 and A549), among which compound 24 (tubocapsanolide A) exhibited the highest activities against the MDA-MB-231 cells with an IC₅₀ value of 1.89 ± 1.03 μM. Further studies showed that 24 exhibited significant damage to mitochondria in MDA-MB-231 cells, including excess reactive oxygen species, decreased mitochondrial membrane potential, and apoptosis initiation. In addition, compound 24 also inhibited cell migration. These findings show that tubocapsanolide A may be a promising molecule for triple-negative breast cancer treatment and merit further evaluation.

The synthesis and cytotoxic activity of derivatives of 4β-hydroxywithanolide E

4β-Hydroxywithanolide E, which can be obtained in large amounts from the Physalis genus, possessed anti-proliferative effects on a variety of human cancer cell lines. For discussing its anti-tumor structure-activity relationship, a series of 4β-hydroxywithanolide E derivatives (1-17) were synthesized and evaluated for their antitumor activity in vitro towards acute promyelocytic leukemia NB4 cell line by the Alarma blue assay. Cytotoxicity data revealed that the enone structure and C-4 hydroxyl substituents of ring A, together with the side chain (C-20-C-28) play an important effect on the cytotoxicity.

Characterization of Ethyl Acetate and Trichloromethane Extracts from Phoebe zhennan Wood Residues and Application on the Preparation of UV Shielding Films

In this work, ethyl acetate (EA) and trichloromethane (TR) extracts were extracted from Phoebezhennan wood residues and the extracts were then applied to the preparation of UV shielding films (UV-SF). The results revealed that substances including olefins, phenols and alcohols were found in both EA and TR extracts, accounting for about 45% of all the detected substances. The two extracts had similar thermal stability and both had strong UV shielding ability. When the relative percentage of the extract is 1 wt% in solution, the extract solution almost blocked 100% of the UV-B (280–315 nm), and UV-A (315–400 nm). Two kinds of UV-SF were successfully prepared by adding the two extracts into polylactic acid (PLA) matrix. The UV-SF with the addition of 24 wt% of the extractive blocked 100% of the UV-B (280–315 nm) and more than 80% of the UV-A (315–400 nm). Moreover, the UV shielding performance of the UV-SF was still stable even after strong UV irradiation. Though the addition of extracts could somewhat decrease the thermal stability of the film, its effect on the end-use of the film was ignorable. EA extracts had less effect on the tensile properties of the films than TR extracts as the content of the extract reached 18%. The results of this study could provide fundamental information on the potential utilization of the extracts from Phoebe zhennan wood residues on the preparation of biobased UV shielding materials.

Three new C23 steroids from the leaves and stems of Nicandra physaloides

Nicandra physaloides is a medicinal and edible plant and has been used as traditionally herbal medicine to treat various diseases in folk. Its characteristic withanolides, a kind of ergostane-type steroids, are reported to display plentiful biological activities that many explain the effect of N. physaloides to some extent. Thus, to further find bioactive steroids, the stems and leaves of N. physaloides were investigated and three new C23 steroids, nic-physatones I-J (1-2), and nic-physatone S (3), together with a known C25 steroid, nic 17 (4), were isolated. Their structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, ¹H-¹H COSY, and ROESY), UV and MS analyses. Compounds 1-3 possess a rare C23 steroid skeleton. Among them, compound 3 represented the first example of a C23 steroid featuring a benzene ring (D ring). The isolated compounds showed no cytotoxic activity.

The absolute configurations of hyperilongenols A–C: rare 12,13-seco-spirocyclic polycyclic polyprenylated acylphloroglucinols with enolizable β,β′-tricarbonyl systems from Hypericum longistylum Oliv

Three PPAPs were isolated from H. longistylum Oliv.

Leishmanicidal Activity of Withanolides from Aureliana Fasciculata var. Fasciculata

Leishmaniasis is the generic denomination to the neglected diseases caused by more than 20 species of protozoa belonging to the genus Leishmania. The toxic and parenteral-delivered pentavalent antimonials remain to be the first-line treatment. However, all the current used drugs have restrictions. The species Aureliana fasciculata (Vell.) Sendtner var. fasciculata is a native Brazilian species parsimoniously studied on a chemical point of view. In this study, the antileishmanial activity of A. fasciculata was evaluated. Among the evaluated samples of the leaves, the dichloromethane partition (AFfDi) showed the more pronounced activity, with IC₅₀ 1.85 µg/ml against promastigotes of L. amazonensis. From AFfDi, two active withanolides were isolated, the Aurelianolides A and B, with IC₅₀ 7.61 μM and 7.94 μM, respectively. The withanolides also proved to be active against the clinically important form, the intracellular amastigote, with IC₅₀ 2.25 μM and 6.43 μM for Aurelianolides A and B, respectively. Furthermore, withanolides showed results for in silico parameters of absorption, distribution, metabolism, excretion, and toxicity (ADMET) similar to miltefosine, the reference drug, and were predicted as good oral drugs, with the advantage of not being hepatotoxic. These results suggest that these compounds can be useful as scaffolds for planning drug design.

Three new withanolides from the calyces of Nicandra physaloides

Chemical investigation on ethyl acetate extract of the calyces of Nicandra physaloides resulted in the isolation of three new withanolides named as nicphysatone A (1), nicphysatone B (2), nicphysatone C (3), together with five known withanolides, nic 17 (4), nic 7 (5), nic 2 (6), withahisolide G (7) and nicaphysalin B (8). The structures were determined by comprehensive spectroscopic experiments. The discovery enriched the diversity of natural withanolides and could serve as scaffolds for the synthesis of more potent modified withanolides.

Phytochemical Study of the Genus Salpichroa (Solanaceae), Chemotaxonomic Considerations, and Biological Evaluation in Prostate and Breast Cancer Cells

Twelve Salpichroa taxa have been phytochemically analyzed. From the aerial parts of S. scandens, four known salpichrolides A, C, I, S, and an unreported withanolide named salpichrolide V (1), were isolated. In S. dependens, S. gayi, S. glandulosa subsp. glandulosa, S. glandulosa subps. weddellii, S. leucantha, S. micrantha, S. microloba, S. proboscidea, S. ramosissima, S. tristis var. tristis, and S. weberbauerii, no withanolides were found. The chemical content of ca. 85% of the Salpichroa taxa is in agreement with molecular studies, which suggest that Salpichroa and Jaborosa, a genus considered morphologically close to Salpichroa, are distant in the systematic of the Solanoideae subfamily. Moreover, the in vitro cytotoxic activity of a set of natural salpichrolides and derivatives was examined against two prostate carcinoma cell lines (PC3 and LNCaP) and two human breast cancer cell lines (MCF-7 and T47D). Several compounds showed moderate activity (IC₅₀  = 64.91 - 29.97 μm).

Cytotoxic withanolides from Physalis angulata

A new withanolide (1), physagulide P, together with five known withanolides (2-6), was isolated from the aerial parts of Physalis angulata L. The structure of new compound was elucidated on the basis of extensive spectroscopic techniques, including 1D, 2D NMR and HRESIMS. The activity screening indicated that compound 1 showed significant cytotoxicities against the human osteosarcoma cell line MG-63, HepG-2 hepatoma cells and breast cancer cells MDA-MB-231 with the IC₅₀ value of 3.50, 4.22 and 15.74 μM.

Withanolides from aerial parts of Nicandra physalodes

Twenty withanolides, including previously unknown nicanlodes A-M, were isolated from aerial parts of Nicandra physalodes. Their structural elucidations were unambiguously achieved through interpretation of extensive spectroscopic data (NMR and HRMS) and by comparison with literature data. Nicanlodes A and B have an unusual aromatic amine moiety. The isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines.

Anti-inflammatory labdane-type diterpenoids from Physalis angulata

Twelve new labdane-type diterpenoid glycosides were isolated from the stems and leaves of P. angulata.

Withanolides and Sucrose Esters from Physalis neomexicana

Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 μM, respectively.