Two new halogenated sesquiterpene lactones from Palisada intermedia.

Two new sesquiterpene lactones, laurenolide A (1) and laurenolide B (2), along with six known compounds, palmitic acid (3), (R,R)-hexahydrofarnesyl acetone (4), trans-phytol acetate (5), cholesterol (6), cholesteryl acetate (7), cholesteryl heptadecanoate (8) were isolated from Palisada intermedia. The chemical structures of all compounds were elucidated by 1D and 2D-NMR spectroscopy and HR-ESI-MS analysis as well as compared with data in the literature. The petroleum ether, chloroform, ethyl acetate, methanol extracts and compounds 1, 2 were tested for the inhibition of two cancer cell lines MCF-7, NCI-H460 and they showed weak or none activities.

Nepetifoliol - a new glutinane-triterpenoid from Leonotis nepetifolia.

A new glutinane-triterpenoid, nepetifoliol (1), together with two known compounds, dymacrin D (2), and (+)-ar-tumerone (3) were isolated from the n-hexane extract of the aerial parts of Leonotis nepetifolia. Their chemical structures were elucidated by spectroscopic data analysis as well as the comparison of their NMR data with the ones published in the literatures. A putative biosynthetic pathway for the formation of the new compound (anti-diaxial-5,6-diol) (1) from the precursor triterpene glutinol was proposed. Compounds (2), (3) and some previously reported ones, isolated from this extract, including 5α-stigmasta-22-ene-3-one (4), friedelin (5), chrysophanol (6), physcion (7), and 4'-O-methylalpinumisoflavone (8) were evaluated for their α-glucosidase inhibition. Among tested compounds, 3 and 6 showed good activities with their IC50 values of 5.3 ± 0.2 and 4.9 ± 0.3 µg/mL, respectively, comparing to the positive control, acarbose (IC50 127.7 ± 0.2 µg/mL).

Two new sesquiterpenes from the stems of Miliusa velutina.

From the ethyl acetate extract of the stems of Miliusa velutina, seven compounds (1-7) were isolated, including two new compounds such as mivelutina A acid (1), mivelutina B acid (2) and one known compound mivelutina B methyl ester (3). For this NMR data were not known previously. Their relative structures were elucidated based on NMR spectroscopic analysis. The absolute configuartions were determined based on DFT calculations of 13C chemical shifts. All of the seven compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay. Epoxyconiferyl alcohol (7) showed the highest potential for the cytotoxicity of cancer cell lines HepG2 with the IC50 values of 95.94 µg/mL (527 µM).

A new lignan from the flowers of Hibiscus sabdariffa L. (Malvaceae).

From MeOH-soluble fraction of the flowers of Hibiscus sabdariffa (Malvaceae), one new lignan, (+)-4-O-methyl-5'-methoxy-secoisolariciresinol (1), together with four known compounds (2-5) were isolated. The structures were elucidated based on NMR spectroscopic analysis. The absolute configuration of 1 was determined based on the Cotton effects in the CD spectrum. Compounds 1, 3 and 4 showed antioxidant activities with the SC50 values of 56.9, 19.3 and 22.7 µM, respectively.

Utilization of Crab Waste for Cost-Effective Bioproduction of Prodigiosin.

This study aimed to establish the culture process for the cost-effective production of prodigiosin (PG) from demineralized crab shell powder (de-CSP), a fishery processing byproduct created via fermentation. Among the tested PG-producing strains, Serratia marcescens TNU02 was demonstrated to be the most active strain. Various ratios of protein/de-CSP were used as the sources of C/N for PG biosynthesis. The PG yield was significantly enhanced when the casein/de-CSP ratio was controlled in the range of 3/7 to 4/6. TNU02 produced PG with a high yield (5100 mg/L) in a 15 L bioreactor system containing 4.5 L of a newly-designed liquid medium containing 1.6% C/N source (protein/de-CSP ratio of 3/7), 0.02% (NH4)2SO4, 0.1% K2HPO4, and an initial pH of 6.15, at 27 °C for 8 h in dark conditions. The red pigment was purified from the culture broth and then quantified as being PG by specific Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and UV spectra analysis. The purified PG demonstrated moderate antioxidant and effective inhibition against four cancerous cell lines. Notably, this study was the first to report on using crab wastes for PG bioproduction with high-level productivity (5100 mg/L) in a large scale (4.5 L per pilot) in a short period of fermentation time (8 h). The salt compositions, including (NH4)2SO4 and K2HPO4, were also a novel finding for the enhancement of PG yield by S. marcescens in this report.

Chemical constituents of Geum urbanum L. roots.

A new dehydrodigallic acid derivative (1), along with 19 known compounds, including 6 phenolic derivatives, 2 steroids and 11 triterpenoids were isolated from the ethanol extract of the root of Geum urbanum. Herein, there is the first report of steroid and triterpene in Geum urbanum. The purified metabolites were characterised by NMR spectroscopic and mass spectrometric analyses. The identification of the known compounds (2-20) was based on the comparison of their NMR spectroscopic features with previously published data. The structural characteristics of compound 1 were elucidated by comprehensive 1D and 2D NMR spectroscopic methods and acid hydrolysis.