Polyhydroxylated Sirostanol Saponins from the Rhizomes of Paris dulongensis.

Three new polyhydroxylated spirostanol steroidal saponins, dulongenosides B-D (2-4), along with 14 known compounds, dulongenoside A (1), padelaoside B (5), parisyunnanoside G (6), polyphyllin D (7), ophiopogonin C' (8), formosanin C (9), dioscin (10), paris saponin VII (11), paris H (12), parisyunnanoside I (13), protodioscin (14), proprotogracillin (15), crustecdysone (16), and stigmasterol-3-O-ß-d-glucopyranoside (17), were isolated from the rhizomes of Paris dulongensis (Melanthiaceae). Their chemical structures were elucidated based on extensive analyses of NMR and MS data and acidic hydrolyses. The isolates were evaluated for their cytotoxicity to five human cancer cell lines (HL-60, SW480, MDA-MB-231, A549, and A549/Taxol) and the normal human bronchial epithelial cell line BEAS-2B by the MTS test. Compounds 7-12 and 14 showed cytotoxic activity, with IC50 values ranging from 0.20 to 4.35 µM.  Proprogracillin selectively inhibited A549(IC50 = 0.58 µM) and A549/Taxol (IC50 = 0.74 µM) cells, with no significant cytotoxic activity against HL-60, SW480, MDA-MB-231, or BEAS-2B cells, with IC50 values greater than 40 µM.

Turning weeds into feed: Ensiling Calotropis gigantea (Giant milkweed) reduces its toxicity and enhances its palatability for dairy cows.

Calotropis gigantea (Giant milkweed, GM) has the potential to be utilized as a new feed additive for ruminants, however, the presence of unpalatable or toxic compounds decreases animal feed intake. This study aimed to valorize GM as a potential new feed resource through the chemical and microbial biotransformation of toxic compounds that will henceforth, make the plant palatable for cows. After GM's ensiling using fermentative bacteria, the plant was sampled for UHPLC-MS/MS to analyse the metabolomic changes. Illumina Miseq of the 16 S rRNA fragment genes and ITS1 were used to describe the microbial composition and structure colonizing GM silage and contributing to the biodegradation of toxic compounds. Microbial functions were predicted from metataxonomic data and KEGG pathways analysis. Eight Holstein dairy cows assigned in a cross-over design were supplemented with GM and GM silage to evaluate palatability and effects on milk yield and milk protein. Cows were fed their typical diet prior to the experiment (positive control). After ensiling, 23 flavonoids, 47 amino acids and derivatives increased, while the other 14 flavonoids, 9 amino acids and derivatives decreased, indicating active metabolism during the GM ensiling process. Lactobacillus buchneri, Bacteroides ovatus, and Megasphaera elsdenii were specific to ensiled GM and correlated to functional plant metabolites, while Sphingomonas paucimobilis and Staphylococcus saprophyticus were specific to non-ensiled GM and correlated to the toxic metabolite 5-hydroxymethylfurfural."Xenobiotics biodegradation and metabolism", "cancer overview" and "neurodegenerative disease" were the highly expressed microbial KEGG pathways in non-ensiled GM. Non-ensiled GM is unpalatable for cows and drastically reduces the animal's feed intake, whereas ensiled GM does not reduce feed intake, milk yield and milk protein. This study provides essential information for sustainable animal production by valorizing GM as a new feed additive.

Comparative transcriptome analysis reveals nicotine metabolism is a critical component for enhancing stress response intensity of innate immunity system in tobacco.

The pyridine alkaloid nicotine acts as one of best-studied plant resistant traits in tobacco. Previous research has shown that NtERF199 and NtERF189, acting as master regulators within the NIC1 and NIC2 locus, quantitatively contribute to nicotine accumulation levels in N. tabacum. Genome editing-created Nic1(Nterf199) and Nic2 (Nterf189) double mutant provides an ideal platform for precisely dissecting the defensive role of nicotine and the connection between the nicotine biosynthetic pathway with other putative metabolic networks. Taking this advantage, we performed a comparative transcriptomic analysis to reevaluate the potential physiological and metabolic changes in response to nicotine synthesis defect by comparing the nic1nic2 and NIC1NIC2 plants. Our findings revealed that nicotine reduction could systematically diminishes the expression intensities of genes associated with stimulus perception, signal transduction and regulation, as well as secondary metabolic flux. Consequently, this global expression reduction might compromise tobacco adaptions to environmental fitness, herbivore resistances, and plant growth and development. The up-regulation of a novel set of stress-responsive and metabolic pathway genes might signify a newly established metabolic reprogramming to tradeoff the detrimental effect of nicotine loss. These results offer additional compelling evidence regarding nicotine's critical defensive role in nature and highlights the tight link between nicotine biosynthesis and gene expression levels of quantitative resistance-related genes for better environmental adaptation.

Bacillus subtilis YZ-1 surfactins are involved in effective toxicity against agricultural pests.

BACKGROUND: Insect pests negatively affect crop quality and yield. The excessive use of chemical pesticides has serious impacts on the environment and food safety. Therefore, development of effective management strategies in the form of bio-agents have important agricultural applications. Tenebrio molitor, a storage pest, causes losses of grains, medicinal materials, and various agricultural and related products in the warehouse. Bacillus subtilis YZ-1 isolated from naturally deceased Pieris rapae has been found to exhibit significant toxicity against T. molitor. RESULTS: Treatment with B. subtilis YZ-1 fermentation broth resulted in a 90-95% mortality rate of T. molitor within 36 h post-treatment, indicating some active substances may have insecticidal activity in the bacterial supernatant. A bioactivity-guided fractionation method was used to isolate the insecticidal compounds from YZ-1, which led to the identification of surfactins. Additionally, a surfactin deletion mutant YZ-1△srfAA was constructed and the surfactin production by the mutant YZ-1△srfAA was verified through liquid chromatography-mass spectrometry (LC-MS). Further, YZ-1△srfAA exhibited loss of insecticidal activity against T. molitor, Plutella xylostella and Achelura yunnanensis. The insecticidal activity and surfactins contents of several strains of Bacillus sp. were also tested and correlation was found between varying surfactins yield and insecticidal activity exhibited by different strains. CONCLUSION: Conclusively, our results suggest that B. subtilis YZ-1 may provide a novel approach for plant protection against agricultural pests. © 2023 Society of Chemical Industry.

[Chemical constituents from Paris rugosa rhizomes and their antimicrobial activities].

Paris rugosa(Melanthiaceae) only grows in Yunnan province of China at present, and its chemical constituents have not been systematically studied. In this study, nine compounds, including one new compound pariposide G(1) and eight known compounds of cerin(2), stigmast-4-en-3-one(3), ß-ecdysone(4), ophiopogonin C'(5), methyl protogracillin(6), gracillin(7), parissaponin H(8), and parisyunnanoside G(9), were isolated and identified from the ethanol extract of P. rugosa rhizomes by column chromatography methods and semi-preparative high-performance liquid chromatography(HPLC). Compounds 1-9 were isolated from this plant for the first time. The antibacterial and antifungal activities of all the compounds were evaluated. The results showed that ophiopogonin C' had strong inhibitory effects on Candida albicans [MIC_(90)=(4.68±0.01) µmol·L~(-1)] and the fluconazole-resistant strain of C. albicans [MIC_(90)=(4.66±0.02) µmol·L~(-1)].

Fengycin produced by Bacillus subtilis XF-1 plays a major role in the biocontrol of Chinese cabbage clubroot via direct effect and defense stimulation.

Bacillus subtilis XF-1 is a well-investigated biocontrol agent against the biotrophic Plasmodiophora brassicae Woron., the causal agent of clubroot disease of cruciferous crops. The present study demonstrates that XF-1 could efficiently control clubroot disease via leaf spraying and provides an understanding of the biocontrol mechanisms. High-performance thin-layer chromatography (HTPLC) analysis indicated the presence of fengycin-type cyclopeptides in the supernatant. A ppsB deletion mutant of XF-1 resulted in no fengycin production, significantly reduced the lysis rate of testing spores in vitro and the primary infection rate of root hair in vivo, and decreased the protection value against clubroot disease under the greenhouse conditions. Confocal laser scanning microscopy proved that fengycin was not required for leaf internalization and root colonization. Moreover, the expression level of the ppsB gene in XF-1 was regulated by its cell density in root during interaction with P. brassicae. In addition, the ΔppsB mutant of XF-1 could not efficiently control disease because it led to a lower activation level of the jasmonic acid and salicylic acid signaling pathways in roots, which are necessary for the plant defense reaction upon pathogen invasion. Altogether, the present study provides a new understanding of specific cues in the interaction between B. subtilis and P. brassicae as well as insights into the application of B. subtilis in agriculture.

A new amide from the fruiting bodies of Tricholoma bakamatsutake.

A new amide tricholomine C was isolated from the dried fruiting bodies of Tricholoma bakamatsutake. Its structure was identified by a combination of nuclear magnetic resonance spectroscopic analysis and electronic circular dichroism (ECD) calculations. The ethyl alcohol crude extract and tricholomines A-C from T. bakamatsutake were evaluated for neuroprotective activities. Of these substances, the crude extract showed weak neurite outgrowth-promoting activity in rat pheochromocytoma (PC12) cells, as well as weak inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE).

Heterodimers with a cucurbitane-type triterpenoid skeleton from the branches of Elaeocarpus dubius.

Four undescribed and two known cucurbitane-type triterpenoids, including two heterodimers, elaeocarpudubins A and B, were isolated from the branches of Elaeocarpus dubius (Elaeocarpaceae). The chemical structures of these undescribed isolates were determined by analyses of 1D and 2D NMR and MS data, electronic circular dichroism (ECD) calculations, and chemical transformation. Biogenetically, elaeocarpudubins A and B might be derived from cucurbitacin F through Michael addition with vitamin C and (-)-catechin, respectively. These six isolates were evaluated for their cytotoxic activities against human leukemia HL-60, human lung adenocarcinoma A549, human hepatoma SMMC-7721, human breast cancer MCF-7, human colon cancer SW480, and paclitaxel-resistant A549 (A549/Taxol) cell lines, for their antioxidant properties using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and for their differentiation effects on nerve growth factor (NGF)-mediated neurite outgrowth in rat pheochromocytoma PC12 cells. Cucurbitacins F (IC50 of 4.98-38.11 µM) and D (IC50 of 0.03-4.40 µM) showed growth-inhibitory activities against these six cancer cell lines. Elaeocarpudubin B (IC50 of 61.04 µM) and elaeocarpudoside B (IC50 of 6.93 µM) showed antioxidant activities. Elaeocarpudubin B and elaeocarpudoside B also showed neurite outgrowth-promoting activities in PC12 cells at a concentration of 10 µM.

Potential of citrus endophyte Bacillus subtilis L1-21 in the control of Candidatus Liberibacter asiaticus in Asian citrus psyllid, Diaphorina citri.

BACKGROUND: Asian citrus psyllid (ACP), also known as Diaphorina citri, is the natural vector of Candidatus Liberibacter asiaticus (CLas), which is responsible for Huanglongbing (HLB), a devastating citrus disease. Previously, the pathogen was successfully excluded from diseased citrus plants by using the indigenous endophyte Bacillus subtilis L1-21. However, the pathogen elimination and colonization potential of B. subtilis L1-21 in the carrier vector ACP, as well as the recruitment of native microbial communities of psyllid in the presence of endophytes, are still unknown. RESULTS: Initially, we suggested that endophyte L1-21 reduced the CLas copies in ACP from 6.58 × 106 to 5.04 × 104 per insect after 48 h, however, the pathogen copies remained stable in the negative control. The endophyte was stable for 48 h after application. Among the bacterial genera those highlighted in ACP were Candidatus Liberibacter, Pseudomonas, Candidatus Profftella, Methylobacterium-Methylorubrum, Pantoea, Curtobacterium, Wolbachia, Actinomycetospora, and Bacillus. Interestingly, B. subtilis L1-21 easily colonizes the midgut of ACP but cannot be detected in eggs. When ACP with endophyte L1-21 was allowed to feed on new citrus leaves, the highest colonization was observed. We also found that psyllids carrying endophyte L1-21 after feeding on citrus leaves reduced the CLas copies in leaves on the 0, 3rd and 5th day from 8.18 × 10,4 2.6 × 10,3 and 0 pathogen copies/g fresh midvein, respectively. CONCLUSIONS: We propose that B. subtilis L1-21 is a native endophyte in citrus and psyllid, which efficiently reduces the CLas pathogen in both citrus and psyllids, provides a more protective effect by increasing the number of cultivable endophytes, and successfully colonizes the midgut of ACP. © 2022 Society of Chemical Industry.

Bioassay-guided isolation of cytotoxic constituents from the flowers of Aquilaria sinensis.

Bioassay-guided fractionation of the EtOH extract from the flowers of Aquilaria sinensis (Lour.) Spreng. (Thymelaeaceae) led to the isolation of a new cucurbitane-type triterpenoid, aquilarolide A (1), along with five known compounds (2-6). The structure of 1 was elucidated by extensive 1D and 2D nuclear magnetic resonance (NMR) experiments and mass spectrometry (MS) data and theoretical calculations of its electronic circular dichroism (ECD) spectra. Aquilarolide A, cucurbitacin E (3), cucurbitacin B (4), and 7-hydroxy-6-methoxy-2-[2-(4-methoxyphenyl)ethyl]-4H-1-benzopyran-4-one (6) showed significant cytotoxicity against human lung adenocarcinoma SPC-A-1, human lung squamous cell carcinoma NCI-H520, human lung adenocarcinoma A549, and paclitaxel-resistant A549 (A549/Taxol) cell lines. All four active compounds, with IC50 values ranging from 0.002 to 0.91 µM, had better inhibitory activities against A549/Taxol cells than paclitaxel (IC50 = 1.80 µM). Among them, cucurbitacin E (IC50 = 0.002 µM) is the most active. Further studies are needed to evaluate their in vivo antitumor activities and to clarify their mechanisms.

Corrigendum: Defeating Huanglongbing Pathogen Candidatus Liberibacter asiaticus With Indigenous Citrus Endophyte Bacillus subtilis L1-21.

[This corrects the article DOI: 10.3389/fpls.2021.789065.].

Developing Penicillium digitatum Management Strategies on Post-Harvest Citrus Fruits with Metabolic Components and Colonization of Bacillus subtilis L1-21.

Citrus is among the most important plants in the fruit industry severely infected with pathogens. Citrus green mold caused by Penicillium digitatum is one of the most devastating diseases during post-harvest stages of citrus fruit. In this study, a potential endophyte Bacillus subtilis L1-21, isolated from healthy citrus plants, was assessed for its biocontrol activity against the pathogen P. digitatum. Based on an in vitro crosstalk assay, we suggested that B. subtilis L1-21 inhibits the pathogen with an inhibition zone of 3.51 ± 0.08 cm. Biocontrol efficacy was highest for the fermented culture filtrate of B. subtilis L1-21. Additionally, using GC-MS analysis, 13 compounds were detected in the extract of this endophyte. The culture filtrate in Landy medium could enlarge and deform pathogen spores and prevent them from developing into normal mycelium. Accordingly, the Landy culture filtrate of B. subtilis L1-21 was stable in the temperature range of 4-90 °C and pH of 3-11. Further, MALDI-TOF-MS for B. subtilis L1-21 detected surfactin, fengycin, bacillaene and bacilysin as potential antifungal compounds. GFP-tagged B. subtilis L1-21 easily colonized in citrus fruit peel and pulp, suggesting its role in eliminating the fungal pathogen. Altogether, it is highly expected that the production of antifungal compounds, and the colonization potential of B. subtilis L1-21 are required against the post-harvest P. digitatum pathogen on citrus fruit.

Five new 2-(2-phenylethyl)chromone derivatives and three new sesquiterpenoids from the heartwood of Aquilaria sinensis, an aromatic medicine in China.

Five new 2-(2-phenylethyl)chromone derivatives, (5S,6R,7R,8S,7'R)-7'-hydroxyagarotetrol (1), (5S,6R,7R,8S,7'S)-7'-hydroxyagarotetrol (2), (6S,7S,8R)-2­[2­(4-methoxyphenyl)ethyl]­6,7,8­trihydroxy­5,6,7,8­tetrahydrochromone (3), (6S,7S,8R)-2­(2-phenylethyl)­6,7,8­trihydroxy­5,6,7,8­tetrahydrochromone (4), (5S,6R,7S,8R)-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydro-8-[2-(2-phenylethyl)-7-methoxychromonyl-6-oxy]chromone (5), three new sesquiterpenoids, (4S,5S,7S,8S,10S,13R)-7,8,13-trihydroxyrotunda-1,11-dien-3-one (6), (4S,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one (7), and (4R,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one (8), along with 14 known compounds were isolated from the resinous heartwood of Aquilaria sinensis (Thymelaeaceae). The chemical structures of these new compounds were elucidated by 1D and 2D NMR and MS data, single-crystal X-ray diffraction analysis, and electronic circular dichroism (ECD) calculations. The neuroprotective activities of these isolates were evaluated using an in vitro model of rat adrenal pheochromocytoma (PC12) cell injury induced by corticosterone. At concentrations from 5 to 40 µM, compounds 4 and 6, agarotetrol (9), and 6-hydroxy-2-(2-phenylethyl)chromone (17) showed significant protective activities against corticosterone-induced PC12 cell injury (P < 0.001).

Evaluation on Antidiabetic Properties of Medicinal Plants from Myanmar.

OBJECTIVES: To explore the effective and safe medicines for treating diabetes. METHODS: Hydroalcoholic extracts of 130 medicinal plants belonging to 66 families were evaluated using porcine pancreatic lipase (PPL) inhibition and glucose uptake methods together with a literature review. RESULTS: The extracts of 22 species showed the PPL inhibition activity; 18 extracts of 15 species stimulated glucose uptake in 3T3-L1 adipocytes. Among them, Mansonia gagei J.R. Drumm., Mesua ferrea L., and Centella asiatica (L.) Urb. exhibited both activities. The extracts of Caladium lindenii (André) Madison rhizomes and Azadirachta indica A. Juss. leaves presented the utmost lipase inhibitory activity with IC50 of 6.86 ± 0.25 and 11.46 ± 0.06 µg/mL, respectively. The extracts of Coptis teeta Wall. rhizomes and Croton tiglium L. seeds stimulated the maximum glucose uptake. Ten species are reported to have antidiabetic activity for the first time. Flavonoids and triterpenoids are the dominant antidiabetic compounds in selected medicinal plants from Myanmar. CONCLUSIONS: P. zeylanica, L. cubeba, H. crenulate, M. gagei, C. teeta, and M. ferrea are worthy to advance further study according to their strong antidiabetic activities and limited research on effects in in vivo animal studies, unclear chemical constitutes, and safety.

Wild plants used by the Lhoba people in Douyu Village, characterized by high mountains and valleys, in southeastern Tibet, China.

BACKGROUND: Douyu Village, inhabited by the Lhoba people, is situated within the Eastern Himalayas, in southeastern Tibet, China. The village is located among high mountains and valleys, which feature complex terrain with cold and dry climates and distinctive vegetation types and species. The Lhoba people in this village are isolated from other groups in China. The Lhoba people have lived in this village since the 15th century and mainly depended on gathering, hunting, and swidden agriculture before the 1960s. Because they have a long history and live under extreme climatic, geographical, and ecological conditions, the Lhoba people in Douyu Village may have unique traditional knowledge about wild plants. Thus, this research aims to record the traditional botanical knowledge of the Lhoba people in Douyu. METHODS: An ethnobotanical study was conducted on the Lhoba people in Douyu Village in Longzi County, Tibet, China. Semi-structured interviews and group discussions with informed consent were used in the study. We interviewed 41 informants (14 key informants) between 18 and 75 years of age. All information was collected, organized, and compiled into "use reports" for quantitative analysis. The informant consensus factor (ICF) was used to determine the homogeneity of the informants' knowledge of medicinal plants, while the cultural importance index (CI) was used to estimate the cultural importance of shared species. RESULTS: A total of 91 wild species (90 vascular plants and 1 fungus) belonging to 71 genera and 39 families utilized by the Lhoba people in Douyu were documented. Of these species, Pimpinella xizangense and Wikstroemia lungtzeensis are endemic to Longzi County, while Sinopodophyllum hexandrum and Paeonia ludlowii are endangered species in China. All habitats, from the field vegetation at the valley bottoms to the alpine shrubland and meadows, were used for plant collection, and the numbers of species of plants collected from the various vegetation types (except for fields) decreased with increasing altitude. Our study found that 55 species are edible plants and fungi, 29 species are medicinal plants, and 38 species are used for other purposes. Medicinal plants are used for 11 categories of diseases, among which diseases of blood-forming organs (ICF = 0.96) and gastrointestinal diseases (ICF = 0.95) exhibited the highest ICF values. Based on the CI values, the most important plants in this study area are Berberis xanthophloea, B. kongboensis, Sinopodophyllum hexandrum, Vicatia thibetica, and Hippophae rhamnoides subsp. gyantsensis. Moreover, a comparison of the wild plants used by Lhoba ethnic groups in three counties in China showed significant differences among these regions. CONCLUSIONS: Our study demonstrates that the wild plants utilized by the Lhoba people in Douyu Village are highly diverse, at 90 plant and one fungal species, which reflects not only the number of species but also their diversified functions. The extreme climatic, geographical, and ecological conditions of Douyu within the high mountains and valleys of the Eastern Himalayas potentially affect the Lhoba people's culture, including plant utilization practices, and contribute to the rich diversity of the wild plants used by the local people.

Photocatalytic degradation of sulfamonomethoxine by mesoporous phosphorus-doped titania under simulated solar light irradiation.

Photocatalytic degradation of sulfamonomethoxine (SMM) by mesoporous phosphorus-doped TiO2 (P-TiO2) was studied under simulated solar light irradiation. The morphological structure and chemical composition of P-TiO2 were analyzed by XRD, SEM, HRTEM, BET, XPS and FTIR. Using the central composite design (CCD) of response surface methodology (RSM), the degradation of SMM was investigated with a range of antibiotic concentrations (4-8 mg L-1), catalyst dosages (400-900 mg L-1), P doping amounts (5-15 wt %) and irradiation time (90-150 min). The Ti-O-P bond formed during the calcination of TiO2, thereby generating plate-like P-TiO2, where P was uniformly distributed. Phosphorus doping can stabilize anatase TiO2, which has a larger specific surface area and a lower average particle and pore size than bare TiO2. The result obtained from the RSM model showed a significant correlation between the predicted values and the experimental results of SMM degradation (P < 0.05). Under the optimal experimental conditions (antibiotic concentration = 6 mg/L, catalyst dosage = 800 mg/L, P doping = 5 wt% and irradiation time = 90 min), the degradation rate of SMM was 99.51%, and the TOC was 50%. Toxicity showed a considerable reduction towards Vibrio-qinghaiensis sp.-Q67 after SMM photocatalytic degradation. Through free radical capture experiments, LC-MS detection and DFT calculations, the possible photocatalytic degradation mechanism of SMM using P-TiO2 as the catalyst was revealed.

An ethnobotanical study of forage plants in Zhuxi County in the Qinba mountainous area of central China.

In the Qinba mountainous area of Central China, pig farming has a significant impact on the growth of the rural economy and has substantially increased farmer incomes. Traditional knowledge plays an important role in the selection of forage plant species for pig farming by local people. This study aimed to identify the forage plants used for pig feeding and to catalog indigenous knowledge regarding their use. During 2016 and 2017, ethnobotanical surveys and inventories were conducted in Zhuxi County, Hubei Province, China. Data were collected using semi-structured interviews, key informant reports, free listings, guided field walks, and participatory observations with 77 households in 16 villages in 13 towns/townships. The obtained data were analyzed using a relative frequency citation (RFC) index. Overall, 145 wild forage plants from 91 genera and 31 families were recorded. The most cited families were Asteraceae, Polygonaceae, Urticaceae, Amaranthaceae, Fabaceae, Cruciferae, Caryophyllaceae, and Lamiaceae. Whole plants (75.9%) and tender leaves (12.4%) were the most frequently used parts of the plants. Most of the forage plants were herbaceous (88.9%). Almost all forage plants could be collected throughout the year (62.7%). Raw and cooked were the two main preparation methods. The most frequently cited species were Taraxacum mongolicum, Bidens pilosa, Sonchus oleraceus, Pilea verrucosa, and Pilea pumila var. obtusifolia. A total of 14 species were identified as the top forage plants in Zhuxi County based on their RFC values (RFC value greater than 0.5). Local people possess rich traditional knowledge about the utilization and management of forage plants for pig feeding. However, the maintenance of this traditional knowledge may be seriously threatened by changes in pig feeding modes and the lack of successors. Appropriate strategies and action plans have been suggested for the conservation of traditional knowledge associated with biodiversity and the sustainable use of forage species resources. These include 1) taking targeted measures to protect forage resources and associated traditional knowledge; 2) strengthening research on the forage plants with the highest RFC values for nutritional value, digestibility, other functions, and ecological status; and 3) enhancing the identification of poisonous forage plants.

Sesquiterpenoids and 2-(2-Phenylethyl)chromone Derivatives from the Resinous Heartwood of Aquilaria sinensis.

One novel spirolactone, aquilarisinolide (1), three new sesquiterpenoids, (2R,4S,5R,7R)-2-hydroxyeremophila-9,11-dien-8-one (2), (1R,4S,5S,7R,11R)-13-hydroxyepidaphnauran-9-en-8-one (3), and (4R,5S,7R,8S,10S,13R)-8,13-dihydroxyrotunda-1,11-dien-3-one (4), together with 13 known compounds (5-17) were isolated from the resinous heartwood of Aquilaria sinensis (Thymelaeaceae). The structures of the new compounds were elucidated based on the analysis of NMR and MS data and theoretical calculations their ECD spectra. The isolated compounds were evaluated for their protective activities against PC12 cell injury induced by corticosterone (CORT) and 1-methyl-4-phenylpyridine ion (MPP+), as well as inhibitory activities against BACE1. Compound 4, 5,6-dihydroxy-2-(2-phenylethyl)chromone (5), daphnauranol B (7), 6-methoxy-2-[2-(3-methyoxyphenyl)ethyl]chromone (10), isoagarotetrol (14), and 1-hydroxy-1,5-diphenylpentan-3-one (16) showed significant protective effects on CORT-induced injury in PC12 cells at a concentration of 20 µM (P < 0.001). Isoagarotetrol (14) showed a significant protective effect on MPP+-induced injury in PC12 cells at a concentration of 20 µM (P < 0.001), while compound 4 showed a moderate activity (P < 0.01). The BACE1-inhibitory activities of all tested compounds were very weak with less than 30% inhibition at a concentration of 20 µM.

Traditional Uses and Pharmacologically Active Constituents of Dendrobium Plants for Dermatological Disorders: A Review.

Dendrobium Sw. is one of the largest genera in the orchidaceous family and includes 900-2000 species. Among them, more than 80 Dendrobium species have been reported in China. However, there are only six Dendrobium species, namely, D. bigibbum var. superbum (syn. D. phalaenopsis), D. chrysanthum, D. fimbriatum, D. loddigesii, D. nobile, and D. officinale (syn. D. candidum), listed in the New Inventory of Existing Cosmetic Ingredients in China Launched. Artificial planting of Dendrobium species has been a great success in China. To better utilize Dendrobium resources for medicinal and cosmetic purposes, we summarize their traditional uses and pharmacologically active compounds for treating dermatological disorders in this review. "Orchidaceae", "Dendrobium", "traditional use", "ethnobotany", "dermatological disorder", and "skin disease" were used as search terms to screen the literature. Cited references were collected between 1970 and 2020 from the Web of Science, China National Knowledge Internet (CNKI), SciFinder, Google Scholar, and Chinese books. From the search, it was found that there are 22 Dendrobium species with traditional uses in dermatological disorders, and 131 compounds from Dendrobium plants have been reported to possess anti-inflammatory, antimicrobial, antioxidant, antiaging, anti-psoriasis, and tyrosinase-inhibitory activities, implying that Dendrobium plants are important resources for the discovery of active compounds and the development of new drugs and cosmetics. D. crepidatum, D. denneanum, D. loddigesii, D. nobile, and D. officinale have been extensively studied. More research on other Dendrobium species is needed. The major active compounds found in Dendrobium species are phenanthrenes, alkaloids, flavonoids, phenylpropanoids, and lignans. Several compounds, such as loddigesiinol A, (S)-5-methoxy-2,4,7,9-tetrahydroxy-9,10-dihydrophenanthrene, (S)-4-methoxy-2,5,7,9-tetrahydroxy-9,10-dihydrophenanthrene, 2,5-dihydroxy-4-methoxy-phenanthrene 2-O-ß-D-glucopyranoside, (9R)-1,2,5,9-tetrahydroxy-9,10-dihydrophenanthrene 5-O-ß-D-glucopyranoside, (+)-homocrepidine A, and vicenin 2, have significant anti-inflammatory activities and inhibit nitric oxide (NO) production with IC50 values less than 5 µM, and these compounds are worthy of further study.

Volatile Constituents of Endophytic Fungi Isolated from Aquilaria sinensis with Descriptions of Two New Species of Nemania.

Algae, bacteria, and fungi, as well as higher plants, produce a wide variety of secondary metabolites known as natural products. Natural products are well known as remarkable sources of many therapeutic agents. The genus Nemania is a wood-decaying fungus that belongs to family Xylariaceae. Nemania is often found as an endophyte in diverse hosts and some species are known to produce useful secondary metabolites. In this study, two Nemania species were isolated as an endophytic fungus from Aquilaria sinensis. Multi-gene phylogenetic studies showed that the newly described strains of Nemania are new to science, and this is the first report of Nemania from the host Aquilaria. One of the fermented species, Nemania aquilariae (KUMCC 20-0268), resulted in five sesquiterpenoids, which were previously reported from agarwood, and their structures were identified by gas chromatography-mass spectrometry (GC-MS). In addition, five different media were investigated in vitro to optimize conditions for growing the fungal biomass of Nemania aquilariae and N. yunnanensis.