Records of Natural Products

 A new lathyrane-type diterpenoid, named euphorbia factor L35 (1), along with twenty-two known analogues (2-23) were isolated from the seeds of Euphorbia lathyris. Their structures were elucidated by using 1D- and 2D-NMR spectra and HRESIMS analysis. The cytotoxic effects of the isolated compounds against BT-549 and MDA-MB-231 cancer cells lines were evaluated by the SRB assay. Compounds 3, 10, 14, and 22 were found to exhibit considerable cytotoxic activities against BT-549 cells, with IC50 values ranging from 4.7 to 10.1 μM. Compounds 1, 2, 14 and 22 were able to inhibit the MDA-MB-231 cells growth with IC50 values of 5.7 to 21.3 μM, while other compounds showed no obvious inhibitory effects.

Essential oils from the leaves of Alphonsea monogyma Merr. & Chun and Goniothalamus banii B. H. Quang, R. K. Choudhary & V.T. Chinh from Vietnam were obtained by hydrodisitllation and the chemical components determined by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). Also the microdilution broth assay was used to test the antimicrobial activity of the essential oils. The respective yields of the essential oils were 0.18% (v/w) and 0.355% (v/w), respectively. The major components of A. monogyma were (E)-caryophyllene (13.8%), d-cadinene (12.5%), bicyclogermacrene (12.4%), cis-β-elemene (12.1%), and germacrene D (11.4%). However, myrcene (47.1%), α-pinene (9.7%) and (E)-caryophyllene (9.1%) were the dominant constituents of the essential oil of G. banii. The leaf essential oil of A. monogyma displayed potent antimicrobial activity towards the Gram-positive microorganisms of Enterococcus faecalis ATCC299212, Staphylococcus aureus ATCC25923 and Bacillus cereus ATCC14579 with minimum inhibitory concentration (MIC) values of 2.23 µg/mL, 10.45 µg/mL and 10.33 µg/mL, respectively. On the other hand, essential oil from G. banii exhibited the most effective antibacterial against Gram-negative Pseudomonas aeruginosa ATCC27853 (MIC 5.67 µg/mL), and anti-candidal action towards Candida albicans ATCC10231 (MIC 32.67 µg/mL). The chemical constituents and antimicrobial activity of the essential oils of A. monogyma and G. banii were being reported for the first time.

The traditional European medicinal plant Laserpitium siler L. was studied for the first time for the chemical composition and in vitro biological potential of extracts from fruits and aerial parts. Eight extracts were subjected to spectrophotometric detection and LC-MS quantification of phenolics. The bioactivity assessment comprised antioxidant, antimicrobial, anti-denaturation, acetylcholinesterase, tyrosinase, α-amylase, and α-glucosidase inhibition assays. The spectrophotometric analyses showed that the alcoholic extracts contained the most phenolic acids and coumarins. Among the twenty quantified compounds in the methanolic extracts, chlorogenic acid (29.098 mg/kg in the fruits; 47.438 mg/kg in the aerial parts) and p-coumaric acid (7.468 mg/kg in the fruits; 9.482 mg/kg in the aerial parts) were the most abundant. The DPPH/ABTS/BBT tests showed the strongest antioxidant effect of the methanolic extract of the aerial parts. The results of the microdilution assay referred to stronger antibacterial than antifungal activity, with the essential oil being as effective as the antibiotics used. The extracts expressed promising activity against P. aeruginosa PAO1 biofilm formation and pyocyanin synthesis. The prevention of BSA denaturation by the ethanolic extracts was comparable to diclofenac (91.08%-fruits, 95.08%-aerial parts, and 95.60%-diclofenac). IC50 values showed greater enzyme inhibitory potential of aerial parts and the highest reduction of α-glucosidase activity.

A new chalcone compound, methyl 5-cinnamoyl-2-hydroxy-4-methoxybenzoate (1), and a new cinnamylphenol compound, methyl 3-cinnamyl-5-hydroxy-4-methoxybenzoate (2) together with four known compounds (3-6) were obtained from the CH2Cl2 soluble fraction of Dalbergia melanoxylon. Their structures were elucidated by comprehensive spectral measurements, single crystal X-ray diffraction and literature data. According to the determination results of compound 1 and 2 on RAW 264.7 cell viability, the IC50 values of compounds 1-2 were 4.11 and 113.99 μg/mL, respectively. Compared with LPS model group, compound 1 and 2 could significantly reduce the release of NO in the concentration rages of 0.375~3.0 μg/mL and 10 μg/mL (P<0.01), and significantly inhibit the secretion of LDH with 1.5~3 μg/mL and 5~10 μg/mL.