Anti-hyperglycemic fraction from Alternanthera sessilis L. leaves gets elucidated following bioassay-guided isolation and mass spectrometry

Abstract The anecdotal use of Alternanthera sessilis L. as a relief for diabetes has been known in the Philippines for generations, and antidiabetic activity of similar varieties in other countries is likewise documented. However, the compounds responsible for this activity remain unclear. This study aims to isolate the anti-hyperglycemic fraction of local A. sessilis leaves and identify the compounds in this fraction. Methanol extract of A. sessilis leaves and its hexane, ethyl acetate (ASE), and water fractions were administered to alloxan-induced diabetic mice. ASE (250mg/kg) had the highest anti-hyperglycemic activity at 6-h post-treatment (25.81%±12.72%), with almost similar blood glucose reduction rate as metformin (30.13±3.75%, p=0.767). Repeated fractionation employing chromatographic separation techniques followed by in vivo anti-hyperglycemic assay yielded partially purified subfractions. A. sessilis ethyl acetate subfraction 4-2 (100mg/kg) displayed remarkable suppression of blood glucose rise in diabetic mice at 6-h post-treatment (26.45±3.75%, p<0.0001), with comparable activity with metformin (100mg/kg, 27.87±5.65%, p=0.652). Liquid chromatography/mass spectrometry showed eight distinct peaks, with four peaks annotated via the Traditional Chinese Medicine library and custom library for A. sessilis. Among these, luteolin, apigenin, ononin, and sophorabioside were identified as putative compounds responsible for the anti-hyperglycemic activity. This result provided basis for the reported anecdotal claims and potential utility of the local variety of A. sessilis leaves as sources of anti-hyperglycemic agents

Sterols possess immunomodulatory property: Activity guided isolation and in vitro screening of phytoconstituents of Pongamia glabra and Ficus glomerata / 中草药·英文版

Objective: To isolate the phytoconstituents from the methanolic extracts of the stem bark of Pongamia glabra and Ficus glomerata, characterize spectroscopically and screen for in vitro immunomodulatory activity on human neurophils. Methods: A flavonoid (PGF) and an alkaloidal compound (PGA) from the extract of P. glabra and a steroidal compound (FGS) and tannin fraction (FGT) from the extract of F. glomerata were isolated using column chromatography technique and were subjected for the spectroscopic (FT-IR, 1HNMR and LC-MS) and TLC studies to identify the compounds. The isolated compounds were screened for in vitro immunomodulatory activity on human neutrophils using nitroblue tetrazolium (NBT) dye test, phagocytosis of Candida albicans and neutrophil locomotion and chemotaxis assay at the concentration range of 100, 50, 25, 12.50 and 5.00 µg/mL. Results: From the spectroscopic and TLC studies data, the isolated compounds were identified as glabrin (PGA), karanjin (PGF), β-sitosterol (FGS), and tannin fraction (FGT). The isolated compounds PGA, PGF, FGS, and FGT exhibited significant (P < 0.05) in vitro immunomodulatory activity in all the parameters studied. Conclusion: The steroidal compound, i.e. FGS was found to be more immunopotent than all constituents alkaloid, flavonoid and tannins. Hence, these constituents could be attributed to the immunomodulatory property of the plants.

A new feruloyl glyceride from the roots of Asian rice (Oryza sativa)

Abstract Oryza sativa L., Poaceae, is the most important staple food in the world and provides food for more than half of the world's population. The roots of O. sativa have been used as a traditional medicine in Korea. As part of our continuing efforts to explore structurally new compounds from Korean natural resources, two feruloyl glycerides, 2-O-(E)-feruloyl glyceride (1) and 2-O-(Z)-feruloyl glyceride (2), which is a new compound, together with one known flavonoid, 8-hydroxyacacetin (3), were isolated from the ethanolic extract of the roots of O. sativa using an LC/MS-guided isolation method. The chemical structure of compound 2 was elucidated based on comprehensive 1D and 2D NMR spectroscopic experiments and HR-ESIMS. This study represents the first report of feruloyl glycerides (1-2) identified in O. sativa. In addition, the identification of compound 3 is reported from Asian rice (O. sativa) for the first time. The cytotoxic activities of the isolates 1-3 were evaluated by determining their inhibitory effects on A2780 human ovarian carcinoma cells.

Bioactivity-guided isolation of anti-angiotensin converting enzyme constituents from Trichosanthis Pericarpium / 中国中药杂志

To isolate the anti-angiotensin converting enzyme (ACE) constituents from Trichosanthis Pericarpium based on bioactivity-guided separation. Trichosanthis Pericarpium was extracted with boiling water and precipitated by ethanol, then its supernatant was collected and dialyzed. The retentate of the fractions above 1 000 was lyophilized to obtain GLP, which was then successively separated by DEAE Sepharose fast flow anion-exchange and Superdex-75 gel permeation chromatographic steps to achieve GLP-1-1. A combination of HPGPC, monosaccharide compositions determination and ACE inhibitory activity studies was performed to investigate the structure and bioactivity. The results showed that an anti-angiotensin converting enzyme oligosaccharide, GLP-1-1, was obtained from Trichosanthis Pericarpium based on activity tracking, whose average molecular weight was estimated to 1 367; mainly composed of arabinose, mannose, and glucose at a ratio of 0.2∶4.3∶10.0. GLP-1-1 showed potent anti-angiotensin converting enzyme effect with the IC₅₀of (113.4±8.6) mg•L⁻¹. In this study, an oligosaccharide with anti-angiotensin converting enzyme effect was isolated from Trichosanthis Pericarpium, which could lay the foundation for the substance basis study of Trichosanthis Pericarpium.

Bioassay-guided isolation of functional components from hot water extract of Chlorella pyrenoidosa / 生物工程学报

The main functional ingredients of hot water extract of Chlorella pyrenoidosa (CPE) were investigated through a bioassay-guided fractionation based on free radical scavenging and macrophage proliferation effects. The main functional ingredients of CPE were polysaccharides (PS) that were isolated by high pressure extraction, Sevag method, ethanol precipitation and ultrafiltration separation. Crude polysaccharides were further separated and purified by ion exchange chromatography DEAE52 and size exclusion chromatography Sephadex G-100. The purified fractions were analyzed by gel permeation chromatography. Molecular weights of the purified fractions PS-1-4-2, PS-1-3-2 and PS-2-3-3 were 3.97×10⁴, 2.28×10⁴ and 4.1×10³ Da, respectively. Bioassay-guided fractionation results indicated that CPE could remove free radicals and promote Ana-1 cells proliferation, mainly due to its various components working together. The components of free radicals scavenging mainly concentrated in PS-1-3, PS-1-4, PS-2-3 and PS-2-4. The components of Ana-1 proliferation mainly concentrated in PS-1-3, PS-1-4 and PS-2-3. This study established the activity screening method of main functional component from CPE, and got three new functional ingredients. It can be used to guide the development of high value products, further promote the industrialization process of microalgae energy, and realize microalgae 'high value products, microalgae energy and microalgae carbon' integration of exemplary role.

Biological activities of four Parmotrema species of Malaysian origin and their chemical constituents.

The present study was carried out to evaluate the antibacterial and antioxidant potential of acetone and methanol extracts of lichen (Parmotrema praesorediosum, P. rampoddense, P. tinctorum and P. reticulatum) and isolated chemical constituents which are praesorediosic acid, protocetraric acid, usnic acid, α–collatolic acid, β-alectoronic acid, atranorin and chloroatranorin. The antibacterial activity was evaluated using broth dilution method. Acetone extracts (except for P. reticulatum) showed good inhibitory activity against S. aureus and B. subtilis with MIC values ranging from 500–125 µg/mL, whereas, no activity was observed for the methanol extracts. Extracts exhibited zero inhibitory activity against E. coli. The antioxidant ability was measured using a DPPH free radical scavenging activity assay. Only methanol extract of P. praesorediosum exhibited more than 50% scavenging activity. Among the isolates, usnic acid exhibited the strongest antibacterial activity against S. aureus and B. subtilis with MIC value 7.81 µg/mL. Praesorediosic acid and protocetraric acid isolates exclusively inhibited E. coli at concentration 125 µg/mL and displayed results exceeding 50% scavenging activity (57.57% and 63.97%, respectively). Hitherto, it is the first evaluation of antibacterial activity on lichens of Malaysian origin and to our knowledge; the first reported study on the biological activity of praesorediosic acid and Parmotrema rampoddense.

Bioassay-Guided Isolation and Identification of Compounds from Arecae Pericarpium with Anti-inflammatory, Anti-oxidative, and Melanogenesis Inhibition Activities

This study describes the anti-inflammatory, anti-oxidant, and melanogenesis inhibition activities of methanol extract and various organic solvent fractions of Arecae Pericarpium. We examined the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells, 1,1-diphenyl-2-picrylhydrazine (DPPH) scavenging activity, mushroom tyrosinase inhibition activity and melanin contents. The study showed that, among all tested fractions, methylene chloride fraction showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells (IC₅₀ value 8.89 µg/mL) and DPPH radical scavenging activity (EC₅₀ value 21.39 µg/mL). Methylene chloride and ethyl acetate fractions similarly inhibited mushroom tyrosinase activity. Methanol extract exhibited strongest reduction of melanin content in B16F10 melanoma cells. Based on the bioactivity assay results, methylene chloride and ethyl acetate fractions were further separated. Eight phenolic compounds were isolated, which are dimeric syringol (1), catechol (2), 4-hydroxybenzaldehyde (3), vanillin (4), 4-hydroxyacetophenone (5), apocynin (6), protocatechuic acid (7) and 4-hydroxybenzoic acid (8). Among the isolated compounds tested, catechol showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells. Catechol also showed the concentration-dependent NF-κB inhibition activity. Arecae Pericarpium might have potentials to be developed as anti-inflammatory agent or dermatological product for skin-whitening agent.

Taxonomic characterization and isolation of antitrypanosomal compound from Streptomyces sp. FACC-A032 isolated from Malaysian forest soil

Aims: The present study is aimed at taxonomic characterization and isolation of active compound MS01 from Streptomyces sp. FACC-A032 which exhibited strong antitrypanosomal activity (IC50 0.02 μg/mL). Methodology and results: Isolate FACC-A032 was characterized based on its cultural, morphological, physiological and genomic properties. Isolate FACC-A032 was tentatively identified as Streptomyces sp. Biochemical analysis of diaminopimelic acid (DAP) isomer of whole-cell hydrolysates further confirmed the isolate FACC-A032 that contained LL-DAP isomer as species belonging to the genus Streptomyces. The inoculum for submerged cultures of isolate FACCA032 was prepared from cultures on ISP2 agar. After eight days of growth at 28  2 °C and 200 rpm in fermentation medium M3, fermentation broth was extracted with butanol and the crude extracts (solvent layer) were separated and dried in vacuo. Further studies were carried out to isolate the active compound from the culture extracts of isolate FACCA032. Using bioassay-guided isolation, crude extract was partitioned based on different polarity. After which, the resulting elutes were tested for antitrypanosomal activity. The active fraction was analyzed with HPLC-DAD analysis. Based on the analysis, major peak in the active fraction was collected using HPLC preparative. Active compound MS01 was isolated and structure elucidated using NMR spectroscopy. Conclusion, significance and impact of study: Bioassay-guided isolation techniques used in this study had discovered an active antitrypanosomal compound, staurosporine, from Streptomyces sp. FACC-A032. This is the first discovery of staurosporine, a protein kinase inhibitor, from Malaysian soil actinobacteria Streptomyces sp. Therefore, the study demonstrated the potential of Malaysian soil actinobacteria as antitrypanosomal therapeutic agent.

Antidepression constituents from Angelica Sinensis Radix in Xiaoyao Powder / 中草药

Objective: This current study focused on the identification of active constituents from Angelica Sinensis Radix in Xiaoyao Powder based on UPLC-PDA-guided isolation technique. Methods: The UPLC-PDA chromatogram of Xiaoyao Powder was compared with that of Angelica Sinensis Radix. The relative retention time of each peak and the Uhraviolet spectra provided by PDA were used in the analyses. The constituents were isolated from Angelica Sinensis Radix under the guidance of UPLC-PDA investigation. The structures of the isolates were elucidated by NMR techniques. The antidepression effect was evaluated on glutamate-induced neurons. Results: Five marker peaks of Xiaoyao Powder fingerprint belonged to Angelica Sinensis Radix and they were determined as coniferyl ferulate (1), E-butylidenephthalide (2), ligustilide (3), Z-butylidenephthalide (4), and 14-acetoxy-12-senecioyloxytetradeca-2E,8E,10E-trien-4,6-diyn-1-ol (5). Compound 5 was isolated from the plants in Umbelliferae for the first time. The treatment with compounds 1, 3, and 4 could protect PC12 and SH-SY5Y cells from glutamate-induced cytotoxicity. Antidepression bioactivity of compound 1 was first investigated. Conclusion: UPLC-PDA-guided isolation technique is confirmed to be a rapid and accurate method to identify the main active constituents from Angelica Sinensis Radix in Xiaoyao Powder.