Microflow High-p,T Intensification of Vitamin D3 Synthesis Using an Ultraviolet Lamp

Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing a plethora of opportunities to synthetic organic chemists. However, performing a photochemical transformation can be quite a challenge because of various issues related to the delivery of photons. These challenges have barred the widespread adoption of photochemical steps in the chemical industry. However, in the past decade, several technological innovations have led to more reproducible, selective, and scalable photoinduced reactions. Herein, we provide a comprehensive overview of these exciting technological advances, including flow chemistry, high-throughput experimentation, reactor design and scale-up, and the combination of photo- and electro-chemistry.

Vitamin D deficiency in pregnant women: Influenced by multiple risk factors and increase the risks of spontaneous abortion and small-for-gestational age

OBJECTIVE

To analyze the level of vitamin D and its influencing factors in pregnant women, and to explore the influence of vitamin D deficiency on common adverse pregnancy outcomes in pregnant women, providing evidence for prevention and intervention of vitamin D deficiency in pregnant women.

METHODS

The basic data and blood samples of pregnant women in our hospital from January 2019 to June 2020 were collected, and the 25-(OH) D levels of the serum samples were detected. Then the vitamin D levels and its influencing factors were analyzed, and the relationships between vitamin D levels and common adverse pregnancy outcomes in the pregnant women as well as the incidence of small-for-gestational-age newborns were analyzed.

RESULTS

The vitamin D deficiency rate, insufficiency rate and sufficiency rate of pregnant women were 83.28%, 15.36%, and 1.36% respectively, with vast majority of the pregnant women in a state of vitamin D deficiency. Analysis of the influencing factors on the vitamin D level of pregnant women showed "28 weeks ≤ gestational age ≤32 weeks, summer and autumn, high school education and above, weekly time outdoors ≥10 hours, supplement of vitamin D and trace elements during pregnancy" were protective factors for vitamin D sufficiency in pregnant women. Linear correlation analysis showed the vitamin D level of pregnant women was highly positively correlated with temperature, the higher the temperature, the higher the vitamin D level (r = 0.907, t = 6.818, P < .001). The level of vitamin D in pregnant women was related to the occurrence of spontaneous abortion and small-for-gestational age (SGA), with the incidence of spontaneous abortion and SGA in the "vitamin D deficiency group" higher than those of other groups (P = .018, P = .016).

CONCLUSIONS

The vitamin D level of pregnant women in this area is relatively low, which is affected by multiple factors such as gestational age, season, education level of pregnant women, weekly time outdoors, vitamin D and trace element supplement during pregnancy. Low vitamin D levels can increase the risk of spontaneous abortion and SGA in pregnant women, so relevant measures should be adopted to improve the vitamin D status of pregnant women.

Automated High-Pressure Atline Analysis of Photo-High-P,T Vitamin D3 Microfluidic Synthesis

Process analytical technology has become a relevant topic in both industry and academia as a mechanism to control process quality by measuring critical parameters; being mainly applied in pharmaceutical industry. An emerging topic is process monitoring with subsequent process automation in flow chemistry using inline, online and atline analyzers. Flow chemistry often deliberately and favorably uses harsh conditions (termed Novel Process Windows) to achieve process intensification which raises the need for sampling under these conditions. This demands for setting in place a stabilization of the sample before exposing it to the processing. Ignoring this may result in being unable to use inline/online analytics and posing the need for a separation step before quantitative analysis, leaving atline analysis as the only feasible option. That means that sampling and connected operations need also to be automated. This is where this study sets in, and this is enabled by a modified high-performance liquid chromatography (HPLC) autosampler coupled to the photo-high-p,T flow synthesis of vitamin D3. It shows that sampling variables, such as decompression speed, can be even more critical in terms of variability of results than process variables such as concentration, pressure, and temperature. The modification enabled the autosampler fully automated and unattended sampling from the reactor and enabled pressure independent measurements with 89% accuracy, &gt;95% reproducibility, and &gt;96% repeatability, stating decompression speed as the primary responsibility for measurements’ uncertainty.

Continuous Flow Photochemistry for the Preparation of Bioactive Molecules

The last decade has witnessed a remarkable development towards improved and new photochemical transformations in response to greener and more sustainable chemical synthesis needs. Additionally, the availability of modern continuous flow reactors has enabled widespread applications in view of more streamlined and custom designed flow processes. In this focused review article, we wish to evaluate the standing of the field of continuous flow photochemistry with a specific emphasis on the generation of bioactive entities, including natural products, drugs and their precursors. To this end we highlight key developments in this field that have contributed to the progress achieved to date. Dedicated sections present the variety of suitable reactor designs and set-ups available; a short discussion on the relevance of greener and more sustainable approaches; and selected key applications in the area of bioactive structures. A final section outlines remaining challenges and areas that will benefit from further developments in this fast-moving area. It is hoped that this report provides a valuable update on this important field of synthetic chemistry which may fuel developments in the future.

Everything Flows: Continuous Micro-Flow for Pharmaceutical Production

The pre-Socratic philosophers made the first honest attempt, at least in the western world, to describe natural phenomena in a rudimentary scientific manner and to exploit those for technological application [1]. Pythagoras of Samos (570–495 BC) was an Ionian Greek philosopher and the first to actually call himself a “philosopher”. He was credited with many mathematical and scientific discoveries, including the Pythagorean theorem, Pythagorean tuning, the five regular solids, the theory of proportions, and the sphericity of the Earth. The Pythagorean triple is also well-known. Heraclitus of Ephesus (535–475 BC) was famous for his insistence on ever-present change as the fundamental essence of the universe, as stated in the famous saying “panta rhei” —everything flows.

Continuous-Flow In-Line Solvent-Swap Crystallization of Vitamin D3

A continuous tandem in-line evaporation–crystallization is presented. The process includes an in-line solvent-swap step, suitable to be coupled to a capillary based cooler. As a proof of concept, this setup is tested in a direct in-line acetonitrile mediated crystallization of Vitamin D₃. This configuration is suitable to be coupled to a new end-to-end continuous microflow synthesis of Vitamin D₃. By this procedure, vitamin particles can be crystallized in continuous flow and isolated using an in-line continuous filtration step. In one run in just 1 min of cooling time, ∼50% (w/w) crystals of Vitamin D₃ are directly obtained. Furthermore, the polymorphic form as well as crystals shape and size properties are described in this paper.