NMR-based Structural Classification, Identification, and Quantification of Triterpenoids from Edible Mushroom Ganoderma resinaceum

Mid-Infrared Spectroscopic Study of Cultivating Medicinal Fungi Ganoderma: Composition, Development, and Strain Variability of Basidiocarps

Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was proposed for rapid, versatile, and non-invasive screening of Ganoderma basidiocarps to assess their potential for specific applications. Fifteen species and strains of this fungus were selected for analysis, and fine sections at different parts of young and mature basidiocarps were obtained. The spectra of fungal samples showed significant differences interpreted in terms of biochemical composition using characteristic bands of proteins, polysaccharides, lipids, and triterpenoids. Obviously, for the transverse sections in trama, especially in the basal part, the most intense bands at 950-1200 cm-1 corresponded to polysaccharide vibrations, while for the superficial sections, the bands of carbonyl and aliphatic groups of triterpenoids at 1310-1470, 1550-1740, and 2850-2980 cm-1 predominated. The pilei, especially hymenium tubes, apparently contained more proteins than the bases and stipes, as evidenced by the intense bands of amide vibrations at 1648 and 1545-1550 cm-1. The specificity of the Ganoderma basidiocarp is a densely pigmented surface layer rich in triterpenoids, as proved by ATR-FTIR spectroscopy. The spectral differences corresponding to the specificity of the triterpenoid composition may indicate the prospects of individual strains and species of this genus for cultivation and further use in food, cosmetics, or medicine.

Influence of the Growing Region on the Phytochemical Composition and Antioxidant Properties of North American Cranberry Fruit (Vaccinium macrocarpon Aiton)

The impact of the growth environment on the production of health-promoting phytochemicals in cranberry fruit (Vaccinium macrocarpon Aiton) is not well established despite increased production worldwide. We investigated the secondary metabolite composition among the cranberry fruit of nine cultivars produced in two major coastal North American growing regions that differ in climate. Using 1H NOESY NMR to generate metabolic fingerprints, principal component analysis revealed variation between the two regions and identified likely contributing metabolites. Triterpenoids ursolic and oleanolic acid, as well as citric and malic acids, were quantified using 1H qNMR, and anthocyanins and flavonols were determined by HPLC-DAD. Total proanthocyanidins (PACs), total soluble phenolics, and DPPH free-radical scavenging antioxidant activity were also evaluated. Across all cultivars, anthocyanins, flavonols, and total phenolic content were significantly higher in West Coast fruit than East Coast fruit, correlating with a regional trend of higher antioxidant activity in fruit grown on the West Coast. The opposite trend was observed for triterpenoids and organic acids, which were significantly higher across cultivars in East Coast fruit. These trends persisted over two growing seasons. The study demonstrates that climate plays an important role in the production of antioxidant and anti-inflammatory phytochemicals in cranberry plants.

1H NMR-guided isolation of hasubanan alkaloids from the alkaloidal extract of Stephania longa

1H NMR-guided fractionation led to the isolation of 16 alkaloids from the alkaloidal extract of Stephania longa, including 11 new hasubanan alkaloids (1-11) and five known alkaloids (12-16). Interestingly, compounds 2 and 11 are typically considered protonated tertiary amine compounds, whereas compounds 1 and 10 are regarded as oxidized versions of the corresponding compounds. Their gross structures were determined through an extensive analysis of spectroscopic data (NMR (nuclear magnetic resonance) and HRESIMS (high resolution electrospray ionization mass spectroscopy)), and their absolute configurations were established by comparing their experimental and calculated electronic circular dichroism (ECD) spectra. The new (3) and a known (12) compounds in all isolates displayed stronger antineuroinflammatory effects (IC50 values of 1.8 and 11.1 μM, respectively) than minocycline (IC50 value of 15.5 μM) against NO production on LPS-activated BV2 cells.

NMR-tracking for 15,16-seco-cycloartane triterpenes from Cimicifuga acerina

Twelve undescribed 15,16-seco-cycloartane triterpenoids, 15,16-seco-cimiterpenes C-N, as well as five previously reported analogs were isolated by NMR-tracking methods from the rhizomes of Cimicifuga acerina (Sieb. et Zucc.) Tanaka. Among them, 15,16-seco-cimiterpenes C-N were the first 15,16-seco-cycloartane triterpenoids featuring acetal or hemiacetal structures at C-15. The chemical structures of 15,16-seco-cimiterpenes C-N were determined based on comprehensive spectroscopic analysis, chemical method, and comparison with the previous literature data. After that, all these compounds were evaluated for their lipid-lowering effects on 3T3-L1 adipocytes.15,16-seco-cimiterpene D was found to exhibit a comparable reducing lipid effect at the concentration of 50 μM, with an inhibition rate at 35.96%.

Application of Band-Selective HSQC NMR in Species Discrimination and Adulteration Identification of Panax Linn

The quality of Panax Linn products available in the market is threatened by adulteration with different Panax species, such as Panax quinquefolium (PQ), Panax ginseng (PG), and Panax notoginseng (PN). In this paper, we established a 2D band-selective heteronuclear single quantum coherence (bs-HSQC) NMR method to discriminate species and detect adulteration of Panax Linn. The method involves selective excitation of the anomeric carbon resonance region of saponins and non-uniform sampling (NUS) to obtain high-resolution spectra in less than 10 min. The combined strategy overcomes the signal overlap limitation in ¹H NMR and the long acquisition time in traditional HSQC. The present results showed that twelve well-separated resonance peaks can be assigned in the bs-HSQC spectra, which are of high resolution, good repeatability, and precision. Notably, the identification accuracy of species was found to be 100% for all tests conducted in the present study. Furthermore, in combination with multivariate statistical methods, the proposed method can effectively determine the composition proportion of adulterants (from 10% to 90%). Based on the PLS-DA models, the identification accuracy was greater than 80% when composition proportion of adulterants was 10%. Thus, the proposed method may provide a fast, practical, and effective analysis technique for food quality control or authenticity identification.

Alkaloids, sesquiterpenoids and hybrids of terpenoid with p-hydroxycinnamic acid from Ganoderma sinensis and their biological evaluation

The fruiting bodies of Ganoderma sinensis are used as food raw materials of marketed healthcare products. To gain an insight into the chemical and biological profling of G. sinensis, twenty-five compounds including eleven undescribed ones (ganodermasines A‒K) and fourteen known ones were isolated. Among them, ganodermasines A‒D are undescribed diketopiperazine alkaloids, ganodermasines E and F are alkaloids containing a pyridine. The structures of undescribed compounds were identified by spectroscopic, computational, and crystallographic methods. The results of acetylcholinesterase (AchE) inhibitory activity show that ganodermasines I and J could inhibit AchE with IC₅₀ values of 26.05 and 20.40 μM, respectively. In addition, neurotrophic assay in PC-12 cells showed that (+)-ganodermasine E, (-)-ganodermasine E, and ganodermasine I could stimulate neurite outgrowth at 10 μM, while the other isolates are inactive. The present findings will lend a hand for further utilization of G. sinensis.

Triterpenoids and meroterpenoids from the edible Ganoderma resinaceum and their potential anti-inflammatory, antioxidant and anti-apoptosis activities

Ganoderma resinaceum, as a traditional edible mushroom, has been widely reported to improve neurodegenerative diseases characterized by oxidative stress and inflammation. In this study, five new terpenoids, including four lanostane triterpenoids, named ganoresinoid A-D (1-4) and one meroterpenoid, named ganoresinoid E (5), along with 27 known compounds (6-32), were isolated from the fruiting bodies of edible mushroom G. resinaceum. These structures were identified by NMR, HRESIMS data analysis. All metabolites were evaluated for anti-inflammatory, antioxidative and anti-apoptosis activities. Among them, ganoresinoid A showed notably restrained nitric oxide (NO), IL-1β, IL-6 and TNF-α levels in LPS-activated BV-2 microglial cells via suppressing TLR-4/ NF-κB and MAPK signaling pathway. Simultaneously, ganoresinoid A remarkably alleviated LPS-induced apoptosis by means of the decrease of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). In addition, ganoresinoid A demonstrated antioxidant effects in H₂O₂-induced SH-SY5Y cells by activating the Akt/GSK-3β/Nrf2 signaling pathway. Taken together, these results may provide a stronger theoretical basis for ganoresinoid A from G. resinaceum as nutrition intervention to alleviate neurodegenerative diseases.

Metabolomic profiling of M. speciosa champ at different growth stages

Millettia speciosa Champ (M. speciosa) is an edible food and folk medicine and extracts from its roots exhibit a hepatoprotective effect. However, its metabolic growth process and the best harvest time have not been reported. This study systematically evaluated the metabolomic profiling of M. speciosa root extracts at different growth stages through the UPLC-Q-TOF-MS, nuclear magnetic resonance (NMR) and An orthogonal partial least squares-discriminant analysis (OPLS-DA). The results revealed there were significant differences among extracts from six ages of M. speciosa, and 110 compounds were identified. Pharmacological studies showed that 5-year and 20-year old M. speciosa roots may exhibit higher fat-lowering effects, while 5-year-old (M.s-5Y) showed better hepatoprotective activity in high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) mice. Hence, our study suggested that M.s-5Y may have potent efficacy in ameliorating NAFLD, which might be useful in determining the optimum time to harvest M. speciosa.