Phenolic Constituents from Platycodon grandiflorum Root and Their Anti-Inflammatory Activity

Six lignols (1–6), including two new compounds (+)-(7R,8R)-palmitoyl alatusol D (1) and (+)-(7R,8R)-linoleyl alatusol D (2), along with four phenolics (7–10), a neolignan (11), three alkyl aryl ether-type lignans (12–14), two furofuran-type lignans (15–16), three benzofuran-type lignans (17–19), a tetrahydrofuran-type lignan (20), and a dibenzylbutane-type lignan (21) were isolated from the ethyl acetate-soluble fraction of the methanol extract of Platycodon grandiflorum (Jacq.) A. DC. root. The chemical structures of the obtained compounds were elucidated via high-resolution mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy analyses. The obtained spectroscopic data agreed well with literature. Among the isolated compounds, eighteen (1–7 and 11–21) were isolated from P. grandiflorum and the Campanulaceae family for the first time. This is the first report on lignol and lignan components of P. grandiflorum. The anti-inflammatory effects of the isolated compounds were examined in terms of their ability to inhibit the production of pro-inflammatory cytokines IL-6, IL-12 p40, and TNF-α in lipopolysaccharide-stimulated murine RAW264.7 macrophage cells. Nine compounds (4–6, 12, and 15–19) exhibited inhibitory effects on IL-12 p40 production, eleven compounds (1–6, 12, 15–17, and 19) exhibited inhibitory activity on IL-6 production, and eleven compounds (1–6 and 15–19) exhibited inhibitory effects against TNF-α. These results warrant further investigation into the potential anti-inflammatory activity and general benefits of the phenolic constituents of P. grandiflorum root.     

Structure and Cytotoxicity of Novel Lignans and Lignan Glycosides from the Aerial Parts of Larrea tridentata

Previously, the authors conducted phytochemical investigations of the aerial parts of Larrea tridentata and reported triterpene glycosides and lignan derivatives. In continuation of the preceding studies, 17 lignans and lignan glycosides (1–17) were isolated, including seven new compounds (1–7). Herein, the structure of the new compounds was determined based on spectroscopic analysis and enzymatic hydrolysis. The cytotoxicity of 1–17 against HL-60 human promyelocytic leukemia cells was examined. Compounds 4–11 and 14–16 were cytotoxic to HL-60 cells, with IC₅₀ values in the range of 2.7–17 μM. Compound 6, which was the most cytotoxic among the unprecedented compounds, was shown to induce apoptotic cell death in HL-60 cells.     

Methoxy-Substituted γ-Oxa-ε-Lactones Derived from Flavanones—Comparison of Their Anti-Tumor Activity In Vitro

Background: The study investigated four flavanone-derived γ-oxa-ε-lactones: a parent unsubstituted compound and its three derivatives with the methoxy group in positions 2′, 4′ and 8. Our objective was to find out if the introduction of the methoxy group into the aromatic ring affects in vitro anti-tumor potency of the investigated lactones. Methods: Cytotoxic and pro-apoptotic effects were assessed with cytometric tests with propidium iodide, annexin V, and Western blot techniques. We also investigated potential synergistic potency of the tested lactones and glucocorticoids in canine lymphoma/leukemia cell lines. Results: The tested flavanone-derived lactones showed anti-cancer activity in vitro. Depending on its location, the methoxy group either increased or decreased cytotoxicity of the derivatives as compared with the parent compound. The most potent lactone was the one with the methoxy group at position 4′ of the B ring (compound 3), and the weakest activity was observed when the group was located at C-8 in the A ring. A combination of the lactones with glucocorticoids confirmed their synergy in anti-tumor activity in vitro. Conclusions: Methoxy-substituted flavanone-derived lactones effectively kill canine lymphoma/leukemia cells in vitro and, thanks to their synergistic action with glucocorticoids, may potentially be applied in the treatment of hematopoietic cancers.     

Euphorbia Diterpenes: An Update of Isolation,Structure, Pharmacological Activities and Structure–Activity Relationship

Euphorbia species have a rich history of ethnomedicinal use and ethnopharmacological applications in drug discovery. This is due to the presence of a wide range of diterpenes exhibiting great structural diversity and pharmacological activities. As a result, Euphorbia diterpenes have remained the focus of drug discovery investigations from natural products. The current review documents over 350 diterpenes, isolated from Euphorbia species, their structures, classification, biosynthetic pathways, and their structure–activity relationships for the period covering 2013–2020. Among the isolated diterpenes, over 20 skeletal structures were identified. Lathyrane, jatrophane, ingenane, ingenol, and ingol were identified as the major diterpenes in most Euphorbia species. Most of the isolated diterpenes were evaluated for their cytotoxicity activities, multidrug resistance abilities, and inhibitory activities in vitro, and reported good activities with significant half-inhibitory concentration (IC₅₀) values ranging from 10–50 µM. The lathyranes, isopimaranes, and jatrophanes diterpenes were further found to show potent inhibition of P-glycoprotein, which is known to confer drug resistance abilities in cells leading to decreased cytotoxic effects. Structure–activity relationship (SAR) studies revealed the significance of a free hydroxyl group at position C-3 in enhancing the anticancer and anti-inflammatory activities and the negative effect it has in position C-2. Esterification of this functionality, in selected diterpenes, was found to enhance these activities. Thus, Euphorbia diterpenes offer a valuable source of lead compounds that could be investigated further as potential candidates for drug discovery.     

Flavones from Combretum quadrangulare Growing in Vietnam and Their Alpha-Glucosidase Inhibitory Activity

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3′,5′-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8–11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6–9, and 11–14 showed good alpha-glucosidase inhibition with IC₅₀ values in the range of 30.5–282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.     

Garcinielliptone G from Garcinia subelliptica Induces Apoptosis in Acute Leukemia Cells

Cytotoxicity and apoptosis-inducing properties of compounds isolated from Garcinia subelliptica leaves were investigated. The hexane-soluble portion of MeOH extracts of G. subelliptica leaves that showed cytotoxic activity was separated to yield seven compounds 1–7. Chemical structure analysis using NMR spectroscopy and mass spectrometry confirmed that compound 1 was canophyllol, and compounds 2–7 were garcinielliptones N, O, J, G, F, and garcinielliptin oxide, respectively. Among them, garcinielliptone G (5) showed growth inhibition by causing apoptosis in THP-1 and Jurkat cells derived from human acute monocytic leukemia and T lymphocyte cells, respectively. Apoptosis induced by garcinielliptone G (5) was demonstrated by the detection of early apoptotic cells with fluorescein-labeled Annexin V and increases in cleaved caspase-3 and cleaved PARP protein levels. However, the addition of caspase inhibitor Z-VAD-FMK did not affect growth arrest or apoptosis induction. These results suggest that garcinielliptone G (5) can induce both caspase-3 activation and caspase-independent apoptosis. Therefore, garcinielliptone G (5) may be a potential candidate for acute leukemia treatment.     

Schisandra rubriflora Fruit and Leaves as Promising New Materials of High Biological Potential: Lignan Profiling and Effect-Directed Analysis

The effect-directed detection (EDD) of Schisandra rubriflora fruit and leaves extracts was performed to assess their pharmacological properties. The EDD comprised TLC—direct bioautography against Bacillus subtilis, a DPPH assay, as well as α-glucosidase, lipase, tyrosinase, and acetylcholinesterase (AChE) inhibition assays. The leaf extracts showed stronger antioxidant activity than the fruit extract as well as inhibition of tyrosinase and lipase. The fruit extract was found to be extremely active against B. subtilis and to inhibit α-glucosidase and AChE slightly more than the leaf extracts. UHPLC–MS/MS analysis was carried out for the bioactive fractions and pointed to the possible anti-dementia properties of the dibenzocyclooctadiene lignans found in the upper TLC fractions. Gomisin N (518 mg/100 g DW), schisanhenol (454 mg/100 g DW), gomisin G (197 mg/100 g DW), schisandrin A (167 mg/100 g DW), and gomisin O (150 mg/100 g DW) were the quantitatively dominant compounds in the fruit extract. In total, twenty-one lignans were found in the bioactive fractions.     

Cytotoxic Polyhydroxylated Oleanane Triterpenoids from Cissampelos pareira var. hirsuta

Three new polyhydroxylated oleanane triterpenoids, cissatriterpenoid A−C (1−3), along with one known analogue (4), were isolated from the whole plant of Cissampelos pareira var. hirsuta. Their chemical structures were elucidated by extensive spectroscopic data (IR, HR-ESI-MS, ¹H-NMR, ¹³C-NMR, DEPT, ¹H-¹H COSY, HSQC, HMBC, NOESY) and the microhydrolysis method. The isolation of compounds 1–4 represents the first report of polyhydroxylated oleanane triterpenoids from the family Menispermaceae. All isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines, and the inhibitory activity against NO release in LPS-induced RAW 264.7 cells. Compound 3 showed the most potent cytotoxic activities against the A549, SMMC-7721, MCF-7, and SW480 cell lines, with IC₅₀ values of 17.55, 34.74, 19.77, and 30.39 μM, respectively, whereas three remaining ones were found to be inactive. The preliminary structure–activity relationship analysis indicated that the γ-lactone ring at C-22 and C-29, and the olefinic bond at C-12 and C-13 were structurally required for the cytotoxicity of polyhydroxylated oleanane triterpenoids against these four cell lines. Based on lipid-water partition coefficients, compound 3 is less lipophilic than 1 and 4, which agrees with their cytotoxic activities. This confirms the potential of C. pareira var. hirsuta in the tumor treatment.     

Structure–Activity Relationships of the Antimalarial Agent Artemisinin 10. Synthesis and Antimalarial Activity of Enantiomers of rac-5β-Hydroxy-d-Secoartemisinin and Analogs: Implications Regarding the Mechanism of Action

An efficient synthesis of rac-6-desmethyl-5β–hydroxy-d-secoartemisinin 2, a tricyclic analog of R-(+)-artemisinin 1, was accomplished and the racemate was resolved into the (+)-2b and (−)-2a enantiomers via their Mosher Ester diastereomers. Antimalarial activity resided with only the artemisinin-like enantiomer R-(−)-2a. Several new compounds 9–16, 19a, 19b, 22 and 29 were synthesized from rac-2 but the C-5 secondary hydroxyl group was surprisingly unreactive. For example, the formation of carbamates and Mitsunobu reactions were unsuccessful. In order to assess the unusual reactivity of 2, a single crystal X-ray crystallographic analysis revealed a close intramolecular hydrogen bond from the C-5 alcohol to the oxepane ether oxygen (O-11). All products were tested in vitro against the W-2 and D-6 strains of Plasmodium falciparum. Several of the analogs had moderate activity in comparison to the natural product 1. Iron (II) bromide-promoted rearrangement of 2 gave, in 50% yield, the ring-contracted tetrahydrofuran 22, while the 5-ketone 15 provided a monocyclic methyl ketone 29 (50%). Neither 22 nor 29 possessed in vitro antimalarial activity. These results have implications in regard to the antimalarial mechanism of action of artemisinin.     

Novel Pyridothienopyrimidine Derivatives: Design,Synthesis and Biological Evaluation as Antimicrobial and Anticancer Agents

The growing risk of antimicrobial resistance besides the continuous increase in the number of cancer patients represents a great threat to global health, which requires intensified efforts to discover new bioactive compounds to use as antimicrobial and anticancer agents. Thus, a new set of pyridothienopyrimidine derivatives 2a,b–9a,b was synthesized via cyclization reactions of 3-amino-thieno[2,3-b]pyridine-2-carboxamides 1a,b with different reagents. All new compounds were evaluated against five bacterial and five fungal strains. Many of the target compounds showed significant antimicrobial activity. In addition, the new derivatives were further subjected to cytotoxicity evaluation against HepG-2 and MCF-7 cancer cell lines. The most potent cytotoxic candidates (3a, 4a, 5a, 6b, 8b and 9b) were examined as EGFR kinase inhibitors. Molecular docking study was also performed to explore the binding modes of these derivatives at the active site of EGFR-PK. Compounds 3a, 5a and 9b displayed broad spectrum antimicrobial activity with MIC ranges of 4–16 µg/mL and potent cytotoxic activity with IC₅₀ ranges of 1.17–2.79 µM. In addition, they provided suppressing activity against EGFR with IC₅₀ ranges of 7.27–17.29 nM, higher than that of erlotinib, IC₅₀ = 27.01 nM.     

Design,Synthesis, and Antimicrobial Activity of Certain New Indole-1,2,4 Triazole Conjugates

The increasing prevalence of microbial infections and the emergence of resistance to the currently available antimicrobial drugs urged the development of potent new chemical entities with eminent pharmacokinetic and/or pharmacodynamic profiles. Thus, a series of new indole-triazole conjugates 6a-u was designed and synthesized to be assessed as new antimicrobial candidates using the diameter of the inhibition zone and minimum inhibitory concentration assays against certain microbial strains. Their in vitro antibacterial evaluation revealed good to moderate activity against most of the tested Gram-negative strains with diameter of the inhibition zone (DIZ) values in the range of 11–15 mm and minimum inhibition concentration (MIC) values around 250 µg/mL. Meanwhile, their in vitro antifungal evaluation demonstrated a potent activity against Candida tropicalis with MIC value as low as 2 µg/mL for most of the tested compounds. Moreover, compound 6f is the most potent congener with an MIC value of 2 µg/mL against Candida albicans.     

Structural Characterization and Assessment of Anti-Inflammatory Activities of Polyphenols and Depsidone Derivatives from Melastoma malabathricum subsp. normale

The roots of Melastoma malabathricum subsp. normale (D. Don) Karst. Mey have been used in traditional ethnic medicine systems in China to treat inflammation-triggered ailments, such as trauma, toothache, and fever. Therefore, the aim of this study is to screen for compounds with anti-inflammatory activity in the title plant. The extract of M. malabathricum subsp. normale roots was separated using various chromatographic methods, such as silica gel, ODS C18, MCI gel, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. One new complex tannin, named whiskey tannin D (1), and an undescribed tetracyclic depsidone derivative, named guanxidone B (2), along with nine known polyphenols (2–10) and three known depsidone derivatives (12–14) were obtained from this plant. The structures of all compounds were elucidated by extensive NMR and CD experiments in conjunction with HR-ESI-MS data. All these compounds were isolated from this plant for the first time. Moreover, compounds 1–4, 8, and 10–14 were obtained for the first time from the genus Melastoma, and compounds 1, 2, and 11–14 have not been reported from the family Melastomataceae. This is the first report of complex tannin and depsidone derivatives from M. malabathricum subsp. normale, indicating their chemotaxonomic significance to this plant. Compounds 1–12 were investigated for their anti-inflammatory activities on the production of the nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and compounds 1, 11, and 12 showed anti-inflammatory activities with IC₅₀ values of 6.46 ± 0.23 µM, 8.02 ± 0.35 µM, and 9.82 ± 0.43 µM, respectively. The structure–activity relationship showed that the catechin at glucose C-1 in ellagitannin was the key to its anti-inflammatory activity, while CH₃O- at C-16 of aromatic ring A in depsidone derivatives had little effect on its anti-inflammatory activity. The study of structure–activity relationships is helpful to quickly discover new anti-inflammatory drugs. The successful isolation and structure identification of these compounds, especially complex tannin 1, not only provide materials for the screening of anti-inflammatory compounds, but also provide a basis for the study of chemical taxonomy of the genus Melastoma.     

Five New Terpenes with Cytotoxic Activity from Pestalotiopsis sp.

Five new compounds called Pestalotis A–E (1–5), comprising three monoterpene-lactone compounds (1–3), one tetrahydrobenzofuran derivative (4), and one sesquiterpene (5), were isolated from the EtOAc extract of Pestalotiopsis sp. The structures of the new compounds were elucidated by analysis of their NMR, HRMS, and ECD spectra, and the absolute configurations were established through the comparison of experimental and calculated ECD spectra. All compounds were tested for antitumor activity against SW-480, LoVo, HuH-7, and MCF-7. The results showed that compounds 2 and 4 exhibited potent antitumor activity against SW-480, LoVo, and HuH-7 cell lines. Furthermore, compound 4 was assessed against HuH-7, and the results indicated that the rate of apoptosis was dose-dependent.     

Enzyme inhibiting lignans from Vitex negundo

Two new lignans trivially named negundins A (1) and B (2), were isolated along with (+)-diasyringaresinol (3), (+)-lyoniresinol (4), vitrofolal E (5) and vitrofolal F (6), reported for the first time from this species. The structures of the new compounds were established through spectral studies. Compound 2 showed potent inhibitory activity against lipoxygenase enzyme, while 5 showed moderate activity against butyryl-cholinesterase.     

Tuliposides H–J and Bioactive Components from the Bulb of Amana edulis

Three new tuliposides H–J (1–3) and 11 known compounds were obtained from the methanolic extracts of the bulbs of Amana edulis for the first time. Their structures were elucidated by NMR, MS, and IR spectroscopic data, optical rotation, and Mosher’s method. The melanogenesis properties of all the isolates were evaluated in B16 melanoma cells. Consequently, tributyl citrate (9) had anti-melanogenesis activity but was cytotoxic toward B16. (+)-Pyroglutamic acid (4), (+)-butyl 5-oxopyrrolidine-2-carboxylate (6), (–)-3-hydroxy-2-methylbutyrolactone (10), and 5-(hydroxymethyl)furfural (12) had increased melanin productions and tyrosinase activities. Those active components could be further studied as the candidates against melanoma and vitiligo for skin diseases or whitening/hypopigmentation for hair.     

Microbial Transformation and Biological Activities of the Prenylated Aromatic Compounds from Broussonetia kazinoki

Broussonetia kazinoki has been used as a traditional medicine for the treatment of burns and acne, and its extracts have been found to show tyrosinase inhibitory and anticancer activities. In this study, the tyrosinase inhibitory and cytotoxic activities of B. kazinoki were explored, leading to the isolation of kazinol C (1), kazinol E (2), kazinol F (3), broussonol N (4), and kazinol X (5), of which the compounds 4 and 5 have not been previously reported. Microbial transformation has been recognized as an efficient tool to generate more active metabolites. Microbial transformation of the major compounds 1 and 3 was conducted with Mucor hiemalis, where four glucosylated metabolites (6–9) were produced from 1, while one hydroxylated (10) and one glucosylated (11) metabolites were obtained from 3. Structures of the isolated metabolites were determined by extensive spectroscopic analyses. All compounds were evaluated for their tyrosinase inhibitory and cytotoxic activities. Compound 3 and its metabolites, kazinol Y (10) and kazinol F-4″-O-β-d-glucopyranoside (11), exhibited the most potent tyrosinase inhibitory activities with the IC₅₀ values ranging from 0.71 to 3.36 µM. Meanwhile, none of the metabolites, except for kazinol C-2′,3″-di-O-β-d-glucopyranoside (7), showed moderate cytotoxic activities (IC₅₀ 17.80 to 24.22 µM) against A375P, B16F10 and B16F1 cell lines.     

Synthesis of Silver Nanoparticles from Extracts of Wild Ginger (Zingiber zerumbet) with Antibacterial Activity against Selective Multidrug Resistant Oral Bacteria

Antibiotic resistance rate is rising worldwide. Silver nanoparticles (AgNPs) are potent for fighting antimicrobial resistance (AMR), independently or synergistically. The purpose of this study was to prepare AgNPs using wild ginger extracts and to evaluate the antibacterial efficacy of these AgNPs against multidrug-resistant (MDR) Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis. AgNPs were synthesized using wild ginger extracts at room temperature through different parameters for optimization, i.e., pH and variable molar concentration. Synthesis of AgNPs was confirmed by UV/visible spectroscopy and further characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy analysis (EDXA), and Fourier-transform infrared spectroscopy (FTIR). Disc and agar well diffusion techniques were utilized to determine the in vitro antibacterial activity of plant extracts and AgNPs. The surface plasmon resonance peaks in absorption spectra for silver suspension showed the absorption maxima in the range of 400–420 nm. Functional biomolecules such as N–H, C–H, O–H, C–O, and C–O–C were present in Zingiber zerumbet (Z. zerumbet) (aqueous and organic extracts) responsible for the AgNP formation characterized by FTIR. The crystalline structure of ZZAE-AgCl-NPs and ZZEE-AgCl-NPs was displayed in the XRD analysis. SEM analysis revealed the surface morphology. The EDXA analysis also confirmed the element of silver. It was revealed that AgNPs were seemingly spherical in morphology. The biosynthesized AgNPs exhibited complete antibacterial activity against the tested MDR bacterial strains. This study indicates that AgNPs of wild ginger extracts exhibit potent antibacterial activity against MDR bacterial strains.     

Isolation of Anti-Diabetic Active Compounds from Benincasae Exocarpium and Development of Simultaneous Analysis by HPLC-PDA

Diabetes is a chronic metabolic disease that is a constant problem. Previous studies have reported that Benincasa cerifera Savi. extracts are effective in treating diabetes and its complications. Benincasae Exocarpium (BE) is a fruit peel of B. cerifera that has been reported to be used for the prevention and treatment of metabolic diseases such as hyperglycemia, obesity, and hyperlipidemia. However, there are not enough studies on the compounds and bioassays to support the efficacy of BE. The inhibitory activity of the BE extracts and fractions against advanced glycation end-products (AGE) formation and α-glucosidase activity was evaluated. These assays are relevant for the treatment of type 2 diabetes and its complications. Based on these results, compounds 1–11 were isolated through bioassay-guided isolation. In addition, we developed a high-performance liquid chromatography (HPLC) method that can simultaneously analyze these 11 compounds. Activity evaluation of the compounds was also conducted, and eight compounds exhibited significant activity. Among these, flavonoid compounds showed strong activity. A quantitative evaluation of eight bioactive compounds (2, 5–11) was conducted. In conclusion, this study demonstrated the potential of BE for prevention and treatment of type 2 diabetes and its complications.     

Synthesis,Characterization and Biological Evaluation of New 3,5-Disubstituted-Pyrazoline Derivatives as Potential Anti-Mycobacterium tuberculosis H37Ra Compounds

A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (¹H, ¹³C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound.     

New Polyenes from the Marine-Derived Fungus Talaromyces cyanescens with Anti-Neuroinflammatory and Cytotoxic Activities

Three new polyene compounds, talacyanols A–C (1–3), along with two known compounds, ramulosin (4) and eurothiocin A (5), were isolated from the marine fungus Talaromyces cyanescens derived from a seaweed Caulerpa sp. Structures of 1–5 were established by one-dimensional and two-dimensional (1D/2D) NMR, HR-ESIMS, and the modified Mosher’s methods, as well as comparison with previously reported literature data. All the compounds (1–5) were tested for their in vitro cytotoxic and anti-neuroinflammatory activities. Among them, 1 showed moderate cytotoxic activity against a panel of cancer cell lines (HCT-15, NUGC-3, NCI-H23, ACHN, PC-3, and MDA-MB-231) with GI₅₀ values ranging from 44.4 to 91.6 μM, whereas compounds 2 and 5 exhibited anti-neuroinflammatory effect without cytotoxicity against all the tested cell lines.