Identification and Molecular Characterization of the Alkaloid Biosynthesis Gene Family in Dendrobium catenatum

As one of the main active components of Dendrobium catenatum, alkaloids have high medicinal value. The physicochemicalproperties, conserved domains and motifs, phylogenetic analysis, and cis-acting elements of the genefamily members in the alkaloid biosynthesis pathway of D. catenatum were analyzed by bioinformatics, and theexpression of the genes in different years and tissues was analyzed by qRT-PCR. There are 16 gene families,including 25 genes, in the D. catenatum alkaloid biosynthesis pathway. The analysis of conserved domains andmotifs showed that the types, quantities, and orders of domains and motifs were similar among members ofthe same family, but there were significant differences among families. Phylogenetic analysis indicated that thegene family members showed some evolutionary conservation. Cis-acting element analysis revealed that therewere a large number of light-responsive elements and MYB (v-myb avian myeloblastosis viral oncogene homolog)-related elements in these genes. qRT-PCR showed that expressions of gene family members involved in alkaloidsynthesis were different in different years and tissues of D. catenatum. This study provides a theoretical basisfor further exploration of the regulatory mechanisms of these genes in the alkaloid biosynthesis of D. catenatum.

New Neuraminidase Inhibitory Alkaloids from the Mangrove Soil-Derived Fungus Arthrinium sp.SCSIO 41305

New alkaloid,(E)-2-(hydroxyimino)-4-methylpentanamide(1)and a new cyclopentano[b]pyridine,4-hydroxy-7-methyl-6,7-dihydro-5H-cyclopenta[c]pyridin-5-one(2),together with ten known compounds(3–12)were isolated from the mangrove soil-derived fungus Arthrinium sp.SCSIO 41305.Extensive spectroscopic analysis and X-Ray crystallographic analysis were used to elucidate the structure of(E)-2-(hydroxyimino)-4-methylpentanamide(1),including its absolute configuration.All the isolated compounds(1–12)were evaluated for their antimicrobial and enzyme inhibitory activities against acetylcholinesterase(ACh E),neuraminidase(NAs),and phosphatidylinositol 3-kinase(PI3K).Among them,compounds 1 and 3 exhibited strong neuraminidase inhibitory activity with IC_(50)values of 12.04,1.92μmol L^(-1)(IC_(50)20μmol L^(-1)for oseltamivir acid),while compounds 5,6,8,and 10showed moderate neuraminidase inhibitory activity,and compounds 6–10 displayed weak enzyme inhibitory activities against PI3K.

Design,Synthesis and Bioactivity Study of Marine Alkaloid Neobacillamide-A Derivatives

The Janus kinases(JAKs)are a family of intracellular tyrosine kinases that play an essential role in many basic biological processes,such as apoptosis and inflammation.Thus any dysfunction of the proteins in this pathway may lead to a variety of diseases,including cancer and diseases that affect the immune system,such as severe combined immune deficient(SCID).Marine biological resources have become an important source in new drug research and development due to their diversity,complexity and speciality.In this study,Marine alkaloid Neobacillamide A was isolated from the greedy and stubborn sponge symbiotic Bacillus atrophicus C89 in the South China Sea.Totally 24 novel marine alkaloid Neobacillamide A derivatives were designed and synthesized,which were evaluated for their inhibitory activity against JAK/STAT signaling pathway and their cytotoxicity to A549 cells.Compounds 13c,13o,14d,14g and 14h showed potent JAK/STAT inhibition capability(concentration of 25μmol L^(-1),all inhibitory potencies were above 60%),especially compound 14g exhibited superior JAK/STAT inhibition effect(89.70%inhibition).In addition,all these compounds with a concentration of 25μmol L^(-1)displayed weak or no cytotoxicity to A549 cells,which means that these Neobacillamide A derivatives with JAK/STAT inhibition capability may have potential anti-inflammatory function.

Discovery of prenylated indole alkaloid and natural xanthone from cold-seep sediment derived fungus Talaromyces funiculosus SD-523

A new prenylated indole alkaloid 11,17-epi-mangrovamide A(1),a new natural occurring product,1,7-dihydroxy-6-methyl-8-hydroxymethyl-xanthone(2),two known alkaloids,mangrovamide A(3)and mangrovamide G(4),and four known polyketide derivatives(5–8)were isolated and identified from the cold-seep sediment derived fungal strain Talaromyces funiculosus SD-523.Their structures were elucidated by combination of nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),quantum chemical electronic circular dichroism(ECD),and DP4+probability analysis as well as by comparison of the data with literature reports.All isolated compounds were tested for antibacterial activities.

A Pair of New Spirocyclic Alkaloid Enantiomers with TrxR Inhibitory Activities Were Isolated from Marine-Derived Aspergillus ruber TX-M4-1

One new spirocyclic alkaloid,5-isopentenyl-cryptoechinuline D(1),along with 11 known compounds(2–12),were iso-lated from a marine fungus Aspergillus ruber TX-M4-1.The structures of compounds 1–12 were elucidated by spectroscopic evi-dences.Compound 1 was initially isolated as an enantiomer,and further separation of 1 by chiral HPLC afforded a pair of enantio-mers,including(-)-5-isopentenyl-cryptoechinuline D(1a)and(+)-5-isopentenyl-cryptoechinuline D(1b).Their absolute configura-tions were elucidated by ECD spectroscopic data.Compounds 1a,5 and 10 could inhibit thioredoxin reductase(TrxR)activity with IC50 values of 6.2,36.3 and 18.6μmol L^(-1),respectively.Surface plasmon resonance(SPR)study also demonsrated the interactions between compounds 6,8 and Niemann-Pick C1 Like 1(NPC1L1)respectively,which indicate that compounds 6 and 8 are potential NPC1L1 inhibitors.

Effects of Different Alkaloids in Coptis chinensis on Inhibiting TGEV Proliferation

[Objectives]To study the effects of different alkaloids in Coptis chinensis on inhibiting the proliferation of Transmissible gastroenteritis virus(TGEV).[Methods]The components and content of the main alkaloids in the extract of C.chinensis were analyzed.The main alkaloids were selected as drugs to inhibit the proliferation of TGEV.The maximum non-toxic concentration of Columbamine,Jatrorrhizine,Epiberberine,Coptisine,Palmatine,and Berberine was screened.The protective rate of each drug on TGEV-infected ST cells was determined,and the transcriptional inhibitory effect of the drug on TGEV N gene was detected by fluorescent quantitative PCR.[Results]The extract of C.chinensis mainly contains 6 alkaloids:Columbamine,Jatrorrhizine,Epiberberine,Coptisine,Palmatine,and Berberine,accounting for 2.03%,8.88%,9.21%,15.07%,14.63%,and 50.18%,respectively.In the range of the safe concentration,Jatrorrhizine,Palmatine,and Coptisine had better protective effects on ST cells infected with TGEV;compared with the Columbamine group,the cell protection rate was significantly different(P<0.05);compared with the Berberine group,the difference was extremely significant(P<0.01).The Coptisine and Palmatine groups had significant inhibitory effects on the transcription of TGEV N gene,and the difference was extremely significant compared with the virus group(P<0.05).[Conclusions]Jatrorrhizine and Palmatine in C.chinensis are the main components to inhibit the proliferation of TGEV.

Investigation of benzylisoquinoline alkaloid biosynthetic pathway and its transcriptional regulation in lotus

Lotus predominantly accumulates benzylisoquinoline alkaloids(BIAs),but their biosynthesis and regulation remain unclear.Here,we investigated structural and regulatory genes involved in BIA accumulation in lotus.Two clustered CYP80 genes were identified to be responsible for the biosynthesis of bis-BIAs and aporphine-type BIAs,respectively,and their tissue-specific expression causes divergence in alkaloid component between leaf and embryo.In contrast with the common(S)-reticuline precursor for most BIAs,aporphine alkaloids in lotus leaf may result from the(S)-N-methylcoclaurine precursor.Structural diversity of BIA alkaloids in the leaf is attributed to enzymatic modifications,including intramolecular C–C phenol coupling on ring A and methylation and demethylation at certain positions.Additionally,most BIA biosynthetic pathway genes show higher levels of expression in the leaf of high-BIA cultivar compared with low-BIA cultivar,suggesting transcriptional regulation of BIA accumulation in lotus.Five transcription factors,including three MYBs,one ethylene-responsive factor,and one basic helix–loop–helix(bHLH),were identified to be candidate regulators of BIA biosynthesis in lotus.Our study reveals a BIA biosynthetic pathway and its transcriptional regulation in lotus,which will enable a deeper understanding of BIA biosynthesis in plants.

A new monoterpenoid indole alkaloid from Rauvolfia yunnanensis

One new monoterpenoid indole alkaloid, l l-methoxyburnamine-17-O-3′,4′,5′-trimethoxybenzoate （1）, was isolated from Rauvolfia yunnanensis Tsiang. Its structure was identified by speclroscopic evidences.

Acute and Sub-Acute Toxicological Evaluations of Bioactive Alkaloidal Extract from Melodinus henryi and Their Main Chemical Constituents

Melodinus henryi is a good source of terpenoid indole alkaloids,and traditionally used as a folk medicine in the treatment of meningitis and fracture.In order to further exploit their potential uses,its anti-inflammatory and immunosuppressive activi-ties,safety evaluations and chemical profiles have been illustrated.Compared to the crude methanol extract from M.henryi and its non-alkaloidal fraction,the total alkaloidal fraction(MHTA)had the strongest anti-inflammatory and immunosup-pressive activities.In the acute oral toxicity assay,the half lethal dose(LD50)of MHTA was more than 2000 mg/kg.The sub-acute toxicity assay for consecutive 28 days exhibited MHTA at a lower concentrations of less than 500 mg/kg might be regarded as safe,and might damage spleen,liver,kidney,and heart when the dose is higher than 1000 mg/kg.In addition,a phytochemical investigation on MHTA led to the isolation of 15 monoterpenoid indole alkaloids.Thus,in regard with the potent side effects of MHTA,it should be used with caution in the development of phytomedicine.

A New Indole Alkaloid from Limonia Crenulata

A new indole alkaloid, crenulatine 1, was isolated from the stems of Limonia Crenulata. The structure was identified by spectral means.

Pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome: Pathogenesis, clinical manifestations, diagnosis,treatment, and outcomes

Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by the intake of pyrrolizidine alkaloids (PAs). To date, PAs-induced HSOS has not been extensively studied. In view of the difference in etiology of HSOS between the West and China, clinical profiles, imaging findings, treatment, and outcomes of HSOS associated with hematopoietic stem cell transplantation or oxaliplatin might be hardly extrapolated to PAs-induced HSOS. Reactive metabolites derived from PAs form pyrrole-protein adducts that result in toxic destruction of hepatic sinusoidal endothelial cells. PAs-induced HSOS typically manifests as painful hepatomegaly, ascites, and jaundice. Laboratory tests revealed abnormal liver function tests were observed in most of the patients with PAs-induced HSOS. In addition, contrast computed tomography and magnetic resonance imaging scan show that patients with PAs-induced HSOS have distinct imaging features, which reveal that radiological imaging provides an effective noninvasive method for the diagnosis of PAs-induced HSOS. Liver biopsy and histological examination showed that PAs-induced HSOS displayed distinct features in acute and chronic stages. Therapeutic strategies for PAs-induced HSOS include rigorous fluid management, anticoagulant therapy, glucocorticoids, transjugular intrahepatic portosystemic shunt, liver transplantation, etc. The aim of this review is to describe the pathogenesis, clinical profiles, diagnostic criteria, treatment, and outcomes of PAs-induced HSOS.

A review on medicinal importance,pharmacological activity and bioanalytical aspects of beta-carboline alkaloid "Harmine"

Harmine,a beta-carboline alkaloid,is widely distributed in the plants,marine creatures,insects, mammalians as well as in human tissues and body fluids.Harmine was originally isolated from seeds of Peganum harmal in 1847 having a core indole structure and a pyridine ring.Harmine has various types of pharmacological activities such as antimicrobial,antifungal,antitumor,cytotoxic, antiplasmodial,antioxidaant,antimutagenic,antigenotoxic and hallucinogenic properties.It acts on gamma-aminobutyric acid type A and monoamine oxidase A or B receptor,enhances insulin sensitivity and also produces vasorelaxant effect.Harmine prevents bone loss by suppressing osteoclastogenesis.The current review gives an overview on pharmacological activity and analytical techniques of harmine,which may be useful for researcheres to explore the hidden potential of harmine and and will also help in developing new drugs for the treatment of various diseases.

Qualitative and Quantitative Analysis of Alkaloids in Cortex Phellodendri by HPLC-ESI-MS/MS and HPLC-DAD

A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was applied to the qualitative and quantitative analyses of alkaloids in Cortex Phellodendri（CP） samples, and to the differentiation of two species of CP, Cortex Phellodendri Chinensis（CPC） and Cortex Phellodendri Amurensis（CPA）. Twenty-two peaks appeared in the HPLC-MS base peak chromatogram of CP detected by the HPLC-ESI-MS/MS analysis, and the alkaloids were identified according to the MSn data, the known MS fragmentation rules and the literature data. Five alkaloids including berberine, palmatine, jatrorrhizine, phellodendrine and magnoflorine were simultaneously determinated by the HPLC-DAD. Berberine was the primary component in all CP samples, and the contents of berberine and palmatine were exploited to be two critical parameters for effective discrimination between the two species of CP. The average content of berberine in CPC（58.75 mg/g） was higher than that in CPA（9.16 mg/g）, while the content of palmatine was less, only 0.25 mg/g in CPC and 4.19 mg/g in CPA. With the use of PCA, samples datasets were separated successfully into two different clusters corresponding to the two species, and berberine, pahnatine, phellodendrine and magnoflorine contribute most to the above mentioned calssifying . The proposed method oroved to be a useful tool in the aualitv control of Chinese herbal medicines.

Effect of processing on the alkaloids in Aconitum tubers by HPLC-TOF/MS

According to the Chinese Pharmacopoeia 2015, only processed Aconitum tubers can be clinically applied, and the effect of processing is unclear. This research aimed to explore the effect of processing on cardiac efficacy of alkaloids in Aconitum tubers. First, the chemical ingredients in unprocessed and processed Aconitum tubers were identified and compared by using high performance liquid chromatography time-of-flight mass spectrometry(HPLC-TOF/MS) and multivariate pattern recognition methods. Then the representative alkaloids in Aconitum tubers, aconitine, benzoylaconine, and aconine, which belong to diester-diterpenoid alkaloids,monoester-diterpenoid alkaloids, and amine-diterpenoid alkaloids, respectively, were selected for further validation of attenuated mechanism. Subsequent pharmacological experiments with aconitine, benzoylaconine,and aconine in SD rats were used to validate the effect of processing on cardiac functions. After processing the Aconitum tubers, it was found that the contents of diester-diterpenoid alkaloids were reduced, and those of monoester-diterpenoid alkaloids and amine-diterpenoid alkaloids were increased, suggesting that diesterditerpenoid alkaloids were transformed into monoester-diterpenoid alkaloids and amine-diterpenoid alkaloids.Through further decocting the aconitine in boiling water, it was confirmed that the three alkaloids could be progressively transformed. Pharmacological experiments with aconitine, benzoylaconine, and aconine in SD rats showed that aconitine at a dose of 0.01 mg/kg and aconine at a dose of 10 mg/kg enhanced the cardiac function, while benzoylaconine at a dose of 2 mg/kg weakened the cardiac function. The effect of processing is attributed to the transformation of the most toxic diester-diterpenoid alkaloids into less toxic monoesterditerpenoid alkaloids and amine-diterpenoid alkaloids.

Two New Indole Alkaloids from Evodia rutaecarpa

Two new indole alkaloids. wuchuyuamide I and II were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth and their structures were elucidated on the basis of spectral data.

Protective effects of Dendrobium nobile Lindl. alkaloids on amyloid beta(25–35)-induced neuronal injury

Dendrobium nobile Lindl.alkaloids（DNLA）,the active ingredients of a traditional Chinese medicine Dendrobium,have been shown to have anti-oxidative effects,anti-inflammatory action,and protective effect on neurons against oxygen-glucose deprivation.However,it is not clear whether DNLA reduces amyloid-beta（Aβ）-induced neuronal injury.In this study,cortical neurons were treated with DNLA at different concentrations（0.025,0.25,and 2.5 mg/L）for 24 hours,followed by administration of Aβ（25-35）（10μM）.Aβ（25-35） treatments increased cell injury as determined by the leakage of lactate dehydrogenase,which was accompanied by chromatin condensation and mitochondrial tumefaction.The damage caused by Aβ（25-35） on these cellular properties was markedly attenuated when cells were pretreated with DNLA.Treatment with Aβ（25-35）down-regulated the expressions of postsynaptic density-95 mRNA and decreased the protein expression of synaptophysin and postsynaptic density-95,all changes were significantly reduced by pretreatment of cells with DNLA.These findings suggest that DNLA reduces the cytotoxicity induced by Aβ（25-35） in rat primary cultured neurons.The protective mechanism that DNLA confers on the synaptic integrity of cultured neurons might be mediated,at least in part,through the upregulation of neurogenesis related proteins synaptophysin and postsynaptic density-95.

A New Dendrobine-Type Alkaloid from Dendrobium nobile

A new dendrobine-type alkaloid has been isolated from stems of Dendrobium nobile lindl.. Its structure has been identified on the basis of spectroscopic method.

A new benzylisoquinoline alkaloid from stems of Nelumbo nucifera

A new benzylisoquinoline alkaloid, named nelumstemine （1）, 1-（4＇-hydroxybenzoyl）-6,7-dimethoxy-3,4-dihydroisoquinoline, was isolated from the stems of Nelumbo nucifera Geartn. Its structure was established on the basis of spectral analysis.