Introduction

Veratraldehyde (also known as 3,4-Dimethoxy Benzaldehyde) is an important compound isolated from fruits such as mint, ginger, bourbon vanilla and raspberry. It has a very sweet, woody, vanilla and heliotrope flavor and is widely used in perfume, agrochemical and pharmaceutical industries. In addition, veratraldehyde is also used as a food additive, odorant and redox cycler.

Figure 1 Characteristics of Veratraldehyde

Synthesis Methods

Veratraldehyde can be prepared by continuous treatment of resveratrol with a catalyst system consisting of SBA-15/TiO2/SO4/Ni. The results showed that the selectivity and yield of veratraldehyde were the highest under the optimal reaction conditions (including the reaction time of catalyst SBA-15/TiO2/SO4/Ni(8%) for 2 hours). This catalyst worked best, with a selectivity and conversion of veratraldehyde of 100% and 99.5%, respectively.

Applications

Mosquito Repellent Effect

The study found that veratraldehyde and WJ-1041 formulations containing 10% veratraldehyde had repellent effects against female Aedes albopictus and Culex pipiens pallens mosquitoes and nymphs of Haemaphysalis longicornis ticks. Veratraldehyde had similar or lower repellency than n,n-diethyl-m-toluamide (DEET) against Aedes albopictus, but was more active than DEET against Haemaphysalis longicornis ticks. The 10% veratraldehyde solution was comparable to 20% DEET in repellency against both mosquito species. When the WJ-1041 formulation (10% veratraldehyde) and 10% DEET were compared for repellency against Culex pipiens pallens, Aedes albopictus, and Haemaphysalis longicornis, both showed similar repellency and complete protection time (CPT) values. However, the effects varied slightly depending on the insect tested. Veratraldehyde has little or no skin absorption. The pharmacokinetic parameters (Cmax and Tmax) of veratraldehyde in rat blood samples were not different from those of the control group. Based on these results, veratraldehyde has a high probability of being commercialized as a repellent against infectious pests in the near future.

Pharmaceutical intermediates

Veratraldehyde can be used as an intermediate in the synthesis of some drugs, including aminoquinacine, hoquizil, piquizil, prazosin, quinazoline, thiapamil, toborine, verazine, and vertrobutin.

References

[1]Molleti J, Yadav G D. Green synthesis of veratraldehyde using potassium promoted lanthanum–magnesium mixed oxide catalyst[J]. Organic Process Research & Development, 2017, 21(7): 1012-1020.

[2]Dhinagaran G, Harichandran G, Suvaitha S P, et al. The catalytic activity of SBA-15 supported CuO for the selective oxidation of veratryl alcohol to veratraldehyde[J]. Molecular catalysis, 2022, 528: 112454.

[3] SOON-IL KIM. Repellency of Veratraldehyde (3,4-Dimethoxy Benzaldehyde) against Mosquito Females and Tick Nymphs[J]. Applied Sciences-Basel, 2021, 11 1: 4861. DOI:10.3390/APP11114861.

[4] N. YOGANANDHAN . TiO2/SO4/Ni@SBA-15 catalysts for the selective oxidation of veratryl alcohol to veratraldehyde in a continuous reactor[J]. Molecular Catalysis, 2023, 546: Article 113250. DOI:10.1016/j.mcat.2023.113250