Induction of apoptosis in murine leukemia by diarylheptanoids from Curcuma comosa Roxb.

Diarylheptanoids, isolated from the rhizome of Curcuma comosa Roxb., have several biological activities including anti-oxidant and anti-inflammation. The present study investigated the effect of five diarylheptanoids isolated from C. comosa rhizome on the proliferation of murine P388 leukemic cells. Compound-092, (3S)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol, bearing a catechol moiety, was the most potent diarylheptanoid (IC₅₀ of 4 μM) in inhibiting P388 leukemic cell viability by causing DNA breakage and inducing apoptosis. Apoptotic cell death was characterized by the presence of chromatin condensation, formation of apoptotic bodies, DNA fragmentation, and externalization of plasma membrane phosphatidylserine. This compound increased caspase-3 activity about fivefold above the untreated control, decreased the intracellular reduced glutathione level, and impaired mitochondrial transmembrane potential. In the presence of Cu(II) ion, the compound exhibited a pro-oxidant activity causing DNA strand breakage and enhancing the anti-proliferative activity. The results provide evidence for the pro-oxidant activity of the diarylheptanoid bearing a catechol moiety in the induction of apoptosis in murine P388 leukemia.     

Novel racemic tetrahydrocurcuminoid dihydropyrimidinone analogues as potent acetylcholinesterase inhibitors

The synthesis of racemic tetrahydrocurcumin- (THC-), tetrahydrodemethoxycurcumin- (THDC-) and tetrahydrobisdemethoxycurcumin- (THBDC-) dihydropyrimidinone (DHPM) analogues was achieved by utilizing the multi-component Biginelli reaction in the presence of copper sulphate as a catalyst. The evaluation of acetylcholinesterase inhibitors for Alzheimer’s disease of these compounds showed that they exhibited higher inhibitory activity than their parent analogues. THBDC–DHPM demonstrated the most potent inhibitory activity with an IC₅₀ value of 1.34 ± 0.03 μM which was more active than the approved drug galanthamine (IC₅₀ = 1.45 ± 0.04 μM).     

Highly oxygenated ecdysteroids from Vitex canescens root bark

Highly oxygenated ecdysteroids, (24R)-11 alpha, 20,24-trihydroxyecdysone and 11 alpha,20,26-trihydroxyecdysone, have been isolated from the polar fraction of Vitex canescens root bark. The latter exists as two C-25 epimers which could be separated by reversed-phase HPLC.     

Flavonoid glycosides from the aerial parts of Curcuma comosa

Four new flavonoid glycosides, curcucomosides A–D (1–4), three known flavonoid glycosides, 5–7, and four known diarylheptanoids, 8–11, were isolated from the ethanol extract of the aerial parts of Curcuma comosa. The structures of the new compounds were established as rhamnazin 3-O-α-l-arabinopyranoside (1), rhamnocitrin 3-O-α-l-arabinopyranoside (2), rhamnazin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (3), and rhamnocitrin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (4) by spectroscopic analysis and chemical reactions whereas those of the known compounds were identified by spectral comparison with those of the reported values.     

Iterative pruning PCA improves resolution of highly structured populations

Background  

Non-random patterns of genetic variation exist among individuals in a population owing to a variety of evolutionary factors. Therefore, populations are structured into genetically distinct subpopulations. As genotypic datasets become ever larger, it is increasingly difficult to correctly estimate the number of subpopulations and assign individuals to them. The computationally efficient non-parametric, chiefly Principal Components Analysis (PCA)-based methods are thus becoming increasingly relied upon for population structure analysis. Current PCA-based methods can accurately detect structure; however, the accuracy in resolving subpopulations and assigning individuals to them is wanting. When subpopulations are closely related to one another, they overlap in PCA space and appear as a conglomerate. This problem is exacerbated when some subpopulations in the dataset are genetically far removed from others. We propose a novel PCA-based framework which addresses this shortcoming.     

Synthetic analogues of durantoside I from Citharexylum spinosum L. and their cytotoxic activity

New iridoid glycoside derivatives from durantoside I, the latter from the dried flowers and leaves of Citharexylum spinosum, were synthesized by variously modifying a sugar moiety by silylation or acetylation and/or removal of cinnamate group at C-7 position and subsequent screening for comparative cytotoxicity against several cancer cell lines. Addition of alkylsilane to durantoside I and removal of cinnamate group were most effective in improving cytotoxicity.     

Synthesis of 14-deoxy-11,12-didehydroandrographolide analogues as potential cytotoxic agents for cholangiocarcinoma

A series of 14-deoxy-11,12-didehydroandrographolide analogues were synthesized from naturally occurring andrographolide and their cytotoxicity evaluated against nine cancer cell lines including cholangiocarcinoma. Analogues 5a and 5b exhibited the most potent cytotoxicity with ED₅₀s of 3.37 and 3.08?μM on KKU-M213 cell lines and 2.93 and 3.27?μM on KKU-100 cell lines, respectively. Selective cytotoxicity on cholangiocarcinoma cell lines identified in this study highlight the importance of structural modification in the development of drugs for this cancer.     

Mapping of Genes for Cooking and Eating Qualities in Thai Jasmine Rice (KDML105)

Thai jasmine rice, KDML 105, is known as the best quality rice.It is known not only for its aroma but also for its good cookingand eating qualities. Amylose content (AC), gel consistency(GC) and gelatinization temperature (GT) are important traitsdetermining rice quality. A population of recombinant inbredlines (RIL) derived from KDML105 x CT9993 cross was used tostudy the genetic control of AC, GC and GT traits. A total of191 markers were used in the linkage map construction. The 1605.3cM linkage map covering nearly the whole rice genome was usedfor QTL (define QTL) analysis. Four QTLs for AC were detectedon chromosomes 3, 4, 6 and 7. These QTLs accounted for 80% ofphenotypic variation explained (PVE) in AC. The presence ofone major gene as well as several modifiers was responsiblefor the expression of the trait. Two QTLs on chromosome 6 andone on chromosome 7 were detected for GC, which accounts for57% of PVE. A single gene of major effect along with modifiergenes controls GC from this cross. The QTLs in the vicinityof waxy locus were major contributors in the expression of ACand GC. The finding that the position of QTLs for AC and GCwere near each other may reflect tight linkage or pleiotropy.Three QTLs were detected, one on chromosome 2 and two on chromosome6, which accounted for 67% of PVE in GT. Just like AC and GC,one major gene and modifier genes governed the variation inGT resulting from the KDML105 x CT9993 cross. Breeding for cookingand eating qualities will largely rely on the preferences ofthe end users.