Four sulfur-containing compounds with anti-colon cancer effect from marine-derived fungus Aspergillus terreus.

Sulfur-containing natural products possess a variety of biological functions including antitumor, antibacterial, anti-inflammatory and antiviral activities. In this study, four previously undescribed sulfur-containing compounds asperteretals L and M, terreins A and B, together with 17 known compounds were obtained from a culture of marine fungus A. terreus supplemented with inorganic sulfur source Na2SO4. Their planar structures and absolute configurations were elucidated by NMR, HRESIMS, and ECD experiments. The in vitro cytotoxicities of compounds 1-21 against HCT-116 and Caco-2 were evaluated by SRB assay. Asperteretal M (2) exhibited activity against HCT-116 with the IC50 value at 30µM. The antiproliferative effect of asperteretal M was confirmed by colony formation assay and cell death staining. Furthermore, the preliminary study on the anti-colon cancer mechanism of asperteretal M was performed by RNA-seq analysis. Western blotting validated that asperteretal M significantly decreased the expression of cell-cycle regulatory proteins CDK1, CDK4, and PCNA in a concentration-dependent manner.

Lentinuses A-B, two alkaloids from the marine-derived fungus Lentinus sajor-caju with potent anti-pulmonary fibrosis activity.

By adding natural amino acids into the medium as sole nitrogen source, twenty-four compounds, including two new alkaloids lentinuses A-B (1-2) with a rare oxazinone core in marine natural products, one new natural product 3-acetamido-4-phenylfurazan (3), 9ß-ergosterol (22) were firstly discovered from a marine fungus, and twenty known compounds (4-21, 23-24) were isolated from the marine-derived fungus Lentinus sajor-caju. The chemical structures of all these compounds were elucidated by HRMS, NMR spectroscopy and X-ray diffraction. Compounds 1-24 were evaluated for their inhibitory activity against TGF-ß1-induced collagen accumulation in human fetal lung fibroblasts (HFL1). Compounds 2, 3, 12, 22, and 23 showed potent activity against TGF-ß1-induced collagen accumulation and low toxicity to HFL1 cells. The binding mode of lentinus B (2) with TGF-ß1 receptor was then performed by using Schrödinger software, and the result showed that lentinus B possesses a strong binding force such as hydrogen bonding and hydrophobic interactions to the protein, which may provide a theoretical basis to design more potent anti-fibrotic drugs in the future.

Synthesis of Melatonin Derivatives and the Neuroprotective Effects on Parkinson's Disease Models of Caenorhabditis elegans.

Melatonin (MT) is a hormone with antioxidant activity secreted by the pineal gland in the human brain, which is highly efficient in scavenging free radicals and plays an important role in the neuro-immuno-endocrine system. Emerging evidence showed that MT supplementation was a potential therapeutic strategy for Parkinson's disease (PD), which inhibits pathways associated with oxidative stress in PD. In this study, we reported a C7-selective olefination of melatonin under rhodium catalysis with the aid of PIII-directing groups and synthesized 10 new melatonin-C7-cinnamic acid derivatives (6a-6j). The antioxidant potential of the compounds was evaluated both by ABTS and ORAC methods. Among these newly synthesized melatonin derivatives, 6a showed significantly higher activity than MT at 10-5 M. In the transgenic Caenorhabditis elegans model of PD, 6a significantly reduces alpha-synuclein aggregation and dopaminergic neuronal damage in nematodes while reducing intracellular ROS levels and recovers behavioral dysfunction induced by dopaminergic neurodegeneration. Further study of the mechanism of action of this compound can provide new therapeutic ideas and treatment strategies for PD.

Characterization of the complete plastid genome of Chinese medicinal plant Isodon serra (Lamiaceae).

The herb Isodon serra (Maximowicz) Kudô, which is widely distributed in China and its neighbor regions, is a well-known traditional Chinese medicinal plant. In this study, we characterized the complete plastid genome sequence of I. serra using Illumina sequencing data. The plastome is 152,676 bp in length and contains a typical quadripartite structure. The inverted repeat (IR), large-single copy (LSC) and small-single copy (SSC) regions each has 25,716 bp, 83,564 bp, and 17,680 bp. The genome contains 80 protein coding genes (PCGs), 30 transfer RNAs (tRNA), and four ribosomal RNAs (rRNA). The phylogenetic result indicates I. serra together with genera Ocimum and Lavandula formed tribe Ocimeae clade.

The complete plastome of a folk medicinal herb Isodon lophanthoides var. graciliflorus.

Isodon lophanthoides var. graciliflorus is a folk medicinal herb that is distributed in tropical and subtropical Asia. In this study, the complete plastome of I. lophanthoides var. graciliflorus was assembled and annotated. The plastome is 152,195 bp in length, consisting of a large single-copy (LSC) region of 83,095 bp, a small single-copy (SSC) region of 17,699 bp, and two inverted repeat (IR) regions of 25,701 bp, each. It has 113 genes, including 80 protein-coding genes, 29 tRNA genes, and 4 rRNA genes. The overall GC content of the plastome is 37.6%. Phylogenetic analysis showed that I. lophanthoides var. graciliflorus was sister to Isodon serra.

The pharmacokinetic study of sinomenine, paeoniflorin and paeonol in rats after oral administration of a herbal product Qingfu Guanjiesu capsule by HPLC.

An accurate and reliable high-performance liquid chromatography-diode array detector (HPLC-DAD) method was developed and validated for determination of sinomenine (SI), paeoniflorin (PF) and paeonol (PA), which was further applied to assess the pharmacokinetics of SI, PF and PA in an anti-arthritic herbal product, Qingfu Guanjieshu (QFGJS) capsule, in rats. Successful separation was achieved with a C18 column and a mobile phase composed of acetonitrile and aqueous phase (containing 0.1% formic acid, adjusted with triethylamine to pH 3.5 ± 0.2). The method was validated with excellent precision, accuracy, recovery and stability in calibration ranges from 0.06 to 11.62 µg/mL for SI, from 0.09 to 35.70 µg/mL for PF, and from 0.15 to 4.53 µg/mL for PA (with r(2) > 0.999 for all three compounds). Our results showed that absorption of PF after administration of QFGJS was similar to that after oral administration of PF alone; the absorption of SI was decreased while the absorption of PA was increased after giving QFGJS orally compared with pure compounds. We may conclude that pharmacokinetic studies of complex herbal products are not only necessary but also feasible by using representative bioactive chemicals as indicators of establishing quality control standards and of determining pharmacokinetic behavior of herbal medicines.