Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions.

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà dien, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC50 values <10 µg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC50 <10 µg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, ß-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.

Three New Abietane-Type Diterpenoids from Callicarpa macrophylla Vahl.

Three new abietane-type diterpenoids, named callicapoic acid M3 (1), callicapoic acid M4 (2) and callicapoic acid M5 (3), were isolated from the Callicarpa macrophylla Vahl. Their structures were established by spectroscopic techniques (IR, UV, MS, 1D and 2D NMR). All the isolated three compounds were evaluated for inhibitory activity on NO production in LPS-activated RAW 264.7 macrophage cells by using MTT assays. Compounds 1, 2 and 3 showed potent inhibitory activity, with inhibition rates of 34.47-40.13%.

Five undescribed abietane-type diterpenes of Callicarpa macrophylla.

A phytochemical investigation of the medicinal plant Callicarpa macrophylla resulted in the characterization of two rare rearrangement abietane-type diterpenoids, macrophypene F-G (1-2), and three abietane diterpenoids, named macrophypene H-J (3-5). Additionally, five known diterpenoids (6-10) were identified. The structures of the newly discovered compounds were fully established through extensive analysis of HRESIMS, 1D and 2D NMR data. The absolute configurations of the isolated compounds were determined using CD comparison, chemical methods, and X-ray crystal diffraction experiments. Subsequently, all isolated diterpenoids were evaluated for their inhibitory effects on extracellular PCSK9 protein levels by PCSK9 AlphaLISA screening. Jiadfenoic acid B (6, 56.80% inhibition at 20 µM) and holophyllin F (10, 43.18% inhibition at 20 µM) significantly decreased PCSK9 protein levels in medium of HepG2 cells.

The complete chloroplast genome of Callicarpa macrophylla Vahl.

Callicarpa macrophylla Vahl. belongs to the family Lamiaceae. Its root is a widely used Yao Medicine (YM) to treat internal and external bleeding at the Yao minority areas in southern China. Here, we provide the complete chloroplast genome of C. macrophylla which was collected from Laibin city in Guangxi, China. The total length of the chloroplast genome is 154,141 bp, including a large single-copy (LSC) region, a small single-copy (SSC) region, and a pair of inverted repeats (IRs) regions which are separated by the LSC and SSC, with lengths of 84,904 bp, 17,839 bp, and 25,699 bp, respectively. One hundred and thirty-one genes were identified, including 89 protein-coding genes, 34 tRNA genes, and eight rRNA genes. The overall GC content is 38%. Phylogenetic analysis revealed that C. macrophylla is closely related to C. integerrima var. chinensis.

Two new terpenoids from the leaves of callicarpa macrophylla.

Two new terpenoids (1-2) and seven known compounds (3-9) were isolated from methanol extract of Callicarpa macrophylla leaves. Their structures were determined to be ent-7α,16ß,17,18-tetrahydroxykaur-15-one (1), 3ß-acetoxy-urs-12-ene-11-one-12-ol (2), ent-1ß-acetoxy-7α,14ß-dihydroxykaur-16-en-15-one (3), 3ß-acetoxy-11α,13ß-dihydroxyolean-12-one (4), ß-amyrin (5), spinasterol (6), ursolic acid (7), ß-sitosterol (8), and daucosterol (9) by analyses of their MS, NMR spectroscopic data and by comparison with those reported in the literature. Compounds 1 - 4, and 7 displayed potential cytotoxic activity towards HepG-2, LU-1, and MCF-7 human cancer cell lines with IC50 values ranging from 0.46 ± 0.21 to 18.14 ± 0.33 µM. Compound 6 showed IC50 values of 14.17 ± 0.21 and 5.72 ± 0.42 µM against Hep-G2 and MCF-7 cell lines, respectively.

Three new labdane-type diterpenoids from Callicarpa macrophylla Vahl.

Three new labdane-type diterpenoids, callicapene M3-M5 (1-3) were isolated from the Callicarpa macrophylla Vahl. Their structures were identified by spectroscopic method. The isolated compounds were evaluated for inhibitory activity on NO production in LPS-activated RAW 264.7 macrophage cells by using MTT assays. Compounds 1-3 showed potent inhibitory activity, with IC50 value of 48.15, 46.31 and 38.72 µM respectively.