ABSTRACT
Three undescribed isosteroidal alkaloids, przewalskines A-C (1-3), as well as seven known alkaloids (4-10) were obtained from Fritillaria przewalskii bulbs. Their structures were deduced by extensive HRESIMS, 1D NMR, and 2D NMR analyses, and their bioactivities were evaluated involving the anti-inflammatory and inhibitory potencies on AChE, BChE, and Aß aggregation. Compound 4 revealed the potent effect on inhibiting Aß aggregation activity with IC50 value of 33.1â µM, AChE activity with IC50 value of 6.9â µM, and also showed NO release inhibitory acitivity with IC50 value of 32.6â µM. These findings contribute new multi-.target anti-AD agents and embody the chemical diversity of F. przewalskii.
Subject(s)
Alkaloids , Fritillaria , Fritillaria/chemistry , Alkaloids/pharmacology , Alkaloids/chemistryABSTRACT
Introduction: Fritillaria przewalskii Maxim. is a Chinese endemic species with high medicinal value distributed in the northeastern part of the Tibetan Plateau. F. przewalskii root-associated rhizosphere bacterial communities shaped by soil properties may maintain the stability of soil structure and regulate F. przewalskii growth, but the rhizosphere bacterial community structure of wild F. przewalskii from natural populations is not clear. Methods: In the current study, soil samples from 12 sites within the natural range of wild F. przewalskii were collected to investigate the compositions of bacterial communities via high-throughput sequencing of 16S rRNA genes and multivariate statistical analysis combined with soil properties and plant phenotypic characteristics. Results: Bacterial communities varied between rhizosphere and bulk soil, and also between sites. Co-occurrence networks were more complex in rhizosphere soil (1,169 edges) than in bulk soil (676 edges). There were differences in bacterial communities between regions, including diversity and composition. Proteobacteria (26.47-37.61%), Bacteroidetes (10.53-25.22%), and Acidobacteria (10.45-23.54%) were the dominant bacteria, and all are associated with nutrient cycling. In multivariate statistical analysis, both soil properties and plant phenotypic characteristics were significantly associated with the bacterial community (p < 0.05). Soil physicochemical properties accounted for most community differences, and pH was a key factor (p < 0.01). Interestingly, when the rhizosphere soil environment remained alkaline, the C and N contents were lowest, as was the biomass of the medicinal part bulb. This might relate to the specific distribution of genera, such as Pseudonocardia, Ohtaekwangia, Flavobacterium (relative abundance >0.01), which all have significantly correlated with the biomass of F. przewalskii (p < 0.05). Discussion: F. przewalskii is evidently averse to alkaline soil with high potassium contents, but this requires future verification. The results of the present study may provide theoretical guidance and new insights for the cultivation and domestication of F. przewalskii.
ABSTRACT
Objective:To explore the effects of anti-microbial compound （T1） from<italic> Bacillus </italic>（Phylum Firmicutes） and anti-microbial compound （T2） from <italic>Pseudomonas</italic> and <italic>Rhizobium</italic>， two growth-promoting agents， on the physiological characteristics and growth of <italic>Fritillaria przewalskii</italic>， in order to lay a foundation for the development of functional microbial agents and the promotion of ecological planting. Method:The endophytic bacteria of <italic>F. przewalskii</italic> were isolated and identified using conventional methods. The leaves of three-year-old <italic>F. przewalskii</italic> were sprayed with T1 and T2， followed by yield determination. The enzyme activities and physiological and biochemical indexes in the plant and microorganisms were measured using the corresponding assay kits， and the contents of related hormones by liquid chromatography-mass spectrometry （LC-MS）. Result:The isolated endophytic bacteria were classified into Firmicutes，Proteobacteria， and Actinomycetes. The activities of superoxide dismutase（SOD） and peroxidase（POD） and auxin content after T2 treatment were significantly higher than those after T1 treatment， while the contents of siderophore，salicylic acid， and gibberellin were lower. Compared with the blank （CK） group， T1 and T2 increased the contents of endogenous gibberellin，cytokinin， and auxin in <italic>F. przewalskii</italic> leaves，but did not significantly change jasmonic acid and abscisic acid. T1 promoted the accumulation of endogenous salicylic acid in <italic>F. przewalskii</italic> leaves， but there was no significant change after T2 treatment. Compared with CK，T1 and T2 enhanced the activities of SOD， POD， and catalase （CAT） and decreased the content of malondialdehyde. T2 promoted the accumulation of hydrogen peroxide in <italic>F. przewalskii</italic> leaves， but no significant difference was observed after T1 treatment. Compared with CK，both T1 and T2 increased chlorophyll，average iron content in rhizosphere soil， and 100-plant weight. Conclusion:T1 and T2 treatments help to increase the yield，and their specific mechanisms differ from each other. T1 exhibits better effect than T2.
ABSTRACT
Objective:To investigate the effect of iron nanoparticles and melatonin on yield and quality of <italic>Fritillaria przewalskii</italic> and provide technical support for its domesticated cultivation. Method:Hundred grain weight was measured by conventional method；alkaloid content was detected according to protocols of the edition of 2020 <italic>Chinese Pharmacopoeia</italic>，chlorophyll，hydrogen peroxide，malondialdehyde，superoxide dismutase （SOD），peroxidase （POD） and catalase （CAT） were detected by spectrophotometric analysis，auxins，cytokinins，gibberellins，salicylic acid，jasmonic acid and abscisic acid were detected by ultra performance liquid chromatography tandem mass spectrometry analysis. Result:Zero-valent iron nanoparticles and melatonin significantly increased the hundred grain weight without affecting the quality. The effect of the two treatments on physiological and biochemical indexes in different stages were quite different，but the effects on content of endogenous hormones were basically the same. Correlation analysis showed that hundred grain weight was negatively correlated with malondialdehyde content，SOD activity and jasmonic acid content，but positively correlated with POD activity，salicylic acid content，gibberellins content，auxin content and abscisic acid content. The two treatments were separated effectively by principal component analysis，indicating that there were some differences in the mechanisms of growth promoting. The treatment of zero-valent iron nanoparticles mainly affected auxins，salicylic acid and abscisic acid. The treatment of melatonin mainly affected SOD，malondialdehyde and gibberellins. Conclusion:Zero-valent iron nanoparticles and melatonin can be used as a simple and practical technology to improve the stress resistance and yields of <italic>F. przewalskii</italic> in domesticated cultivation conditions.