Simultaneous purification of minor components in natural products using twin-column recycling chromatography with a step solvent gradient

The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).

Natural Products Improve Organ Microcirculation Dysfunction Following Ischemia/Reperfusion-and Lipopolysaccharide-Induced Disturbances:Mechanistic and Therapeutic Views

Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and thrombosis.These disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and platelets.In clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory disturbances.Natural products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory disturbances.In recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international journals.In 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,respectively.This review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue injury.Based on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.

Research progress on natural products against hepatocellular carcinoma

Hepatocellular carcinoma(HCC)remains a prevalent and challenging malignancy globally,characterized by its numerous causal factors and generally unfavorable prognosis.In the relentless pursuit of effective treatment modalities,natural products have emerged as a promising and relatively non-toxic alternative,garnering significant interest.The integration of natural products with contemporary medical research has yielded encouraging therapeutic outcomes in the management of HCC.This review offers a comprehensive overview of the causal factors underlying HCC,and the diverse treatment options available,and highlights the advancements made by natural products in anti-HCC research.Particularly,we provide an outline of the various types of natural products,their corresponding nomenclature,target molecules,and mechanisms of action that exhibit anti-HCC activities.Natural products are anticipated to play a pivotal role in future comprehensive treatment plans for liver cancer,potentially offering patients improved survival rates and an enhanced quality of life.

Targeting oxidative stress with natural products: A novel strategy for esophageal cancer therapy

Esophageal cancer(ESC)is a malignant tumor that originates from the mucosal epithelium of the esophagus and is part of the digestive tract.Although the exact pathogenesis of ESC has not been fully elucidated,excessive oxidative stress is an important characteristic that leads to the development of many cancers.Abnormal expression of several proteins and transcription factors contributes to oxidative stress in ESCs,which alters the growth and proliferation of ESCs and promotes their metastasis.Natural compounds,including alkaloids,terpenes,polyphenols,and xanthine compounds,can inhibit reactive oxygen species production in ESCs.These compounds reduce oxidative stress levels and subsequently inhibit the oc-currence and progression of ESC through the regulation of targets and pathways such as the cytokine interleukins 6 and 10,superoxide dismutase,the NF-+ACY-kappa+ADs-B/MAPK pathway,and the mammalian Nrf2/ARE target pathway.Thus,targeting tumor oxidative stress has become a key focus in anti-ESC therapy.This review discusses the potential of Natural products(NPs)for treating ESCs and summarizes the application prospects of oxidative stress as a new target for ESC treatment.The findings of this review provide a reference for drug development targeting ESCs.Nonetheless,further high-quality studies will be necessary to determine the clinical efficacy of these various NPs.

Current therapeutic modalities and chemopreventive role of natural products in liver cancer:Progress and promise

Liver cancer is a severe concern for public health officials since the clinical cases are increasing each year,with an estimated 5-year survival rate of 30%–35%after diagnosis.Hepatocellular carcinoma(HCC)constitutes a significant subtype of liver cancer(approximate75%)and is considered primary liver cancer.Treatment for liver cancer mainly depends on the stage of its progression,where surgery including,hepatectomy and liver transplantation,and ablation and radiotherapy are the prime choice.For advanced liver cancer,various drugs and immunotherapy are used as first-line treatment,whereas second-line treatment includes chemotherapeutic drugs from natural and synthetic origins.Sorafenib and lenvatinib are first-line therapies,while regorafenib and ramucirumab are secondline therapy.Various metabolic and signaling pathways such as Notch,JAK/STAT,Hippo,TGF-β,and Wnt have played a critical role during HCC progression.Dysbiosis has also been implicated in liver cancer.Drug-induced toxicity is a key obstacle in the treatment of liver cancer,necessitating the development of effective and safe medications,with natural compounds such as resveratrol,curcumin,diallyl sulfide,and others emerging as promising anticancer agents.This review highlights the current status of liver cancer research,signaling pathways,therapeutic targets,current treatment strategies and the chemopreventive role of various natural products in managing liver cancer.

Role of natural products and intestinal flora on type 2 diabetes mellitus treatment

Diabetes mellitus(DM)is a complicated,globally expanding disease that is influenced by hereditary and environmental variables.Changes in modern society’s food choices,physical inactivity,and obesity are significant factors in the development of type 2 DM(T2DM).The association between changes in intestinal flora and numerous disorders,including obesity,diabetes,and cardiovascular diseases,has been studied in recent years.The purpose of this review is to analyze the mechanisms underlying the alteration of the diabetic patients’intestinal flora,as well as their therapeutic choices.Also included is a summary of the antidiabetic benefits of natural compounds demonstrated by studies.The short-chain fatty acids theory,the bile acid theory,and the endotoxin theory are all potential methods by which intestinal flora contributes to the establishment and progression of T2DM.Due to an intestinal flora imbalance,abnormalities in shortchain fatty acids and secondary bile acids have been found in diabetic patients.Additionally,metabolic endotoxemia with altering flora induces a systemic inflammatory response by stimulating the immune system via bacterial translocation.The agenda for diabetes treatment includes the use of short-chain fatty acids,probiotics,prebiotics in the diet,fecal bacteria transplantation,and antibiotics.Animal studies have proven the antidiabetic benefits of numerous bioactive substances,including Flavonoids,Alkaloids,Saponin,and Allicin.However,further research is required to contribute to the treatment of diabetes.

Natural products and extracts from plants as natural UV filters for sunscreens:A review

Although solar exposure is necessary for human health,phototoxicology induced by excessive UVB and UVA radiation,which involves sunburns,skin aging and even tu-morigenesis,has been widely researched.Sunscreen is one of the most important ways to protect skin from UV phototoxic damage.As well as inorganic and organic UV filters,some natural products or plant extracts with aromatic rings in their structures,such as flavonoids or polyphenols,can absorb UV to reduce sunburn,acting as a natu-ral UV filter;they also show antioxidant or/and anti-inflammatory activity.This could explain why,although there are no officially approval natural commercial sun-filters,more and more commercial sunscreen products containing plant extracts are avail-able on the market.Here we summarize articles focusing on natural UV filters from plant published in the last 6 years,selecting the most significant data in order to better understand the photoprotective activity of natural products and extracts from plants,including their major constituents and main biological effects,methods for evaluating UV radiation resistance,anti-UV radiation experimental models and anti-UV radiation mechanisms.

Prioritised identification of structural classes of natural products from higher plants in the expedition of antimalarial drug discovery

The emergence and spread of drug-recalcitrant Plasmodium falciparum parasites threaten to reverse the gains made in the fight against malaria.Urgent measures need to be taken to curb this impending challenge.The higher plant-derived sesquiterpene,quinoline alkaloids,and naphthoquinone natural product classes of compounds have previously served as phenomenal chemical scaffolds from which integral antimalarial drugs were developed.Historical successes serve as an inspiration for the continued investigation of plant-derived natural products compounds in search of novel molecular templates from which new antimalarial drugs could be developed.The aim of this study was to identify potential chemical scaffolds for malaria drug discovery following analysis of historical data on phytochemicals screened in vitro against P.falciparum.To identify these novel scaffolds,we queried an in-house manually curated database of plant-derived natural product compounds and their in vitro biological data.Natural products were assigned to different structural classes using NPClassifier.To identify the most promising chemical scaffolds,we then correlated natural compound class with bioactivity and other data,namely(i)potency,(ii)resistance index,(iii)selectivity index and(iv)physicochemical properties.We used an unbiased scoring system to rank the different natural product classes based on the assessment of their bioactivity data.From this analysis we identified the top-ranked natural product pathway as the alkaloids.The top three ranked super classes identified were(i)pseudoalkaloids,(ii)naphthalenes and(iii)tyrosine alkaloids and the top five ranked classes(i)quassinoids(of super class triterpenoids),(ii)steroidal alkaloids(of super class pseudoalkaloids)(iii)cycloeudesmane sesquiterpenoids(of super class triterpenoids)(iv)isoquinoline alkaloids(of super class tyrosine alkaloids)and(v)naphthoquinones(of super class naphthalenes).Launched chemical space of these identified classes of compounds was,by and large,distinct from that of‘legacy’antimalarial drugs.Our study was able to identify chemical scaffolds with acceptable biological properties that are structurally different from current and previously used antimalarial drugs.These molecules have the potential to be developed into new antimalarial drugs.

Occurrence of D-amino acids in natural products

Since the identified standard genetic code contains 61 triplet codons of three bases for the 20 L-proteinogenic amino acids(AAs),no D-AA should be found in natural products.This is not what is observed in the living world.D-AAs are found in numerous natural compounds produced by bacteria,algae,fungi,or marine animals,and even vertebrates.A review of the literature indicated the existence of at least 132 peptide natural compounds in which D-AAs are an essential part of their structure.All compounds are listed,numbered and described herein.The two biosynthetic routes leading to the presence of D-AA in natural products are:non-ribosomal peptide synthesis(NRPS),and ribosomally synthesized and post-translationally modified peptide(RiPP)synthesis which are described.The methods used to identify the AA chirality within naturally occurring peptides are briefly discussed.The biological activity of an all-L synthetic peptide is most often completely different from that of the D-containing natural compounds.Analyzing the selected natural compounds showed that D-Ala,D-Val,D-Leu and D-Ser are the most commonly encountered D-AAs closely followed by the non-proteinogenic D-allo-Thr.D-Lys and D-Met were the least prevalent D-AAs in natu-rally occurring compounds.

Acute kidney injury:microRNAs and new therapeutic opportunities for natural products

In the past few decades,acute kidney injury(AKI),characterized by an abrupt decrease in kidney filtration rate,has become a public health issue affecting between 1%and 15%of the population,which causes high morbidity and death.There is mounting evidence that miRNAs are noncoding single-stranded RNAs with a short length of about 20 nucleotides and have been highly conserved through evolution.Through targeting mRNAs,miRNA may mediate intercellular communication during AKI’s physiological and pathological processes.It is interesting to note that natural products can improve AKI by regulating miRNA expression,which might represent a potentially innovative therapeutic strategy.This review aims at providing an overview of the new data obtained on miRNAs in the treatment and diagnosis of AKI,summarizing studies on natural products improving AKI through regulating miRNAs’expression;in the same time,it will shed new light on AKI risk biomarkers and therapeutic intervention as well.We summarized the roles of miRNAs involved in AKI progression or protection against renal injury in 32 articles;we found five natural products can improve AKI by regulating miRNA expression,which will potentially provide a reference for clinical treatment.Natural products might represent a potentially innovative therapeutic strategy;in the same time,miRNAs will shed new light on AKI risk biomarkers and therapeutic intervention.

Research progress of natural products in treating polycystic ovary syndrome

Polycystic ovary syndrome(PCOS)is a common metabolic disorder reproductive endocrine disease in puberty and women of childbearing age.At present,metformin is mainly used in clinical to treat PCOS.From recent researches,many natural products,such as flavonoids,alkaloids,cumarins,etc,showed curing effects on PCOS.These have been attracting more and more attention.By searching the researches from database of CNKI,PubMed etc,this paper aims at providing a reference for PCOS drug research and development.

A Review of Textile Fabrication Using Bioactive Compounds Derived from Natural Products

Antimicrobial-treated textiles should exhibit efficacy against a broad spectrum of bacterial and fungal species,all while maintaining user safety with a non-toxic profile.Natural antimicrobial compounds play a vital role in textile finishing processes.The proliferation of synthetic antimicrobial agents introduces environmental and consumer safety concerns.Given these potential hazards associated with synthetic agents,the utilization of natural antimicrobial agents is gaining traction,as they tend to have fewer adverse effects on users and are more environmentally sustainable.Numerous natural antimicrobial compounds,sourced from plants such as neem,basil,turmeric,aloe vera,and clove oil,have been developed,showcasing inherent antimicrobial properties.This review article highlights the importance of incorporating bioactive components in the creation of antibacterial textile fabrics.

Mechanisms of action of natural products on type 2 diabetes

Over the past several decades,type 2 diabetes mellitus(T2DM)has been considered a global public health concern.Currently,various therapeutic modalities are available for T2DM management,including dietary modifications,moderate exercise,and use of hypoglycemic agents and lipid-lowering medications.Although the curative effect of most drugs on T2DM is significant,they also exert some adverse side effects.Biologically active substances found in natural medicines are important for T2DM treatment.Several recent studies have reported that active ingredients derived from traditional medicines or foods exert a therapeutic effect on T2DM.This review compiled important articles regarding the therapeutic effects of natural products and their active ingredients on isletβcell function,adipose tissue inflammation,and insulin resistance.Additionally,this review provided an in-depth understanding of the multiple regulatory effects on different targets and signaling pathways of natural medicines in the treatment of T2DM as well as a theoretical basis for clinical effective application.

Exploring the efficacy of natural products in alleviating Alzheimer’s disease

Alzheimer’s disease(hereafter AD) is a progressive neurodegenerative disorder that affects the central nervous system. There are multiple factors that cause AD, viz., accumulation of extracellular Amyloid-beta 42 plaques, intracellular hyper-phosphorylated Tau tangles, generation of reactive oxygen species due to mitochondrial dysfunction and genetic mutations. The plaques and tau tangles trigger aberrant signaling, which eventually cause cell death of the neurons. As a result, there is shrinkage of brain, cognitive defects, behavioral and psychological problems. To date, there is no direct cure for AD. Thus, scientists have been testing various strategies like screening for the small inhibitor molecule library or natural products that may block or prevent onset of AD. Historically, natural products have been used in many cultures for the treatment of various diseases. The research on natural products have gained importance as the active compounds extracted from them have medicinal values with reduced side effects, and they are bioavailable. The natural products may target the proteins or members of signaling pathways that get altered in specific diseases. Many natural products are being tested in various animal model systems for their role as a potential therapeutic target for AD, and to address questions about how these natural products can rescue AD or other neurodegenerative disorders. Some of these products are in clinical trials and results are promising because of their neuroprotective, anti-inflammatory, antioxidant, anti-amyloidogenic, anticholinesterase activities and easy availability. This review summarizes the use of animal model systems to identify natural products, which may serve as potential therapeutic targets for AD.

Gut microbiota as a target for prevention and treatment of type 2 diabetes:Mechanisms and dietary natural products

Type 2 diabetes mellitus(T2DM)is among the most remarkable public health concerns globally.Accumulating research evidence documents that alteration of gut microbiota has an indispensable role in the onset and progression of obesity and T2DM.A reduced microbial diversity is linked to insulin resistance and energy metabolism,especially for the rise of the Firmicutes/Bacteroidetes ratio.Changes in metabolites followed by the gut dysbacteriosis are linked to the presence of T2DM.Moreover,endotoxin leakage and gut permeability caused by gut dysbacteriosis is more of a trigger for the onset and progression of T2DM.Research documents that natural products are remarkable arsenals of bioactive agents for the discovery of anti-T2DM drugs.Many studies have elucidated that the possible mechanisms of the anti-T2DM effects of natural products are remarkably linked to its regulation on the composition of gut microflora and the successive changes in metabolites directly or indirectly.This review presents a brief overview of the gut microbiota in T2DM and several relevant mechanisms,including short-chain fatty acids,biosynthesis and metabolism of branched-chain fatty acids,trimethylamine N-oxide,bile acid signaling,endotoxin leakage,and gut permeability,and describes how dietary natural products can improve T2DM via the gut microbiota.

Recent Advances in Separation of Bioactive Natural Products

Bioactive natural products are a main source of new drugs,functional foods and food additives.The separation of bioactive natural products plays an important role in transformation and use of biomass.The isolation and purification of bioactive principle from a complex matrix is often inherent bottleneck for the utilization of natural products,so a series of extraction and separation techniques have been developed.This review covers recent advances in the separation of bioactive natural products with an emphasis on their solubility and diffusion coefficients,recent extraction techniques and isolation techniques.This overview of recent technological advances,discussion of pertinent problems and prospect of current methodologies in the separation of bioactive natural products may provide a driving force for development of novel separation techniques.

Current Perspective in the Discovery of Anti-aging Agents from Natural Products

Aging is a process characterized by accumulating degenerative damages,resulting in the death of an organism ultimately.The main goal of aging research is to develop therapies that delay age-related diseases in human.Since signaling pathways in aging of Caenorhabditis elegans(C.elegans),fruit flies and mice are evolutionarily conserved,compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human.Natural products have special resource advantage and with few side effect.Recently,many compounds or extracts from natural products slowing aging and extending lifespan have been reported.Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C.elegans or other species,and the prospect in developing antiaging medicine from natural products.

Natural Products in Cancer Therapy: Past, Present and Future

Natural products,with remarkable chemical diversity,have been extensively investigated for their anticancer potential for more than a half-century.The collective efforts of the community have achieved the tremendous advancements,bringing natural products to clinical use and discovering new therapeutic opportunities,yet the challenges remain ahead.With remarkable changes in the landscape of cancer therapy and growing role of cutting-edge technologies,we may have come to a crossroads to revisit the strategies to understand nature products and to explore their therapeutic utility.This review summarizes the key advancements in nature product-centered cancer research and calls for the implementation of systematic approaches,new pharmacological models,and exploration of emerging directions to revitalize natural products search in cancer therapy.

A Systemic Review on Topical Marketed Formulations, Natural Products, and Oral Supplements to Prevent Androgenic Alopecia: A Review

Androgens have an intense consequence on the human scalp and body hair.Scalp hair sprouts fundamentally in awol of androgens whereas the body hair hike is vulnerable to the activity of androgens.Androgenetic alopecia(AGA)invoked as males emulate Alopecia due to the cause of the dynamic reduction of scalp hair.Androgens are medium of terminus growth of hair although the body.Local and system androgens convert the extensive terminal follicles into lesser vellus like structure.The out start of this type of alopecia is intensely irregular and the reason behind this existence of enough circulating steroidal hormones androgens and due to genetic predisposition.Effective treatments are available in the market as well as under clinical and preclinical testing.Many herbal formulations are also available but not FDA approved.Different conventional and NDDS formulations are already available in the market.To avoid various systemic side effects of both Finasteride and Minoxidil,topical formulations and natural products(nutrients,minerals,vitamins)now a days are being widely used to treat Androgenic alopecia.CAM(complementary and alternative medicine)provides the option to elect favorable,low-risk,adjuvant and alternative therapies.Herein,we offer a widespread review of topical marketed formulations,natural products,and CAM treatment options for AGA.

Residual Dipolar Couplings in Structure Determination of Natural Products

The determination of natural products stereochemistry remains a formidable task.Residual dipolar couplings(RDCs)induced by anisotropic media are a powerful tool for determination of the stereochemistry of organic molecule in solution.This review will provide a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.Graphical Abstract This review provides a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.