Chi-Lin Wu

Antifungal activity of essential oil and its constituents from Calocedrus macrolepis var. formosana Florin leaf against plant pathogenic fungi.

Resistance to conventional fungicides causes the poor disease control of agriculture. Natural products from plants have great potential as novel fungicide sources for controlling pathogenic fungi. In this study antipathogenic activity of the leaf essential oil and its constituents from Calocedrus macrolepis var. formosana Florin were evaluated in vitro against six plant pathogenic fungi. Chemical analysis of leaf oil by GC/MS allowed identification of alpha-pinene (44.2%), limonene (21.6%), beta-myrcene (8.9%), beta-caryophyllene (8.2%), caryophyllene oxide (2.4%), alpha-cadinol (1.6%), beta-pinene (1.2%), and T-muurolol (1.1%) as main components. Sesquiterpenoid components of the oil were more effective than monoterpenoid components of the oil. In particular, T-muurolol and alpha-cadinol strongly inhibited the growth of Rhizoctonia solani and Fusarium oxysporum, with the IC(50) values < 50 microg ml(-1). These compounds also efficiently inhibited the mycelial growths of Colletotrichum gloeosporioides, P. funerea, Ganoderma australe and F. solani. These results showed that T-muurolol and alpha-cadinol possess antifungal activities against a broad spectrum of tested plant pathogenic fungi and could be used as potential antifungal agents for the control of fungal diseases in plants.

Comparison of the antifungal activity of cadinane skeletal sesquiterpenoids from Taiwania (Taiwania cryptomerioides Hayata) heartwood.

Summary The antifungal activity of cadinane skeletal sesquiterpenoids from Taiwania (Taiwania cryptomerioides Hayata) heartwood is demonstrated. Using spectral analyses, the absolute structures of three main cadinanes, T-cadinol, T-muurolol, and α-cadinol, all isolated from Taiwania with HPLC, were identified. The amount of these cadinanes was also quantified using GC. The results showed that the total amount of cadinanes extracted from heartwood with n-C6H14 was 6.49 mg per kg of wood. This was much more than the essential oils collected by water distillation from leaves (0.04 mg/kg), sapwood (0.36 mg/kg), or heartwood (1.77 mg/kg). Moreover, results obtained from the antifungal assays demonstrated that αcadinol exhibited the highest antifungal index for both Coriolus versicolor and Laetiporus sulphureus, followed by T-cadinol and T-muurolol. As a matter of fact, α-cadinol completely inhibited the growth of C. versicolor and L. sulphureus at the level as low as 100 ppm. Further comparison of the molecular configuration of these cadinanes reveals that cadinane skeletal sesquiterpenoids with an equatorial hydroxyl group at C-9 and a trans configuration at the ring junction, such as the case for α-cadinol, exhibited the strongest antifungal activity.

Antitermitic and antifungal activities of essential oil of Calocedrus formosana leaf and its composition.

Calocedrus formosana Florin (Cupressaceae) is an endemic tree species in Taiwan; its timber is recognized for natural decay resistance. To examine the antitermitic and antifungal activities of leaf essential oil and its main constituents, C. formosana leaves were extracted and the essential oils analyzed by GC-MS. Bioactivity tests against the termite Coptotermes formosanus demonstrate that the LC50 value of leaf essential oil is 27.6 mg/g. Furthermore, exposure to T-muurolol caused 100% mortality at a dosage of 5 mg/g after 14 d. Leaf oil constituents displayed activity against four fungi, Lenzites betulina, Pycnoporus coccineus, Trametes versicolor, and Laetiporus sulphureus. Two compounds, α-cadinol and T-muurolol, exhibited the strongest antifungal activity. The LC50 values of α-cadinol against L. sulphureus, L. betulina, and T. versicolor are 9.9, 28.6, and 30.4 μ g/ml, respectively.

Cytotoxicity of extractives from Taiwania cryptomerioides heartwood

The cytotoxicity of the dominant lignans and sesquiterpenoids from Taiwania (Taiwania cryptomerioides Hayata) was investigated. Three human tumor cells including A-549 lung carcinoma. MCF-7 breast adenocarcinoma and HT-29 colon adenocarcinoma were selected to illustrate the structure-cytotoxicity relationships of Taiwanias dominant compounds. Taiwanin A, taiwanin E and dimethylmatairesinol exhibited significant cytotoxicity against three human tumor cells. Among them, taiwanin A possesses the strongest cytotoxic activity. In addition, the morphology-based evaluation, flow cytometric analysis, and DNA fragmentation assays demonstrated that the tumor cell death induced by taiwanin A was due to apoptosis.

Antifungal compounds in the ethyl acetate soluble fraction of the extractives of Taiwania (Taiwania cryptomerioides Hayata) heartwood

Summary This study was to isolate and identify the antifungal compounds in the ethyl acetate soluble fraction of the methanol extractives of Taiwania (Taiwania cryptomerioides Hayata) heartwood and to examine their antifungal activity. Five compounds were obtained by open column chromatography and HPLC and based upon the results from Mass, 1H-NMR, and 13C-NMR analyses. Their structures were identified, namely ferruginol, helioxanthin, savinin, taiwanin C, and hinokiol. According to the results of antifungal test, the order of antifungal index of these compounds for Coriolus versicolor (L. ex Fr.) Quel. was ferruginol > taiwanin C > savinin > hinokiol. For Laetiporus sulphureus (B. ex Fr.) Bond. it was taiwanin C > savinin > ferruginol > hinokiol.

Structure-activity relationships of cadinane-type sesquiterpene derivatives against wood-decay fungi

Abstract Cadinane-type sesquiterpenes have a wide spectrum of biological activity, but their use as wood preservatives and the structure-activity relationships of their derivatives have not yet been reported. A total of 13 compounds were synthesized from T-cadinol, T-muurolol, and α-cadinol and their chemical structures were confirmed by IR, MS, and 1H and 13C NMR. The antifungal properties of 16 compounds against three wood-decay fungi were evaluated in vitro. α-Cadinol showed strong antifungal activity against Lenzites betulina, Trametes versicolor, and Laetiporus sulphureus (total mean IC50 0.10 mM). Among the derivatives synthesized, 3β-ethoxy-T-muurolol (0.24 mM), 4ξH-cadinan-10β-ol (0.25 mM), 4ξH-muurolan-10β-ol (0.29 mM), and 4ξH-cadinan-10α-ol (0.25 mM) showed good antifungal activity against all fungi tested. Correlation was observed between the antifungal activity of the compounds tested and log P. Furthermore, the presence of an unsaturated double bond and oxygen-containing functional groups in the compounds plays a key role in their antifungal activity. The stereo configuration of cadinane-type sesquiterpenes also influences their antifungal activity. Understanding how the structure of natural compounds relates to their antifungal function is important and may facilitate their application as novel wood preservatives.

Alpinia pricei Hayata rhizome extracts have suppressive and preventive potencies against hypercholesterolemia

The aim of this study was to investigate the effects of 70% ethanol extracts of Alpinia pricei (APE) on lipid profiles and lipid peroxidation. Syrian hamsters were fed a chow-based hypercholesterolemic diet (HCD) for 2 weeks to induce hypercholesterolemia (>250 mg/dl). To evaluate the potency of APE in suppressing hypercholesterolemia, hamsters were then fed HCD plus a high dose (500 mg/kg body weight) or a low dose (250 mg/kg body weight) of APE, or only HCD for another 4 weeks. We found that hypercholesterolemic hamsters fed a high dose of APE had lower serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels, lower thiobarbituric acid reactive substances (TBARS) and alanine aminotransferase (ALT) activities, lower atherogenic indices (LDL-C/HDL-C and TC/HDL-C ratios), and lower hepatic protein expression of peroxisome proliferators activated receptor gamma (PPARgamma) than hamsters fed a HCD diet. In addition, we also determined the preventive effects of APE on hamsters fed a HCD for 6 weeks. The hypocholesterolemic effects were also found in hamsters co-fed a high dose of APE and HCD for 6weeks. These results suggest that APE has both suppressive and preventive potencies against hypercholesterolemia and has the potency to protect against lipid peroxidation.