Chemistry and Bioactivity of Croton Essential Oils: Literature Survey and Croton hirtus from Vietnam.

Using essential oils to control vectors, intermediate hosts, and disease-causing microorganisms is a promising approach. The genus Croton in the family Euphorbiaceae is a large genus, with many species containing large amounts of essential oils, however, essential oil studies are limited in terms of the number of Croton species investigated. In this work, the aerial parts of C. hirtus growing wild in Vietnam were collected and analyzed by gas chromatography/mass spectrometry (GC/MS). A total of 141 compounds were identified in C. hirtus essential oil, in which sesquiterpenoids dominated, comprising 95.4%, including the main components ß-caryophyllene (32.8%), germacrene D (11.6%), ß-elemene (9.1%), α-humulene (8.5%), and caryophyllene oxide (5.0%). The essential oil of C. hirtus showed very strong biological activities against the larvae of four mosquito species with 24 h LC50 values in the range of 15.38-78.27 µg/mL, against Physella acuta adults with a 48 h LC50 value of 10.09 µg/mL, and against ATCC microorganisms with MIC values in the range of 8-16 µg/mL. In order to provide a comparison with previous works, a literature survey on the chemical composition, mosquito larvicidal, molluscicidal, antiparasitic, and antimicrobial activities of essential oils of Croton species was conducted. Seventy-two references (seventy articles and one book) out of a total of two hundred and forty-four references related to the chemical composition and bioactivity of essential oils of Croton species were used for this paper. The essential oils of some Croton species were characterized by their phenylpropanoid compounds. The experimental results of this research and the survey of the literature showed that Croton essential oils have the potential to be used to control mosquito-borne and mollusk-borne diseases, as well as microbial infections. Research on unstudied Croton species is needed to search for species with high essential oil contents and excellent biological activities.

Bioactive compounds from the aerial parts of Hypericum sampsonii.

Hypericum sampsonii is an important medicinal plant used in Vietnam to treat many diseases such as backache, burns, diarrhea, and swelling. In order to study the chemical constituents in the aerial parts of H. sampsonii, five compounds, including two xanthones (1-2), and three benzophenones (3-5) were isolated from the aerial parts of the H. sampsonii with various chromatographic separations. Their chemical structures were established on the basis of spectroscopic data such as 1D- and 2D-NMR, HR-ESI-MS. Their anti-inflammatory activities were investigated by measuring nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 cells. Moreover, the DPPH radical scavenging was evaluated. As the obtained results, compound 5 showed the strongest inhibitory activity against LPS-stimulated NO production in RAW264.7 cells with IC50 value ranging from 2.00 ± 0.34 µM.

Identification Of Potential Cytotoxic Inhibitors From Physalis Minima.

A phytochemical investigation of Physalis minima led to the isolation of six withanolides, including withanolide E (1), withaperuvin C (2), 4ß-hydroxywithanolide E (3), 28-hydroxywithaperuvin C (4), physaperuvin G (5), and 4-deoxywithaperuvin (6). Their chemical structures were elucidated by 1 D-NMR and 2 D-NMR data, as well as comparison with the data reported in the literature. All isolated compounds were evaluated for their cytotoxic activity against HepG2, SK-LU-1, and MCF7 cancer cell lines. As the obtained results, compounds 1 and 3 displayed the strongest cytotoxicity against HepG2, SK-LU-1, and MCF7 cell lines with IC50 value ranging from 0.051 ± 0.004 to 0.86 ± 0.09 µg/mL.