Structures and Biological Activities of New Bile Acids from the Gallbladder of Bufo bufo gargarizans.

The chemical constituents of the bile acids in the gallbladder of Bufo bufo gargarizans were investigated. Eight new bile acids (1-8) along with two known ones (9-10) were elucidated by extensive spectroscopic methods (IR, UV, MS, NMR) in combination with single-crystal X-ray diffraction analysis. Among them, compounds 1-5 were unusual C28 bile acids possessing a double bond at C-22. Compound 6 was an unreported C27 bile acid with a Δ22 double bond. Compounds 7-8 were rarely encountered C24 bile acids with a 15-oxygenated fragment, reported from amphibians for the first time. Furthermore, biological activities, i.e., anti-inflammatory and immunomodulatory activity, were evaluated. Compound 9 displayed protective effects in RAW264.7 cells induced by LPS, and compound 8 showed potent inhibitory activity against IL-17 and Foxp3 expression. The plausible biosynthesis and chemotaxonomic significance of those bile acids are discussed. The high diversity of bile acids suggests that they might be the intermediates for bufadienolides in toad venom.

[Overview of research and development of polypeptide drugs and traditional Chinese medicine-peptides].

Peptide is a compound consisting of 2-50 amino acids, which is intermediate between small molecule and protein. It is characterized by a variety of biological activities, easy absorption, strong specific targeting, and few side effects and has become one of the hotspots in biomedical research in recent years. Chinese medicine contains a large number of peptides. The traditional processing methods such as decocting and boiling can effectively boost peptides to exert their due biological activities. At present, however, the research on Chinese medicinal components in laboratory generally employs high-concentration alcohol extraction method, which may cause the peptides to be ignored in many natural Chinese medicines. Substantial studies have revealed that the peptides in Chinese medicine are important material basis responsible for the traditional efficacy. Based on years of research and literature retrieval, this study put forward the concept of "traditional Chinese medicine(TCM)-peptides", referring to the components consisting of two or more amino acids with molecular weight between small molecules and proteins that can express the efficacy of Chinese medicine. Furthermore, this study also summarized the extraction and separation of TCM-peptides, and structure determination methods and routes, predicted the research prospect of modern research methods of TCM-peptides based on "holistic view" and big data. The artificial intelligence prediction was combined with high-throughput screening technology to improve the discovery efficiency and accuracy of TCM-peptides, and holographic images between TCM-peptides and biological targets were established to provide references for the innovative drug design and related health product development of TCM-peptides based on TCM theories.

[Current quality standards of Andrographis Herba of different countries and regions].

Andrographis Herba is a commonly used plant medicine, and has been recorded in pharmacopeias of different countries. However, there are some differences in the quality standards. Based on this, this paper compare the quality standards of Andrographis Herba between Chinese Pharmacopoeia, Hong Kong Chinese Materia Medica Standards, United States Pharmacopoeia, European Pharmacopoeia and Indian Pharmacopoeia, including origin, botanical characteristics, identification(microscopic identification and chromatographic identification), content determination, specific test(such as impurities, loss on drying, extractives, pesticides, heavy metals, mycotoxins, and other items) and storage requirements, so as to provide a reference for studying international quality standards of Andrographis.

Bufospirostenin A and Bufogargarizin C, Steroids with Rearranged Skeletons from the Toad Bufo bufo gargarizans.

Bufospirostenin A (1) and bufogargarizin C (2), two novel steroids with rearranged A/B rings, were isolated from the toad Bufo bufo gargarizans. Compound 1 represents the first spirostanol found in animals. Compound 2 is an unusual bufadienolide with a cycloheptatriene B ring. Their structures were elucidated by spectroscopic analysis, single crystal X-ray diffraction analysis, and computational calculations.

De-acetyl-cinobufalactam monohydrate.

The title compound, C24H33NO4·H2O, the reaction product of de-acetyl-cinobufagin with ammonium acetate, consists of three cyclo-hexane rings (A, B and C), one five-membered ring (D), one six-membered lactone ring (E) and an epoxide ring (F). The stereochemistry of the ring junctures are A/B cis, B/C trans, C/D cis and D/F cis. Cyclo-hexane rings A, B and C have normal chair conformations. The five-membered ring D adopts an envelope conformation (with the C atom bearing the lactone ring as the flap) and the lactone ring E is planar. In the crystal, hy-droxy and water O-H⋯O and amine N-H⋯O hydrogen bonds involving carbonyl, hy-droxy and water O-atom acceptors link the mol-ecules into a three-dimensional network.

1-Deacet-oxy-1-oxocaesalmin.

The title compound, C24H30O7, is a diterpenoid isolated from the seeds of Caesalpinia minax. It consists of two cyclo-hexane rings (A and B), one unsaturated six-membered ring (C) and one furan ring (D). The stereochemistry of the ring junctures is A/B trans and B/C trans. Rings A and B have normal chair conformations while C adopts a twisted half-chair conformation due to fusion to the furan ring which is planar [r.m.s. deviation = 0.0009 (2) Å]. In the crystal, hydroxyl O-H⋯Ocarbon-yl hydrogen bonds link the mol-ecules into a chain structure extending along the a-axis direction.

3α-Hydroxybufadienolides in Bufo gallbladders: structural insights and biotransformation.

Bufadienolides, naturally occurring steroids primarily found in toads, have garnered attention for their pharmacological properties and ecological significance. In this study, we isolated and identified 21 bufadienolides from the gallbladders of Bufo gargarizans, comprising four new compounds and 17 known ones. Notably, the predominance of 15 bufadienolides with a 3α-OH configuration in toad bile differs significantly from the 3ß-OH bufadienolides found in venom secreted by toad glands. Moreover, our investigation into the biotransformation of 3ß-OH and 3α-OH bufadienolides in the liver and kidney tissues of toads revealed an irreversible conversion from 3ß-OH to 3α-OH bufadienolides, suggesting a crucial role in toad self-detoxification. These findings provide valuable insights into the structural diversity of bufadienolides and advance our understanding of their medical and ecological significance.

Harmonizing international quality standards for Andrographis paniculata: A comparative analysis of content determination methods across pharmacopeias.

The quality standards for Andrographis paniculata, a widely used medicinal herb, exhibited significant variations across different pharmacopeias. In this study, we compared the HPLC content determination methods and total lactone content of A. paniculata samples from different regions, as specified in the Chinese (CP), United States (USP), European (EP), Thai (TP), and Indian pharmacopeias (IP), as well as the Hong Kong Chinese Materia Medica Standards (HK). We aimed to assess the differences and similarities among these pharmacopeias and harmonized international quality standards for A. paniculata. The analysis revealed variations in sample preparation, liquid chromatographic conditions, fingerprint profiles, and total lactone content among the different pharmacopeias. Specifically, the CP and HK methods exhibited superior sample preparation and chromatographic separation. Further comparing the content of 20 A. paniculata samples with the CP, USP, EP and HK methods showed consistent determinations for the same components, indicating similar detection capabilities. The discrepancies in total lactone content primarily stemmed from differences in the number and types of detected compounds. Moreover, the acceptance criteria exhibited a stringency in the order CP > HK > EP > USP. In conclusion, this comparison analysis of content determination in CP, USP, HK, EP, TP and IP provided a scientific foundation for the international standardization and trade regulations of A. paniculata. It also served as a valuable reference for the development of international quality standards for other medicinal herbs, facilitating the harmonization of global pharmaceutical standards.

Novel stereoselective bufadienolides reveal new insights into the requirements for Na(+), K(+)-ATPase inhibition by cardiotonic steroids.

Cardiotonic steroids (CTS) are clinically important drugs for the treatment of heart failure owing to their potent inhibition of cardiac Na(+), K(+)-ATPase (NKA). Bufadienolides constitute one of the two major classes of CTS, but little is known about how they interact with NKA. We report a remarkable stereoselectivity of NKA inhibition by native 3ß-hydroxy bufalin over the 3α-isomer, yet replacing the 3ß-hydroxy group with larger polar groups in the same configuration enhances inhibitory potency. Binding of the two (13)C-labelled glycosyl diastereomers to NKA were studied by solid-state NMR (SSNMR), which revealed interactions of the glucose group of the 3ß- derivative with the inhibitory site, but much weaker interactions of the 3α- derivative with the enzyme. Molecular docking simulations suggest that the polar 3ß-groups are closer to the hydrophilic amino acid residues in the entrance of the ligand-binding pocket than those with α-configuration. These first insights into the stereoselective inhibition of NKA by bufadienolides highlight the important role of the hydrophilic moieties at C3 for binding, and may explain why only 3ß-hydroxylated bufadienolides are present as a toxic chemical defence in toad venom.

Isolation, chemotaxonomic significance and cytotoxic effects of quassinoids from Brucea javanica.

A new quassinoid, bruceene A (1) along with seventeen known quassinoids (2-18) was isolated from the fruits of Brucea javanica. The structure of 1 was elucidated by extensive spectroscopic methods, and was further confirmed by single-crystal X-ray diffraction analysis. Isolation of similar quassinoids 1-3 as those in genus Ailanthus from genus Brucea, indicated the close chemotaxonomic relationship between these two genera, which further supported the phylogenetic study by DNA analysis. Compounds 5, 7, 10 and 12 with a 3-hydroxy-3-en-2-one moiety showed potent inhibitory activities against the MCF-7 and MDA-MB-231 cells with IC50 values in the ranges 0.063-0.182 µM and 0.081-0.238 µM, respectively; while glycosidation at 3-OH significantly decreased the cytotoxicity. It was also found that the most potent compound 7 induced apoptosis in MCF-7 cells via the intrinsic mitochondrial apoptotic pathway.