Iridoid glucosides from Allamanda neriifolia

<正>A new iridoid glucoside,allamanoid(1),was isolated from the aerial parts of Allamanda neriifolia,together with three known glucosides,plumieride,protoplumericin,and nicotiflorin.Their structures were elucidated by 1D and 2D spectroscopic analyses, hydrolysis,and comparison with literature data.     

Synthesis and evaluation of in vitro anticancer activity of novel solasodine derivatives

<正>Solasodine 11 is a steroidal alkaloid with various biological activities.Herein,8 novel solasodine derivatives were synthesized and their effect on prostate cancer cell proliferation was assessed in vitro.Significant improvement in antiproliferative activity was achieved among some of the synthetic analogs.In particular,19 exhibited the most potent inhibitory effect against the proliferation of PC-3 cell line(IC_(50) = 3.91μmol/L).     

First total synthesis of eudistalbin A

<正>Eudistalbin A was isolated from marine tunicate eudistoma album and possess cytotoxic activity(ED_(50)3.2μg/mL) in vitro against the growth of KB human buccal carinoma cells.The synthetic eudistalbin A showed potent inhibitory activity against the breast carcinoma cell line MDA-231 with an IC_(50) value of 2.1μmol/L using the metabolic assay MTT.All structures of new compounds were confirmed by ~1H NMR,~(13)C NMR,HRMS and optical rotation.     

Sterols from the Fungus Catathelasma imperiale

Eight ergostane-type sterols and three their derivatives (one mono-linoleate and two mono-glucosides) were isolated from the ethyl acetate soluble fraction of the fungus Catathelasma imperi.a/e. Two of them are novel compounds, namely 22E,24R-er-gosta-7,22-diene-3β ,5α-diol-6β-linoleate (1) and 22E, 24R-er-gosta-7,22-diene-3β, 5β, 6α-triol (5) with an uncommon c/s-fused A/B ring. Structures of these compounds were demon-strated on the basis of their chemical evidences and spectroscop-ic methods, especially 2D NMR techniques.     

Process Parameters Optimization,Characterization, and Application of KOH-Activated Norway Spruce Bark Graphitic Biochars for Efficient Azo Dye Adsorption

In this work, Norway spruce bark was used as a precursor to prepare activated biochars (BCs) via chemical activation with potassium hydroxide (KOH) as a chemical activator. A Box–Behnken design (BBD) was conducted to evaluate and identify the optimal conditions to reach high specific surface area and high mass yield of BC samples. The studied BC preparation parameters and their levels were as follows: pyrolysis temperature (700, 800, and 900 °C), holding time (1, 2, and 3 h), and ratio of the biomass: chemical activator of 1: 1, 1.5, and 2. The planned BBD yielded BC with extremely high SSA values, up to 2209 m²·g⁻¹. In addition, the BCs were physiochemically characterized, and the results indicated that the BCs exhibited disordered carbon structures and presented a high quantity of O-bearing functional groups on their surfaces, which might improve their adsorption performance towards organic pollutant removal. The BC with the highest SSA value was then employed as an adsorbent to remove Evans blue dye (EB) and colorful effluents. The kinetic study followed a general-order (GO) model, as the most suitable model to describe the experimental data, while the Redlich–Peterson model fitted the equilibrium data better. The EB adsorption capacity was 396.1 mg·g⁻¹. The employment of the BC in the treatment of synthetic effluents, with several dyes and other organic and inorganic compounds, returned a high percentage of removal degree up to 87.7%. Desorption and cyclability tests showed that the biochar can be efficiently regenerated, maintaining an adsorption capacity of 75% after 4 adsorption–desorption cycles. The results of this work pointed out that Norway spruce bark indeed is a promising precursor for producing biochars with very promising properties.     

Structural Revision of Isovalertatins D03 and D23 Isolated from the Culture Filtrate of Streptomyces luteogriseus

In a program of sequentially investigating the chemical constituents of the complex, WC670, extracted from the culture filtrate of Streptomyces luteogriseus, we found it contains the reported aminooligosaccharides, yiwutadings B-F. But, when verifying their structures, there were several inconsistencies against the corresponding ESI ion trap multistage mass spectra. Our previous paper1 reported the structural revision of yiwutadings F, D and C, and these monomers were re-designated as isov…     

Preservation potential of individual couplet and deposition rates on mudflats in the Changjiang Estuary

Non-barrier mudflats in the Changjiang Estuary is examined to obtain preservation potentials and deposition rates over different time scales. The preservation potential of couplet is ca. 46.6% within daily scale and decreases as the time-interval extending, with 9.2% on a semi-lunar scale and 3.7% on a seasonal scale. In the long term, only 1.6% of daily deposition can potentially be preserved in the tidal flat sequence and other 98.4% have been eroded and leave sedimentary discordances, discernable or un-discernable, in the mudflat deposits. A negative log-linear relationship is examined between sedimentation rates and the time spans. The length of sedimentary hiatuses on the mudflat deposition were estimated with considerable uncertainty, but it can provide from an actualistic base some further insights into the nature and origin of ancient mudflat deposits with emphasis on the sedimentary discordances.     

A New Chromone Glycoside from Cassia siamea Lam.

Cassia siamea Lam. (CSL) is a common tree in the southern part of China. It has been used as folk medicine for aperient, antiarthritic and swellings1. We report here the isolation and structural elucidation of a new chromone glucoside, 2-methyl-5-propyl-7, 12-dihydroxy chromone-12-O-(-D-glucopyranoside (1), from the n-butanol-soluble fraction of CSL extract . 1The 80% ethanolic extract of CSL was dissolved in water and partitioned with petroleum ether, dichloromethane and n-butanol. The …     

PHOTOCATALYTIC HYDROGEN EVOLUTION FROM WATER SPLITTING UNDER VISIBLE LIGHT IRRADIATION ON NOVEL PHOTOCATALYST FULLENES-PVP-ZN_(0.999)NI(0.001)S

1. INTRODUCTION1. INTRODUCTIONOne of the most widely discussed subjects these days is the energy crisis, i.e. the oil shortage and the oil price rising, which encouraged us to research and develop new green energy-hydrogen energy in the 21st century. Therefore, hydrogen produced from water splittingwith photocatalyst has been extensively studied from the viewpoint of photo energy, such as solar energy conversion to chemical and electricity energy, and environmental concerns. To date, …     

A new tnterpenoid saponin from Bacopa monniera

A new triterpenoid saponin,bacopasideⅨ,was isolated from the whole plant of Bacopa monniera(L.)Wettst.and its structure was elucidated as 3-O-{β-d-glucopyranosyl(1→4)[α-1-arabinofuranosyl-(1→2)]-β-d-glucop-yranosyl}-20-O-α-1-arabinopyranosyljujubogenin by spectroscopic methods and some chemical transformations.