Cytisine derivatives are a group of alkaloids containing the structural core of cytisine, which are mainly distributed in Fabaceae plants with a wide range of pharmacological activities, such as resisting inflammation, tumors, and viruses, and affecting the central nervous system. At present, a total of 193 natural cytisine and its derivatives have been reported, all of which are derived from L-lysine. In this study, natural cytisine derivatives were classified into eight types, namely cytisine type, sparteine type, albine type, angustifoline type, camoensidine type, cytisine-like type, tsukushinamine type, and lupanacosmine type. This study reviewed the research progress on the structures, plant sources, biosynthesis, and pharmacological activities of alkaloids of various types.
Alkaloids/chemistry* ; Quinolizines/pharmacology* ; Azocines/chemistry* ; Fabaceae

Corydalis hendersonii(CH) is a Tibetan folk medicine with the functions of clearing heat, detoxifying, cooling blood, checking diarrhea, and lowering blood pressure. It is often used to treat high altitude polycythemia, vasculitis, peptic ulcer, and diarrhea. Nine compounds were separated from the ethanol extract of CH by silica gel, ODS, Sephadex LH-20 chromatography and semi-preparative HPLC. Their structures were identified as hendersine H(1),hendersine I(2), dehydrocheilanthifoline(3), protopine(4), izmirine(5), 6,7-methylenedioxy-1(2H)-isoquinolinone(6), icariside D_2(7), ethyl 4-(β-D-glucopyranosyloxy)-3-methoxybenzoate(8), 3-hydroxy-4-methoxybenzoic acid(9), respectively, by the spectroscopic data analysis and comparison with those in the literature. Among them, compounds 1 and 2 are new isoquinoline alkaloids, and compounds 7-9 are reported the first time for Corydalis. The hypoglycemic model of H9c2 cardiomyocytes and the inflammatory model of H9c2 cardiomyocytes induced by conditional supernatant were employed to determine the activities of the above compounds. The results showed that 20 μmol·L~(-1) compound 1 had a protective effect on H9c2 cardiomyocytes and 10 μmol·L~(-1) compounds 4 and 5 inhibited H9c2 cardiomyocyte inflammation induced by conditional supernatant.
Humans ; Corydalis/chemistry* ; Alkaloids/chemistry* ; Inflammation ; Spectrum Analysis ; Isoquinolines/pharmacology*

Radiation-induced intestinal injury(RIII), a common complication of radiotherapy for pelvic malignancies, affects the quality of life and the radiotherapy efficacy for cancer. Currently, the main clinical approaches for the prevention and treatment of RIII include drug therapy, hyperbaric oxygen therapy, and surgical treatment. Among these methods, drug therapy is cost-effective. Traditional Chinese medicine(TCM) containing a variety of active components demonstrates mild side effects and good efficacy in preventing and treating RIII. Studies have proven that TCM active components, such as flavonoids, terpenoids, phenylpropanoids, and alkaloids, can protect the intestine against RIII by inhibiting oxidative stress, regulating the expression of inflammatory cytokines, modulating the mitochondrial apoptosis pathway, adjusting intestinal flora, and suppressing cell apoptosis. These mechanisms can help alleviate the symptoms of RIII. The paper aims to provide a theoretical reference for the discovery of new drugs for the prevention and treatment of RIII by reviewing the literature on TCM active components in the last 10 years.
Medicine, Chinese Traditional ; Drugs, Chinese Herbal/pharmacology* ; Quality of Life ; Intestines ; Alkaloids

Marine microorganisms, especially marine fungi, have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites (Deshmukh et al., 2018; Carroll et al., 2022). The corals constitute a dominant part of reefs with the highest biodiversity, and harbor highly diverse and abundant microbial symbionts in their tissue, skeleton, and mucus layer, with species-specific core members that are spatially partitioned across coral microhabitats (Wang WQ et al., 2022). The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds, terpenes, alkaloids, peptides, aromatics, lactones, and steroids. They demonstrate a wide range of bioactivity such as anticancer, antimicrobial, and antifouling activity (Chen et al., 2022). The genetically powerful genus Emericella (Ascomycota), which has marine and terrestrial sources, includes over 30 species and is distributed worldwide. It is considered a rich source of diverse secondary metabolites with antimicrobial activity or cytotoxicity (Alburae et al., 2020). Notably, Emericella nidulans, the sexual state of a classic biosynthetic strain Aspergillus nidulans, was recently reported as an important source of highly methylated polyketides (Li et al., 2019) and isoindolone-containing meroterpenoids (Zhou et al., 2016) with unusual skeletons.
Animals ; Aspergillus nidulans ; Polyketides/chemistry* ; Anthozoa/microbiology* ; Anti-Infective Agents/pharmacology* ; Alkaloids

Alkaloids are a class of naturally occurring bioactive compounds that are widely distributed in various food sources and Traditional Chinese Medicine. This study aimed to investigate the therapeutic effects and underlying mechanisms of alkaloid extract from Codonopsis Radix (ACR) in ameliorating hepatic lipid accumulation in a mouse model of non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD). The results revealed that ACR treatment effectively mitigated the abnormal weight gain and hepatic injury associated with HFD. Furthermore, ACR ameliorated the dysregulated lipid metabolism in NAFLD mice, as evidenced by reductions in serum triglyceride, total cholesterol, and low-density lipoprotein levels, accompanied by a concomitant increase in the high-density lipoprotein level. ACR treatment also demonstrated a profound anti-oxidative effect, effectively alleviating HFD-induced oxidative stress and promoting ATP production. These effects were achieved through the up-regulation of the activities of mitochondrial electron transfer chain complexes I, II, IV, and V, in addition to the activation of the AMPK/PGC-1α pathway, suggesting that ACR exhibits therapeutic potential in alleviating the HFD-induced dysregulation of mitochondrial energy metabolism. Moreover, ACR administration mitigated HFD-induced endoplasmic reticulum (ER) stress and suppressed the overexpression of ubiquitin-specific protease 14 (USP14) in NAFLD mice. In summary, the present study provides compelling evidence supporting the hepatoprotective role of ACR in alleviating lipid deposition in NAFLD by improving energy metabolism and reducing oxidative stress and ER stress. These findings warrant further investigation and merit the development of ACR as a potential therapeutic agent for NAFLD.
Mice ; Animals ; Non-alcoholic Fatty Liver Disease/metabolism* ; Codonopsis ; Liver ; Lipid Metabolism ; Antineoplastic Agents/pharmacology* ; Alkaloids/pharmacology* ; Endoplasmic Reticulum Stress ; Energy Metabolism ; Lipids ; Diet, High-Fat/adverse effects* ; Mice, Inbred C57BL

Activated fibroblasts and M2-polarized macrophages may contribute to the progression of pulmonary fibrosis by forming a positive feedback loop. This study was aimed to investigate whether fibroblasts and macrophages form this loop by secreting SDF-1 and TGF-β and the impacts of neotuberostemonine (NTS) and tuberostemonine (TS). Mice were intratracheally injected with 3 U·kg^-1 bleomycin and orally administered with 30 mg·kg^-1 NTS or TS. Primary pulmonary fibroblasts (PFBs) and MH-S cells (alveolar macrophages) were used in vitro. The animal experiments showed that NTS and TS improved fibrosis related indicators, inhibited fibroblast activation and macrophage M2 polarization, and reduced the levels of TGF-β and SDF-1 in alveolar lavage fluid. Cell experiments showed that TGF-β1 may activated fibroblasts into myofibroblasts secreting SDF-1 by activating the PI3K/AKT/HIF-1α and PI3K/PAK/RAF/ERK/HIF-1α pathways. It was also found for the first time that SDF-1 was able to directly polarize macrophages into M2 phenotype secreting TGF-β through the same pathways as mentioned above. Moreover, the results of the cell coculture confirmed that fibroblasts and macrophages actually developed a feedback loop to promote fibrosis, and the secretion of TGF-β and SDF-1 was crucial for maintaining this loop. NTS and TS may disturb this loop through inhibiting both the PI3K/AKT/HIF-1α and PI3K/PAK/RAF/ERK/HIF-1α pathways to improve pulmonary fibrosis. NTS and TS are stereoisomeric alkaloids with pyrrole[1,2-a]azapine skeleton, and their effect on improving pulmonary fibrosis may be largely attributed to their parent nucleus. Moreover, this study found that inhibition of both the AKT and ERK pathways is essential for maximizing the improvement of pulmonary fibrosis.
Animals ; Mice ; Pulmonary Fibrosis/metabolism* ; Transforming Growth Factor beta/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; MAP Kinase Signaling System ; Alkaloids/pharmacology* ; Fibroblasts ; Macrophages/metabolism*

Ten alkaloids(1-10) were isolated from the ethyl acetate extract of the fruit of Lycium chinense var. potaninii by silica gel, ODS, and preparative high performance liquid chromatography(HPLC), and identified by NMR and MS as methyl(2S)-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]-3-(phenyl)propanoate(1), methyl(2R)-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]-3-(phenyl)propanoate(2), 3-hydroxy-4-ethyl ketone pyridine(3), indolyl-3-carbaldehyde(4),(R)-4-isobutyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde(5),(R)-4-isopropyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-car-baldehyde(6), methyl(2R)-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]-3-(4-hydroxyphenyl)propanoate(7), dimethyl(2R)-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanedioate(8), 4-[formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanoate(9), 4-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanoic acid(10). All the compounds were isolated from the plant for the first time. Among them, compounds 1-3 were new compounds. Compounds 1-9 were evaluated for hypoglycemic activity in vitro with the palmitic acid-induced insulin resistance in HepG2 cells. At 10 μmol·L~(-1), compounds 4, 6, 7, and 9 can promote the glucose consumption of HepG2 cells with insulin resistance.
Lycium/chemistry* ; Fruit/chemistry* ; Insulin Resistance ; Propionates ; Alkaloids/pharmacology*

Sesquiterpene pyridine alkaloids are important components in Tripterygium plants, possessing a wide range of pharmacological activities, such as anti-inflammation immunosuppression, anti-tumor, anti-virus, and deinsectization, and are of great research value. They are composed of highly oxidized dihydro-β-furansquiterpene and pyridine dicarboxylic acid through ester bonds. According to the structural characteristics of pyridine dicarboxylic acid fragments, they can be divided into various structural subtypes. Up to now, more than 110 sesquiterpene pyridine alkaloids have been isolated and identified from Tripterygium plants. This study reviewed the structural features and spectral(i.e., UV, IR, MS, and NMR) characteristics of sesquiterpene pyridine alkaloids and summarized the structural elucidation process in detail to provide references for their further research and development.
Alkaloids/pharmacology* ; Drugs, Chinese Herbal/pharmacology* ; Molecular Structure ; Pyridines/pharmacology* ; Sesquiterpenes ; Tripterygium/chemistry*

The present study investigated the chemical constituents from Uncaria sessilifructus and their neuroprotective activities. The compounds were separated and purified from the 90% ethanol extract of U. sessilifructus by various chromatographic methods, including silica gel, Sephadex LH-20, and semi-preparative HPLC. Seven compounds were obtained, and their structures were identified as uncanidine J(1), uncanidine K(2), 17-O-ethylhirsutine(3), tetrahydroalstonine(4), akuammigine(5), hirsutine(6), and hirsuteine(7) by physicochemical properties and various spectral techniques, including UV, IR, MS, and NMR. Compounds 1 and 2 are two new compounds. Compound 3 is a new natural product, and compound 4 was isolated from U. sessilifructus for the first time. In addition, the isolated compounds were evaluated for their neuroprotective effects on oxygen and glucose deprivation/reoxygenation(OGD/R) injury in primary cortical neurons in rats. The results showed that compounds 1-7 had different degrees of protective effects on OGD/R injury. The EC_(50) values of compounds 2-4 were(0.17±0.03),(1.70±0.38), and(1.79±0.23) μmol·L~(-1), respectively.
Animals ; Biological Products ; Drugs, Chinese Herbal/pharmacology* ; Ethanol ; Glucose ; Indole Alkaloids ; Neuroprotective Agents/pharmacology* ; Oxygen ; Rats ; Secologanin Tryptamine Alkaloids ; Silica Gel ; Uncaria/chemistry*

The endophytic fungus Nigrospora sphaerica S5 derived from the semi-mangrove plant Myoporum bontioides was fermented. Its metabolites were purified by column chromatography. Nine compounds were obtained and identified as terezine P(1), 3-(1-hydroxyethyl)-4-methyl dihydrofuran-2(3H)-one(2), methylhydroheptelidate(3), hydroheptelidic acid(4), 5, 7-dimethoxy-4, 6-dimethylphthalide(5),(3R,4S)-(-)-4-hydroxymellein(6), pestalopyrone(7), indole-3-formaldehyde(8) and p-hydroxybenzaldehyde(9) by spectroscopic techniques. Terezine P(1) was a new alkaloid belonging to the terezine class with a pyrazine ring. Compounds 2-7 were lactones, of which 3 and 4 belonged to sesquiterpenes. Compounds 8 and 9 were indole alkaloids and phenols, respectively. Compounds 3-6 were purified from Nigrospora sp. for the first time. These compounds showed different degrees of antibacterial activity against Staphylococcus aureus, Escherichia coli of O6 serotype and E. coli of O78 serotype.
Alkaloids ; Anti-Bacterial Agents/pharmacology* ; Ascomycota/chemistry* ; Escherichia coli ; Formaldehyde ; Indoles/pharmacology* ; Lactones ; Molecular Structure ; Myoporum/microbiology* ; Phenols ; Pyrazines ; Sesquiterpenes