Glaucarubinone from Simarouba glauca DC. as a potential biocontrol agent for mosquito vector management

The study explored Simarouba glauca DC. for mosquito larvicidal potential by performing bioactivity-guided chemical investigation of its root extract resulting in isolation of the known bioactive metabolite glaucarubinone (1). Mosquito larvicidal activity of glaucarubinone (1) against the three vector species viz. Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined using a modified WHO 2005 protocol. It was observed that Culex quinquefasciatus larvae were the most susceptible species with LC50 13.88 ppm and LC90 70.01 ppm followed by Aedes aegypti and Anopheles stephensi at 24 h of exposure. The mode of action as observed microscopically is the lysis of midgut and thorax cells of the third instar larvae. The crystal structure of the glaucarubinone (1) is reported for the first time using X-ray crystallography. This phytochemical product has the potential to act as a green alternative to existing chemical-based insecticides for integrated vector management.

Probing the stereochemical structure of carenes using Raman and Raman optical activity spectroscopy

The great interest in terpene compounds such as 2-, 3- and 4-carene is due to their undeniable biological activity. However, in recent years, there has been increasing interest in carenes in the context of biofuels. The current growing and insatiable demand for petroleum fuels creates an area for alternative biofuels. Research shows that natural products, which contain compounds from the carenes family, such as pine oil or turpentine (3-carene can constitute up to 70% of the composition of turpentine), can be successfully used as biofuels or additives in biofuels. In this work, both experimental and calculated (DFT/B3LYP/aug-cc-pVDZ) Raman and ROA (Raman optical activity) spectra of 1S,3R-cis-4-carene and 1S,3S-trans-4-carene were reported and analyzed for the first time. Then these spectra were compared with Raman and ROA spectra of other chiral members of the carenes family (1S-2-carene and 1S-3-carene). This knowledge about the spectra of individual carenes made it possible to identify (+)-1S-3-carene in selected samples of pine essential oil from the needles of Pinius sylvestris (Scots pine).

Bioguided Phytochemical Study of Ipomoea cairica Extracts with Larvicidal Activity against Aedes aegypti

Vector-borne diseases, such as those transmitted by Aedes aegypti, are a constant threat to inhabitants of tropical regions of the planet. Synthetic chemicals are commonly used as a strategy to control them; however, these products are known to persist in ecosystems and drive the appearance of resistance genes in arthropod vectors. Thus, the use of natural products has emerged as an environmentally friendly alternative in integrated vector control strategies. The present bioguided study investigated the larvicidal potential of Ipomoea cairica extracts, fractionated using thin-layer and open-column chromatography, because this species has been shown to exert larvicidal effects on the genus Aedes. The objective of this study was to evaluate the nonvolatile components in ethanolic extract of I. cairica stems as a potential natural larvicidal, and coumarins, such as 7-hydroxy-6-methoxychromen-2-one (scopoletin) and 7-hydroxychromen-2-one (umbelliferone), were identified as major compounds; however, they were not shown to be responsible for the larvicidal activity. Based on the results of the larvicidal action tests, these coumarins are not directly responsible for the larvicidal activity, but this activity might be attributed to a synergistic effect of all the compounds present in the most active secondary fraction, called F.DCM, which had an LC₅₀ value of 30.608 mg/L. This type of study has yet not been conducted in the region; therefore, it is an important contribution to recognizing a natural and easy-to-cultivate source of vector control, such I. cairica.

Plant-derived alkaloids acting on dengue virus and their vectors: from chemistry to pharmacology

Dengue is a mosquito-borne viral infection, with its prevention and control depending on effective vector control measures. At present, dengue virus (DENV) is an epidemic in more than 100 countries of Southeast Asia, Africa, Eastern Mediterranean, the Americas and the Western Pacific. Several alkaloids isolated from natural herbs can serve as a reservoir for antiDENV drug development. Traditionally, plant extracts rich in alkaloids are used for the treatment of fever and have also revealed antimicrobial activity against various pathogenic bacteria, fungi and virus. The present narrative review collates the literature-based scenario of alkaloids and derivatives acting on DENV. The mechanism of action of such alkaloids with antiDENV and vector activity is also discussed.

Conifers Phytochemicals: A Valuable Forest with Therapeutic Potential

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers' phytochemicals and illustrates their potential role as drugs.