Three new C27N3-type Lycopodium alkaloids, serramyuines A–C (1–3) were isolated from Lycopodim serratum Thunb. var. serratum and their structures including relative configurations were elucidated on the basis of spectroscopic data. Serramyuines A and B (1 and 2) feature a new lucidine-type skeleton with an N-1 to C-11 connection and an α-hydroxy group at C-14 and serramyuine C (3) is a stereoisomer of lycolucine.
Nine previously undescribed meroterpenoid glucosides, named nemophilosides A–I, were isolated from the whole plant extract of Nemophila menziesii. Their molecular structures were determined from their NMR and MS spectra, and the absolute configurations were confirmed using ECD spectroscopy by comparing the experimental data with calculated data. The meroterpenoids consist of monoterpenoids and hydroquinone moieties; however, meroterpenoids obtained as glycosides are relatively rare, which distinguishes this class of compounds. Their skeletons are similar to those of cannabinoids and shikonins, suggesting homologous biosynthetic pathways. Compared with the well-known meroterpenoids, the monoterpenoid moieties of the compounds isolated in this study were characterized by oxidation. Although these compounds showed little or no inhibitory activity against fatty acid amide hydrolase and acetylcholinesterase, compound 6 regulated NO production in RAW264.7 cells.
β-cell regeneration through the transdifferentiation of intra-islet cells presents a promising strategy for diabetes therapy. To identify the potential compound for induction of α-to-β cell transdifferentiation, we employed an in vivo screening using lineage trajectory analyses in zebrafish. We screened a library with 303 natural compounds from Chinese herbal medicine. We identified mosloflavone, a principal component of Mosla soochouensis Matsuda, which significantly induced the conversion of pancreatic α cells to β cells in zebrafish. Moreover, mosloflavone also converted α cells into β cells when β cells were extremely lost in zebrafish. Furthermore, mosloflavone administration increased the β-/α-cell ratio and β-cell mass, as well as improved glucose tolerance in HFD/STZ diabetic mice. Mechanistically, mosloflavone significantly increased the level of Pdx1 in α cells, both in zebrafish and mice. Hence, our study identified mosloflavone as an active compound derived from traditional Chinese medicine (TCM) that effectively induced the conversion of α cells to β cells, highlighting its potential to promote β cells regeneration as a therapeutic strategy for diabetes treatment.
Working model for Mosloflavone induced α-cell to β-cell conversion
Three previously undescribed clerodane diterpenoids, named as tincrispoids A‒C (1‒3), accompanied by nine known analogues (4‒12), were isolated from the stems of Tinospora crispa. Structural determination, including assignment of absolute configurations, was achieved through a combination of spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) computations. The heterocyclic skeletons of the isolates exhibit remarkable structural diversity, comprising 6/6/6- (1 and 5), 6/6- (2, 3, and 7‒9), 6/6/5- (4), 6/5/6/6- (6), and 6/5/6- (10‒12) fused ring systems. Compound 4 showed moderate inhibitory effect on ATP-citrate lyase (ACLY). Molecular docking simulations revealed the specific interaction between compound 4 and ACLY.
A new dimeric indole alkaloid, cyclosebistine A consisting of an aspidosperma type and a modified iboga type through [2 + 2] cycloaddition was isolated from Catharanthus roseus, and the structure including absolute stereochemistry was determined on the basis of the 2D NMR data and CD calculation. Cyclosebistine A showed reasonably potent anti-malarial activity.
Mushroom poisoning caused by Tricholoma kakishimeji (Kakishimeji) remains a public health concern in Japan. Ingestion of this mushroom induces acute gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea, and neurological symptoms have also been reported. The toxic principle, ustalic acid (UA), has previously been detected by liquid chromatography–mass spectrometry (LC–MS) and visualized by MALDI-imaging mass spectrometry, but these methods require laborious preparation and prolonged analysis. Here, we report a rapid and preparation-free method for detecting UA in freshly collected specimens using probe electrospray ionization tandem mass spectrometry (PESI-MS/MS). Fruiting bodies collected in October 2024 from the Iizuna Highlands (Nagano Prefecture) were analyzed in the laboratory, and UA was consistently detected within ~ 30 s in negative-ion mode with high sensitivity. This workflow highlights the potential for near-immediate chemical screening of toxic mushrooms, providing same-day diagnostic capability. Our findings demonstrate that PESI-MS/MS provides practical means for rapid chemical screening of freshly harvested mushrooms, offering timely support for toxicological investigations and food safety monitoring.
New seco-apotirucallane triterpenoids, pachyphylinin A (1) and B (2), were isolated from the stem bark of Aglaia pachyphylla alongside nine triterpenoid compounds (3–11). The structures were elucidated and identified through various spectroscopic analyses, including 1D and 2D NMR, HRTOF-MS, FTIR, as well as ECD, complemented by computational calculation using TD-DFT. In the process, pachyphylinin A (1) and B (2) were tested for cytotoxic activity against the breast cancer cell line (MCF-7). The results showed cytotoxic activities against MCF-7 with IC50 values in the range of 98.8–500 µM.
Two highly condensed resveratrol octamers, vateriaphenol A and a newly discovered analogue, vaticanol Q, were isolated from the stem of Vatica albiramis. Vaticanol Q represents the first naturally occurring resveratrol octamer bearing a rare ortho-quinone moiety, as unambiguously established through comprehensive spectroscopic analyses, including low-temperature NMR and circular dichroism. The absolute configuration of vaticanol Q was deduced based on biosynthetic considerations and chiroptical data, further supported by micro-electron diffraction and synchrotron X-ray crystallography of its biosynthetic precursor, (−)-hopeaphenol. Vateriaphenol A exhibited potent virucidal activities against feline calicivirus, influenza A virus, and mumps virus, highlighting the potential of highly condensed stilbenoids as promising antiviral leads.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：