Biologically active isoquinoline alkaloids covering 2019-2022.

Isoquinoline alkaloids are an important class of natural products that are abundant in the plant kingdom and exhibit a wide range of structural diversity and biological activities. With the deepening of research in recent years, more and more isoquinoline alkaloids have been isolated and identified and proved to contain a variety of biological activities and pharmacological effects. In this review, we introduce the research progress of isoquinoline alkaloids from 2019 to 2022, mainly in the part of biological activities, including antitumor, antimicrobial, antidiabetic, antiviral, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, analgesic, and other activities. This study provides a clear direction for the rational development and utilization of isoquinoline alkaloids, suggesting that these alkaloids have great potential in the field of drug research.

Short pathways to highly active antimicrobial: structurally diverse polyamines derivatives from Amino-Aldehyde condensation strategy.

BACKGROUND: Chemical fungicides are the mainstay of plant disease control in agricultural production, but there are a very limited number of drugs that can effectively control plant diseases. Two series of secondary amine derivatives were synthesized using the diamine skeleton combined with saturated aromatic and aliphatic aldehydes, and their antibacterial and antifungal activities against plant pathogens were determined. In addition, the antimicrobial mechanism of the highly active compound A26 was preliminarily examined against Xanthomonas oryzae (Xoo). RESULTS: Compound A26 exhibited the highest antibacterial potency among all the target compounds, with MIC values of 3.12, 3.12 and 12.5 µg mL-1 against Xoo, Xanthomonas axonopodis pv. Citri and Pseudomonas sollamacearum, respectively. In addition, compound A26 had powerful curative and protective effects against Xoo at 200 µg mL-1 , and was better than the control agent Xinjunan. Preliminary mechanistic studies showed that compound A26 reduced the bacterial pathogenicity by targeting cell membranes and inhibiting the secretion of extracellular polysaccharides. Meanwhile, the toxicity of compound A26 to Human Embryonic Kidney 293 cells and Human Liver-7702 was similar to that of Xinjunan, and it had moderate toxicity according to the World Health Organization classification standard of oral exogenous toxicity, with an LD50 of 245.47 mg kg-1 . CONCLUSION: Secondary amines have efficient and broad-spectrum antibacterial activity against plant pathogenic bacteria and are expected to be a new class of candidate compounds for antibacterial drugs. © 2023 Society of Chemical Industry.

Efficacy of pterostilbene suppression on Aspergillus flavus growth, aflatoxin B1 biosynthesis and potential mechanisms.

Aspergillus flavus, a widespread saprotrophic filamentous fungus, could colonize agricultural crops with aflatoxin contamination, which endangers food security and the agricultural economy. A safe, effective and environmentally friendly fungicide is urgently needed. Pterostilbene, a natural phytoalexin originated from Pterocarpus indicus Willd., Vaccinium spp. and Vitis vinifera L., has been reported to possess excellent antimicrobial activity. More importantly, it is quite safe and healthy. In our screening tests of plant polyphenols for the inhibition of A. flavus, we found that pterostilbene evidently inhibited mycelial growth of Aspergillus flavus (EC50 = 15.94 µg/mL) and the inhibitory effect was better than that of natamycin (EC50 = 22.01 µg/mL), which is a natural product widely used in food preservation. Therefore, we provided insights into the efficacy of pterostilbene suppression on A. flavus growth, aflatoxin B1 biosynthesis and its potential mechanisms against A. flavus in the present study. Here, pterostilbene at concentrations of 250 and 500 µg/mL could effectively inhibit the infection of A. flavus on peanuts. And the biosynthesis of the secondary metabolite aflatoxin B1 was also inhibited. The antifungal effects of pterostilbene are exerted by inducing a large amount of intracellular reactive oxygen species production to bring the cells into a state of oxidative stress, damaging cellular biomolecules such as DNA, proteins and lipids and destroying the integrity of the cell membrane. Taken together, our study strongly supported the fact that pterostilbene could be considered a safe and effective antifungal agent against A. flavus infection.

Antimicrobial activity of natural and semi-synthetic carbazole alkaloids.

Since the first natural carbazole alkaloid, murrayanine, was isolated from Mwraya Spreng, carbazole alkaloid derivatives have been widely concerned for their anti-tumor, anti-viral and anti-bacterial activities. In recent decades, a growing body of data suggest that carbazole alkaloids and their derivatives have different biological activities. This is the first comprehensive description of the antifungal and antibacterial activities of carbazole alkaloids in the past decade (2012-2022), including natural and partially synthesized carbazole alkaloids in the past decade. Finally, the challenges and problems faced by this kind of alkaloids are summarized. This paper will be helpful for further exploration of this kind of alkaloids.

UV photodissociation dynamics of the acetone oxide Criegee intermediate: experiment and theory.

The photodissociation dynamics of the dimethyl-substituted acetone oxide Criegee intermediate [(CH3)2COO] is characterized following electronic excitation to the bright 1ππ* state, which leads to O (1D) + acetone [(CH3)2CO, S0] products. The UV action spectrum of (CH3)2COO recorded with O (1D) detection under jet-cooled conditions is broad, unstructured, and essentially unchanged from the corresponding electronic absorption spectrum obtained using a UV-induced depletion method. This indicates that UV excitation of (CH3)2COO leads predominantly to the O (1D) product channel. A higher energy O (3P) + (CH3)2CO (T1) product channel is not observed, although it is energetically accessible. In addition, complementary MS-CASPT2 trajectory surface-hopping (TSH) simulations indicate minimal population leading to the O (3P) channel and non-unity overall probability for dissociation (within 100 fs). Velocity map imaging of the O (1D) products is utilized to reveal the total kinetic energy release (TKER) distribution upon photodissociation of (CH3)2COO at various UV excitation energies. Simulation of the TKER distributions is performed using a hybrid model that combines an impulsive model with a statistical component, the latter reflecting the longer-lived (>100 fs) trajectories identified in the TSH calculations. The impulsive model accounts for vibrational activation of (CH3)2CO arising from geometrical changes between the Criegee intermediate and the carbonyl product, indicating the importance of CO stretch, CCO bend, and CC stretch along with activation of hindered rotation and rock of the methyl groups in the (CH3)2CO product. Detailed comparison is also made with the TKER distribution arising from photodissociation dynamics of CH2OO upon UV excitation.

Electronic Spectroscopy and Dissociation Dynamics of Vinyl-Substituted Criegee Intermediates: 2-Butenal Oxide and Comparison with Methyl Vinyl Ketone Oxide and Methacrolein Oxide Isomers.

The 2-butenal oxide Criegee intermediate [(CH3CH═CH)CHOO], an isomer of the four-carbon unsaturated Criegee intermediates derived from isoprene ozonolysis, is characterized on its first π* ← π electronic transition and by the resultant dissociation dynamics to O (1D) + 2-butenal [(CH3CH═CH)CHO] products. The electronic spectrum of 2-butenal oxide under jet-cooled conditions is observed to be broad and unstructured with peak absorption at 373 nm, spanning to half maxima at 320 and 420 nm, and in good accord with the computed vertical excitation energies and absorption spectra obtained for its lowest energy conformers. The distribution of total kinetic energy released to products is ascertained through velocity map imaging of the O (1D) products. About half of the available energy, deduced from the theoretically computed asymptotic energy, is accommodated as internal excitation of the 2-butenal fragment. A reduced impulsive model is introduced to interpret the photodissociation dynamics, which accounts for the geometric changes between 2-butenal oxide and the 2-butenal fragment, and vibrational activation of associated modes in the 2-butenal product. Application of the reduced impulsive model to the photodissociation of isomeric methyl vinyl ketone oxide reveals greater internal activation of the methyl vinyl ketone product arising from methyl internal rotation and rock, which is distinctly different from the dissociation dynamics of 2-butenal oxide or methacrolein oxide.

Photodissociation dynamics of methyl vinyl ketone oxide: A four-carbon unsaturated Criegee intermediate from isoprene ozonolysis.

The electronic spectrum of methyl vinyl ketone oxide (MVK-oxide), a four-carbon Criegee intermediate derived from isoprene ozonolysis, is examined on its second π* ← π transition, involving primarily the vinyl group, at UV wavelengths (λ) below 300 nm. A broad and unstructured spectrum is obtained by a UV-induced ground state depletion method with photoionization detection on the parent mass (m/z 86). Electronic excitation of MVK-oxide results in dissociation to O (1D) products that are characterized using velocity map imaging. Electronic excitation of MVK-oxide on the first π* ← π transition associated primarily with the carbonyl oxide group at λ > 300 nm results in a prompt dissociation and yields broad total kinetic energy release (TKER) and anisotropic angular distributions for the O (1D) + methyl vinyl ketone products. By contrast, electronic excitation at λ ≤ 300 nm results in bimodal TKER and angular distributions, indicating two distinct dissociation pathways to O (1D) products. One pathway is analogous to that at λ > 300 nm, while the second pathway results in very low TKER and isotropic angular distributions indicative of internal conversion to the ground electronic state and statistical unimolecular dissociation.

Photodissociation Dynamics of CH2OO on Multiple Potential Energy Surfaces: Experiment and Theory.

UV excitation of the CH2OO Criegee intermediate across most of the broad span of the (B 1A')-(X 1A') spectrum results in prompt dissociation to two energetically accessible asymptotes: O (1D) + H2CO (X 1A1) and O (3P) + H2CO (a 3A''). Dissociation proceeds on multiple singlet potential energy surfaces that are coupled by two regions of conical intersection (CoIn). Velocity map imaging (VMI) studies reveal a bimodal total kinetic energy release (TKER) distribution for the O (1D) + H2CO (X 1A1) products with the major and minor components accounting for ca. 40% and ca. 20% on average of the available energy (Eavl), respectively. The unexpected low TKER component corresponds to highly internally excited H2CO (X 1A1) products accommodating ca. 80% of Eavl. Full dimensional trajectory calculations suggest that the bimodal TKER distribution of the O (1D) + H2CO (X 1A1) products originates from two different dynamical pathways: a primary pathway (69%) evolving through one CoIn region to products and a smaller component (20%) sampling both CoIn regions enroute to products. Those that access both CoIn regions likely give rise to the more highly internally excited H2CO (X 1A1) products. The remaining trajectories (11%) dissociate to O (3P) + H2CO (a 3A'') products after traversing through both CoIn regions. The complementary experimental and theoretical investigation provides insight on the photodissociation of CH2OO via multiple dissociation pathways through two regions of CoIn that control the branching and energy distributions of products.

Synthesis, Electronic Spectroscopy, and Photochemistry of Methacrolein Oxide: A Four-Carbon Unsaturated Criegee Intermediate from Isoprene Ozonolysis.

Ozonolysis of isoprene, one of the most abundant volatile organic compounds in the earth's atmosphere, generates the four-carbon unsaturated methacrolein oxide (MACR-oxide) Criegee intermediate. The first laboratory synthesis and direct detection of MACR-oxide is achieved through reaction of photolytically generated, resonance-stabilized iodoalkene radicals with oxygen. MACR-oxide is characterized on its first π* ← π electronic transition using a ground-state depletion method. MACR-oxide exhibits a broad UV-visible spectrum peaked at 380 nm with weak oscillatory structure at long wavelengths ascribed to vibrational resonances. Complementary theory predicts two strong π* ← π transitions arising from extended conjugation across MACR-oxide with overlapping contributions from its four conformers. Electronic promotion to the 11ππ* state agrees well with experiment, and results in nonadiabatic coupling and prompt release of O 1D products observed as anisotropic velocity-map images. This UV-visible detection scheme will enable study of its unimolecular and bimolecular reactions under thermal conditions of relevance to the atmosphere.

Electrochemical metallization cell with solid phase tunable Ge2Sb2Te5 electrolyte.

Electrochemical metallization (ECM) cell kinetics are strongly determined by the electrolyte and can hardly be altered after the cell has been fabricated. Solid-state property tunable electrolytes in response to external stimuli are therefore desirable to introduce additional operational degree of freedom to the ECM cells, enabling novel applications such as multistate memory and reconfigurable computation. In this work, we use Ge2Sb2Te5(GST) as the electrolyte material whose solid state is switched from the amorphous(a) to the crystalline(c) phase thermally. Electrical heating too is readily achievable. The resistive switching characteristics of the cells with different GST phases are examined. The magnitude of the high resistance, the SET voltage and the on/off ratio are found to be considerably affected by the solid phase of GST, whereas the magnitude of the low resistance is least affected. Moreover, a transition from volatile to nonvolatile SET switching is only observed for c-GST based cell under prolonged voltage sweep, but not for a-GST based cell. This work provides a springboard for more studies on the manipulation of the ECM cell kinetics by tunable electrolyte and the resulting unprecedented device functionalities.

Clinical Characteristics of Patients Who Underwent Surgery for Genital Tract Malformations at Peking Union Medical College Hospital across 31 Years.

BACKGROUND: Female genital malformations represent miscellaneous deviations from normal anatomy. This study aimed to explore the clinical characteristics of patients who underwent surgery for genital tract malformations at Peking Union Medical College Hospital (PUMCH) during a 31-year period. METHODS: We retrospectively reviewed surgical cases of congenital malformation of the female genital tract at PUMCH for a 31-year period, analyzed the clinical characteristics of 1634 hospitalized patients, and investigated their general condition, diagnosis, and treatment process. RESULTS: The average patient age was 27.6 ± 9.9 years. The average ages of patients who underwent surgery for uterine malformation and vaginal malformation were 31.9 ± 8.8 years and 24.7 ± 9.0 years, respectively; these ages differed significantly (P < 0.01). Among patients with genital tract malformation, the percentages of vaginal malformation, uterine malformation, vulva malformation, cervical malformation, and other malformations were 43.9%, 43.5%, 7.4%, 2.3%, and 2.8%, respectively. Among patients with uterine malformation, 34.5% underwent surgery for the genital tract malformation, whereas in patients with vaginal malformation, the proportion is 70.6%; the difference between the two groups was statistically significant (P < 0.01). The percentage of complications of the urinary system in patients with vaginal malformations was 10.2%, which was statistically significantly higher than that (5.3%) in patients with uterine malformations (P < 0.01). CONCLUSIONS: Compared to patients with uterine malformations, patients with vaginal malformations displayed more severe clinical symptoms, a younger surgical age, and a greater need for attention, early diagnosis, and treatment. Patients with genital tract malformations, particularly vaginal malformations, tend to have more complications of the urinary system and other malformations than patients with uterine malformations.

[Clinical monitoring of myocardial injury in neonates with intrauterine distress].

OBJECTIVE: To investigate whether no asphyxia neonates with intrauterine distress are complicated with myocardial injury and determine the sensitive biochemical diagnostic parameters. METHODS: A total of 89 neonates born in the First Affiliated Hospital of Sun Yat-sen University from July 2009 to December 2009 were enrolled. Fifty-three fetal distress cases with Apgar score > 7 at 1 and 5 minutes were enrolled in the study group; while the rest 36 healthy neonates, whose Apgar score = 10 at 1 and 5 minutes, were the control group. Umbilical artery blood samples of all cases were collected for blood gas analysis and biochemical measurement. RESULTS: (1) pH (7.23 ± 0.07) and BE [(-4.8 ± 3.0) mmol/L] in the study group were significantly lower than pH (7.31 ± 0.03) and BE [(-2.1 ± 1.5) mmol/L ] in the control group(P < 0.05). The lactic acid of study group [(5.2 ± 2.3) mmol/L] was higher than that of the control group [(2.3 ± 1.1) mmol/L], and the difference was significant (P < 0.01). However, there was no significant difference between the two groups in PaO2 [(16.2 ± 7.9) mm Hg (1 mm Hg = 0.133 kPa) vs. (17.5 ± 6.7) mm Hg] and PaCO2 [(54.0 ± 11.2) mm Hg vs. (48.5 ± 5.4) mm Hg; P > 0.05]. (2) The level of CK-MB in neonates with fetal distress[ (48 ± 59) U/L] was significantly higher than that of healthy neonates [(36 ± 27) U/L]. However, no significant difference was found in CK [(194 ± 73) U/L vs. (162 ± 95) U/L] and BNP levels [(519 ± 309) ng/L vs. (481 ± 216) ng/L; P > 0.05]. (3) Spearman rank correlation analysis showed that CK-MB level was negatively correlated with pH (r = -0.296, P < 0.05) and BE (r = -0.318, P < 0.05) of umbilical artery blood, while BNP level was positively correlated with umbilical lactic acid (r = 0.278, P < 0.05). No correlation was found between other parameters (P > 0.05). CONCLUSIONS: Intrauterine distress without neonatal asphyxia had effect on fetal myocardial injury. CK-MB can be used as a sensitive parameter for monitoring the development of myocardial injury. The severity of myocardial injury was related to fetal acidosis.

[New method of multi-components quantitation by one marker new method for quality evaluation of Guanmaikang capsula].

OBJECTIVE: To establish a new quality evaluation method for traditional Chinese medicine preparations, using one chemical reference substance to calcutate multi-components simultaneously. METHOD: Employed puerarin as the maker component, puerarin relative correction factors (RCF) of salvianolic acid B to puerarin and paidzein to puerarin were calcatated in the chromatographic conditions for determination of the three components in Guanmaikang capsules. The contents of Puerarin were determined by external standard method, and those of salvianolic acid B and paidzein were calculated by puerarin and their RCF. The accuracy of the new method was evaluated by comparing the calculated contents with the determined. RESULT: The analysis methods were established, and it has been no significant difference between the calculated contents and determined contents. CONCLUSIONS: The method can control the components without providing salvianolic acid B and paidzein reference. It is to be a suitable quality evaluation pattern for TCM Preparation.

[Hydroquinone inhibits NF-kappaB expression in human bone marrow stromal cells in vitro].

This study was aimed to investigate whether hydroquinone (HQ) can inhibit NF-kappaB expression activated by phorbol myristate acetate (PMA), and to explore the relationship between the mechanism and the hematology toxicity of benzene tentatively. The human bone marrow stromal cells (BMSC) were harvested by in vitro culture and their change of morphology were observed. The activity and protein expression of NF-kappaB p65 extracted from those BMSC were measured with immunohistochemistry and TransAM P65 kit. The results showed that in cells exposed to HQ, P65 transferred from cell nucleus to cytoplasma around cell nucleus and its concentration lowered by immunohistochemistry. And TransAM P65 kit assay revealed that HQ effects at different concentrations were distinctive at respective time. The detected parameters in 100 micromol/L HQ group were significantly different from control group after exposure for 72 hours. But the parameters at different time in micromol/L HQ group were not obviously different. It is concluded that hydroquinone can inhibit NF-kappaB activated by PMA in BMSCs culture. This kind of inhibitory action correlated with the concentration of HQ and exposure time.