A new class of 16-membered macrolides, the epothilones (Epos), has been synthesized and evaluated for antitumor potential in vitro and in vivo. Recent studies in these and other laboratories showed that epothilones and paclitaxel (paclitaxel) share similar mechanisms of action in stabilizing microtubule arrays as indicated by binding-displacement studies, substitution for paclitaxel in paclitaxel-dependent cell growth, and electron microscopic examinations. The present study examined cell growth-inhibitory effects in two rodent and three human tumor cell lines and their drug-resistant sublines. Although paclitaxel showed as much as 1,970-fold cross-resistance to the sublines resistant to paclitaxel, adriamycin, vinblastine, or actinomycin D, most epothilones exhibit little or no cross-resistance. In multidrug-resistant CCRF-CEM͞VBL 100 cells, IC 50 values for EpoA (1), EpoB (2), desoxyEpoA (3) (dEpoA), desoxyEpoB (4) (dEpoB), and paclitaxel were 0.02, 0.002, 0.012, 0.017, and 4.14 M, respectively. In vivo studies, using i.p. administration, indicated that the parent, EpoB, was highly toxic to mice and showed little therapeutic effect when compared with a lead compound, dEpoB. More significantly, dEpoB (25-40 mg͞kg, Q2Dx5, i.p.) showed far superior therapeutic effects and lower toxicity than paclitaxel, doxorubicin, camptothecin, or vinblastine (at maximal tolerated doses) in parallel experiments. For mammary adenocarcinoma xenografts resistant to adriamycin, MCF-7͞ Adr, superior therapeutic effects were obtained with dEpoB compared with paclitaxel when i.p. regimens were used. For ovarian adenocarcinoma xenografts, SK-OV-3, dEpoB (i.p.), and paclitaxel (i.v.) gave similar therapeutic effects. In nude mice bearing a human mammary carcinoma xenograft (MX-1), marked tumor regression and cures were obtained with dEpoB.

During our continuous survey (2012–2016) of saprobic hyphomycetes from dead branches in the forest ecosystems of southern China, we collected several acrodictys-like species. Acrodictys-like species are characterized by darkly pigmented and muriform conidia produced from holoblastic conidiogenous cells on macronematous, mononematous, cylindrical and unbranched or infrequently branched conidiophores. Phylogenetic analyses of ncLSU, ncSSU, ITS and tub2 sequence data lead us to propose two novel families in Sordariomycetes, Acrodictyaceae and Junewangiaceae. In addition, a new species, Acrodictys hainanensis, two new combinations, Junewangia queenslandica and Distoseptispora martinii, three new Chinese records, Acrodictys liputii, A. peruamazonensis and Junewangia sphaerospora are introduced. Two names, Acrodictys globulosa and A. malabarica, are resurrected.

Phytophthora capsici causes serious diseases in numerous crop plants. Polygalacturonases (PGs) are cell wall-degrading enzymes that play an important role in pathogenesis in straminopilous pathogens. To understand PGs as they relate to the virulence of P. capsici, Pcipg2 was identified from a genomic library of a highly virulent P. capsici strain. Pcipg2 was strongly expressed during symptom development after the inoculation of pepper leaves with P. capsici. The wild protein (PCIPGII) was obtained from the expression of pcipg2 and found that increasing activity of PGs in PCIPGII-treated pepper leaves was consistent with increasing symptom development. Asp residues in active sites within pcipg2 affected PCIPGII activity or its virulence on pepper leaves. Results show that pcipg2 is an important gene among pcipg genes, and illustrate the benefit of analyzing mechanisms of pathogenicity during the period of host/parasite interaction.

Pectolytic enzymes are found mainly in fungi and bacteria. The most widely occurring enzymes are polygalacturonase (PGs), pectin methylesterase (PMEs) and pectate lyase (PLs) produced during the infection process and during culturing. The secretion of these enzymes results in the disorganization of the plant cell walls, which is responsible for the pathogenicity of the pathogens. These enzymes degrade the pectin of plants causing maceration of plant tissues and the enzyme activity increases under favourable environmental conditions. We have found that Phytophthora capsici, a pathogenic oomycete, produces levels of these three enzymes equal to those produced by soft-rotting Erwinia chrysanthemi. The activity of PGs, PLs and PMEs was investigated at the optimum temperature, pH and ionic strength in highly pathogenic P. capsici strains cultivated in two kinds of liquid medium containing either crude pepper extracts plus pectin or pectin as the carbon source. Virulence tests and enzymes activity showed that there was a high correlation between the enzyme activity and the pathogenicity of P. capsici. The effects of different carbon sources on the enzyme activity showed that pepper extract plus pectin was the best source for the carbon source.