Discovery and Biomimetic Semisynthesis of Spirophyllines A-D from Uncaria rhynchophylla.

Spirophyllines A-D (1-4), four new spirooxindole alkaloids all characterized by the spiro[pyrrolidin-3,3'-oxindole] core and a rare isoxazolidine ring, were isolated from Uncaria rhynchophylla. Their structures were determined by spectroscopic methods and confirmed by X-ray crystallography. Based on the biomimetic semisynthesis strategy, compounds 1-8 were synthesized in three steps via the key reactions of 1,3-dipolar cycloaddition and Krapcho decarboxylation from corynoxeine. Interestingly, compound 3 showed moderate inhibitory activity against the Kv1.5 potassium channel (IC50 = 9.1 µM).

Development of a novel phosphoramidite-selenide ligand for Pd-catalyzed asymmetric allylic substitution.

A novel chiral P,Se-heterodonor ligand has been designed and prepared through an efficient and simple operation. This ligand can be successfully applied to Pd-catalyzed asymmetric allylic substitution with C- and N-nucleophiles, producing a diverse range of chiral allylic products in high yields and enantioselectivities (up to 99% yield and 95% ee).

Eleven undescribed alkaloids from the rhizomes of Sinomenium acutum and their IDO1 and TDO inhibitory activities.

Eleven previously undescribed alkaloids, named sinometumines A-K, along with three known alkaloids, were isolated from the rhizomes of Sinomenium acutum. The chemical structures of these unreported compounds were established using extensive spectroscopic methods (IR, UV, HRESIMS, and NMR), and their absolute configurations were determined by single crystal X-ray diffraction analyses and calculated electronic circular dichroism spectroscopy (ECD). Sinometumine D was the first aporphine-type derived alkaloid inner salt with a rearranged dibenzofuran ring backbone. Sinometumine E was a rare protoberberine-type alkaloid with a complex 6/6/6/6/6/6 hexacyclic skeleton. This was the first report of alkaloids with these two skeletons isolated from S. acutum. All isolates were evaluated for their inhibitory activities against indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO). Lysicamine possessed noteworthy inhibitory activities as an IDO1/TDO dual inhibitor with IC50 values of 6.22 ± 0.26 µM and 23.76 ± 2.93 µM, respectively, and liriodenine revealed moderate dual inhibition with IC50 values of 31.65 ± 4.44 µM and 15.64 ± 0.26 µM. The intermolecular interactions and binding modes between lysicamine and IDO1/TDO were elaborated by molecular docking studies.

Cassane diterpenoids from the seeds of Caesalpinia bonduc and their nitric oxide production and α-glucosidase inhibitory activities.

Ten previously undescribed cassane diterpenoids, cassabonducins A-J, and eleven known compounds were isolated from the seeds of Caesalpinia bonduc. The structures of the undescribed compounds were elucidated by extensive analysis of spectroscopic data (IR, HRESIMS, and 1H, 13C and 2D NMR) and their absolute configurations were determined by the ECD data and single-crystal X-ray diffraction analysis. ε-Caesalpin-Ⅶ was obtained from natural resources for the first time. Cassabonducin A possessed noteworthy inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages with IC50 value of 6.12 µM. Cassabonducin D and neocaesalpin N showed moderate α-glucosidase inhibition at the concentration of 50 µM with inhibitory capacities of 47.17% and 43.83%, respectively.

Rhynchines A-E: Cav3.1 Calcium Channel Blockers from Uncaria rhynchophylla.

Rhynchines A-E (1-5), five new indole alkaloids with an unprecedented skeleton, were isolated from Uncaria rhynchophylla. The new skeleton was characterized by an indole moiety and a 2-oxa-8-azatricyclo[6,5,01,5,01,8]tridecane core, forming a unique 6/5/7/5/5 ring system. Their structures were determined by nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, infrared spectroscopy, and calculated electronic circular dichroism (ECD) and were confirmed by X-ray crystallography. Interestingly, 1 and 2 showed strong inhibitory activities against the Cav3.1 calcium channel with IC50 values of 6.86 and 10.41 µM.

Neo-clerodane Diterpenoids with Hypoglycemic Effects in Vivo from the Aerial Parts of Salvia hispanica L.

A new neo-clerodane diterpenoid, salvihispin H (1), and six known ones (2-7) were identified from the aerial parts of Salvia hispanica L. The structure and absolute configuration of 1 were elucidated by extensive analysis of spectroscopic (1 H, 13 C, and 2D NMR, and HR-ESI-MS) and single-crystal X-ray diffraction data. The anti-diabetic effects of salvihispin H (1) and salvifaricin (2) were evaluated in diabetic db/db mice. The data showed that 1 and 2 could significantly reduce fasting blood glucose level and improve insulin resistance, and compound 1 exerted glucose-lowering effect more quickly than metformin. In addition, 1 and 2 could also reduce serum TG level in db/db mice. These results demonstrated that compounds 1 and 2 could be considered as potent candidates for the therapy of type 2 diabetes mellitus (T2DM).

Rearranged neoclerodane diterpenoids from the aerial parts of Salvia hispanica L.

Six new rearranged neoclerodane diterpenoids (1-6), as well as three known ones, were obtained from the aerial part of Salvia hispanica L. Their structures were elucidated by extensive analysis of spectroscopic data (1D, 2D NMR, and HRESIMS) and Mosher's method. The absolute configurations of 1, 2, and 4 were determined by single-crystal X-ray diffraction analysis. All isolated compounds were evaluated for their cardioprotective effects against H2O2-induced cardiomyocytes injury, and compound 5 showed statistically significant cardioprotective effect in vitro assays.

Huperserratines A and B, Two Macrocyclic Lycopodium Alkaloids with an Unusual Skeleton from Huperzia serrata.

Huperserratines A (1) and B (2), two Lycopodium alkaloids with an unprecedented 5-aza-bicyclo[10.4.0]hexadecane skeleton and an oxime function, were isolated from Huperzia serrata. Their structures including absolute configurations were determined by extensive NMR spectroscopic and X-ray diffraction analysis. Compounds 1 and 2 were the first examples of macrocyclic Lycopodium alkaloids with an aza-12-membered ring. A plausible biogenetic pathway of these compounds was also proposed. Compound 1 exhibited moderate anti-HIV-1 activity with an EC50 of 52.91 µg/mL and a therapy index greater than 3.78.

Phytochemical constituents of the pericarps of Illicium difengpi and their anti-inflammatory activity.

Phytochemical investigation on the pericarps of Illicium difengpi lead to the isolation and structure elucidation of a new sesquiterpene, sesquicaranoic acid C (1), a new neolignan, difengpiol C (2), and 10 known compounds. The structures and absolute configurations of two new compounds were determined by a combination of NMR and CD spectroscopic analyses. All isolates were evaluated for their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells.

The Role of Endolymphatic Hydrops in Patients with Pantonal Idiopathic Sudden Sensorineural Hearing Loss: A Cause or Secondary Reaction.

The purpose of this study was to investigate the presence of endolymphatic hydrops (EH) in both affected and unaffected ears of patients with pantonal unilateral idiopathic sudden sensorineural hearing loss (ISSNHL) using three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) and further evaluate the significance of EH in this disorder. Twenty-seven ISSHL patients were enrolled in this study. 3D-FLAIR MRI was performed 24 h after intratympanic injection of gadolinium-diethylenetriaminepentaacetic acid (Gd-DPTA). The incidences of EH in the affected ears and contralateral unaffected ears were compared and the correlations of EH with vertigo or prognosis were analyzed using the Chi-square test. The results showed that the incidence of EH was 68.0% (17/25) in the affected ears and 34.8% (8/23) in the unaffected ears. There was a statistically significant difference between affected ears and unaffected ears in regard to the incidence of EH (P<0.05). There were no significant correlations of EH with vertigo (P=1.000) or with prognosis (P=0.359) in the affected ears. In conclusion, there is EH in the inner ear of patients with pantonal ISSNHL; EH is not related to vertigo, a concomitant symptom of ISSNHL, and the prognosis of this condition. The presence of EH may be a secondary reaction following the impairment of the inner ears with pantonal ISSNHL.

Neo-clerodane diterpenoids from aerial parts of Salvia hispanica L. and their cardioprotective effects.

Ten undescribed neo-clerodane diterpenoids, named hispanins A-J, together with six known ones, were isolated from the aerial parts of Salvia hispanica L. Their structures were established by extensive spectroscopic analysis. The absolute configurations of the undescribed compounds were determined by the ECD data and single crystal X-ray diffraction analysis. Hispanins B and C represented the first neo-clerodane diterpenoids with a unique oxygen bridge between C-19 and C-20. All isolated compounds were evaluated for their protective effects against H2O2-induced cardiomyocyte injury. Five of these compounds showed significant cardioprotective effects.

[Effect of electrical stimulation at auricular points combined with sound masking on the expression of CREB, BDNF and TrkB in the auditory cortex of tinnitus rats].

OBJECTIVE: To explore the effect of electrical stimulation at auricular points (EAS) combined with sound masking on the expression of cAMP-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB) in the auditory cortex of tinnitus rats. METHODS: A total of 27 adult male SD rats were randomly divided into a control group, a model group and an EAS group. The rats in the model group and the EAS group were intervened with intraperitoneal injection of sodium salicylate to induce tinnitus model, while the rats in the control group were intervened with injection of 0.9% NaCl solution. After the model was successfully established, the rats in the EAS group were treated with electrical stimulation at "Shenmen" (TF4) and "Yidan" (CO11), combined with sound masking; the treatment was given once a day for 15 days. The gap prepulse inhibition of acoustic startle (GPIAS) and prepulse inhibition (PPI) testing were performed using the acoustic startle reflex starter package for rats. The expression of BDNF, TrkB, CREB and p-CREB in the auditory cortex of each group were measured with Western Blot analysis. RESULTS: ① Compared with the control group, the GPIAS values in 12 kHz, 16 kHz, 20 kHz and 28 kHz were significantly decreased in the model group (all P<0.05); compared with the model group, GPIAS values in 12 kHz, 16 kHz, 20 kHz and 28 kHz were significantly increased in the EAS group (all P<0.05). ② Compared with the control group, the expression of BDNF and p-CREB in the model group was significantly increased (P<0.01), and the expression of TrkB in the model group was significantly increased (P<0.05); the differences of expression of BDNF, TrkB, CREB and p-CREB between the model group and the EAS group had no statistics significance (all P>0.05). CONCLUSION: EAS could improve the GPIAS values of high-frequency background sound in tinnitus rats, which may be related with the upregulation of the BDNF/TrkB/CREB signaling pathway in the auditory cortex, leading to the reversion of the maladaptive plasticity.

Diterpenoids and sesquiterpenoids from the stem bark of Metasequoia glyptostroboides.

A phytochemical study on the stem bark of Metasequoia glyptostroboides led to the isolation of sixty-one diterpenoids and sesquiterpenoids, including seventeen previously undescribed compounds, metaglyptins A-Q. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, and 1H, 13C and 2D NMR). The absolute configurations of metaglyptins I, J, and O were determined by the ECD data and single-crystal X-ray diffraction analysis. The undescribed compounds were evaluated for their cytotoxicity against HeLa, AGS, and MDA-MB-231 cancer cell lines. The results revealed that metaglyptin A exhibited moderate cytotoxicity against MDA-MB-231 cell line with IC50 value of 20.02 µM.

Three new Lycopodium alkaloids from Lycopodium japonicum.

Three new Lycopodium alkaloids (1-3), together with 15 known alkaloids, were isolated from club moss Lycopodium japonicum. Their structures were determined by extensive spectroscopic analysis, including 1D and 2D NMR spectra. Compound 1 has an unusual ß-oriented methyl group substituted at C-15 and an α-hydroxy cyclopentenone moiety. All new alkaloids were evaluated for the inhibition of T-type calcium channel.

Expression of E-prostanoid receptors in nasal polyp tissues of smoking and nonsmoking patients with chronic rhinosinusitis.

BACKGROUND: Different inflammatory reactions have been observed in the polyp tissues of nonsmokers and smokers with chronic rhinosinusitis (CRS). E-prostanoid (EP) receptors play a role in the inflammatory processes. Cigarette smoke (CS) exposure regulates EP-receptor expression levels promoting inflammatory mediator release from various inflammatory cells. In this study, we characterize the EP-receptor expression profiles in the polyps of nonsmoking and smoking CRS patients to explore the possible role of CS in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: Polyp biopsies were obtained from 28 non-smoking and 21 smoking CRSwNP patients. Histopathological characteristics were observed under a light microscope. The prostaglandin E2 (PGE2), TNF-α, and IL-8 contents in polyp tissues were detected using enzyme-linked immunosorbent assay. Immunostaining was used to locate EP receptors in polyps. Messenger RNA and protein expression of EP receptors were examined using quantitative real-time polymerase chain reaction and Western blot, respectively. RESULTS: More severe inflammatory reactions occurred in polyp tissues of smoking CRSwNP patients. The PGE2, TNF-α, and IL-8 in tissue homogenate levels were significantly higher in smoking CRSwNP patients than those in nonsmoking CRSwNP patients. Moreover, the distribution of each EP receptor subtype was similar in both groups. Compared with the EP-receptor expression in nonsmokers, messenger RNA and protein of EP2 and EP4 receptor were significantly down-expressed in smoking patients, but EP1 and EP3 receptors did not show significant differences. CONCLUSION: CS exposure downregulates the expression levels of EP2 and EP4 receptors and stimulates the production of PGE2 and the proinflammatory cytokine IL-8 and TNF-α in polyp tissues of CRS patients. The down-expressed EP2 and EP4 receptors might be associated with severe inflammatory reactions in smoking CRSwNP patients.

Protostane-Type Triterpenoids from Alisma orientale.

Twenty-eight protostane triterpenoids, including a new degraded one (1), nine new ones (2 - 10), and two new natural ones (11 and 12), have been isolated from the dried rhizomes of Alisma orientale. Alisol R (1) was the first 20,21,22,23,24,25,26,27-octanorprotostane triterpenoid. The absolute configurations of 25-methoxyalisol F (2) and 16ß-hydroperoxyalisol B 23-acetate (3) were determined by X-ray diffraction analysis. In addition, alismaketone-B 23-acetate (28) showed potent vasorelaxant activity on endothelium-intact thoracic aorta rings precontracted with KCl.

Lycodine-Type Lycopodium Alkaloids from the Whole Plants of Huperzia serrata.

Three new lycodine-type Lycopodium alkaloids, namely 1-methyllycodine (1), 8α-hydroxy-15,16-dehydro-des-N-methyl-α-obscurine (2), N-methyl-16-hydroxyhuperzine B (3), and one new natural lycodine-type Lycopodium alkaloid, N-methylhuperzine A (4), along with 11 known analogues (5-15), were isolated from the whole plants of club moss Huperzia serrata. The structures of 1-4 were elucidated on the basis of NMR spectroscopic and mass spectrometry data. Among them, compound 1 was the first lycodine-type alkaloid possessing a methyl group at C-1. In addition, the structure of 5 was confirmed by the single-crystal X-ray crystallography data and its 13C NMR was reported for the first time in current study. Compounds 1-5 were tested their BACE1 inhibitory activity.

Guaiane-Type Sesquiterpenoids from Alismatis Rhizoma and Their Anti-inflammatory Activity.

Twelve guaiane-type sesquiterpenoids, including four new ones, 10-O-methyl-orientalol A (1), 10-O-ethyl-alismoxide (2), 3ß,4ß-expoxy-chrysothol (3), orientalol G (4), and a new norsesquiterpenoid, orientalol H (5), were isolated from Chinese Alismatis Rhizoma, the dried rhizome of Alisma orientale. The structures of new compounds were elucidated on the basis of spectroscopic data. Moreover, the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells of all compounds was tested.

Sesquiterpenoids from the twigs and leaves of Fokienia hodginsii.

A rare carotane-type sesquiterpenoid, forkienin A (1), a new eudesmane-type sesquiterpenoid, forkienin B (2), and a new natural eudesmane-type sesquiterpenoid, forkienin C (3), were isolated from the twigs and leaves of Fokienia hodginsii, along with eight known sesquiterpenoids. The structures of the new compounds were elucidated on the basis of their spectroscopic analysis, including 1D and 2D NMR methods. All compounds were evaluated for cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines.

Sauruchinenols A and B, unprecedented monocyclic diterpenes with new carbon skeleton from the aerial parts of Saururus chinensis.

Sauruchinenols A (1) and B (2), two novel monocyclic diterpenes with unique carbon skeleton, as well as two new structurally related diterpenes, sauruchinenols C (3) and D (4), were isolated from the aerial part of Saururus chinensis. Their structures were elucidated based on the analysis of spectroscopic data. A hypothetical biogenetic pathway for sauruchinenols A and B was proposed.