No abstract

Six new chiro-inositol derivatives (1–6) were isolated from the leaves of Chisocheton paniculatus collected in Vietnam. Their chemical structures were elucidated by 1D and 2D NMR and HRESIMS analyses. All isolated compounds were evaluated for their inhibitory activity against lipopolysaccharide-induced nitric oxide (NO) production in the RAW 264.7 macrophage cell line. Compound 4 exhibited potent inhibitory activity for NO production with an IC50 value of 7.1 μM.

Haemanthamine (HAE) has been proven as a potential anticancer agent. However, the therapeutic use of this plant-origin alkaloid to date is limited due to the chemical instability and poorly water-soluble characteristics of the agent. To overcome these challenges, we developed novel amphiphilic electrospun nanofibers (NFs) loaded with HAE, phosphatidylcholine (PC) and polyvinylpyrrolidone (PVP), and intended for a stabilizing platform (template) of self-assembled liposomes of the active agent. The NFs were fabricated with a solvent-based electrospinning method. The chemical structure of HAE and the geometric properties, molecular interactions and physical solid-state properties of the NFs were investigated using nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), photon correlation spectroscopy (PCS), Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC), respectively. An in-house dialysis-based dissolution method was used to investigate the drug release in vitro. The HAE-loaded fibers showed a nanoscale size ranging from 197 nm to 534 nm. The liposomes with a diameter between 63 nm and 401 nm were spontaneously formed as the NFs were exposed to water. HAE dispersed inside liposomes showed a tri-modal dissolution behavior. In conclusion, the present amphiphilic NFs loaded with HAE are an alternative approach for the formulation of a liposomal drug delivery system and stabilization of the liposomes of the present alkaloid.

The aerial parts of Anthemis tinctoria L. and Angelica sylvestris L. and the roots of A. sylvestris have been used as traditional anticancer remedies in Estonian ethnomedicine. The aim of this study was to investigate content of essential oils (by gas chromatography) and polyphenolic compounds (using two different methods of high performance liquid chromatography–mass spectrometry (HPLC–MS)) of both plant species, as well as the in vitro anti-cancer effects of their essential oils and methanolic extracts. The average (n = 5 samples) yield of essential oils was 0.15%, 0.13%, and 0.17%, respectively. The principal compounds of the essential oil from the aerial parts of A. tinctoria were palmitic acid (15.3%), p-cymene (12.6%), and α-muurolene (12.5%), and α-pinene (45.4%), p-cymene (15.5%), and β-myrcene (13.3%) in aerial parts of A. sylvestris, while isocaryophyllene oxide (31.9%), α-bisabolol (17.5%), and α-pinene (12.4%) were the main constituents in the roots. The most abundant phenolic compounds in aerial parts were the derivatives of caffeic acid, quinic acid, and quercetin; the main compounds in roots of A. sylvestris were chlorogenic acid, quinic acid, and naringenin. The strongest anticancer effects were observed in essential oils of A. sylvestris roots and aerial parts on human carcinoma in the mouth cells (KB, IC50 19.73 μg/mL and 19.84 μg/mL, respectively). The essential oil of A. tinctoria showed a strong effect on KB and LNCaP cells (27.75–29.96 μg/mL). The methanolic extracts of both plants had no effect on the cancer cells studied.

A new flavanol derivative, (2R,3R)-3-acetoxy-7-hydroxy-3′,4′-methylenedioxyflavan (1), was co-isolated from the rhizomes of Zephyranthes ajax Hort. with the following seven known compounds: 7-hydroxyflavan (2), 7,4′-dihydroxyflavan (3), 7,4′-dihydroxy-8-methylflavan (4), 7,3′-dihydroxy-4′-methoxyflavan (5), 5,4′-dihydroxy-7-methoxy-6-methylflavan (6), 7-hydroxy-3′,4′-methylenedioxyflavanone (7) and haemanthamine (8). Their structures were elucidated by combining 1D-/2D-NMR, CD, UV and HRESIMS data, and comparisons with reported data in literature were made. Among these known compounds, 2, 3, 4, 6 and 7 were isolated from the genus Zephyranthes for the first time. In addition, the cytotoxicity assay indicated that compound 8 has potent cytotoxic activity against human hepatocellular carcinoma (the HepG2 cell line), human lung carcinoma (the SK-LU-1 cell line), human carcinoma in the mouth (the KB cell line), human colon carcinoma (the SW480 cell line) and human stomach gastric adenocarcinoma (the AGS cell line), with IC50 values ranging from 4.4 to 11.3 µM. This is the first study reporting the cytotoxicity of compound 8 against the SK-LU-1 cancer cell lines.

Context: Bioactivities of Alphonsea tonkinensis A.DC have not been reported previously, while the knowledge about its chemical composition is limited. Aims: To investigate the phytochemical constituents and bioactivities of the stems and leaves of Alphonsea tonkinensis A.DC. Methods: Combination of various extraction, chromatographic methods and crystallization techniques were performed to obtain pure compounds. Chemical structures of isolated compounds were determined by spectroscopic analyses (1D and 2D NMR). The in vitro anti-inflammatory and cytotoxic activities of isolates were evaluated by a Griess assay and a sulforhodamine B assay. Results: A phytochemical study of the stems and leaves of Alphonsea tonkinensis A.DC. resulted in the isolation of liriodenine (1), N–trans-feruloyltyramin (2), corydaldine (3), 8-oxopseudopalmatine (4), 3-hydroxy-7,8-dehydro-β-ionone (5), pseudopalmatine (6), pseudocolumbamine (7), and stigmasterol (8). Compound 5 showed potent inhibitory activity for NO production with an IC50 value of 20.4 μM, which was comparable to that of positive control. Compound 4 and 5 displayed inhibitions against the HepG2, SK-LU-1 cancer cell lines with IC50 values ranging from 54.4 and 69.6 µM. Conclusions: Among eight compounds isolated from Alphonsea tonkinensis A.DC., compounds 3 and 5 were isolated from the genus Alphonsea for the first time. Compound 5 was stronger inhibitor of NO production than positive control L-NMMA. In addition, this is the first investigation showing the bioactivities of 5 and cytotoxicity against the HepG2, SK-LU-1 cancer cell lines of 4.

Stigmasterol (STIG) among the most plentiful plant sterols has been demonstrated to possess a wide range of biological activities. However, the therapeutic use and efficacy of this plant sterol are limited due to its poorly water-soluble characteristics. To overcome these challenges, the present study was undertaken to formulate novel amphiphilic electrospun nanofibers (NFs) loaded with STIG, phosphatidylcholine and polyvinylpyrrolidone. The chemical structure of STIG, surface morphology, physical solid state, and drug-polymer interactions of NFs were characterized using nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC), respectively. The drug release of NFs was investigated in vitro using an in-house dialysis-based dissolution method. The STIG-loaded NFs presented a nano-scale size of 297 ± 56 nm. The liposomes with a diameter of 436 ± 64 nm were spontaneously formed as the NFs were exposed to water. The entrapment efficiency of liposomes was 57%. In conclusion, the present amphiphilic NFs loaded with STIG enable a promising alternative approach for drug delivery of the present poorly water-soluble plant sterol.

Knowledge of the bioactivity of Alphonsea tonkinensis A.DC is limited. We have investigated the in vitro acetylcholinesterase inhibitory and antioxidant activities of extracts and pure compounds isolated from stems and leaves of this species collected from Dakrong district, Quang Tri Province, Vietnam. Extracts and isolated compounds were obtained by using an in-house extraction and chromatographic technique. The in vitro acetylcholinesterase inhibitory and antioxidant activities were evaluated using an Ellman test and 2,2-diphenyl-1-picryl-hydrazyl test, respectively. The total MeOH and CH2Cl2 extracts, the MeOH portion of the CH2Cl2 extract, pseudocolumbamine, and pseudopalmatine showed potential inhibitory activity against acetylcholinesterase with IC50 values of 22.7, 32.9, 14.6, 18.9, and 8.6 μM, respectively. The aqueous phase (pH 9), MeOH portion of the CH2Cl2 extract, and N- trans-feruloyltyramin exhibited significant antioxidant activities with IC50 values of 24.5, 72.1, and 61.2 µM, respectively. This is the first study showing such bioactivities of various extracts obtained from A. tonkinensis.