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A pair of undescribed dihydrobenzofuran neolignan enantiomers, (+/−)-phybrenan A (1a/1b), two new benzofuran neolignans, phybrenan B and C (2 and 3), along with four known neolignans (4 − 7) were obtained from the plants of Phyllanthodendron breynioides P. T. Li. The planar structures of all isolates were demonstrated by the analysis of detailed spectroscopic evidence (NMR, HRMS, and IR), and the absolute configurations of novel neolignans were elucidated by combined calculated and experimental ECD data analysis. The neuroprotective activities of all benzofuran neolignans against sodium nitroprusside (SNP)-induced cell death were examined in rat pheochromocytoma PC12 cells. The results exhibited that three compounds (4 − 6) possessed remarkable neuroprotective activities at 10 µM, better than the positive drug edaravone. [ABSTRACT FROM AUTHOR]

Marine toxins (MTs) are a group of structurally complex natural products with unique toxicological and pharmacological activities. In the present study, two common shellfish toxins, okadaic acid (OA) (1) and OA methyl ester (2), were isolated from the cultured microalgae strain Prorocentrum lima PL11. OA can significantly activate the latent HIV but has severe toxicity. To obtain more tolerable and potent latency reversing agents (LRAs), we conducted the structural modification of OA by esterification, yielding one known compound (3) and four new derivatives (4–7). Flow cytometry-based HIV latency reversal activity screening showed that compound 7 possessed a stronger activity (EC50 = 46 ± 13.5 nM) but was less cytotoxic than OA. The preliminary structure–activity relationships (SARs) indicated that the carboxyl group in OA was essential for activity, while the esterification of carboxyl or free hydroxyls were beneficial for reducing cytotoxicity. A mechanistic study revealed that compound 7 promotes the dissociation of P-TEFb from the 7SK snRNP complex to reactivate latent HIV-1. Our study provides significant clues for OA-based HIV LRA discovery. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum stress (ERS) is involved in the pathological process of vascular dementia (VD). GJ-4 is extracted from Gardenia jasminoides J. Ellis and has been reported to have protective roles in ischemia-related brain damage. However, the role of GJ-4 in ERS has not been elucidated. We established a VD rat model through bilateral common carotid arteries occlusion (2-VO). The rats were intragastrically administrated with GJ-4 (10, 25, and 50 mg/kg) and nimodipine (10 mg/kg). Data from a Morris water maze test showed that GJ-4 could significantly alleviate learning and memory deficits in VD rats. Nissl and cleaved caspase-3 staining revealed that GJ-4 can inhibit apoptosis and thus exert a protective role in the brain of 2-VO rats. Western blot results suggested that GJ-4 significantly reduced ERS-related protein expression and inhibited apoptosis through suppression of the PERK/eIF2 α /ATF4/CHOP signaling pathway. For in vitro studies, the oxygen-glucose deprivation (OGD) SH-SY5Y model was employed. Western blot and Hoechst 33342/PI double staining were utilized to explore the effects of crocetin, the main active metabolite of GJ-4. Like GJ-4 in vivo, crocetin in vitro also decreased ERS-related protein expression and inhibited the activation of the PERK/eIF2 α /ATF4/CHOP signaling pathway. Thus, crocetin exerted similar protective roles on OGD challenged SH-SY5Y cells in vitro. In summary, GJ-4 and crocetin reduce the ERS in the brain of VD rats and SY5Y cells subjected to OGD and inhibit neuronal apoptosis through suppression of the PERK/eIF2 α /ATF4/CHOP pathway, suggesting that GJ-4 may be useful for the treatment of VD. [ABSTRACT FROM AUTHOR]

PurposeTo develop a predictive model using machine learning for levothyroxine (L-T4) dose selection in patients with differentiated thyroid cancer (DTC) after resection and radioactive iodine (RAI) therapy and to prospectively validate the accuracy of the model in two institutions.MethodsA total of 266 DTC patients who received RAI therapy after thyroidectomy and achieved target thyroid stimulating hormone (TSH) level were included in this retrospective study. Sixteen clinical and biochemical characteristics that could potentially influence the L-T4 dose were collected; Significant features correlated with L-T4 dose were selected using machine learning random forest method, and a total of eight regression models were established to assess their performance in prediction of L-T4 dose after RAI therapy; The optimal model was validated through a two-center prospective study (n=263).ResultsSix significant clinical and biochemical features were selected, including body surface area (BSA), weight, hemoglobin (HB), height, body mass index (BMI), and age. Cross-validation showed that the support vector regression (SVR) model was with the highest accuracy (53.4%) for prediction of L-T4 dose among the established eight models. In the two-center prospective validation study, a total of 263 patients were included. The TSH targeting rate based on constructed SVR model were dramatically higher than that based on empirical administration (Rate 1 (first rate): 52.09% (137/263) vs 10.53% (28/266); Rate 2 (cumulative rate): 85.55% (225/263) vs 53.38% (142/266)). Furthermore, the model significantly shortens the time (days) to achieve target TSH level (62.61 ± 58.78 vs 115.50 ± 71.40).ConclusionsThe constructed SVR model can effectively predict the L-T4 dose for postoperative DTC after RAI therapy, thus shortening the time to achieve TSH target level and improving the quality of life for DTC patients.

Chromatographic fractionation of the EtOH extracts of the marine-derived fungus Aspergillus versicolor A18 has led to the isolation of 11 homo/hetero-dimers of aromatic bisabolane sesquiterpenoids including eight diphenyl ether-coupled aromatic bisabolanes (1a/1b and 5–10) and three homodimers (2–4), together with their monomers including three aromatic bisabolanes (11–13) and two diphenyl ethers (14 and 15). Their structures and absolute configurations were elucidated by extensive spectroscopic analysis including HRESIMS, 1D/2D NMR, calculated ECD, and the optical rotatory data. Among the four new compounds, (+/−)-asperbisabol A (1a/1b), asperbisabol B (2), and asperbisabol C (3), the enantiomers 1a and 1b represent an unprecedented skeleton of diphenyl ether-coupled aromatic bisabolane sesquiterpenoids with a spiroketal core moiety. The neuroprotective effects of selected compounds against sodium nitroprusside (SNP)-induced injury were evaluated in PC12 cells by the MTT assay. Five compounds (1a, 6, and 8–10) showed remarkable neuroprotective activities at 10 μM, being more active than the positive control edaravone. [ABSTRACT FROM AUTHOR]

Two new triterpenoids, 3β-hydroxytirucall-7,25-dien-24-one (1) and 3β-acetoxytirucall-7,23,25-triene (2), along with one new sesquiterpenoid, alloaromadendrane-12α,14β-dioic acid (3), were isolated from the vines and leaves of Chonemorpha megacalyx Pierre. Their structures were established on the basis of extensive spectroscopic data. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the leaves and twigs of Croton yanhuii led to the isolation of seven highly modified nor -clerodane diterpenoids (1 – 7), including three new ones, croyanoids A-C (1 – 3), along with four known analogues (4 – 7). Compound 1 incorporates a 5,12-epoxy ring, forming a unique cage-like, 6/6/6/5-fused tetracyclic ring system. Their structures were established by extensive spectroscopic analysis, and the absolute configurations of 1 – 4 were determined by a combination of circular dichroism (CD) analysis and single-crystal X-ray diffraction. All compounds were tested in an array of bioassays, but were inactive. Crotoeurin A (7), a nor -clerodane dimer with a high yield of 0.2‰ isolated in current study, was considered as a chemotaxonomic marker for this species. [Display omitted] [ABSTRACT FROM AUTHOR]

The quaternary selenide Ba 4 GeSb 2 Se 11 was prepared by a high-temperature solid state reaction method. Ba 4 GeSb 2 Se 11 crystallizes in an acentric orthorhombic space group Cmc 2 1 with the lattice constants a = 9.370(11) Å, b = 25.850(0) Å, and c = 8.798(10) Å. The compound is composed of a [SbSe 3 ] 3- trigonal pyramid, [GeSbSe 5 ] 3- dimers, V-shaped Se 3 2- , and the adjacent Ba 2+ ions. It has indirect band gap of 1.35 eV and exhibits a second harmonic generation intensity of about 0.2 times that of the benchmark compound AgGaS 2 at the same particle size. Interestingly, theoretical analyses show that the central Se atom of Se 3 2- has the largest contribution (8.1%) to d 31 compared to that of other Se atoms, which may be due to its easy swing in the a -axis direction.

Pregnane X receptor (PXR) that orchestrates the intricate network of xeno- and endobiotic metabolism is considered as a promising therapeutic target for cholestasis. In this study, the human PXR (hPXR) agonistic bioassay-guided isolation of Euphorbia lathyris followed by the structural modification led to the construction of a lathyrane diterpenoid library ( 1 - 34 ). Subsequent assay of this library led to the identification of a series of potent hPXR agonists, showing better efficacy than that of typical hPXR agonist, rifampicin. The most active compound, 8 , could dose-dependently activate hPXR at micromolar concentrations and significantly up-regulate the expressions of PXR downstream genes CYP3A4 , CYP2B6 , and MDR1 . The structure-activity relationships (SARs) studied in combination with molecular modeling suggested that acyloxy at C-7 and the presence of 14-carbonyl were essential to the activity. These findings suggested that lathyrane diterpenoids could serve as a new type of hPXR agonist for future anticholestasis drug development., Competing Interests: The authors declare no competing financial interest., (© 2021 American Chemical Society.)

Crotonpenoids A ( 1 ) and B ( 2 ), two highly modified clerodane diterpenoids featuring a new 10-(butan-2-yl)-1,6,12-trimethyltricyclo[7.2.1.0 2,7 ]dodecane skeleton, were isolated from the leaves and twigs of Croton yanhuii . Their structures including the absolute configurations were determined by spectroscopic analysis, single-crystal X-ray diffraction, and biomimetic semisynthesis. Compounds 1 and 2 exhibited an agonistic effect on pregnane X receptor at 10 μM.

Mid- and far-infrared nonlinear optical (MFIR NLO) materials are important in modern laser technologies. However, it is very challenging to develop materials that can achieve a subtle balance between the key requirements, such as large NLO response, high laser-induced damage threshold (LIDT), wide IR transparency, and phase-matching. In this work, a new wide IR transparency (0.38-15.3 μm) NLO crystal Ba 10 In 6 Zn 7 S 26 (SS26) is synthesized. Further, its composite system Ba 10 In 6 Zn 7 S 26 - nZnS is synthesized by eutectic reaction. In particular, Ba 10 In 6 Zn 7 S 26 -14ZnS (SS40) shows excellent balanced NLO performance that includes a large band gap of 3.05 eV, high LIDT (13.3 × AgGaS 2 ), large second harmonic generation (SHG) response (2.1 × AgGaS 2 at 2050 nm, 5.2 × KDP at 1064 nm), and wide optical transmission window (0.37-15.4 μm). Importantly, the phase-matching condition is realized for SS40 by interfaces formed between the crystal face (112) of matrix SS26 and the crystal face (111) of reinforcement cubic ZnS by topological chemical reaction, and the NLO performance can be tuned by different concentrations of ZnS. First-principles simulations are employed to study NLO properties of SS26 and the interfaces. This work demonstrates that SS40 is a promising MFIR NLO material, and tuning components of the composite material system is a useful way to develop new MFIR NLO materials with excellent comprehensive performance.