Total Synthesis of Cyclosenegalin A.

A Pro-Gly-typed cyclopeptide, cyclosenegalin A, was firstly isolated from Annona senegalensis and Annona scleroderma. In this study, we reported synthesis the cycloheptapeptide with a combination of solid- and solution-phase synthetic methods. This study also compared the effectiveness of ß-turn inducer type I and II in cyclosenegalin A to facilitate the cyclization process. The synthesis of cyclosenegalin A were prepared using two different sequences of linear peptides for cyclization. First sequence employed ß-turn type I inducer (Ser-Ala-Val-Thr) as turning point and second sequence employed ß-turn type II inducer (Thr-Pro-Gly-Leu). The successful cyclization was obtained using the linear sequence of NH2-Ala-Val-Thr-Pro-Gly-Leu-Ser-OH with ß-turn type II. The final product was obtained in 8.2 % yield with PyBOP/DIEA act as coupling agent. The synthetic cyclosenegalin A were characterized with HR-ToFMS, 1H NMR, 13C NMR, HSQC, HMBC, TOCSY, and ROESY. The synthetic product was also evaluated for its antimicrobial activity.

Bioinformatics Study of Flavonoids From Genus Erythrina As Ace2 inhibitor Candidates For Covid-19 Treatment.

Purpose: This study aimed to screen potential drug candidates from the flavonoids of the genus Erythrina for the Corona Virus Disease 2019 (COVID-19) treatment. Patients and Methods: A comprehensive screening was conducted on the structures of 473 flavonoids derived from the genus Erythrina, focusing on their potential toxicity and pharmacokinetic profiles. Subsequently, flavonoids that were non-toxic and possessed favorable pharmacokinetic properties underwent further analysis to explore their interactions with the angiotensin-converting enzyme 2 (ACE2) receptor, employing molecular docking and molecular dynamics simulations. Results: Among 473 flavonoids, 104 were predicted to be safe from being mutagenic, hepatotoxic, and inhibitors of the human ether-a-go-go-related gene (hERG). Among these 104 flavonoids, 18 compounds were predicted not to be substrates of P-glycoprotein (P-gp). Among these 18 flavonoids, gangetinin (471) and erybraedin D (310) exhibit low binding affinities and root mean square deviation (RMSD) values, indicating stable binding to the ACE2 receptor. The physicochemical attributes of compounds 310 and 471 suggest that they possess drug-like properties. Conclusion: Gangetinin (471) and erybraedin D (310) may serve as promising candidates for COVID-19 treatment due to their potential to inhibit the ACE2-RBD interaction. This warrants further investigation into their inhibitory effects on ACE2-RBD binding through in vitro experiments.

Virtual Screening and ADMET Prediction to Uncover the Potency of Flavonoids from Genus Erythrina as Antibacterial Agent through Inhibition of Bacterial ATPase DNA Gyrase B.

The emergence of antimicrobial resistance due to the widespread and inappropriate use of antibiotics has now become the global health challenge. Flavonoids have long been reported to be a potent antimicrobial agent against a wide range of pathogenic microorganisms in vitro. Therefore, new antibiotics development based on flavonoid structures could be a potential strategy to fight against antibiotic-resistant infections. This research aims to screen the potency of flavonoids of the genus Erythrina as an inhibitor of bacterial ATPase DNA gyrase B. From the 378 flavonoids being screened, 49 flavonoids show potential as an inhibitor of ATPase DNA gyrase B due to their lower binding affinity compared to the inhibitor and ATP. Further screening for their toxicity, we identified 6 flavonoids from these 49 flavonoids, which are predicted to have low toxicity. Among these flavonoids, erystagallin B (334) is predicted to have the best pharmacokinetic properties, and therefore, could be further developed as new antibacterial agent.

An overview of techniques and strategies for isolation of flavonoids from the genus Erythrina.

Plants in the genus Erythrina is a potential source of chemical constituents, one of which is flavonoids, which have diverse bioactivities. To date, literature on the flavonoids from the genus Erythrina has only highlighted the phytochemical aspects, so this review article will discuss isolation techniques and strategies for the first time. More than 420 flavonoids have been reported in the Erythrina genus, which are grouped into 17 categories. These flavonoid compounds were obtained through isolation techniques and strategies using polar, semi-polar, and non-polar solvents. Various chromatographic techniques have been developed to isolate flavonoids using column flash chromatography, quick column chromatography, centrifugally accelerated thin-layer chromatography, radial chromatography, medium-pressure column chromatography, semi-preparative high-performance liquid chromatography, and preparative high-performance liquid chromatography. Chromatographic processes for isolating flavonoids can be optimized using multivariate statistical applications such as response surface methodology with central composite design, Box-Behnken design, Doehlert design, and mixture design.

Tirucallane-type triterpenoid from the stem bark of Chisocheton lasiocarpus and its cytotoxic activity against MCF-7 breast cancer cells.

Chisocarpene A (1) is a new tirucallane-type triterpenoid together with odoratone (2) and 24-methylenecycloartanol (3), isolated from the stem bark of Chisocheton lasiocarpus. The chemical structures of compounds 1-3 were elucidated through a detailed analysis of their spectroscopic data (IR, MS, 1 D, and 2 D NMR). The isolated compounds were evaluated for cytotoxic activity against the MCF-7 breast cancer cell line using a resazurin-based assay. Compound 1 showed the most potent activity (IC50 26.56 ± 1.01 µM) and was two-fold more active than the positive control.

Sesquiterpenoids and sesquiterpenoid dimers from the stem bark of Dysoxylum parasiticum (osbeck) kosterm.

Two undescribed sesquiterpenoids, namely dysoticans A and B, and three undescribed sesquiterpenoid dimers, namely dysoticans C-E, together with six analogs, were isolated from the stem bark of Dysoxylum parasiticum (Osbeck) Kosterm. (Meliaceae), growing in West Java, Indonesia. Their structures were elucidated based on extensive spectroscopic analysis and theoretical simulations of ECD spectra and 13C NMR shifts. Dysoticans A and B possessed undescribed cadinanes with minor modifications, while C and D featured unprecedented pseudo-sesquiterpenoid dimers through O-ether linkages of cadinanes and guaianes, respectively. Dysotican E was also characterized as the true-sesquiterpenoid dimer featuring eudesmane-germacrene hybrid framework from the Meliaceae family. Furthermore, A-C and E showed moderate activities against the human breast cancer MCF-7 and cervical cancer HeLa cell lines with IC50 values ranging from 22.15 to 45.14 µM. D selectively exhibited significant cytotoxicity against the HeLa cell line with an IC50 value of 13.00 ± 0.13 µM.

Dammarane-Type Triterpenoid from the Stem Bark of Aglaia elliptica (Meliaceae) and Its Cytotoxic Activities.

Two new dammarane-type triterpenoid fatty acid ester derivatives, 3ß-oleate-20S-hydroxydammar-24-en (1) and 3ß-oleate-20S,24S-epoxy-25-hydroxydammarane (2) with a known dammarane-type triterpenoid compound, such as 20S-hydroxydammar-24-en-3-on (3), were isolated from the stem bark of Aglaiaelliptica (C.DC.) Blume. The chemical structures were determined by spectroscopic methods, including FTIR, NMR (one and two-dimensional), and HRESITOF-MS analysis, as well as chemical derivatization and comparison with previous literature. Furthermore, the synthetic analog resulting from transesterification of 1 and 2 also obtained 3ß,20S-dihydroxy-dammar-24-en (4) and 20S,24S-epoxy-3ß,25-dihydroxydammarane (5), respectively. The cytotoxic effect of all isolated and synthetic analog compounds was evaluated using PrestoBlue reagent against MCF-7 breast cancer cell and B16-F10 melanoma cell lines. The 20S-hydroxydammar-24-en-3-on (3) showed the strongest activity against MCF-7 breast cancer and B16-F10 melanoma cell, indicating that the ketone group at C-3 in 3 plays an essential role in the cytotoxicity of dammarane-type triterpenoid. On the other hand, compounds 1 and 2 had very weak cytotoxic activity against the two cell lines, indicating the presence of fatty acid, significantly decreasing cytotoxic activity. This showed the significance of the discovery to investigate the essential structural feature in dammarane-type triterpenoid, specifically for the future development of anticancer drugs.

Flavanones from Erythrina crista-galli Twigs and Their Antioxidant Properties Determined through In Silico and In Vitro Studies.

Flavonoids are a secondary metabolite group with various bioactivities, such as antioxidants. They are rich in the genus Erythrina, such as Erythrina crista-galli. This research aims to isolate and characterize flavonoids from the twigs of E. crista-galli and determine their antioxidant properties through in silico and in vitro assays. The ethyl acetate extract of E. crista-galli twigs were separated by column chromatography and characterized using spectroscopic methods. Density functional theory (DFT) calculations were performed on the isolated flavonoids and the reference compounds (ascorbic acid and quercetin) to obtain global descriptive parameters and a donor-acceptor map (DAM). We successfully isolated lupinifolin (1) and citflavanone (2) for the first time from E. crista-galli, along with lonchocarpol A (3), which has been discovered previously. The DAM suggests that these flavanones are good antiradicals with effective electron donors. However, they tend to be electron acceptors in methanol. The frontier molecular orbital analysis implies that lupinifolin (1) is a better antiradical than the other flavanones. The DPPH assays show that lupinifolin (1) has the highest antioxidant (antiradical) activity, with an IC50 value of 128.64 ppm. The in silico studies showed similar trends to the in vitro assays using the DPPH method.

Microencapsulation of lime (Citrus aurantifolia) oil for antibacterial finishing of cotton fabric.

Functional cotton fabric incorporated with antibacterial microcapsules of lime (C. aurantifolia) essential oil (LO) was prepared. The coacervation method, employing two biopolymers of alginate and gelatin as the shells, was preferentially selected to produce the LO microcapsules, whereas immobilization of the LO microcapsules onto the fabric was done using the pad-dry-cure method using various concentrations of citric acid binder. The antibacterial inhibition zone of the functional fabric was subsequently analysed using the Kirby Bauer method. The LO microcapsules were produced with a yield, encapsulation efficiency (EE), and oil content (OC) of 47 ± 4%, 84 ± 11%, and 58 ± 4%, respectively. The homogenous spherical and soft microcapsules (1.554 µm) bonded effectively by 4% citric acid onto the surface of the fabric and detached back by only 3% after 15 cycles of washing. Overall, the optimized functional fabric exhibited the highest antibacterial activities among others against typical skin bacteria, such as S. aureus, E. coli, K. pneumoniae, and S. epidermidis, and thus it can be potentially applied to obtain antibacterial functional textile.

A new antiplasmodial sterol from Indonesian marine sponge, Xestospongia sp.

A new antimalarial sterol, kaimanol (1), along with a known sterol, saringosterol (2) was isolated from the Indonesian Marine sponge, Xestospongia sp. The chemical structure of the new compound was determined on the basis of spectroscopic evidences and by comparison to those related compounds previously reported. Isolated compounds, 1 and 2 were evaluated for their antiplasmodial effect against Plasmodium falciparum 3D7 strains. Compounds 1 and 2 exhibited antiplasmodial activity with IC50 values of 359 and 0.250 nM, respectively.

Potential Allylpyrocatechol Derivatives as Antibacterial Agent Against Oral Pathogen of S. sanguinis ATCC 10,556 and as Inhibitor of MurA Enzymes: in vitro and in silico Study.

BACKGROUND: Streptococcus sanguinis is Gram-positive bacteria that contribute to caries. Many antibacterial agents are resistant against bacteria so that the discovery of new antibacterial agents is a crucial issue. Mechanism of antibacterial agents by disrupting cell wall bacteria is a promising target to be developed. One of the enzymes contributing to the cell wall is MurA enzyme. MurA is an enzyme catalyzing the first step of peptidoglycan biosynthesis in the cell wall formation. Inhibiting MurA is an effective and efficient way to kill the bacteria. Source of bioactive compounds including the antibacterial agent can be found in natural product such as herbal plant. Piper betle L. was reported to contain active antibacterial compounds. However, there is no more information on the antibacterial activity and molecular mechanism of P. betle's compound against S. sanguinis. PURPOSE: The study aims to identify antibacterial constituents of P. betle L. and evaluate their activities through two different methods including in vitro and in silico analysis. MATERIALS AND METHODS: The antibacterial agent was purified by bioactivity-guided isolation with combination chromatography methods and the chemical structure was determined by spectroscopic methods. The in vitro antibacterial activity was evaluated by disc diffusion and dilution methods while the in silico study of a compound binds on the MurA was determined using PyRx program. RESULTS: The antibacterial compound identified as allylpyrocatechol showed inhibitory activity against S. sanguinis with an inhibition zone of 11.85 mm at 1%, together with MIC and MBC values of 39.1 and 78.1 µg/mL, respectively. Prediction for molecular inhibition mechanism of allylpyrocatechols against the MurA presented two allylpyrocatechol derivatives showing binding activity of -5.4, stronger than fosfomycin as a reference with the binding activity of -4.6. CONCLUSION: Two allylpyrocatechol derivatives were predicted to have a good potency as a novel natural antibacterial agent against S. sanguinis through blocking MurA activity that causes disruption of bacterial cell wall.

A new limonoid from stem bark of Chisocheton pentandrus (Meliaceae).

A new limonoid, pentandricine (1), along with three known limonoids, ceramicine B (2), 6-de(acetyloxy)-23-oxochisocheton (3), 6-de(acetyloxy)-23-oxo-7-O-deacetylchisocheton (4), have been isolated from the stembark of Chisocheton pentandrus. The chemical structures of the new compound were elucidated on the basis of spectroscopic evidence. All of the compounds were tested for their cytotoxic effects against MCF-7 breast cancer cells. Compounds 1-4 showed weak and no cytotoxicity against MCF-7 breast cancer cells with IC50 values of 369.84, 150.86, 208.93 and 120.09 µM, respectively.

Dataset of curcumin derivatives for QSAR modeling of anti cancer against P388 cell line.

The dataset of curcumin derivatives consists of 45 compounds (Table 1) with their anti cancer biological activity (IC50) against P388 cell line. 45 curcumin derivatives were used in the model development where 30 of these compounds were in the training set and the remaining 15 compounds were in the test set. The development of the QSAR model involved the use of the multiple linear regression analysis (MLRA) method. Based on the method, r2 value, r2(CV) value of 0.81, 0.67 were obtained. The QSAR model was also employed to predict the biological activity of compounds in the test set. Predictive correlation coefficient r2 values of 0.88 were obtained for the test set.

Anti-inflammatory Flavonoid C-Glycosides from Piper aduncum Leaves.

Four new compounds, acacetin 8-C-[ß-D-apiofuranosyl-(1 → 2)-ß-D-glucopyranoside] (1), 7-methoxyacacetin 8-C-[ß-D-apiofuranosyl-(1 → 3)-ß-D-glucopyranoside] (2), 7-methoxyacacetin 8-C-[ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranoside] (3), and 4‴-O-acetylacacetin 8-C-[α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranoside] (4), along with ten known compounds (5-14), were isolated from Piper aduncum leaves. The effects of these compounds on lipopolysaccharide-induced expression of the proinflammatory cytokines IL-12 p40, IL-6, and TNF-α in bone marrow-derived dendritic cells were evaluated. Compounds 2, 3, 6, 8, 9, and 11-13 inhibited the production of both IL-12 p40 and IL-6, with IC50 values ranging from 0.35 ± 0.01 to 1.40 ± 0.04 µM and 1.22 ± 0.02 to 3.79 ± 0.10 µM, respectively. Compounds 5 and 10 only showed strong inhibition effects on the production of IL-12 p40, with IC50 values of 2.76 ± 0.08 and 0.39 ± 0.05 µM, respectively. However, all compounds showed weak activity or no activity on TNF-α production at the tested concentrations.

Crystal structures of 3,5-bis-[(E)-3-hy-droxy-benzyl-idene]-1-methyl-piperidin-4-one and 3,5-bis-[(E)-2-chloro-benzyl-idene]-1-methyl-piperidin-4-one.

The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).