Effects of wind-driven current and thermal dynamics in a temperate monomictic reservoir: Implications for manganese transport and treatment in water supply systems.

Increasing manganese (Mn) concentrations in source water contribute to aesthetic and health-related concerns in drinking water. The challenges with Mn in drinking water primarily arise from elevated Mn concentrations in the water supply reservoir, with the inefficacy of Mn treatment largely attributed to fluctuating Mn levels in the water source. A three-dimensional Mn cycle model in a temperate monomictic reservoir, Tarago Reservoir, and a decision support system reflecting Mn variations in the local water treatment plant have been established in previous research. This study aimed to examine Mn variations from the reservoir to raw water and treated water under the influence of wind conditions during different stages of thermal structure, and discover valuable recommendations for Mn treatment in the local water supply system. We crafted 12 scenarios to scrutinize the impact of varying intensities of offshore and onshore winds on hydrodynamic processes and Mn transport during strong thermal stratification, weak thermal stratification, and turnover. The scenario analysis revealed that, during the gradual weakening of thermal stratification, offshore wind induced a substantial amount of Mn to the upper layers near the water intake point. Conversely, onshore wind hindered the upward transport of Mn. The simulated Mn in the raw water under the 12 scenarios indicated that the timing of turnover in the Tarago Reservoir is the primary concern for Mn treatment in the water treatment plant. Additionally, close attention should be given to the frequency and intensity of offshore winds during the weakening of thermal stratification.

Comparison of two different multiple dual-mode counter-current chromatograph for separation of ketoconazole enantiomers.

In this work, two different multiple dual-mode (MDM) counter-current chromatography methods, conventional MDM and modified MDM elution modes, were compared for the chiral separation of the ketoconazole enantiomers. The biphasic solvent system which consisted of n-hexane: isobutyl acetate: 0.1 mol/L phosphate buffer (2:4:6, v/v) (pH = 8.5) was employed as stationary phase and mobile phase. And the hydroxypropyl-ß-cyclodextrin (HP-ß-CD) with a concentration of 100 mmol/L was dissolved in the phosphate buffer, as the chiral selector. Under two different methods, dual-mode (DM) elution was performed to determine the time of the transformed phase roles and multiple cycles were performed to isolate ketoconazole, respectively. The result indicated that the modified MDM elution had a significant improvement on the separation, increasing the resolution from 0.51 to 1.19, while the resolution was increased from 0.40 to 0.79 by the conventional MDM elution. Ultimately, baseline separation of ketoconazole enantiomers was essentially achieved by high-speed counter-current chromatography under optimized modified MDM separation conditions. The final recoveries of the two enantiomers, R-(K) and S-(K), were 92.5 % and 83.3 %, respectively, corresponding to enantiomeric excess values of 99.0 % and 97.0 %, as determined by HPLC.

Recent trends in multidimensional countercurrent chromatography.

Countercurrent chromatography (CCC) is a potent separation approach known for its remarkable efficiency and capacity in preparation. It's applied as a substitute or combined with different chromatographic techniques, resulting in its rebranding as multidimensional CCC (MDCCC). Numerous essential mixtures from natural products contain hundreds or thousands of distinct components of importance. These mix types are too complicated to separate in any reasonable time using a single CCC dimension. However, if a multidimensional technique is utilized, where a complex mixture is separated by an initial dimension, smaller fractions of that separation are gathered. Each fraction is studied individually; complex mixes can be resolved relatively quickly. Thus, several MDCCC separation features have been studied to demonstrate their advantages, limitations, and prospective capacity to separate exceedingly complex mixtures. In this review, MDCCC aspects, including principles, multiple columns system, multilayer coil J-type, on-line monitoring system, and applications, have been thoroughly_explored.

Analyzing lung cancer risks in patients with impaired pulmonary function through characterization of gut microbiome and metabolites.

BACKGROUND: Lung cancer (LC) is one of the most devastating diseases worldwide, there is growing studies confirm the role of impaired lung function in LC susceptibility. Moreover, gut microbiota dysbiosis is associated with LC severity. Whether alterations in gut microbiota and metabolites are associated with long-term lung dysfunction in LC patients remain unclear. Our study aimed to analyze the risk factors in LC patients with impaired pulmonary function based on the characteristics of the gut microbiome and metabolites. METHODS: Fecal samples from 55 LC patients and 28 benign pulmonary nodules patients were collected. Pulmonary ventilation function was graded according to the American Thoracic Society/ European Respiratory Society (ATS/ERS) method. LC patients were divided into 3 groups, including 20 patients with normal lung ventilation, 23 patients with mild pulmonary ventilation dysfunction and 12 patients with moderate or above pulmonary ventilation dysfunction. The fecal samples were analyzed using 16 S rRNA gene amplicon sequencing and metabolomics. RESULTS: The gut microbiome composition between LC patients and benign pulmonary nodules patients presented clearly differences based on Partial Least Squares Discriminant Analysis (PLS-DA). Pulmonary ventilation function was positively correlated with LC tumor stage, the richness and diversity of the gut microbiota in LC patients with moderate or above pulmonary ventilation dysfunction increased significantly, characterized by increased abundance of Subdoligranulum and Romboutsia. The metabolomics analysis revealed 69 differential metabolites, which were mainly enriched in beta-Alanine metabolism, styrene degradation and pyrimidine metabolism pathway. The area under the curve (AUC) combining the gut microbiome and metabolites was 90% (95% CI: 79-100%), indicating that the two species and four metabolites might regarded as biomarkers to assess the prediction of LC patients with impaired pulmonary function. CONCLUSIONS: Our results showed that microbiome and metabolomics analyses provide important candidate to be used as clinically diagnostic biomarkers and therapeutic targets related to lung cancer with impaired pulmonary function.

Polycyclic pyrroloindoline-containing natural products with a unique 3-heptyl-2a,4a-diazapentaleno[1,6-ab]indene core isolated from Alstonia scholaris.

Alscholarine C (1), featuring an unprecedented pyrroloindoline-containing natural product (PiNP) with a 6/5/5/5 tetracyclic carbon skeleton, and four known PiNPs (2-5), namely demethylalstoscholarinine E (2), Nb-demethylechitamine (3), winphylline A (4), and echitamine (5), were isolated from Alstonia scholaris. Compound 1 was characterized by a hexahydropyrrolo[2,3-b] indole (HPI) core fused to a unique 4-heptylimidazolidine motif, forming an unparalleled 3-heptyl-2a,4a-diazapentaleno[1,6-ab]indene ring system. Their structures were established by spectroscopic analysis, quantum-chemical calculated 13C NMR data with DP4+ probability analyses, and ECD calculations and comparison. A plausible biosynthetic pathway of 1 was proposed. Compound 1 exhibited potential anti-inflammatory activity against LPS-stimulated NO production in RAW264.7 cells.

Alscholarines A and B, two rearranged monoterpene indole alkaloids from Alstonia scholaris.

Alscholarines A and B (1 and 2), two unprecedented rearranged monoterpene indole alkaloids, were isolated from Alstonia scholaris. Alscholarine A (1) features an imidazole ring fused with a rearranged vallesamine-type alkaloid possessing an unparalleled 6/5/6/6 tetracyclic skeleton through an unprecedented C7-C-19 connectivity. Alscholarine B (2), incorporating an unusual 7-oxa-1-azabicyclo[3.2.1]octane moiety, represents a unique rearranged vallesamine-type alkaloid with a 6/5/6/6/5 ring system via an unprecedented C-6-C-20 connectivity. Their structures were established by spectroscopic analysis, X-ray crystallography, and quantum-chemical calculations. Their plausible biosynthetic pathways were proposed. The vasorelaxant and anti-inflammatory activities of them were also evaluated. Compounds 1-3 showed moderate vasorelaxant activities.

Gold nanoparticle dimer-based immunochromatography for in situ ultrasensitive detection of porcine epidemic diarrhea virus.

The low detection sensitivity of lateral-flow immunochromatography assay (LFIA) based on spherical gold nanoparticle (AuNP) limits its wide applications. In the present study, AuNP dimers with strong plasma scattering and robust signal output were synthesized via the Ag ion soldering (AIS) strategy and used as labeled probes in LFIA to boost the sensitivity without any extra operation process and equipment. The established LFIA exhibited high sensitivity with a limit of detection (LOD) of 2.0 × 102 TCID50/mL for PEDV, which provides 50 times higher sensitivity than commercial LFIA based on spherical colloidal gold. In addition, the AuNP dimer-based LFIA showed strong specificity, good reproducibility, high stability, and good accordance to reverse transcription polymer chain reaction (RT-PCR) when detecting 109 clinical samples. Thus, the AuNP dimers is a promising probe for LFIA and the developed AuNP dimer-based LFIA is suitable for the rapid detection of PEDV in the field.

MicroRNA-125a-5p regulates the effect of Tregs on Th1 and Th17 through targeting ETS-1/STAT3 in psoriasis.

BACKGROUND: Psoriasis is an inflammatory disease mediated by helper T (Th)17 and Th1 cells. MicroRNA-125a (miR-125a) is reduced in the lesional skin of psoriatic patients. However, the mechanism by which miR-125a participates in psoriasis remains unclear. METHODS: The levels of miR-125a-5p and its downstream targets (ETS-1, IFN-γ, and STAT3) were detected in CD4+ T cells of healthy controls and psoriatic patients by quantitative real-time PCR (qRT-PCR). In vitro, transfection of miR-125a-5p mimics was used to analyze the effect of miR-125a-5p on the differentiation of Th17 cells by flow cytometry. Imiquimod (IMQ)-induced mouse model was used to evaluate the role of upregulating miR-125a-5p by intradermal injection of agomir-125a-5p in vivo. RESULTS: miR-125a-5p was downregulated in peripheral blood CD4+ T cells of psoriatic patients, which was positively associated with the proportion of regulatory T cells (Tregs) and negatively correlated with the Psoriasis Area and Severity Index (PASI) score. Moreover, the miR-125a-5p mimics promoted the differentiation of Tregs and downregulated the messenger RNA (mRNA) levels of ETS-1, IFN-γ, and STAT3 in murine CD4+ T cells. Furthermore, agomir-125a-5p alleviated psoriasis-like inflammation in an IMQ-induced mouse model by downregulating the proportion of Th17 cells. CONCLUSIONS: miR-125a-5p may have therapeutic potential in psoriasis by restoring the suppressive function of Tregs on Th17 cells through targeting STAT3, and on Th1 cells indirectly through targeting ETS-1 and IFN-γ.

Molecular Networking Accelerated Discovery of Biflavonoid Alkaloids from Cephalotaxus sinensis.

Four undescribed biflavonoid alkaloids, sinenbiflavones A-D, were isolated from Cephalotaxus sinensis using a MS/MS-based molecular networking guided strategy. Their structures were elucidated by series of spectroscopic methods (HR-ESI-MS, UV, IR, 1D, and 2D NMR). Sinenbiflavones A-D are the first examples of amentoflavone-type (C-3'-C-8'') biflavonoid alkaloids. Meanwhile, sinenbiflavones B and D are the unique C-6-methylated amentoflavone-type biflavonoid alkaloids. Sinenbiflavone D showed weak SARS-CoV-2 3CLpro inhibitory activity with 43 % inhibition rate at 40 µM.

Utilization of two plant polysaccharides to improve fresh goat milk cheese: Texture, rheological properties, and microstructure characterization.

This study aimed to evaluate the effects of added jujube polysaccharide (JP) and Lycium barbarum polysaccharide (LBP) on the texture, rheological properties, and microstructure of goat milk cheese. Seven groups of fresh goat milk cheese were produced with 4 levels (0, 0.2, 0.6, and 1%, wt/wt) of JP and LBP. The goat milk cheese containing 1% JP showed the highest water-holding capacity, hardness, and the strongest rheological properties by creating a denser and more stable casein network structure. In addition, the yield of goat milk cheese was substantially improved as a result of JP incorporation. Cheeses containing LBP expressed lower fat content, higher moisture, and softer texture compared with the control cheese. Fourier-transform infrared spectroscopy and low-field nuclear magnetic resonance analysis demonstrated that the addition of JP improved the stability of the secondary protein structure in cheese and significantly enhanced the binding capacity of the casein matrix to water molecules due to strengthened intermolecular interactions. The current research demonstrated the potential feasibility of modifying the texture of goat milk cheese by JP or LBP, available for developing tunable goat milk cheese to satisfy consumer preferences and production needs.

An overview of recent progress in multiple dual-mode counter-current chromatography.

Counter-current chromatography is a chromatographic separation and purification technique being developed. The development of different elution modes has significantly contributed to this field. Multiple dual-mode elution is a method developed based on dual-mode elution, which consists of a series of changing cycles of the phase role and the direction by switching between normal and reverse elution modes of counter-current chromatography. This dual-mode elution method takes full advantage of the liquid nature of stationary and mobile phases of counter-current chromatography and effectively improves the separation efficiency. So, this unique elution mode has gained extensive attention for separating complex samples. This review mainly describes and summarizes in detail its development, applications, and characteristics in recent years. Meanwhile, its advantages, limitations, and future outlook also have been discussed in this paper.

Structurally diverse monoterpene indole alkaloids with vasorelaxant activities from the branches of Alstonia scholaris.

Seven undescribed monoterpene indole alkaloids alstoscholarinines A‒G, along with nineteen known alkaloids, were isolated from the branches of Alstonia scholaris (L.) R. Br. The isolated alkaloids were classified into ten framework types. The structures of the undescribed alkaloids were elucidated by extensive spectroscopic analysis, ECD calculation, and single-crystal X-ray diffraction analysis. Alstoscholarinine A is an unreported and unusual monoterpene indole alkaloid incorporating three nitrogen atoms, characterized by a compact 6/5/6/6/6/5 hexacyclic system bearing a piperidine ring and a unique oxazolidine ring. Alstoscholarinine B represents the first naturally C-17 nor-isositsirikine-type alkaloid. Plausible biosynthetic pathways of alstoscholarinines A and B were proposed. All isolates were evaluated for their vasorelaxant activities against phenylephrine-induced contraction of rat mesenteric arteries. Among them, seven alkaloids showed significant vasorelaxant activities with EC50 values less than 10 µM. Importantly, the akuammicine-type alkaloids in this study showed much better vasorelaxant activities than other framework type alkaloids, indicating that this type of alkaloid may be a valuable source for the discovery of vasodilators. A preliminary structure-activity relationship for vasorelaxant activities of the isolated akuammicine-type alkaloids is also discussed.

Cytotoxic alkaloids from the twigs and leaves of Cephalotaxus sinensis.

Twelve new Cephalotaxus alkaloids (1-12) and nine known analogues (13-21) were isolated and identified from the twigs and leaves of Cephalotaxus sinensis. The structures of the new compounds (1-12) were elucidated by extensive spectroscopic analysis and single-crystal X-ray diffraction analysis. Cephalosine H (8) is the third example of an alkaloid containing the cephalolancine skeleton. Cephalosines J and K (10 and 11) are the rare natural Δ(2)1-alkene-6-hydroxyl homoerythrina-type alkaloids isolated from the Cephalotaxus genus. The racemization of cephalotaxine-type alkaloids is discussed. Alkaloids 6, 7, 11, 16, 18 and 19 exhibited broad and potent cytotoxicities against five human cancer cell lines, with IC50 values ranging from 0.053 to 10.720 µM, highlighting these compounds as promising leads for the development of new antitumor agents.

Annexin A6 Polymorphism Is Associated with Pro-atherogenic Lipid Profiles and with the Downregulation of Methotrexate on Anti-Atherogenic Lipid Profiles in Psoriasis.

BACKGROUND: Annexin A6 (AnxA6) is a lipid-binding protein that regulates cholesterol homeostasis and secretory pathways. However, the correlation of AnxA6 polymorphism with lipometabolism has never been studied in psoriasis. OBJECTIVES: To investigate the impact of AnxA6 polymorphism on lipid profiles and the expression of AnxA6 protein in both peripheral blood mononuclear cells (PBMCs) and lipometabolism in psoriasis. METHODS: A total of 265 psoriatic patients received methotrexate (MTX) treatment for 12 weeks, after which their lipid profiles were determined by measuring total cholesterol (TC), triglycerides (TGs), lipoprotein (a) [LP(a)], high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL), apolipoprotein (a)1 (ApoA1), and apolipoprotein B (ApoB). In addition, AnxA6 (rs11960458) was genotyped in 262 patients and the expression of AnxA6 in PBMCs was measured by Western blotting at baseline and week 8 post-MTX treatment. RESULTS: The CC genotype carriers of rs11960458 had a lower expression of AnxA6 and lower levels of the pro-atherogenic lipids TC, LDL, and ApoB compared to TC genotype carriers. MTX significantly downregulated the levels of the anti-atherogenic lipids HDL-C and ApoA1 and the level of AnxA6 in TC genotype carriers, as well as the level of TGs in CC genotype carriers. CONCLUSIONS: The polymorphism of AnxA6, rs11960458, was statistically associated with the levels of pro-atherogenic lipids and with the downregulation of MTX on the levels of anti-atherogenic lipids and TGs in psoriasis.

Metabolites with antioxidant and α-glucosidase inhibitory activities produced by the endophytic fungi Aspergillus niger from Pachysandra terminalis.

One new compound and 13 known compounds were isolated from Aspergillus niger, a plant endophytic fungus of Pachysandra terminalis collected from Qinling Mountains, Xi'an, China. The structure of new compound 1 was classically determined by extensive spectroscopic analysis. Compounds 5, 6, 8, and 14 were first reported from Aspergillus, while compound 2 was isolated from A. niger for the first time. All isolated compounds were further evaluated for their antioxidant and α-glucosidase inhibitory activities. Compounds 2 and 3 exhibited significant antioxidant activities with IC50 values of 31.64 µm and 24.32 µm, respectively, similar to the positive control ascorbic acid. Additionally, compound 1 displayed remarkable inhibitory activity against α-glucosidase with an IC50 value of 96.25 µm, which was 3.4-fold more potent than that of the positive control acarbose. Compound 1 has great potential for development as a new lead compound owing to its simple structure and remarkable biological activity.

Isoquinoline alkaloids from Hylomecon japonica and their potential anti-breast cancer activities.

Four pairs of undescribed enantiomeric isoquinoline alkaloids (6S/R-(N,N-diethylacetamido)yl-dihydrochelerythrine, 6R/S-acetonyl-9-hydroxy-dihydrochelerythrine, 6S/R-acroleinyl-dihydrochelerythrine, 6S/R-acetatemethyl-dihydrochelerythrine), five undescribed isoquinoline alkaloids (6,10-dimethoxydihydrochelerythrine, 6-ethoxy-ethaniminyl-dihydrochelandine, 9-hydroxy-dihydrochelerythrine, 9-methoxy-10-hydroxy-norchelerythrine, chelidoniumine A), together with 13 known isoquinoline alkaloids were isolated from an extract of the roots and rhizomes of Hylomecon japonica. The structures of the undescribed compounds were identified by NMR, HRESIMS, UV, IR, and their absolute configurations were defined via electronic circular dichroism data and optical rotation. All of the isolated compounds were tested for their anti-breast cancer activities in MCF-7 cells. Among them, the undescribed alkaloids 6S/R-acroleinyl-dihydrochelerythrine, 6,10-dimethoxydihydrochelerythrine, 6-ethoxy-ethaniminyl-dihydrochelandine, 9-methoxy-10-hydroxy-norchelerythrine and other known alkaloids 6-methoxydihydrosanguinarine, 6-acetaldehyde-dihyrochelerythrine, dihydrosanguinaline and 10-methoxy boconoline had good inhibitory effects on MCF-7 cells of breast cancer with an IC50 lower than 20 µM.

An ultrasensitive sandwich-type electrochemical aptasensor using silver nanoparticle/titanium carbide nanocomposites for the determination of Staphylococcus aureus in milk.

A novel sandwich-type electrochemical aptasensor for the detection of Staphylococcus aureus (S. aureus) was developed. S. aureus aptamers were self-assembled onto the surface of a glassy carbon electrode (GCE) modified with nanocomposites comprising titanium carbide embedded with silver nanoparticles (AgNPs@Ti3C2) through hydrogen bonds and the chelation interaction between phosphate groups and Ti ions. In addition, the self-assembled aptamers were immobilized on CuO/graphene (GR) nanocomposites via π-π stacking interactions to serve as a signal probe. In the presence of the target S. aureus, the sandwich-type recognition system reacted on the surface of GCE, and the CuO/GR nanocomposites catalyzed the hydrogen peroxide + hydroquinone reaction producing a strong current response. Under the optimal experimental conditions, the current response of the aptasensor was linearly correlated with the concentration of S. aureus (52-5.2 × 107 CFU mL-1) with a low detection limit of 1 CFU mL-1. The aptasensor displayed good repeatability and excellent selectivity for S. aureus detection. Moreover, this aptasensor was applied to the detection of S. aureus in cow, sheep, and goat milk samples, affording recoveries ranging from 92.64 to 109.58%. This research provides a new platform for the detection of pathogenic bacteria and other toxic and harmful substances in food.

Prospective, randomized, controlled, noninferiority clinical trial to evaluate the safety and efficacy of absorbable macroporous polysaccharide composites as adjunct to hemostasis during open surgery.

BACKGROUND: To address intraoperative bleeding in cardiac surgery, reducing blood transfusion requirements, is mandatory to achieve effective hemostasis. Hemostatic agents may limit localized persistent bleeding. The introduction of carboxymethyl-chitosan component into the hemostatic agent and the application of the radiation crosslinking technique maintain its capacity for achieving intraoperative hemostasis, thus increasing the clinical utility. METHODS: A prospective, noninferiority and randomized controlled clinical trial to compare the safety and efficacy of absorbable macroporous polysaccharide composites (AMPC, treatment group) with compound microporous polysaccharide hemostatic powder (CMPHP, control group) (2:1 ratio) as adjuncts to hemostasis in open surgery. The main indication was used for hemostasis in various traumatic hemorrhage areas, including cardiothoracic, vascular, and general surgery. The primary endpoint was success rate of hemostasis within 300 s (at a 10% noninferiority margin). The secondary endpoint was hemostasis time. Both endpoints were assessed in the modified intention-to-treat (MITT) population. Safety parameters were assessed. This study is fully compliant with the CONSORT statement. RESULTS: Randomized patients in AMPC and CMPHP groups were 168 and 84, respectively. In MITT population, the success rates of hemostasis within 300 s were 98.8% (163 of 165) in AMPC and 94.0% (78 of 83) in CMPHP (treatment difference 4.8% [95% CI -0.57% to 10.20%]). AMPC was thus noninferior to CMPHP. Hemostasis time (median [interquartile range]) with AMPC (87 [52.5, 180] s) was better than CMPHP (110 [54.5, 181] s). Changes in laboratory parameters over time and shifts to abnormal values were typical of surgeries and similar between two groups. No noticeable adverse effects associated with AMPC or CMPHP were observed. CONCLUSIONS: AMPC is well tolerated as topical hemostatic agent, noninferior to commercial CMPHP, and exhibits excellent safety. This study provides a novel hemostatic agent which appears to offer significant clinical advantage in various hemorrhage areas.

Changes of antibiotic resistance genes and gut microbiota after the ingestion of goat milk.

Antibiotic resistance genes, as newly emerging contaminants, have become a serious challenge to public health through the food chain. The gut of humans and animals is an important reservoir for the development and dissemination of antibiotic resistance genes because of the great abundance and diversity of intestinal microbiota. In the present study, we evaluated the influence of goat milk on the diversity and abundance of antibiotic resistance genes and gut microbial communities, especially pathogenic bacteria. Male mice were used, 12 for each of the 2 groups: a control group that received sterile distilled water and a treated group that received goat milk, and gut microbiota and antibiotic resistance genes were compared in these groups using metagenomic analysis. The results revealed that ingestion of goat milk decreased the diversity and abundance of antibiotic resistance genes in the mice gut. The relative abundance of fluoroquinolone, peptide, macrolide, and ß-lactam resistance genes in the total microbial genes significantly decreased after the intervention. Goat milk intake also significantly reduced the abundance of pathogenic bacteria, such as Clostridium bolteae, Clostridium symbiosum, Helicobacter cinaedi, and Helicobacter bilis. Therefore, goat milk intake might decrease the transfer potential of antibiotic resistance gene to pathogenic bacteria in the gut. In addition, bacteria with multiple resistance mechanisms accounted for approximately 4.5% of total microbial communities in the control group, whereas it was not detectable in the goat milk group, indicating the total inhibition by goat milk intake. This study highlights the influence of goat milk on antibiotic resistome and microbial communities in the gut, and provides a new insight into the function of goat milk for further study.

New phenylpropanoids and monoterpene alkaloids with vasorelaxant activities from the branches of Alstonia scholaris.

Two new phenylpropanoids (1-2), one new nor-monoterpenoid alkaloid (3), one new monoterpene alkaloid (4), together with nine known compounds (5-13) were obtained from the branches of Alstonia scholaris. The structures of the undescribed compounds were determined by extensive spectroscopic analysis. Alkaloid 3 represented the first example of C-4 methylated nor-monoterpenoid alkaloids. A possible biosynthetic pathway for this new type of monoterpene alkaloids was proposed. All the isolates were evaluated for vasorelaxant activity against phenylephrine-induced contraction of rat mesenteric arteries. Compounds 1, 4, 9, 12, and 13 showed significant vasorelaxant activity with relaxation rates above 90% at 200 µM and exhibited moderate vasorelaxant activity with IC50 values ranging from 41.87 to 93.30 µM by further studies. It was the first report on the potential vasorelaxant activity of monoterpene alkaloids. Monoterpene alkaloids 3 and 4 may be served as the potential lead compounds for the discovery of vasodilators, due to their simple and optimizable structures.