The untapped potential of spermidine alkaloids: Sources, structures, bioactivities and syntheses

Spermidine alkaloids are a kind of natural products possessing an aliphatic triamine structure with three or four methylene groups between two N-atoms. Spermidine alkaloids exist in plants, microorganisms, and marine organisms, which usually form amide structures with cinnamic acid or fatty acid derivatives. Their unique structures showed a wide range of biological activities such as neuroprotective, anti-aging, anti-cancer, antioxidant, anti-inflammatory, and antimicrobial. In order to better understand the research status of spermidine alkaloids and promote their applications in human health, this paper systematically reviewed the biological sources, structures, pharmacological actions, and synthetic processes of spermidine alkaloids over the past two decades. This will help to open up new pharmacological investigation fields and better drug design based on these spermidine alkaloids.

Opioid Prescribing and Use Among Cancer Survivors: A Mapping Review of Observational and Intervention Studies

CONTEXT

Recent years show a sharp increase in research on opioid use among cancer survivors, but evidence syntheses are lacking, leaving knowledge gaps. Corresponding research needs are unclear.

OBJECTIVES

To provide an evidence synthesis.

METHODS

We searched PubMed and Embase, identifying articles related to cancer, and opioid prescribing/use published through September 2020. We screened resulting titles/abstracts. Relevant studies underwent full-text review. Inclusion criteria were quantitative examination of and primary focus on opioid prescribing or use, and explicit inclusion of cancer survivors. Exclusion criteria included end-of-life opioid use and opioid use as a secondary or downstream outcome (for intervention studies). We extracted information on the opioid-related outcome(s) examined (including definitions and terminology used), study design, and methods.

RESULTS

Research returned 16,591 articles; 296 were included. Only 22 of 296 studies evaluated an intervention. There were 105 studies evaluating outcomes indicative of potentially high-risk, nonrecommended, or avoidable opioid use, e.g., continuous use-described as chronic use, prolonged use, and persistent use (n = 17); use after completion of curative-intent treatment-described as chronic opioid use, long-term opioid use, persistent opioid use, prolonged opioid use, continued opioid use, late opioid use, post-treatment opioid use (n = 27); use of opioids concurrent with other potentially high-risk medications (n = 13), and opioid misuse (n = 14).

CONCLUSIONS

We found lack of consistency in the measurement of and terms used to describe similar opioid use outcomes, and a lack of interventional research targeting well-documented patterns of potentially nonrecommended, potentially avoidable, or potentially high-risk opioid prescribing or use.

A practicable method to prepare nitrated proteins with peroxynitrite and low concentration of sodium hydroxide

Peroxynitrite is an ion acting as a powerful oxidant and nucleophile, which plays a key role in the inflammation and aging process by nitrating tyrosine or tryptophan residues of the proteins. Nitration of a target protein is considered to be a proper method to study the behavioral change of the proteins being nitrated. The commonly used methods for peroxynitrite preparation in vitro usually contain high concentration of sodium hydroxide, which easily induces hydrolysis of target proteins. Accordingly, the method for peroxynitrite preparation was optimized in vitro by changing the sequence of hydrochloric acid and sodium hydroxide added. After different amount of hydrochloric acid added to the system following sodium nitrite, peroxynitrite can be yielded in a concentration up to 60 mM with sodium hydroxide as low as 17 mM. More importantly, biological activity of the target protein was well maintained after protein nitration since low sodium hydroxide was used.

Chemistry of the Secondary Metabolites of Termites

Isolation, structure determination, synthesis, and biochemistry of the low-molecular-weight compounds of the secretion of exocrine glands of termites are described, with an emphasis on pheromones and defensive compounds.