Quinolizidine alkaloids from Sophora alopecuroides with anti-inflammatory and anti-tumor properties

Aloperine Attenuates Hepatic Ischemia/Reperfusion-Induced Liver Injury via STAT-3 Signaling in a Murine Model

Hepatic ischemia/reperfusion (I/R) damage is one of the most common side effects of liver surgery. This pathophysiological process may lead to excessive hepatic damage. Aloperine is an active ingredient isolated from Sophora alopecuroides Linn and has a variety of therapeutic effects, including organ protection. However, the hepatoprotective effect of aloperine against hepatic I/R damage has not yet been determined. C57BL/6 mice were allocated to the sham-operated (sham), hepatic ischemia/reperfusion (I/R), and aloperine groups. The mice were exposed to 30 min of hepatic hilum occlusion. Then a 3-h reperfusion was performed. Mice in the sham group underwent sham surgery. Hepatic injury was evaluated by plasma aspartate aminotransferase (AST) and transaminase alanine aminotransferase (ALT) levels, histological evaluation, cell apoptosis, the number of activated inflammatory cells, and the expression levels of inflammatory cytokines, including tumor necrosis factor-α and interleukin-6. The protein phosphorylation status of the reperfusion-associated survival pathways was evaluated. Mice with hepatic I/R injury presented increased plasma ALT and AST levels, increased hepatic apoptosis, abnormal histological structure, and elevated inflammatory responses. However, aloperine ameliorated hepatic I/R-induced injury. Moreover, aloperine enhanced the level of signal transducer and activator of transcription (STAT)-3 phosphorylation after I/R. Ag490, an agent that inhibits STAT-3 activity, abolished aloperine-induced STAT-3 phosphorylation and liver protection. Aloperine ameliorates hepatic I/R-induced liver injury via a STAT-3-mediated protective mechanism. Patients with hepatic I/R injury may benefit from aloperine treatment. SIGNIFICANCE STATEMENT: Hepatic I/R can cause excessive liver damage. This study revealed that aloperine, an active component isolated from Sophora alopecuroides Linn, ameliorates hepatic I/R injury and related liver damage in vivo. The underlying protective mechanism may involve the STAT-3 signaling pathway. These findings may lead to the development of a novel approach for treating hepatic I/R damage in clinical practice.

Aloperine protects the testis against testicular ischemia/reperfusion injury in rats

BACKGROUND

Testicular torsion/detorsion can cause testis loss and infertility. Aloperine is a major active alkaloid extracted from Sophora alopecuroides Linn. It has been shown to have organ-protective effects. However, the effects of aloperine on the testis and its underlying mechanisms remain unclear.

OBJECTIVES

This study investigated the effect of aloperine on testicular torsion/detorsion injury in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomized to the sham-operated (sham), testicular I/R (TI/R), or aloperine preconditioning (ALOPre) or postconditioning (ALOPost) groups. All rats except for the sham-operated rats were subjected to 3 h of right spermatic cord torsion (720°, clockwise), followed by 3 h of detorsion. Aloperine (10 mg/kg) was intravenously administered before testicular torsion (ALOPre) or at the onset of testicular detorsion (ALOPost). The therapeutic efficacy of aloperine was evaluated by histological analysis, oxidative stress evaluation, inflammatory response examination, apoptosis analysis, protein analysis, and immunohistological assessment.

RESULTS

Compared with TI/R, aloperine protected both the ipsilateral and contralateral testes against unilateral testicular I/R, as evidenced by a reduced testicular weight to body weight (TW/BW) ratio (ALOPre: p = 0.0037; ALOPost: p = 0.0021) and volume (ALOPre: p = 0.0020; ALOPost: p = 0.0009), less structural damage with better Johnsen (ALOPre: p = 0.0013; ALOPost: p = 0.0021), and Cosentino scores (ALOPre: p < 0.0001; ALOPost: p < 0.0001), increased mean seminiferous tubule diameter and mean seminiferous tubule epithelial height, decreased testicular apoptosis, and less oxidative stress and inflammatory response. In addition, aloperine significantly stimulated the phosphorylation of signal transducer and activator of transcription (STAT)-3 in the ipsilateral testes following detorsion. Administration of Ag490 suppressed STAT-3 phosphorylation, thereby abrogating the protective effects exerted by aloperine on the ipsilateral testis.

DISCUSSION AND CONCLUSION

Aloperine has a strong testicular protective effect on the ipsilateral and contralateral testes after testicular torsion/detorsion. This aloperine-induced ipsilateral testicular protection is mediated via the STAT-3 signaling pathway.

Safety and efficacy indicators of guarana and Brazil nut extract carried in nanoparticles of coenzyme Q10: Evidence from human blood cells and red earthworm experimental model

This study characterized a nanosupplement based on coenzyme Q10 containing guarana (Paullinia cupana) and Brazil nuts oil (Bertholetia excelsa) (G-Nut). Determined cytotoxic and oxi-immunomodulatory effects on human peripheral blood mononuclear cells (PBMCs) and its effect on mortality of red Californian earthworms (Eisenia fetida) and on the immune efficiency of its coelomocytes immune by in vitro exposure to yeast dead microorganism. The cytotoxic and immunomodulatory effects of G-Nut and the GN-Free extract (0.25-3 mg/mL) were determined in PBMC cultures. Apoptotic, oxidative, and inflammatory markers were determined using biochemical, immunological, and molecular protocols. The effects of G-Nut and GN-Free extracts on mortality and immune efficiency were investigated in earthworms. G-Nut and GN-Free did not induce cytotoxic events in PBMCs, triggering the decrease in apoptotic (caspases 3 and 8) gene expression, lipid and protein oxidation levels, or pro-inflammatory cytokine levels. G-Nut and GN-Free did not trigger earthworm mortality and improved coelomocyte immune efficiency by increasing Eisenia neutrophil extracellular DNA traps and brown body formation when exposed to dead yeasts. The G-Nut nanoformulation is safe and can be used as a new form of food supplement by oral or transdermal delivery.

Effects of Water and Nitrogen on Growth, Rhizosphere Environment, and Microbial Community of Sophora alopecuroides: Their Interrelationship

The effective management of water and nitrogen is crucial in the artificial cultivation of medicinal plants. Sophora alopecuroides, a perennial herbaceous plant in the Fabaceae family, is extensively used in medicine, with alkaloids as its primary bioactive constituents. Nevertheless, there remains a significant knowledge gap regarding how rhizospheric microbial communities respond to varying water and nitrogen conditions and their intricate relationships with soil environments and the growth of S. alopecuroides. In this study, two-year-old S. alopecuroides were used in a two-factor, three-level water-nitrogen interaction experiment. The irrigation levels included W1 (30-35% of maximum water holding capacity), W2 (50-55%), and W3 (70-75%), while nitrogen levels comprised N1 (32 mg/kg), N2 (64 mg/kg), and N3 (128 mg/kg). The study assessed plant growth indicators, total alkaloid content, and rhizospheric soil physicochemical parameters of S. alopecuroides. High-throughput sequencing (16S rRNA and ITS) was employed to analyze variations in rhizospheric microbial community composition and structure. The results showed that Proteobacteria and Ascomycota are the predominant bacterial and fungal phyla in the rhizosphere microbial community of S. alopecuroides. The highest biomass and alkaloid accumulation of S. alopecuroides were observed under the N1W3 treatment (50% nitrogen application and 70-75% of maximum water holding capacity). Specifically, six bacterial genus-level biomarkers (TRA3_20, MND1, env_OPS_17, SBR1031, Haliangium, S0134_terrestrial_group) and six fungal genus-level biomarkers (Pseudeurotium, Rhizophagus, Patinella, Pseudeurotium, Patinella, Rhizophagus) were identified under the N1W3 treatment condition. In the partial least squares path modeling (PLS-PM), water and nitrogen treatments demonstrated markedly positive direct effects on soil physicochemical parameters (p < 0.01), while showing significant negative direct impacts on alkaloid accumulation and plant growth indicators (p < 0.05). Soil physicochemical parameters, in turn, significantly negatively affected the rhizosphere fungal community (p < 0.05). Additionally, the rhizosphere fungal community exhibited highly significant negative direct effects on both the plant growth indicators and total alkaloid content of S. alopecuroides (p < 0.01). This study provides new insights into the interactions among rhizosphere soil environment, rhizosphere microbiota, plant growth, and alkaloid accumulation under water and nitrogen regulation, offering a scientific basis for the water and nitrogen management in the cultivation of S. alopecuroides.

Aloperine-Type Alkaloids with Antiviral and Antifungal Activities from the Seeds of Sophora alopecuroides L

As a continuous flow investigation of novel pesticides from natural quinolizidine alkaloids, the chemical compositions of the seeds of Sophora alopecuroides were thoroughly researched. Fifteen new aloperine-type alkaloids (1-15) as well as six known aloperine-type alkaloids (16-21) were obtained from the extract of S. alopecuroides. The structures of 1-21 were confirmed via HRESIMS, NMR, UV, IR, ECD calculations, and X-ray diffraction. The antiviral activities of 1-21 against tobacco mosaic virus (TMV) were detected following the improved method of half-leaf. Compared with ningnanmycin (protective: 69.7% and curative: 64.3%), 15 exhibited excellent protective (71.7%) and curative (64.6%) activities against TMV. Further biological studies illustrated that 15 significantly inhibited the transcription of the TMV-CP gene and increased the activities of polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL). The antifungal activities of 1-21 against Phytophythora capsica, Botrytis cinerea, Alternaria alternata, and Gibberella zeae were screened according to a mycelial inhibition test. Compound 13 displayed excellent antifungal activity against B. cinerea (EC50: 7.38 μg/mL). Moreover, in vitro antifungal mechanism studies displayed that 13 causes accumulation of reactive oxygen species and finally leads to mycelia cell membrane damage and cell death in vitro.

Undescribed matrine-type alkaloids from Sophora alopecuroides with anti-inflammatory activity

A phytochemical investigation on the alkaloid fractions of Sophora alopecuroides L. led to the production of 11 undescribed matrine-type alkaloids, sophaloseedlines I-S (1-11), 12 known analogs (12-23), and an unexpected artificial matrine-derived Al(III) complex (24). The corresponding structures were elucidated by the interpretation of spectroscopic analyses, quantum chemical calculation, and six instances (1-4, 18, and 24), verified by X-ray crystallography. The biological activities screening demonstrated that none of the isolates exhibited cytotoxicity against four human cancer cell lines (HepG2, A549, THP-1, and MCF-7) and respiratory syncytial virus (RSV) at 50 μM, while moderate anti-inflammatory activity with IC50 value from 15.6 to 47.8 μM was observed. The key structure-activity relationships of those matrine-type alkaloids for anti-inflammatory effects have been summarized. In addition, the most potent 7-epi-sophoramine (19) and aluminum sophaloseedline T (24) could effectively inhibit the release of pro-inflammatory factors (TNF-α, IL-6, and IL-1β), as well as the expression of iNOS and COX-2 proteins.

Sophoridine Counteracts Obesity via Src-Mediated Inhibition of VEGFR Expression and PI3K/AKT Phosphorylation

Sophoridine (SRP) is a natural quinolizidine alkaloid found in many traditional Chinese herbs, though its effect on adipose tissue is unclear. We improved serum lipid levels by administering SRP by gavage in high-fat diet (HFD)-fed C57BL/6 mice. After 11 weeks, SRP supplementation significantly reduced body weight gain and improved glucose homeostasis, while reducing subcutaneous fat and liver weight. SRP also inhibited cell proliferation and differentiation of 3T3-L1 cells. Proteomics analysis revealed that SRP inhibits adipocyte differentiation by interacting with Src, thereby suppressing vascular endothelial growth factor receptor 2 (VEGFR2) expression and PI3K/AKT phosphorylation. This study provides an empirical basis for the treatment of obesity with small molecules.

Quinolizidine-Type Alkaloids: Chemodiversity, Occurrence, and Bioactivity

Quinolizidine alkaloids (QAs) are nitrogen-containing compounds produced naturally as specialized metabolites distributed in plants and animals (e.g., frogs, sponges). The present review compiles the available information on the chemical diversity and biological activity of QAs reported during the last three decades. So far, 397 QAs have been isolated, gathering 20 different representative classes, including the most common such as matrine (13.6%), lupanine (9.8%), anagyrine (4.0%), sparteine (5.3%), cytisine (6.5%), tetrahydrocytisine (4.3%), lupinine (12.1%), macrocyclic bisquinolizidine (9.3%), biphenylquinolizidine lactone (7.1%), dimeric (7.1%), and other less known QAs (20.9%), which include several structural patterns of QAs. A detailed survey of the reported information about the bioactivities of these compounds indicated their potential as cytotoxic, antiviral, antimicrobial, insecticidal, anti-inflammatory, antimalarial, and antiacetylcholinesterase compounds, involving favorable putative drug-likeness scores. In this regard, research progress on the structural and biological/pharmacological diversity of QAs requires further studies oriented on expanding the chemical space to find bioactive scaffolds based on QAs for pharmacological and agrochemical applications.

Research Progress of Natural Matrine Compounds and Synthetic Matrine Derivatives

Matrine is a quinoline alkaloid extracted and separated from the dried root, fruit, and other parts of the plant Sophora flavescens using an organic solvent. Matrine exhibits a variety of biological activities and is widely used in pharmacy, agronomy, and other fields. Due to its low bioavailability, poor chemical stability, and toxicity to the central nervous system, a large number of researchers have searched for matrine derivatives with higher biological activity and safety by modifying its structure. In this review article, the research progress of matrine derivatives obtained using two methods (extraction from Sophora flavescens and structural modifications) from 2018 to 2022 in terms of pharmacological activity, mechanism of action, and structure-activity relationship are presented. The modification of matrine over the past five years has been mainly on the D-ring. Many new matrine alkaloids have been extracted from natural products, some of which have good pharmacological activity, which broadens the strategy for matrine structural modification in the future.

Sophflarine A, a novel matrine-derived alkaloid from Sophora flavescens with therapeutic potential for non-small cell lung cancer through ROS-mediated pyroptosis and autophagy

BACKGROUND

Novel compounds and more efficient treatment options are urgently needed for the treatment of non-small cell lung cancer (NSCLC). The decoction of Sophora flavescens has been used to treat NSCLC in the clinic, and matrine-type alkaloids are generally considered to be the key pharmacodynamic material basis. But the previous study showed that common matrine-type alkaloids exhibit significant cytotoxicity only when at concentrations close to the millimolar (mM) level. The key antitumor alkaloids in S. flavescens seem to have not yet been revealed.

PURPOSE

The aim of this study was to screen water-soluble matrine alkaloid with novel skeleton and enhanced activity from S. flavescens, and to reveal the pharmacological mechanism of its therapeutic effect on NSCLC.

METHODS

Alkaloid was obtained from S. flavescens by chromatographic separation methods. The structure of alkaloid was determined by spectroscopic methods, and single-crystal X-ray diffraction. The mechanism of anti-NSCLC in vitro with cellular models was evaluated by MTT assay, western blotting, cell migration and invasion assay, plate colony-formation assay, tube formation assay, immunohistochemistry assay, hematoxylin and eosin staining. The antitumor efficacy in vivo was test in NSCLC xenograft models.

RESULTS

A novel water-soluble matrine-derived alkaloid incorporating 6/8/6/6 tetracyclic ring system, named sophflarine A (SFA), was isolated from the roots of S. flavescens. SFA had significantly enhanced cytotoxicity compared with the common matrine-type alkaloids, having an IC₅₀ value of 11.3 μM in A549 and 11.5 μM in H820 cells at 48 h. Mechanistically, SFA promoted NSCLC cell death by inducing pyroptosis via activating the NLRP3/caspase-1/GSDMD signaling pathway, and inhibited cancer cell proliferation by increasing the ROS production to activate autophagy via blocking the PI3K/AKT/mTOR signaling pathway. Additionally, SFA also inhibited NSCLC cell migration and invasion by suppressing EMT pathway, and inhibited cancer cell colony formation and human umbilical vein endothelial cell angiogenesis. In concordance with the above results, SFA treatment blocked tumor growth in an A549 cell-bearing orthotopic mouse model.

CONCLUSION

This study revealed a potential therapeutic mechanism of a novel matrine-derived alkaloid, which not only described a rational explanation for the clinical utilization of S. flavescens, but also provided a potential candidate compound for NSCLC treatment.

Triterpenoids, steroids and other constituents from Euphorbia kansui and their anti-inflammatory and anti-tumor properties

Six undescribed triterpenoids (euphokanols A-F), two undescribed C21-steroidal glycosides (euphokanosides A and B), together with fifty-four known compounds were isolated from the roots of Euphorbia kansui. Their structures were demonstrated by extensive spectroscopic data (1D, 2D NMR and HR-ESI-MS), and the absolute configuration of euphokanol A was elucidated based on electronic circular dichroism (ECD) calculation. Among them, euphokanol A was a tetracyclic triterpenoid with a 5,10-epoxy moiety and concurrent rearrangement of Me-19(10 → 9) and Me-30 (14 → 8), while euphokanols B and C were rare 19(10 → 9) abeo-tirucallane-type triterpenoids with Δ5(10) double bonds and 7,8-epoxy moieties. In addition, ten C21-steroidal glycosides were isolated from Euphorbia plants for the first time. Moreover, cynotophylloside B, caudatin, 5α,8α-epidioxy-22E-ergosta-6,22-diene-3β-ol, 6β,7β-epoxy-3β,4β,5β-trihydroxyl-20-deoxyingenol, 13-hydroxyingenol-3-(2,3- dimethylbutanoate)-13-dodecanoate, ingenol, 3-O-benzoyl-13-O-dodecanoateingenol, 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol, 20-O-acetylingenol and 20- deoxyingenol exhibited significant inhibition on NO production with IC50 values of 9.10, 17.38, 1.71, 0.55, 0.57, 12.22, 0.56, 0.30, 11.21 and 2.98 μM, respectively. Furthermore, wilfoside KIN, cynsaccatol L, kanesulone A, and 3β,7β,15β-triacetyloxy-5α-benzoyloxy-2α,8α-dihydroxyjatropha-6(17),11E-diene-9, 14-dione showed cytotoxicity against HepG2 cell line, with IC50 values of 12.55, 12.61, 18.24 and 18.26 μM, respectively. 13-Hydroxyingenol-3-(2,3-dimethylbutanoate)-13- dodecanoate exhibited anti-proliferation activity on MCF-7 cell line with an IC50 value of 17.12 μM. Specifically, euphol selectively inhibited the growth of human glioma stem cells (GSC-3# and GSC-12#), with IC50 values of 8.89 and 13.00 μM, respectively.

Diastereoselective and E/Z-Selective Synthesis of Functionalized Quinolizine Scaffolds via the Dearomative Annulation of 2-Pyridylacetates with Nitroenynes

An organocatalytic Michael/aza-Michael cascade reaction was developed to build the functionalized quinolizine scaffolds in 60-82% yields, excellent diastereoselectivities, and E/Z selectivities. This protocol involves the [3 + 3] annulations of 2-pyridylacetates with nitroenynes through the dearomative strategy in the presence of an organic base under mild conditions. The versatile late-stage derivatizations further demonstrated the synthetic utility of this methodology.

Recent development on COX-2 inhibitors as promising anti-inflammatory agents: The past 10 years

Cyclooxygenases play a vital role in inflammation and are responsible for the production of prostaglandins. Two cyclooxygenases are described, the constitutive cyclooxygenase-1 and the inducible cyclooxygenase-2, for which the target inhibitors are the non-steroidal anti-inflammatory drugs (NSAIDs). Prostaglandins are a class of lipid compounds that mediate acute and chronic inflammation. NSAIDs are the most frequent choices for treatment of inflammation. Nevertheless, currently used anti-inflammatory drugs have become associated with a variety of adverse effects which lead to diminished output even market withdrawal. Recently, more studies have been carried out on searching novel selective COX-2 inhibitors with safety profiles. In this review, we highlight the various structural classes of organic and natural scaffolds with efficient COX-2 inhibitory activity reported during 2011–2021. It will be valuable for pharmaceutical scientists to read up on the current chemicals to pave the way for subsequent research.

Genus Sophora: a comprehensive review on secondary chemical metabolites and their biological aspects from past achievements to future perspectives

Sophora is deemed as one of the most remarkable genera of Fabaceae, and the third largest family of flowering plants. The genus Sophora comprises approximately 52 species, 19 varieties, and 7 forms that are widely distributed in Asia and mildly in Africa. Sophora species are recognized to be substantial sources of broad spectrum biopertinent secondary metabolites namely flavonoids, isoflavonoids, chalcones, chromones, pterocarpans, coumarins, benzofuran derivatives, sterols, saponins (mainly triterpene glycosides), oligostilbenes, and mainly alkaloids. Meanwhile, extracts and isolated compounds from Sophora have been identified to possess several health-promising effects including anti-inflammatory, anti-arthritic, antiplatelets, antipyretic, anticancer, antiviral, antimicrobial, antioxidant, anti-osteoporosis, anti-ulcerative colitis, antidiabetic, anti-obesity, antidiarrheal, and insecticidal activities. Herein, the present review aims to provide comprehensive details about the phytochemicals and biological effects of Sophora species. The review spotlighted on the promising phytonutrients extracted from Sophora and their plethora of bioactivities. The review also clarifies the remaining gaps and thus qualifies and supplies a platform for further investigations of these compounds.

Phytotoxic Activity of Alkaloids in the Desert Plant Sophora alopecuroides

Sophora alopecuroides is known to produce relatively large amounts of alkaloids; however, their ecological consequences remain unclear. In this study, we evaluated the allelopathic potential of the main alkaloids, including aloperine, matrine, oxymatrine, oxysophocarpine, sophocarpine, sophoridine, as well as their mixture both in distilled H₂O and in the soil matrix. Our results revealed that all the alkaloids possessed inhibitory activity on four receiver species, i.e., Amaranthus retroflexus, Medicago sativa, Lolium perenne and Setaria viridis. The strength of the phytotoxicity of the alkaloids was in the following order: sophocarpine > aloperine > mixture > sophoridine > matrine > oxysophocarpine > oxymatrine (in Petri dish assays), and matrine > mixture > sophocarpine > oxymatrine > oxysophocarpine > sophoridine > aloperine (in pot experiments). In addition, the mixture of the alkaloids was found to significantly increase the IAA content, MDA content and POD activity of M. sativa seedlings, whereas CTK content, ABA content, SOD activity and CAT activity of M. sativa seedlings decreased markedly. Our results suggest S. alopecuroides might produce allelopathic alkaloids to improve its competitiveness and thus facilitate the establishment of its dominance; the potential value of these alkaloids as environmentally friendly herbicides is also discussed.

Water-soluble matrine-type alkaloids with potential anti-neuroinflammatory activities from the seeds of Sophora alopecuroides

A phytochemical investigation on the alkaloids from water-soluble part of Sophora alopecuroides led to obtain forty matrine-type alkaloids (1-40) including eighteen new ones (1-18), which covers almost all positions of the oxygen substitution in matrine-type structure. Notably, eight compounds (1-8) belong to rare bis-amide matrine-type alkaloid. The new structures were determined based on extensive spectroscopic data, electronic circular dichroism (ECD) calculations, and six instances, verified by X-ray crystallography. Most of isolates showed anti-neuroinflammatory activities based on the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in BV2 microglia cells. Especially, compound 39 can suppress those two mediator secretions in a dose-dependent manner with IC₅₀ values of 21.6 ± 0.5 and 16.7 ± 0.8 μM, respectively. Further mechanistic study revealed that 39 suppressed the phosphorylation of IκBα and p65 subunit to regulate the NF-κB signaling pathway.

Unraveling the Biosynthesis of Quinolizidine Alkaloids Using the Genetic and Chemical Diversity of Mexican Lupins

Quinolizidine alkaloids (QAs) are synthesized by the genus Lupinus as a defense against herbivores. Synthesis of QAs in lupins is species- and organ-specific. Knowledge about their biosynthesis and their corresponding pathways are still fragmentary, in part because lupins of commercial importance were mainly investigated, representing a small sample of the chemodiversity of the genus. Here, we explore the use of three Mexican lupins: Lupinus aschenbornii, Lupinus montanus, and Lupinus bilineatus as a model to study the physiology of QA biosynthesis. The corresponding QA patterns cover widely and narrowly distributed tetracyclic QAs. Quinolizidine alkaloid patterns of seeds and plantlets at different developmental stages were determined by GLC–MS and compared to identify the onset of de novo QA synthesis and to gain insight into specific and common biosynthesis trends. Onset of de novo QA biosynthesis occurred after the metabolization of seed QA during germination and was species-specific, as expected. A common QA pattern, from which the diversity of QA observed in these species is generated, was not found; however, lupanine and 3β-lupanine were found in the three specieswhile sparteine was not found in Lupinus bilineatus, suggesting that this simplest tetracyclic QA is not the precursor of more complex QAs. Similar patterns of metabolization and biosynthesis of structurally related QAs were observed, suggesting a common regulation.

Structurally diversified ent-kaurane and abietane diterpenoids from the stems of Tripterygium wilfordii and their anti-inflammatory activity

Four undescribed ent-kaurane diterpenoids, wilkaunoids A - D (1-4), and three undescribed abietane diterpenoids, wilabinoids A - C (13-15), along with thirteen known ones (5-12 and 16-20), were isolated from Tripterygium wilfordii. Their structures were elucidated by extensive spectroscopic methods, electroniccirculardichroism calculation, and X-ray diffraction analysis. Compounds 1 and 2 were a pair of C-19 epimers of ent-kaurane diterpenoids, featuring a rare 19,20-epoxy-19,20-dimethoxy-kaurane fragment. Compound 3 possessed a rare naturally occurring 1,3-dioxacyclohexane moiety. Compounds 13 and 15 represented the first example of abietane diterpenoids with an isovalerate substitution from the genus of Tripterygium. The possible biosynthetic pathways of 1-3 were postulated. The effect of 1-20 on nitric oxide production was examined in lipopolysaccharide-stimulated RAW 264.7 cells. Abietane diterpenoid quinones 7-13 (IC₅₀: 1.9-10.2 μM) exhibited the significant activity to inhibit nitric oxide production versus positive control (NG-monomethyl-l-arginine acetate salt, IC₅₀ = 24.9 μM). The structure activity relationship of 7-13 in inhibiting nitric oxide production was then discussed. The most potent 7 and 8 were found to significantly suppress the expression of cyclooxygenase-2 and inducible nitric oxide synthase proteins, showing a good anti-inflammatory potential. The findings provided some valuable insights for the discovery and structural modification of abietane diterpenoids towards anti-inflammatory lead compounds.

Biological Activity of Naturally Derived Naphthyridines

Marine and terrestrial environments are rich sources of various bioactive substances, which have been used by humans since prehistoric times. Nowadays, due to advances in chemical sciences, new substances are still discovered, and their chemical structures and biological properties are constantly explored. Drugs obtained from natural sources are used commonly in medicine, particularly in cancer and infectious diseases treatment. Naphthyridines, isolated mainly from marine organisms and terrestrial plants, represent prominent examples of naturally derived agents. They are a class of heterocyclic compounds containing a fused system of two pyridine rings, possessing six isomers depending on the nitrogen atom's location. In this review, biological activity of naphthyridines obtained from various natural sources was summarized. According to previous studies, the naphthyridine alkaloids displayed multiple activities, i.a., antiinfectious, anticancer, neurological, psychotropic, affecting cardiovascular system, and immune response. Their wide range of activity makes them a fascinating object of research with prospects for use in therapeutic purposes.

Rapid screening of active components group with Topoisomerase I inhibitory activity in Sophora alopecuroides L. based on ultrafiltration coupled with UPLC-QTOF-MS

BACKGROUND

Topoisomerase I (Topo I) is a key target of many antitumor drugs in vivo. Alkaloids in Sophora alopecuroides L. can reportedly inhibit Topo I activity, but the pharmacodynamic material basis has not yet been determined.

OBJECTIVE

The objective of this study is to rapidly identify active components group which inhibit Topo I in S. alopecuroides L.

METHODS

Affinity ultrafiltration-ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UF-UPLC-QTOF-MS) screening system based on Topo I protein was established to screen and isolate a total alkaloid fraction in S. alopecuroides L. Topo I inhibitory activity and anti-tuomor proliferation activity of the screened components were evaluated, and their molecular mechanisms were studied.

RESULTS

Six compounds bound specifically to Topo I were obtained. Further screening showed that matrine, cytisine, and sophoridine presented higher inhibitory activity on Topo I and were able to inhibit the proliferation of breast cancer MDA-MB-468 cells with IC50 values of 9.40 ± 1.12 mM, 17.4 ± 2.20 mM and 10.4 ± 1.37 mM, respectively. To the best of our knowledge, their dual molecular mechanisms against Topo I have been discussed here for the first time: (1) stabilization of Topo I-DNA complex and (2) inhibition or blocking of Topo I binding to DNA.

CONCLUSION

Matrine, cytisine, and sophoridine from S. alopecuroides L. were defined as the active components group with Topo I inhibitory activity and their pharmacological mechanism was confirmed, which provided an important base for further research and development of antitumor components fromS. alopecuroides L.