6-[(E)-3,7-Dimethyl­octa-2,6-dien­yl]-5,7-dihydr­oxy-8-(2-methyl­butano­yl)-4-phenyl-2H-chromen-2-one from Mesua kunstleri King (Kosterm)

The title compound, C30H34O5, crystallizes with two symmetry-independent mol­ecules in the asymmetric unit. In the crystal structure, the two independent mol­ecules are disposed about a pseudo-center of inversion. An intra­molecular O—H⋯O hydrogen bond is observed in each independent mol­ecule. The crystal structure is stabilized by C—H⋯O hydrogen bonds

6-[(2E)-3,7-Dimethyl­octa-2,6-dien-1-yl]-5,7-dihy­droxy-8-(2-methyl­butano­yl)-4-phenyl-2H-chromen-2-one–6-[(2E)-3,7-dimethyl­octa-2,6-dien-1-yl]-5,7-dihy­droxy-8-(3-methyl­butano­yl)-4-phenyl-2H-chromen-2-one (1/1) from Mesua elegans 1

The title co-crystal, C30H34O5·C30H34O5, comprises a 1:1 mixture of two mostly superimposed mol­ecules with the same chemical formula that differ in the nature of the substituent (2-methyl­butanoyl or 3-methyl­butano­yl) bound at the exocyclic ketone. The lactone ring is close to planar (r.m.s. deviation = 0.058 Å) and the phenyl ring is twisted out of this plane [dihedral angle = 60.08 (9)°]. The geranyl substituent is almost normal to benzene ring to which it is connected [C—C—Car—Car (ar = aromatic) torsion angle = −87.8 (2)°]. Intra­molecular O—H⋯O and O—H⋯π inter­actions are formed. In the crystal, supra­molecular chains are formed along the a axis owing to C—H⋯O contacts, with the lactone carbonyl atom accepting two such bonds

Phytochemical evaluation and cytotoxic activities of stem bark and leaf extracts of Mesua assamica

Natural products and their derivatives have historically been invaluable as a source of therapeutic agents. The Mesua (Calophyllaceae) has been known to produce various new chemical compounds of medicinal values. Some Mesua species have yielded new potential anticancer agents that are important to the pharmaceutical industry. In this research, phytochemical constituents, antioxidant and cytotoxic activities of different solvent extracts of Mesua assamica stem bark and leaves were evaluated. The stem bark and leaves of M. assamica were successively extracted in hexane, ethyl acetate and methanol. Qualitative phytochemical analysis showed that most of the M. assamica extracts consist of important phytochemicals, namely, anthraquinones, terpenoids, flavonoids, saponins, tannins, phlobatannins, alkaloids, cardiac glycosides, glycosides, decreasing sugars, steroids, lipids, phenols, coumarins, carbohydrates, proteins, and betacyanin indicating its potential for medicinal use. Quantitative determination of total phenolics, total flavonoids, and in vitro antioxidant activities through DPPH assay of M. assamica extracts have been achieved by utilizing colorimetric methods. In vitro cytotoxic evaluation through MTT assay induction against human breast MCF-7 cancer cell lines exhibited that hexane extracts were found to have IC50 value below 30 μg/mL and conferred effectiveness in inducing cell death MCF-7. The diversity of phytochemicals present suggests that the stem bark and leaves of M. assamica could serve as a supply of potentially valuable medications. Exploiting the plant’s pharmacological qualities will necessitate more study on the isolation, purification, and identification of bioactive components

Applications of Circular Dichroism for Structural Analysis of Gelatin and Antimicrobial Peptides

Circular dichroism (CD) is a useful technique for monitoring changes in the conformation of antimicrobial peptides or gelatin. In this study, interactions between cationic peptides and gelatin were observed without affecting the triple helical content of the gelatin, which was more strongly affected by anionic surfactant. The peptides did not adopt a secondary structure in the presence of aqueous solution or Tween 80, but a peptide secondary structure formed upon the addition of sodium dodecyl sulfate (SDS). The peptides bound to the phosphate group of lipopolysaccharide (LPS) and displayed an alpha-helical conformation while (KW)4 adopted a folded conformation. Further, the peptides did not specifically interact with the fungal cell wall components of mannan or laminarin. Tryptophan blue shift assay indicated that these peptides interacted with SDS, LPS, and gelatin but not with Tween 80, mannan, or laminarin. The peptides also displayed antibacterial activity against P. aeruginosa without cytotoxicity against HaCaT cells at MIC, except for HPA3NT3-analog peptide. In this study, we used a CD spectroscopic method to demonstrate the feasibility of peptide characterization in numerous environments. The CD method can thus be used as a screening method of gelatin-peptide interactions for use in wound healing applications

Toxicity of Malaysian Medicinal Plant Extracts Against Sitophilus oryzae and Rhyzopertha dominica

The insecticidal activities of extracts from 22 Malaysian medicinal plant extracts from 8 botanical families were tested against rice weevil: Sitophilus oryzae (L.) and lesser grain borer: Rhyzopertha dominica (F.). The extracts were obtained using hexane, methanol, and dichloromethane to extract potential biopesticides from dried leaves. The toxicity levels were examined periodically based on antifeedant activity and contact toxicity assays using treated grain assay. Hexane extracts of Alpinia conchigera, Alpinia scabra, Curcuma mangga, Curcuma purpurascens, Goniothalamus tapisoides, Piper sarmentosum , and methanol extracts of Curcuma aeruginosa, C. mangga , and Mitragyna speciosa were the most potent extracts against S. oryzae and R. dominica with lethal concentration (LC50) values of ≤ 0.42 mg/mL and ≤ 0.49 mg/mL, respectively. The contact toxicity test results showed that methanol extracts of C. aeruginosa and C. mangga , dichloromethane extracts of Cryptocarya nigra , and hexane extracts of C. mangga, and C. purpurascens resulted in 100% mortality of both pests within 28 days exposure of 5 mg/cm2 concentration

Deoxyelephantopin from Elephantopus scaber Inhibits HCT116 Human Colorectal Carcinoma Cell Growth through Apoptosis and Cell Cycle Arrest

Deoxyelephantopin (DET), one of the major sesquiterpene lactones derived from Elephantopus scaber was reported to possess numerous pharmacological functions. This study aimed to assess the apoptosis inducing effects and cell cycle arrest by DET followed by elucidation of the mechanisms underlying cell death in HCT116 cells. The anticancer activity of DET was evaluated by a MTT assay. Morphological and biochemical changes were detected by Hoescht 33342/PI and Annexin V/PI staining. The results revealed that DET and isodeoxyelephantopin (isoDET) could be isolated from the ethyl acetate fraction of E. scaber leaves via a bioassay-guided approach. DET induced significant dose- and time-dependent growth inhibition of HCT116 cells. Characteristics of apoptosis including nuclear morphological changes and externalization of phosphatidylserine were observed. DET also significantly resulted in the activation of caspase-3 and PARP cleavage. Additionally, DET induced cell cycle arrest at the S phase along with dose-dependent upregulation of p21 and phosphorylated p53 protein expression. DET dose-dependently downregulated cyclin D1, A2, B1, E2, CDK4 and CDK2 protein expression. In conclusion, our data showed that DET induced apoptosis and cell cycle arrest in HCT116 colorectal carcinoma, suggesting that DET has potential as an anticancer agent for colorectal carcinoma

Geranylated 4-Phenylcoumarins Exhibit Anticancer Effects against Human Prostate Cancer Cells through Caspase-Independent Mechanism.

Geranylated 4-phenylcoumarins, DMDP-1 & -2 isolated from Mesua elegans were investigated for anticancer potential against human prostate cancer cells. Treatment with DMDP-1 & -2 resulted in cell death in a time and dose dependent manner in an MTT assay on all cancer cell lines tested with the exception of lung adenocarcinoma cells. DMDP-1 showed highest cytotoxic efficacy in PC-3 cells while DMDP-2 was most potent in DU 145 cells. Flow cytometry indicated that both coumarins were successful to induce programmed cell death after 24 h treatment. Elucidation on the mode-of-action via protein arrays and western blotting demonstrated death induced without any significant expressions of caspases, Bcl-2 family proteins and cleaved PARP, thus suggesting the involvement of caspase-independent pathways. In identifying autophagy, analysis of GFP-LC3 showed increased punctate in PC-3 cells pre-treated with CQ and treated with DMDP-1. In these cells decreased expression of autophagosome protein, p62 and cathepsin B further confirmed autophagy. In contrary, the DU 145 cells pre-treated with CQ and treated with DMDP-2 has reduced GFP-LC3 punctate although the number of cells with obvious GFP-LC3 puncta was significantly increased in the inhibitor-treated cells. The increase level of p62 suggested leakage of cathepsin B into the cytosol to trigger potential downstream death mediators. This correlated with increased expression of cathepsin B and reduced expression after treatment with its inhibitor, CA074. Also auto-degradation of calpain-2 upon treatment with DMDP-1 &-2 and its inhibitor alone, calpeptin compared with the combination treatment, further confirmed involvement of calpain-2 in PC-3 and DU 145 cells. Treatment with DMDP-1 & -2 also showed up-regulation of total and phosphorylated p53 levels in a time dependent manner. Hence, DMDP-1 & -2 showed ability to activate multiple death pathways involving autophagy, lysosomal and endoplasmic reticulum death proteins which could potentially be manipulated to develop anti-cancer therapy in apoptosis resistant cells