Corydecusines A-H, new phthalideisoquinoline hemicetal alkaloids from the bulbs of Corydalis decumbens inhibit Tau pathology by activating autophagy mediated by AMPK-ULK1 pathway.

Twelve phthalideisoquinoline hemiacetal alkaloids including eight new ones (1-8) and one natural alkaloid characterized by an aziridine moiety with unassigned NMR data (9), were isolated and identified from the bulbs of Corydalis decumbens. Their structures were established by comprehensive analyses of HRESIMS, NMR, X-ray crystallography, and ECD analyses. The unambiguously established structures of the phthalideisoquinoline hemiacetal alkaloids indicated that the absolute configurations of C-1, C-9, and C-7' were confusable only relied on coupling constants. A summary of their ECD spectra was concluded and provided an insight for C-1, C-9, and C-7' absolute configuration assignment. These new compounds were evaluated to induce autophagy flux through flow cytometry analysis. Moreover, compounds 2 and 6 could significantly induce autophagy and inhibit Tau pathology by AMPK-ULK1 pathway activation, which provided an avenue for anti-AD lead compounds discovery.

Active Constituents with Tyrosinase Inhibitory Activities from Waste Tobacco Leaves.

One novel compound, (R)-3, 6-diethoxy-4-hydroxycyclohex-3-en-1-one (1) and thirteen known compounds were isolated from the waste tobacco leaves. The structures of two compounds (1-2) were confirmed and attributed firstly by the extensive spectroscopic data, including 1D/2D NMR, IR, HR-ESI-MS, CD, and ECD spectra. Notably, seven compounds (2, 3, 9, 10, 11, 12, and 13) exhibited better tyrosinase inhibitory activity than the positive control kojic acid. The binding modes of these compounds revealed that their structure formed strong hydrogen bonds and van der Waals forces with the active sites of tyrosinase. These results indicated that waste tobacco leaves are good resources for developing tyrosinase inhibitors.

Three new quinolizidine alkaloids from the roots of Sophora tonkinensis.

Three new quinolizidine alkaloids (1 - 3), including one new naturally isoflavone and cytisine polymer (3), along with 6 known ones were isolated from the ethanol extract of Sophora tonkinensis Gagnep. Their structures were elucidated by comprehensive spectroscopic data analysis (IR, UV, HRESIMS, 1D and 2D NMR), combined with ECD calculations. The antifungal activity against Phytophythora capsica, Botrytis cinerea, Gibberella zeae, and Alternaria alternata of the compounds was evaluated in a mycelial inhibition assay. Biological tests indicated that compound 3 exhibited strong antifungal activity against P. capsica with EC50 values of 17.7 µg/ml.

A clue to the evolutionary history of modern East Asian flora: Insights from phylogeography and diterpenoid alkaloid distribution pattern of the Spiraea japonica complex.

Each subkingdom of East Asian flora (EAF) has a unique evolutionary history, but which has rarely been described based on phylogeographic studies of EAF species. The Spiraea japonica L. complex, which is widespread in East Asia (EA), has received considerable attention because of the presence of diterpenoid alkaloids (DAs). It provides a proxy for understanding the genetic diversity and DA distribution patterns of species under various environmental conditions associated with the geological background in EA. In the present study, the plastome and chloroplast/nuclear DNA of 71 populations belonging to the S. japonica complex and its congeners were sequenced, combined with DA identification, environmental analyses, and ecological niche modelling, to investigate their phylogenetic relationships, genetic and DAs distribution patterns, biogeography, and demographic dynamics. An "ampliative" S. japonica complex was put forward, comprising all species of Sect. Calospira Ser. Japonicae, of which three evolutionary units carrying their respective unique types of DAs were identified and associated with the regionalization of EAF (referring to the Hengduan Mountains, central China, and east China). Moreover, a transition belt in central China with its biogeographic significance was revealed by genetic and DA distribution patterns from the perspective of ecological adaptation. The origin and onset differentiation of the "ampliative" S. japonica complex was estimated in the early Miocene (22.01/19.44 Ma). The formation of Japanese populations (6.75 Ma) was facilitated by the land bridge, which subsequently had a fairly stable demographic history. The populations in east China have undergone a founder effect after the Last Glacial Maximum, which may have been promoted by the expansion potential of polyploidization. Overall, the in-situ origin and diversification of the "ampliative" S. japonica complex since the early Miocene is a vertical section of the formation and development of modern EAF and was shaped by the geological history of each subkingdom.

Munronin V with 7/7/6 tricarbocyclic framework from Munronia henryi harms inhibits tau pathology by activating autophagy.

Munronin V (1), isolated from Munronia henryi Harms, is the first example, to the best of our knowledge, of an unprecedented 7/7/6 tricarbocyclic framework featuring an unusual A,B-seco-limonoid ring. The structures of munronin V were established from extensive spectroscopic and electronic circular dichroism (ECD) analyses. The novel A,B-seco with two seven-membered lactones was formed as a result of Baeyer-Villiger oxidation. Compound 1 activated autophagy and inhibited Tau pathology as revealed by flow cytometric analyses, confocal imaging analysis and western blotting, and this effect was mediated by transcription factor EB (TFEB). These findings suggested that 1 might have potential as a compound for combating Alzheimer's disease.

Quinoline Alkaloids from the Roots of Orixa japonica with the Anti-Pathogenic Fungi Activities.

A new quinoline alkaloid, 5-hydroxy-6-methoxy-N-methyl-2-phenylquinoline-4-one (1), and seventeen known quinoline alkaloids (2-18) were isolated from the roots of Orixa japonica. The structure of 1 was determined by analysis of spectroscopic data. Among them, compounds 2, 3, and 13 were isolated from this plant for the first time. All isolates were screened for the anti-pathogenic fungi activities, including Rhizoctonia solani, Magnaporthe oryzae, and Phomopsis sp. The results showed that five compounds (4, 8, 10, 11, and 12) exhibited significant anti-pathogenic fungi effects at 50.0 µg/mL. In special, compound 10 exhibited the best antifungal activities toward R. solani and M. oryzae with the IC50 values of 37.86 and 44.72 µM, respectively, better than that of the positive control, hymexazol (IC50 121.21 and 1518.18 µM, respectively). Moreover, eleven new quinoline alkaloids derivatives (12a-12k) were designed and synthesized to investigate the structure-activity relationships (SARs). The SARs analysis indicated that the furo[2,3-b]quinoline skeleton and the methoxy at C-7 (compounds 8, 11, and 12) played a key role for improving the antifungal activities.

Three New Constituents with Anti-Inflammatory and Antimicrobial Activities in Vitro from the Roots of Capsicum annuum L.

Three new compounds, including two new sesquiterpenes (1-2), named Annuumine E-F, and one new natural product, 3-hydroxy-2,6-dimethylbenzenemethanol (3), together with seventeen known compounds (4-20) were isolated from the ethanol extract of the roots of Capsicum annuum L. Among them, five compounds (4, 5, 9, 10 and 20) were isolated from this plant for the first time. The structures of new compounds (1-3) were determined via detailed analysis of the IR, HR-ESI-MS and 1D and 2D NMR spectra. The anti-inflammatory activities of the isolated compounds were evaluated by their ability to reduce NO release by LPS-induced RAW 264.7 cells. Notably, compound 11 exhibited moderate anti-inflammatory activity (IC50 =21.11 µM). Moreover, the antibacterial activities of the isolated compounds were also evaluated.

Synthesis and Antifungal Activity of 2-(2-Benzoxazolyl)-1-arylethanone and 2-(2-Benzoxazolyl)-1-alkylethanone Derivatives.

To discover more effective antifungal candidates, 33 benzoxazole derivatives, were designed, synthesized, and evaluated for their antifungal activity against seven phytopathogenic fungi by the mycelium growth rate method. Among 33 benzoxazole derivatives had thirteen derivatives no reported, and new derivatives C17 exhibited good inhibitory activity against Phomopsis sp. with EC50 values of 3.26 µM. Structure-activity relationship (SAR) of these derivatives analysis indicated that the substituent played a key role in antifungal activity in ortho-, meta- and para- substituted acetophenones. The preliminary mechanistic exploration demonstrated that C17 might exert its antifungal activity by targeting the mycelia cell membrane, which was verified by the observed changes in mycelial morphology, the formation of extracellular polysaccharides, cellular contents, cell membrane permeability and integrity, among other effects. Furthermore, C17 had potent curative effect against Phomopsis sp. in vivo, which indicated that C17 may be as a novelty potent antifungal agent.

Synthesis and Antifungal Activity of Curcumol Derivatives.

To discover novel and effective antifungal candidates, a series of new curcumol derivatives were designed, synthesized, and evaluated their antifungal activity against five phytopathogenic fungi by the mycelium growth rate method. Derivatives c4, c22 and c23 exhibited excellent antifungal activity against Phomopsis sp. with EC50 values of 3.06, 3.07, and 3.16 µM, respectively. Specifically, compound c4 exhibited the strongest antifungal activity against Phomopsis sp., which was 44 times that of pyrimethanil (EC50 =134.37 µM). The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that compound c4 could cause cell senescence and death of Phomopsis sp. by changing the normal hyphal morphology and disrupting the normal metabolism of hyphal cells. Moreover, compound c4 showed excellent curative effect against Phomopsis sp. on kiwifruit. These findings confirmed that compound c4 has great potential as a potent antifungal agent.

Chemical Constituents of Primulina eburnea (Gesneriaceae) and Their Cytotoxic Activities.

Two new ursane-type triterpenes, eburnealactones A and B (1 and 2), one new flavonoid, eburneatin A (6), and one new phenylethanoid glycoside, chiritoside D (7), along with 9 known compounds (3-5, 8-13) were isolated from the whole plant of Primulina eburnea. Their structures were elucidated by comprehensive spectroscopic data analysis (IR, UV, NMR, and HR-ESI-MS). All the compounds were evaluated for their cytotoxic activities. Compound 1 showed significant cytotoxic activities against MKN-45 cell lines and 5637 cell lines with the IC50 values of 9.57 µM and 8.30 µM, respectively. Compound 1 exhibited moderate cytotoxic activities against A549 and PATU8988T cell lines with the IC50 values of 30.70 µM and 38.22 µM, respectively. Compound 6 exhibited moderate cytotoxic activities against MKN-45, HCT116, PATU8988T, 5637 and A-673 cell lines with the IC50 values of 19.69 µM, 16.44 µM, 18.07 µM, 11.51 µM and 18.15 µM, respectively. Compound 5 showed moderate cytotoxic activities against A549 cell lines with the IC50 values of 24.06 µM.

Two new isoflavones from the roots of Sophora tonkinensis.

Two new isoflavones (1 and 2), as well as eight known ones were isolated from the roots of Sophora tonkinensis Gagnep. Compound 1 represents an unprecedented polymerization pattern constructed by isoflavone and cytisine. Their structures were elucidated by comprehensive spectroscopic data analysis, combined with ECD calculations. Compound 1 displayed significant anti-tobacco mosaic virus (TMV) activity compared with the positive control ningnanmycin. Moreover, compound 6 exhibited potent α-glucosidase inhibitory activity with IC50 value of 47.4 mg/L.

Iridoid glycosides from Morinda officinalis induce lysosomal biogenesis and promote autophagic flux to attenuate oxidative stress.

Morinda officinalis is a traditional Chinese tonic herb, and have been used in the treatment of multiple diseases. Here, three iridoid glycosides isolated from M. officinalis were evaluated for their roles in the autophagy-lysosomal pathway. All three iridoid glycosides could induce TFEB/TFE3-mediated lysosomal biogenesis and trigger autophagy. Interestingly, they promoted the nuclear import of TFEB/TFE3 without affecting their nuclear export, suggesting their role in the maintenance of lysosomal homeostasis. The results from this study shed light on the identification of autophagy activators from M. officinalis and provide a basis for developing them in the treatment of oxidative stress-involved diseases.

New Monoterpenoid Indole Alkaloids from Tabernaemontana crassa Inhibit ß-Amyloid42 Production and Phospho-Tau (Thr217).

Eleven monoterpenoid indole alkaloids, including three new ones, tabercrassines A-C (1-3), were isolated from the seeds of Tabernaemontana crassa. Tabercrassine A (1) is an ibogan-ibogan-type bisindole alkaloid which is formed by the polymerization of two classic ibogan-type monomers through a C3 unit aliphatic chain. Their structures were established by extensive analysis of HRESIMS, NMR, and ECD spectra. Cellular assays showed that alkaloids 1-3 all reduce Aß42 production and inhibit phospho-tau (Thr217), a new biomarker of Alzheimer's disease [AD] associated with BACE1-, NCSTN-, GSK3ß-, and CDK5-mediated pathways, suggesting these alkaloids' potential against AD.

Quassinoids from Twigs of Harrisonia perforata (Blanco) Merr and Their Anti-Parkinson's Disease Effect.

Six new C-20 and one new C-19 quassinoids, named perforalactones F-L (1-7), were isolated from twigs of Harrisonia perforata. Spectroscopic and X-ray crystallographic experiments were conducted to identify their structures. Through oxidative degradation of perforalactone B to perforaqussin A, the biogenetic process from C-25 quassinoid to C-20 via Baeyer-Villiger oxidation was proposed. Furthermore, the study evaluated the anti-Parkinson's disease potential of these C-20 quassinoids for the first time on 6-OHDA-induced PC12 cells and a Drosophila Parkinson's disease model of PINK1B9. Perforalactones G and I (2 and 4) showed a 10-15% increase in cell viability of the model cells at 50 µM, while compounds 2 and 4 (100 µM) significantly improved the climbing ability of PINK1B9 flies and increased the dopamine level in the brains and ATP content in the thoraces of the flies.

Maillard Reaction Products with Anti-Tobacco Mosaic Virus Activities Generated in Processed Thermopsis lanceolata R. Br. Seed Extract.

Six novel Maillard reaction products (MRPs) (1-6) were isolated from the processed Thermopsis lanceolata R. Br. seed extract, along with one biogenetically related intermediate (7). Compounds 1-4 possessed three rare dimerization patterns constructed by cytisine, whereas compounds 5 and 6 represented the first example of the addition products of cytisine and 5,6-dihydroxy-4-hexanolide. Their structures were elucidated by comprehensive spectroscopic data analysis and quantum chemistry calculations including GIAO 13C{1H} NMR and ECD calculation, combined with single-crystal X-ray diffraction analysis. Biologically, compound 3 displayed significant anti-tobacco mosaic virus activity compared with the positive control ningnanmycin.

Hyperpatone A, a polycyclic polyprenylated acylphloroglucinol with a rare 8/6/5/6/5 pentacyclic skeleton from Hypericum patulum.

Hyperpatone A (1), a highly oxidated polycyclic polyprenylated acylphloroglucinol (PPAP), along with a biosynthesized related PPAP (2) was isolated from Hypericum patulum under the guidance of LC-MS investigation. Architecturally, compound 1 represents the first PPAP with an unprecedented 8/6/5/6/5 pentacyclic skeleton and an intramolecular peroxy bridge, which might be derived from the [3.3.1]-type bicyclic polyprenylated acylphloroglucinol via the critical Baeyer-Villiger oxidation, decarboxylation, and intramolecular cyclization. The structures were established by extensive spectroscopic analysis, ACD software calculation, and quantum chemical computations. A plausible biogenetic pathway of 1 and 2 was also proposed. Importantly, both compounds exhibited moderate cytotoxic activities against the HEL cell line with the IC50 values ranging from 10.2 to 19.2 µM. Moreover, compound 1 showed an inhibitory effect on NO production in lipopolysaccharide-stimulated RAW264.7 cells at a lower concentration of 5 or 1 µM.

Design, synthesis and structure-activity relationship optimization of phenanthridine derivatives as new anti-vitiligo compounds.

Humans have been suffering from vitiligo for a long time. Target vitiligo drugs have yet been approved. Activation of Wnt/ß-catenin signalling has potential in the therapeutic use of vitiligo, so exploring new drugs that specifically directly activate Wnt is worthwhile to obtain new anti-vitiligo agents. In this work, two portions design and synthesis were put into effect. firstly, 17 phenanthridine derivatives with C-4 substitutes were designed and synthesized, which compounds 4, 6, 12, 13 served as H-acceptor with protein showed enhance melanogenesis activity; Secondly, 7 hybrid new scaffolds of compounds were designed and synthesized, scaffold hopping compound 36 that aromatic benzene was replaced pyrazole on ring C showed enhance melanogenesis and tyrosinase activity; The last and most important, a comprehensive optimization and SARs of compound 36 were carried out, compounds 41 and 43 shared phenolic hydroxyl or 3-methyl-pyridine substitutes at C-7 position remarkably improved the capacity of melanogenesis and tyrosinase activity. Compound 43 were identified as new anti-vitiligo agents that specifically activate the Wnt/ß-catenin signalling pathway by targeting Axin. Structure-activity relationship analysis implied that H-acceptor substitutions at the C-4 position and phenolic hydroxyl or pyridine substitutions at the C-7 position would improve the activities of the compounds. These findings reveal a new therapeutic strategy for vitiligo, and compounds 41 and 43 may represent potential compounds for vitiligo treatment.

Three New Pregnanes Isolated from the Cynanchum auriculatum.

Three new compounds named cynansteroid A (1), cynansteroid B (2) and cynansteroid C (3), together with nine known C21 -steroidal pregnane sapogenins (4-12) were isolated from the hydrolytic extract of the roots of Cynanchum auriculatum. The structures of cynansteroid A-C (1-3) were ascertained via the detailed analysis of the HR-ESI-MS, 1D and 2D NMR, and the calculated and experimental ECD data of cynansteroid B (2). Compound 11 displayed moderate inhibitory activity toward Verticillium dahliae Kleb (IC50 =37.15 µM), furthermore, compounds 11 and 12 showed significant inhibitory activity against Phomopsis sp. (IC50 =16.49 µM and 17.62 µM, respectively).

Three New Aglain Derivatives from Aglaia odorata Lour. and Their Cytotoxic Activities.

Three new aglain derivatives (1-3), one known aglain derivative (4), two known rocaglamide derivatives (5 and 6), four known triterpenoids (7-10), and three steroids (11-13) were isolated from Aglaia odorata Lour. Their structures were established through the analysis of detailed spectroscopic data and electronic circular dichroism calculations. Five compounds (1 and 4-7) exhibited cytotoxic activities on human leukemia cells (HEL) and human breast cancer cells with IC50 values in the range of 0.03-8.40 µM. In particular, the cytotoxicity of compound 5 was six times stronger than that of the positive control (adriamycin) in HEL cell lines.

Two new cytisine-type alkaloids from the seeds of Thermopsis lanceolata.

Two new (1 and 2) cytisine-type alkaloids that were chemically inseparable isomers (present in a 1:1 ratio) were identified from the seeds of Thermopsis lanceolata R. Br. Their structures were elucidated by comprehensive spectroscopic data analysis (IR, UV, NMR, HRESIMS) and ECD calculation. Compound 1 displayed significant anti-tobacco mosaic virus (TMV) activity, while compounds 1 and 2 displayed moderate insecticidal activities against Aphis fabae with LC50 value of 43.15 and 46.47 mg/L, respectively.