Synthesis and antitumor activity of biotinylated camptothecin derivatives as potent cytotoxic agents.

A series of biotinylated camptothecin derivatives were designed and synthesized. The key to the synthesis was achieved by employing an esterification reaction and click chemistry. All of the new derivatives were tested for cytotoxicity against five human tumor cell lines, including HL-60, SMMC-7721, A-549, MCF-7, and SW480 with IC50 values ranging from 0.13 to 21.53 µM. Most of the derivatives exhibited potent cytotoxicity, especially compound 17 (IC50 = 0.13-3.31 µM) and compound 18 (IC50 = 0.23-1.48 µM), which exhibited the highest potencies. The structure-activity relationships (SARs) of the biotinylated camptothecin derivatives were discussed for exploring novel anticancer agents.

3α,19-Dihydroxyl-ent-pimara-8(14),15-diene, a new diterpenoid from the rhizomes of Ricinus communis.

A new natural product, 3α,19-dihydroxyl-ent-pimara-8(14),15-diene (1), which possesses an α-orientation hydroxymethyl at C-4 and ∆8,14 groups, as well as eight known compounds, was isolated from the rhizomes of Ricinus communis. The structure of 1 was elucidated by extensive spectroscopic methods and its absolute configurations were confirmed by X-ray crystallographic analysis. The inhibitory rate of 1 against protein tyrosine phosphatase 1B (PTP1B) was 49.49% at the concentration of 6.58 × 10-5 mol/L.

Selection of cuffed endotracheal tube for children with congenital heart disease based on an ultrasound-based linear regression formula.

It remains to be discovered whether a formula predicting the subglottic transverse diameter measured by ultrasound (SGDformula) for the selection of an appropriate endotracheal tube (ETT) for children without congenital heart disease (CHD) is useful for children with CHD. A formula for predicting SGD was established after assessing 60 children ≤ 8 years without CHD and validated on 60 children with CHD. We selected the cuffed ETT size based on the SGD by ultrasound (SGDultra). Subsequently, the fit of the ETT cuff in 60 children with CHD was examined via air-leak test. The maximum allowed difference between the SGDformula and the ETT size that fit was 0.2 mm. The agreement among and accuracy of SGDultra, SGDformula, and the ETT used in children was analyzed. For children without CHD, we adopted a linear formula, given by SGDformula (mm) = 0.4 × age + 5.3. For children with CHD, allometric formula was adopted, given by SGDformula (mm) = 5.4 × age0.18. A stronger agreement exists between SGDultra and ETT size compared to that between SGDformula and ETT size. And the mean bias (SGDformula-ETT size and SGDultra-ETT size) was 0.21 mm (95% confidence interval, - 0.59 to 1.01 mm) and 0.00 mm (- 0.79 to 0.84 mm). For the CHD group, the ultrasound-based method yielded a 78% success rate of ETT size choice, while the formula-based method permitted an appropriate ETT size in only 32% of subjects (P < 0.001). Our analysis showed that measuring the SGDultra was more accurate in predicting the correct OD of the ETT in children with CHD undergoing cardiovascular surgery, based on the correlation and agreement with ETT OD.

Phenolic compounds from the twigs and leaves of Tara (Caesalpinia spinosa).

Two new homoisoflavans, 4'-hydroxy-7-methoxy-3-benzyl-2H-chromene (1) and 3,4-cis-di-O-3-hydroxy-7-methoxy-3-(4-hydroxybenzyl)-4-ethoxychroman (2), one new coumarin, 7-methoxy-3-(4-hydroxybenzyl)coumarin (4), together with seven known phenolic compounds, bonducellin (3), anemarcoumarin A (5), (+)-syringaresinol (6), curuilignan D (7), scopoletin (8), and p-hydroxybenzaldehyde (9), were isolated from Tara (Caesalpinia spinosa Kuntze). The structures of the new compounds were characterized from their 1D and 2D NMR spectral data. All the compounds were isolated from this plant for the first time.

[Phenolic compounds from Caesalpinia minax].

Fifteen compounds were obtained from the twigs and leaves of Caesalpinia minax. Their structures were identified as apigenin (1), 5,7,3',4'- tetrahydroxy-3-methoxyflavone (2), luteolin-5, 3 '-dimethyl-ether (3), thevetiaflavon (4), apigenin-7-O-beta-D-glucuronide (5), bonducellin (6), 7-hydroxy-3-( 4-hydroxybenzylidene )-chroman-4-one (7), 3-deoxysappanchalcone (8), 5-acetonyl-7-hydroxy-2-methyl chromone (9), 4-(trans)-acetyl-3,6,8-trihydroxy-3-methyl-dihydronaphthalenone (10), 4-(cis)-acetyl-3,6,8-trihydroxy-3-methyl-dihydronaphthalenone (11), vanillic acid (12), omega-hydroxypropioquaiacone (13), syringaresinol (14) and uracil (15). All compounds were isolated from C. minax for the first time. Compounds 1-14 were phenolic compounds and compounds 1-5, 9-13 and 15 were isolated from the genus Caesalpinia for the first time.

Chemical constituents from the barks of Melia azedarach and their PTP1B inhibitory activity.

One new long-chain ester derivative of trans-ferulic acid 1 and one natural tirucallane-type triterpenoid 2, together with forty known compounds (3-42), were isolated from the barks of Melia azedarach. Their structures were established on the basis of spectroscopic data interpretation. Compounds 7, 9, 10, 12, 13 showed significant inhibitory activities against PTP1B with IC50 values of 13.82 ± 1.29 µM, 13.29 ± 2.26 µM, 20.27 ± 0.52 µM, 24.36 ± 1.25 µM, 15.23 ± 0.6 µM, respectively.

Potential anti-diabetic isoprenoids and a long-chain δ-lactone from frangipani (Plumeria rubra).

A decoction of Plumeria rubra flowers has been used traditionally for the treatment of diabetes in China and Mexico. Chemical investigations on the bioactive constituents of these flowers led to the isolation of 30 compounds, including the four new compounds, one iridoiod (1), two triterpenoids (4, 5), and a long-chain δ-lactone (16). In addition, 26 known compounds (2, 3, 6-15, 17-30) are also reported. All of these compounds were identified on the basis of spectroscopic data interpretation and the absolute configurations of compound 4, 5, 16 were determined by Mosher's method. Compounds 1-4, 7, 8 and 16 showed moderate to significant inhibitory activities against α-glucosidase and protein tyrosine phosphatase 1B, with 4 having IC50 values of 19.45 µM and 0.21 µM, respectively.

Chemical constituents from the leaves of Melia azedarach.

Six compounds, benzyl 3-O-ß-D-glucopyranosyl-7-hydroxybenzoate (1), spathulenol (2), 1,7,8-trihydroxy-2-naphtaldehyde (3), quercetin (4), astragalin (5) and 2-methoxy-4-(2-propenyl)phenyl ß-D-glucoside (6), were isolated from the leaves of Melia azedarach L. The structure elucidation of compound 1 was discussed in detail based on its 2D-NMR data. Compound 1 showed weak cytotoxicity against the cell lines of T-24, NCI-H460, HepG2, SMMC-7721, CNE, MDA-MB-231 and B16F10 with the inhibition rates from 10.01% to 34.05% at the concentration of 80 µM.

Phenolic Constituents with Antioxidative, Tyrosinase Inhibitory and Anti-aging Activities from Dendrobium loddigesii Rolfe.

Aqueous ethanol extracts of powdered stems of Dendrobium loddigesii afforded three new phenolics including threo-7-O-ethyl-9-O-(4-hydroxyphenyl)propionyl-guaiacylglycerol (1), (R)-4,5,4'-trihydroxy-3,3',α-trimethoxybibenzyl (2) and (S)-5,5',7-trihydroxy-3',4'-dimethoxyflavanone (3), together with eleven known analogues. Their structures were determined by extensive spectroscopic analysis. To identify natural antioxidants, whitening, and anti-aging agents, the abilities of these phenolics were assessed to scavenge the 1,2-diphenyl-2-picrylhydrazyl (DPPH) radical, their abilities to inhibit tyrosinase production, and their abilities to stimulate collagen production by human dermal fibroblasts-adult (HDFa) assay. It was found that compounds 1, 4-8, 13 and 14 exhibited significant DPPH radical scavenging activities, compound 10 exhibited tyrosinase inhibitory activity (IC50 37.904 µg/mL), and compound 9 showed significant collagen production with an EC50 value of 3.182 µg/mL. These results suggest that phenolic constituents from D. loddigesii may be candidate antioxidants, skin-whitening and/or anti-aging agents.

Triterpenoids and iridoids from Patrinia scabiosaefolia.

Three new triterpenoids, patrinolides B-D (1-3), and two new iridoids, patriscabioins K-L (9-10), together with five known compounds (4-8) were isolated from the extract of the whole plants of Patrinia scabiosaefolia. Compounds 1, 9, and 10 contained the unique substituents in Valerianaceae family, such as isovalery and 3-methylcrotonyl. Compound 2 was a 24-nor-ursane triterpenoid. Their structures were established on the basis of extensive spectroscopic analysis (UV, IR, MS, 1D and 2D NMR). The inhibitory activities against nitric oxide synthase (NOS) of all triterpenoids were tested. The results showed that compound 4 had moderate inhibitory activity with IC50 of 10.1µM. Furthermore, it also showed strongest inhibitory activities on AChE with IC50 values of 10.0µM.

Oleanane-type triterpene saponins from Hydrocotyle nepalensis.

Five new oleanane-type triterpene saponins including steganogenin 3-O-ß-D-glucopyranoside (1), steganogenin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside (2), steganogenin 3-O-ß-D-glucopyranosyl-(1→2)-ß-D-glucopyranoside (3), chichipegenin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside (4) and chichipegenin 3-O-ß-D-glucopyranosyl-(1→2)-ß-D-glucopyranoside (5), along with four known oleanane-type triterpenes and triterpene saponins (6-9) were isolated from EtOH extract of the whole plant of Hydrocotyle nepalensis. To the best of our knowledge, oleanane-type triterpenes possessing skeleton with 17, 22-seco-backbone (1-3) are not common in natural products. Compound 8 was isolated as a new natural product. The structures of new compounds were elucidated by extensive spectroscopic methods and chemical evidence. Moreover, the cytotoxic activity of all the isolates against five selected human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480) was evaluated and the results indicated that compounds 6 and 7 show stronger cytotoxic activity.

Iridoids and sesquiterpenoids of Valeriana stenoptera and their effects on NGF-induced neurite outgrowth in PC12 cells.

Twenty-one compounds (nine iridoids and twelve sesquiterpenoids), including ten previously unknown (five iridoids and five sesquiterpenoids) were isolated from whole dried material of Valeriana stenoptera. Structures were established on the basis of extensive spectroscopic analysis and the relative stereochemistry of 13-hydroxypatchoulol A was further confirmed by X-ray crystallographic data. All isolates were evaluated for their effects on nerve growth factor (NGF)-mediated neurite outgrowth in pheochromocytoma (PC12) cells and seven compounds showed potent promoting effects.