Flavonoids from the Fruits of Desmos cochinchinesis var. fulvecens and Their Inhibitory Effects on No Production

Secondary metabolites from the twigs and stems of dasymaschalon filipes (ridl.) ban. and their biological activities

Investigation of the crude hexane and ethyl acetate extracts of the twigs and stems of D. filipes (Annonaceae) led to the discovery of five compounds: desmosdumotin D (1), a mixture of stigmasterol and β-sitosterol (2), unonal (3), isounonal (4), and cepharadione B (5). The structural elucidation of the compounds was accomplished using 1H,13C, and 2D NMR techniques. The three crude extracts of D. filipes showed weak activity versus the HIV-1 virus. The cytotoxicity assays showed that the crude hexane extract was particularly effective against A549 cell lines, with an ED50 of 15.24 mg/mL. Meanwhile, the crude ethyl acetate and methanol extracts inhibited KKU-M213 cell lines, demonstrating ED50 values of 13.42 and 10.92 mg/mL, respectively. D. filipes is a rich source of potential compounds with anti-HIV-1RT or cytotoxicity activities. This is the first report on the phytochemistry and bioactivity study of D. filipes.

Biologically Active Constituents from Plants of the Genus Desmos

The combination of traditional knowledge of medicinal plants with scientific rationale has yielded positive results in recent years. Bioactive compounds isolated from herbaceous plants have long been used as drugs that benefit human health, as well as providing useful compounds for drug development lead compound optimization. This chapter aims to provide a systematic overview of the structural types of Desmos secondary metabolites, along with their biological potential. Various chromatographic and spectroscopic methods have been utilized for isolating, purifying, and elucidating the structures of compounds from Desmos species. From 1982 to the present time, more than 200 metabolites have been isolated from members of this genus. Desmos spp. constituents include terpenoids, phytosterols, polyoxygenated cyclohexanes and cyclohexenes, oxepinones, fatty acids, with flavonoids, alkaloids, and miscellaneous phenols being the predominant compounds. The essential oils of Desmos species have also been investigated. Both crude plant extracts and isolated compounds from this genus have been evaluated for their biological activities. Desmos constituents have been found to exhibit cytotoxic, antimicrobial, antioxidative, anti-inflammatory, and aromatase and NFAT transcriptive inhibition effects.

Isolation and crystal structure of lawinal

The structure of the natural product lawinal [systematic name: (-)-(2S)-5,7-dihy-droxy-6-methyl-4-oxo-2-phenyl-chromane-8-carbaldehyde, C17H14O5] at 150 K is reported. The compound crystallizes with monoclinic (I2) symmetry and with Z' = 2. The absolute configuration could not be determined reliably from X-ray analysis only. However, our analysis returns the S-configuration at the C-2 position, consistent with previous stereochemical assignment from specific rotation. The independent mol-ecules form into alternating hydrogen-bonded chains with C-H⋯O=CH inter-molecular linkages that run parallel to the crystallographic a axis and are extended into the ac plane by π-π inter-actions between their phenyl substituents.

Polyoxygenated seco-cyclohexenes derivatives from flower and leaf extracts of Desmos cochinchinensis and their α-glucosidase inhibitory activity

Phytochemical investigations from the flower and leaf extracts of D. cochinchinensis resulted in the isolation and structural elucidation of five new polyoxygenated seco-cyclohexene derivatives, desmoscochinchinenes A-E (1–5), together with 11 known compounds (6–16). The structures on the new compounds were elucidated from their spectroscopic data, including UV, IR, NMR, and HRESITOFMS. Some of the isolated compounds were evaluated for their α-glucosidase inhibitory activities. Chrysin (9), pinocembrin 7-O-benzoate (12), and (−)-(5R)-desmoscochinoxepinone B (16) inhibited α-glucosidase better than the standard control (acarbose, IC₅₀ = 83.5 μM) with IC₅₀ values of 5.7, 33.8, 53.3 μM, respectively.

Alkaloids and styryllactones from Goniothalamus cheliensis

Eight previously undescribed compounds, including four alkaloids and five styryllactones together with 36 known compounds were isolated from the twig and leaf extracts of Goniothalamus cheliensis. Their structures were elucidated by extensive analysis of their spectroscopic data. The absolute configuration of (-)-(4S,5S,6R,7S,8S)-goniochelienlactone and (-)-(4S,5S,6R,7S,8S)-7-acetylgoniochelienlactone were established from single crystal X-ray analysis using Cu Kα radiation. The absolute configurations of the other related compounds were identified by comparisons of their ECD spectra with those of related known compounds. Most of the isolated compounds were evaluated for their cytotoxicities against human colorectal cancer cells (HCT-116). Griffithazanone A was the most potent with an IC₅₀ value of 2.39 μM.